Empathy List Archives

MG

Mohammad Gharaibeh

Wed, May 15, 2024 3:38 PM

Hi All,

A student of mine is trying to do modal analysis of a cantilevered plate
(25mm x 50mm x 1mm) using ANSYS. The plate has TB,ANEL properties defined
using stiffness matrix.

We have experimental results says that the first natural frequency of this
system is 201 Hz.

First, I had him use ANSYS APDL to learn modeling basics and all about
element types. He used SHELL181 and executed modal analysis and the plate’s
1st resonance frequency is calculated as 203 Hz. Then tried SOLID185 to get
a result of 204 Hz. Another student did it in ABAQUS and found a frequency
of 204 Hz using S4R element. Till now life is great.

Going up in the learning ladder, I asked him to do it in WB. SHELL181 is
the element and same mesh properties we used in APDL. Shockingly, the first
natural frequency in WB is 166 Hz. We double checked everything (geometry &
mechanical properties).

Why are we getting a much lower natural frequencies? I would have to guess
something related to element KEYOPT? Any feedback is greatly appreciated.

Best,
Mohammad

---====
Mohammad A Gharaibeh, Ph.D.
Associate Professor
Department of Mechanical Engineering
The Hashemite University
P.O. Box 330127
Zarqa, 13133, Jordan
Tel: +962 - 5 - 390 3333 Ext. 4771
Fax: +962 - 5 - 382 6348

---===

Hi All, A student of mine is trying to do modal analysis of a cantilevered plate (25mm x 50mm x 1mm) using ANSYS. The plate has TB,ANEL properties defined using stiffness matrix. We have experimental results says that the first natural frequency of this system is 201 Hz. First, I had him use ANSYS APDL to learn modeling basics and all about element types. He used SHELL181 and executed modal analysis and the plate’s 1st resonance frequency is calculated as 203 Hz. Then tried SOLID185 to get a result of 204 Hz. Another student did it in ABAQUS and found a frequency of 204 Hz using S4R element. Till now life is great. Going up in the learning ladder, I asked him to do it in WB. SHELL181 is the element and same mesh properties we used in APDL. Shockingly, the first natural frequency in WB is 166 Hz. We double checked everything (geometry & mechanical properties). Why are we getting a much lower natural frequencies? I would have to guess something related to element KEYOPT? Any feedback is greatly appreciated. Best, Mohammad ===================================== Mohammad A Gharaibeh, Ph.D. Associate Professor Department of Mechanical Engineering The Hashemite University P.O. Box 330127 Zarqa, 13133, Jordan Tel: +962 - 5 - 390 3333 Ext. 4771 Fax: +962 - 5 - 382 6348 ====================================

MR

Matthew Ridzon

Wed, May 15, 2024 3:45 PM

I would open up DS.DAT from the workbench model. Also open up the APDL model. I would go through DS.DAT line-by-line to find out what might be different from the APDL model. It might be a keyopt, but it's hard to tell.

—Matt

-----Original Message-----
From: Mohammad Gharaibeh via Xansys xansys-temp@list.xansys.org
Sent: May 15, 2024 11:38 AM
To: XANSYS Mailing List Home xansys-temp@list.xansys.org
Cc: Mohammad Gharaibeh mgharai1@binghamton.edu
Subject: [Xansys] SHELL181 in Workbench vs APDL

Hi All,

A student of mine is trying to do modal analysis of a cantilevered plate (25mm x 50mm x 1mm) using ANSYS. The plate has TB,ANEL properties defined using stiffness matrix.

We have experimental results says that the first natural frequency of this system is 201 Hz.

First, I had him use ANSYS APDL to learn modeling basics and all about element types. He used SHELL181 and executed modal analysis and the plate’s 1st resonance frequency is calculated as 203 Hz. Then tried SOLID185 to get a result of 204 Hz. Another student did it in ABAQUS and found a frequency of 204 Hz using S4R element. Till now life is great.

Going up in the learning ladder, I asked him to do it in WB. SHELL181 is the element and same mesh properties we used in APDL. Shockingly, the first natural frequency in WB is 166 Hz. We double checked everything (geometry & mechanical properties).

Why are we getting a much lower natural frequencies? I would have to guess something related to element KEYOPT? Any feedback is greatly appreciated.

Best,
Mohammad

---====
Mohammad A Gharaibeh, Ph.D.
Associate Professor
Department of Mechanical Engineering
The Hashemite University
P.O. Box 330127
Zarqa, 13133, Jordan
Tel: +962 - 5 - 390 3333 Ext. 4771
Fax: +962 - 5 - 382 6348

---===

Xansys mailing list -- xansys-temp@list.xansys.org To unsubscribe send an email to xansys-temp-leave@list.xansys.org If you are receiving too many emails from XANSYS please consider changing account settings to Digest mode which will send a single email per day.

Please send administrative requests such as deletion from XANSYS to xansys-mod@tynecomp.co.uk and not to the list

I would open up DS.DAT from the workbench model. Also open up the APDL model. I would go through DS.DAT line-by-line to find out what might be different from the APDL model. It might be a keyopt, but it's hard to tell. —Matt -----Original Message----- From: Mohammad Gharaibeh via Xansys <xansys-temp@list.xansys.org> Sent: May 15, 2024 11:38 AM To: XANSYS Mailing List Home <xansys-temp@list.xansys.org> Cc: Mohammad Gharaibeh <mgharai1@binghamton.edu> Subject: [Xansys] SHELL181 in Workbench vs APDL Hi All, A student of mine is trying to do modal analysis of a cantilevered plate (25mm x 50mm x 1mm) using ANSYS. The plate has TB,ANEL properties defined using stiffness matrix. We have experimental results says that the first natural frequency of this system is 201 Hz. First, I had him use ANSYS APDL to learn modeling basics and all about element types. He used SHELL181 and executed modal analysis and the plate’s 1st resonance frequency is calculated as 203 Hz. Then tried SOLID185 to get a result of 204 Hz. Another student did it in ABAQUS and found a frequency of 204 Hz using S4R element. Till now life is great. Going up in the learning ladder, I asked him to do it in WB. SHELL181 is the element and same mesh properties we used in APDL. Shockingly, the first natural frequency in WB is 166 Hz. We double checked everything (geometry & mechanical properties). Why are we getting a much lower natural frequencies? I would have to guess something related to element KEYOPT? Any feedback is greatly appreciated. Best, Mohammad ===================================== Mohammad A Gharaibeh, Ph.D. Associate Professor Department of Mechanical Engineering The Hashemite University P.O. Box 330127 Zarqa, 13133, Jordan Tel: +962 - 5 - 390 3333 Ext. 4771 Fax: +962 - 5 - 382 6348 ==================================== _______________________________________________ Xansys mailing list -- xansys-temp@list.xansys.org To unsubscribe send an email to xansys-temp-leave@list.xansys.org If you are receiving too many emails from XANSYS please consider changing account settings to Digest mode which will send a single email per day. Please send administrative requests such as deletion from XANSYS to xansys-mod@tynecomp.co.uk and not to the list

MG

Mohammad Gharaibeh

Sun, May 19, 2024 2:11 PM

Thank you, Matt, for the good suggestion. I dug into the DS.DAT and caught
the cause. It is a KEYOPT as expected (KEYOP(3)=2 and it should be 0).

Thanks again,
Mohammad

---====
Mohammad A Gharaibeh, Ph.D.
Associate Professor
Department of Mechanical Engineering
The Hashemite University
P.O. Box 330127
Zarqa, 13133, Jordan
Tel: +962 - 5 - 390 3333 Ext. 4771
Fax: +962 - 5 - 382 6348

---====

On Wed, 15 May 2024 at 6:45 PM Matthew Ridzon Matt@prime-engineer.com
wrote:

I would open up DS.DAT from the workbench model. Also open up the APDL
model. I would go through DS.DAT line-by-line to find out what might be
different from the APDL model. It might be a keyopt, but it's hard to tell.

—Matt

-----Original Message-----
From: Mohammad Gharaibeh via Xansys xansys-temp@list.xansys.org
Sent: May 15, 2024 11:38 AM
To: XANSYS Mailing List Home xansys-temp@list.xansys.org
Cc: Mohammad Gharaibeh mgharai1@binghamton.edu
Subject: [Xansys] SHELL181 in Workbench vs APDL

Hi All,

A student of mine is trying to do modal analysis of a cantilevered plate
(25mm x 50mm x 1mm) using ANSYS. The plate has TB,ANEL properties defined
using stiffness matrix.

We have experimental results says that the first natural frequency of this
system is 201 Hz.

First, I had him use ANSYS APDL to learn modeling basics and all about
element types. He used SHELL181 and executed modal analysis and the plate’s
1st resonance frequency is calculated as 203 Hz. Then tried SOLID185 to get
a result of 204 Hz. Another student did it in ABAQUS and found a frequency
of 204 Hz using S4R element. Till now life is great.

Going up in the learning ladder, I asked him to do it in WB. SHELL181 is
the element and same mesh properties we used in APDL. Shockingly, the first
natural frequency in WB is 166 Hz. We double checked everything (geometry &
mechanical properties).

Why are we getting a much lower natural frequencies? I would have to guess
something related to element KEYOPT? Any feedback is greatly appreciated.

Best,
Mohammad

---====
Mohammad A Gharaibeh, Ph.D.
Associate Professor
Department of Mechanical Engineering
The Hashemite University
P.O. Box 330127
Zarqa, 13133, Jordan
Tel: +962 - 5 - 390 3333 Ext. 4771
Fax: +962 - 5 - 382 6348

---===

Xansys mailing list -- xansys-temp@list.xansys.org To unsubscribe send an
email to xansys-temp-leave@list.xansys.org If you are receiving too many
emails from XANSYS please consider changing account settings to Digest mode
which will send a single email per day.

Please send administrative requests such as deletion from XANSYS to
xansys-mod@tynecomp.co.uk and not to the list

Thank you, Matt, for the good suggestion. I dug into the DS.DAT and caught the cause. It is a KEYOPT as expected (KEYOP(3)=2 and it should be 0). Thanks again, Mohammad ===================================== Mohammad A Gharaibeh, Ph.D. Associate Professor Department of Mechanical Engineering The Hashemite University P.O. Box 330127 Zarqa, 13133, Jordan Tel: +962 - 5 - 390 3333 Ext. 4771 Fax: +962 - 5 - 382 6348 ===================================== On Wed, 15 May 2024 at 6:45 PM Matthew Ridzon <Matt@prime-engineer.com> wrote: > I would open up DS.DAT from the workbench model. Also open up the APDL > model. I would go through DS.DAT line-by-line to find out what might be > different from the APDL model. It might be a keyopt, but it's hard to tell. > > —Matt > > -----Original Message----- > From: Mohammad Gharaibeh via Xansys <xansys-temp@list.xansys.org> > Sent: May 15, 2024 11:38 AM > To: XANSYS Mailing List Home <xansys-temp@list.xansys.org> > Cc: Mohammad Gharaibeh <mgharai1@binghamton.edu> > Subject: [Xansys] SHELL181 in Workbench vs APDL > > Hi All, > > A student of mine is trying to do modal analysis of a cantilevered plate > (25mm x 50mm x 1mm) using ANSYS. The plate has TB,ANEL properties defined > using stiffness matrix. > > We have experimental results says that the first natural frequency of this > system is 201 Hz. > > First, I had him use ANSYS APDL to learn modeling basics and all about > element types. He used SHELL181 and executed modal analysis and the plate’s > 1st resonance frequency is calculated as 203 Hz. Then tried SOLID185 to get > a result of 204 Hz. Another student did it in ABAQUS and found a frequency > of 204 Hz using S4R element. Till now life is great. > > Going up in the learning ladder, I asked him to do it in WB. SHELL181 is > the element and same mesh properties we used in APDL. Shockingly, the first > natural frequency in WB is 166 Hz. We double checked everything (geometry & > mechanical properties). > > Why are we getting a much lower natural frequencies? I would have to guess > something related to element KEYOPT? Any feedback is greatly appreciated. > > Best, > Mohammad > > ===================================== > Mohammad A Gharaibeh, Ph.D. > Associate Professor > Department of Mechanical Engineering > The Hashemite University > P.O. Box 330127 > Zarqa, 13133, Jordan > Tel: +962 - 5 - 390 3333 Ext. 4771 > Fax: +962 - 5 - 382 6348 > ==================================== > _______________________________________________ > Xansys mailing list -- xansys-temp@list.xansys.org To unsubscribe send an > email to xansys-temp-leave@list.xansys.org If you are receiving too many > emails from XANSYS please consider changing account settings to Digest mode > which will send a single email per day. > > Please send administrative requests such as deletion from XANSYS to > xansys-mod@tynecomp.co.uk and not to the list >

GB

Grama Bhashyam

Sun, May 19, 2024 2:20 PM

This is puzzling to me. Can you share the input with me please? Keyopt3 == 2 shouldn’t be a cause here.

Regards

Grama Bhashyam
Grama.bhashyam@ansys.com

From: Mohammad Gharaibeh via Xansys xansys-temp@list.xansys.org
Sent: Sunday, May 19, 2024 10:12 AM
Cc: XANSYS Mailing List Home xansys-temp@list.xansys.org; Mohammad Gharaibeh mgharai1@binghamton.edu
Subject: [Xansys] Re: [External Email] RE: SHELL181 in Workbench vs APDL

[External Sender]

Thank you, Matt, for the good suggestion. I dug into the DS.DAT and caught
the cause. It is a KEYOPT as expected (KEYOP(3)=2 and it should be 0).

Thanks again,
Mohammad

---====
Mohammad A Gharaibeh, Ph.D.
Associate Professor
Department of Mechanical Engineering
The Hashemite University
P.O. Box 330127
Zarqa, 13133, Jordan
Tel: +962 - 5 - 390 3333 Ext. 4771
Fax: +962 - 5 - 382 6348

---====

On Wed, 15 May 2024 at 6:45 PM Matthew Ridzon Matt@prime-engineer.com
wrote:

I would open up DS.DAT from the workbench model. Also open up the APDL
model. I would go through DS.DAT line-by-line to find out what might be
different from the APDL model. It might be a keyopt, but it's hard to tell.

—Matt

-----Original Message-----
From: Mohammad Gharaibeh via Xansys xansys-temp@list.xansys.org
Sent: May 15, 2024 11:38 AM
To: XANSYS Mailing List Home xansys-temp@list.xansys.org
Cc: Mohammad Gharaibeh mgharai1@binghamton.edu
Subject: [Xansys] SHELL181 in Workbench vs APDL

Hi All,

A student of mine is trying to do modal analysis of a cantilevered plate
(25mm x 50mm x 1mm) using ANSYS. The plate has TB,ANEL properties defined
using stiffness matrix.

We have experimental results says that the first natural frequency of this
system is 201 Hz.

First, I had him use ANSYS APDL to learn modeling basics and all about
element types. He used SHELL181 and executed modal analysis and the plate’s
1st resonance frequency is calculated as 203 Hz. Then tried SOLID185 to get
a result of 204 Hz. Another student did it in ABAQUS and found a frequency
of 204 Hz using S4R element. Till now life is great.

Going up in the learning ladder, I asked him to do it in WB. SHELL181 is
the element and same mesh properties we used in APDL. Shockingly, the first
natural frequency in WB is 166 Hz. We double checked everything (geometry &
mechanical properties).

Why are we getting a much lower natural frequencies? I would have to guess
something related to element KEYOPT? Any feedback is greatly appreciated.

Best,
Mohammad

---====
Mohammad A Gharaibeh, Ph.D.
Associate Professor
Department of Mechanical Engineering
The Hashemite University
P.O. Box 330127
Zarqa, 13133, Jordan
Tel: +962 - 5 - 390 3333 Ext. 4771
Fax: +962 - 5 - 382 6348

---===

Xansys mailing list -- xansys-temp@list.xansys.org To unsubscribe send an
email to xansys-temp-leave@list.xansys.org If you are receiving too many
emails from XANSYS please consider changing account settings to Digest mode
which will send a single email per day.

Please send administrative requests such as deletion from XANSYS to
xansys-mod@tynecomp.co.uk and not to the list

Xansys mailing list -- xansys-temp@list.xansys.org
To unsubscribe send an email to xansys-temp-leave@list.xansys.org
If you are receiving too many emails from XANSYS please consider changing account settings to Digest mode which will send a single email per day.

Please send administrative requests such as deletion from XANSYS to xansys-mod@tynecomp.co.uk and not to the list

This is puzzling to me. Can you share the input with me please? Keyopt3 == 2 shouldn’t be a cause here. Regards Grama Bhashyam Grama.bhashyam@ansys.com ________________________________ From: Mohammad Gharaibeh via Xansys <xansys-temp@list.xansys.org> Sent: Sunday, May 19, 2024 10:12 AM Cc: XANSYS Mailing List Home <xansys-temp@list.xansys.org>; Mohammad Gharaibeh <mgharai1@binghamton.edu> Subject: [Xansys] Re: [External Email] RE: SHELL181 in Workbench vs APDL [External Sender] Thank you, Matt, for the good suggestion. I dug into the DS.DAT and caught the cause. It is a KEYOPT as expected (KEYOP(3)=2 and it should be 0). Thanks again, Mohammad ===================================== Mohammad A Gharaibeh, Ph.D. Associate Professor Department of Mechanical Engineering The Hashemite University P.O. Box 330127 Zarqa, 13133, Jordan Tel: +962 - 5 - 390 3333 Ext. 4771 Fax: +962 - 5 - 382 6348 ===================================== On Wed, 15 May 2024 at 6:45 PM Matthew Ridzon <Matt@prime-engineer.com> wrote: > I would open up DS.DAT from the workbench model. Also open up the APDL > model. I would go through DS.DAT line-by-line to find out what might be > different from the APDL model. It might be a keyopt, but it's hard to tell. > > —Matt > > -----Original Message----- > From: Mohammad Gharaibeh via Xansys <xansys-temp@list.xansys.org> > Sent: May 15, 2024 11:38 AM > To: XANSYS Mailing List Home <xansys-temp@list.xansys.org> > Cc: Mohammad Gharaibeh <mgharai1@binghamton.edu> > Subject: [Xansys] SHELL181 in Workbench vs APDL > > Hi All, > > A student of mine is trying to do modal analysis of a cantilevered plate > (25mm x 50mm x 1mm) using ANSYS. The plate has TB,ANEL properties defined > using stiffness matrix. > > We have experimental results says that the first natural frequency of this > system is 201 Hz. > > First, I had him use ANSYS APDL to learn modeling basics and all about > element types. He used SHELL181 and executed modal analysis and the plate’s > 1st resonance frequency is calculated as 203 Hz. Then tried SOLID185 to get > a result of 204 Hz. Another student did it in ABAQUS and found a frequency > of 204 Hz using S4R element. Till now life is great. > > Going up in the learning ladder, I asked him to do it in WB. SHELL181 is > the element and same mesh properties we used in APDL. Shockingly, the first > natural frequency in WB is 166 Hz. We double checked everything (geometry & > mechanical properties). > > Why are we getting a much lower natural frequencies? I would have to guess > something related to element KEYOPT? Any feedback is greatly appreciated. > > Best, > Mohammad > > ===================================== > Mohammad A Gharaibeh, Ph.D. > Associate Professor > Department of Mechanical Engineering > The Hashemite University > P.O. Box 330127 > Zarqa, 13133, Jordan > Tel: +962 - 5 - 390 3333 Ext. 4771 > Fax: +962 - 5 - 382 6348 > ==================================== > _______________________________________________ > Xansys mailing list -- xansys-temp@list.xansys.org To unsubscribe send an > email to xansys-temp-leave@list.xansys.org If you are receiving too many > emails from XANSYS please consider changing account settings to Digest mode > which will send a single email per day. > > Please send administrative requests such as deletion from XANSYS to > xansys-mod@tynecomp.co.uk and not to the list > _______________________________________________ Xansys mailing list -- xansys-temp@list.xansys.org To unsubscribe send an email to xansys-temp-leave@list.xansys.org If you are receiving too many emails from XANSYS please consider changing account settings to Digest mode which will send a single email per day. Please send administrative requests such as deletion from XANSYS to xansys-mod@tynecomp.co.uk and not to the list

AP

Attar, Peter J.

Wed, May 22, 2024 12:35 PM

I agree and if the guy was really interested in having his student understand what's going on (in particular the ins and outs of locking and when it should/shouldn't occur...) he would get back to you...

Peter

From: Grama Bhashyam via Xansys xansys-temp@list.xansys.org
Sent: Sunday, May 19, 2024 9:20 AM
To: XANSYS Mailing List Home
Cc: XANSYS Mailing List Home; Grama Bhashyam
Subject: [Xansys] Re: [External Email] RE: SHELL181 in Workbench vs APDL

This is puzzling to me. Can you share the input with me please? Keyopt3 == 2 shouldn’t be a cause here.

Regards

Grama Bhashyam
Grama.bhashyam@ansys.com

From: Mohammad Gharaibeh via Xansys xansys-temp@list.xansys.org
Sent: Sunday, May 19, 2024 10:12 AM
Cc: XANSYS Mailing List Home xansys-temp@list.xansys.org; Mohammad Gharaibeh mgharai1@binghamton.edu
Subject: [Xansys] Re: [External Email] RE: SHELL181 in Workbench vs APDL

[External Sender]

Thank you, Matt, for the good suggestion. I dug into the DS.DAT and caught
the cause. It is a KEYOPT as expected (KEYOP(3)=2 and it should be 0).

Thanks again,
Mohammad

---====
Mohammad A Gharaibeh, Ph.D.
Associate Professor
Department of Mechanical Engineering
The Hashemite University
P.O. Box 330127
Zarqa, 13133, Jordan
Tel: +962 - 5 - 390 3333 Ext. 4771
Fax: +962 - 5 - 382 6348

---====

On Wed, 15 May 2024 at 6:45 PM Matthew Ridzon Matt@prime-engineer.com
wrote:

I would open up DS.DAT from the workbench model. Also open up the APDL
model. I would go through DS.DAT line-by-line to find out what might be
different from the APDL model. It might be a keyopt, but it's hard to tell.

—Matt

-----Original Message-----
From: Mohammad Gharaibeh via Xansys xansys-temp@list.xansys.org
Sent: May 15, 2024 11:38 AM
To: XANSYS Mailing List Home xansys-temp@list.xansys.org
Cc: Mohammad Gharaibeh mgharai1@binghamton.edu
Subject: [Xansys] SHELL181 in Workbench vs APDL

Hi All,

A student of mine is trying to do modal analysis of a cantilevered plate
(25mm x 50mm x 1mm) using ANSYS. The plate has TB,ANEL properties defined
using stiffness matrix.

We have experimental results says that the first natural frequency of this
system is 201 Hz.

First, I had him use ANSYS APDL to learn modeling basics and all about
element types. He used SHELL181 and executed modal analysis and the plate’s
1st resonance frequency is calculated as 203 Hz. Then tried SOLID185 to get
a result of 204 Hz. Another student did it in ABAQUS and found a frequency
of 204 Hz using S4R element. Till now life is great.

Going up in the learning ladder, I asked him to do it in WB. SHELL181 is
the element and same mesh properties we used in APDL. Shockingly, the first
natural frequency in WB is 166 Hz. We double checked everything (geometry &
mechanical properties).

Why are we getting a much lower natural frequencies? I would have to guess
something related to element KEYOPT? Any feedback is greatly appreciated.

Best,
Mohammad

---====
Mohammad A Gharaibeh, Ph.D.
Associate Professor
Department of Mechanical Engineering
The Hashemite University
P.O. Box 330127
Zarqa, 13133, Jordan
Tel: +962 - 5 - 390 3333 Ext. 4771
Fax: +962 - 5 - 382 6348

---===

Xansys mailing list -- xansys-temp@list.xansys.org To unsubscribe send an
email to xansys-temp-leave@list.xansys.org If you are receiving too many
emails from XANSYS please consider changing account settings to Digest mode
which will send a single email per day.

Please send administrative requests such as deletion from XANSYS to
xansys-mod@tynecomp.co.uk and not to the list

Xansys mailing list -- xansys-temp@list.xansys.org
To unsubscribe send an email to xansys-temp-leave@list.xansys.org
If you are receiving too many emails from XANSYS please consider changing account settings to Digest mode which will send a single email per day.

Please send administrative requests such as deletion from XANSYS to xansys-mod@tynecomp.co.uk and not to the list

Xansys mailing list -- xansys-temp@list.xansys.org
To unsubscribe send an email to xansys-temp-leave@list.xansys.org
If you are receiving too many emails from XANSYS please consider changing account settings to Digest mode which will send a single email per day.

Please send administrative requests such as deletion from XANSYS to xansys-mod@tynecomp.co.uk and not to the list

I agree and if the guy was really interested in having his student understand what's going on (in particular the ins and outs of locking and when it should/shouldn't occur...) he would get back to you... Peter ________________________________________ From: Grama Bhashyam via Xansys <xansys-temp@list.xansys.org> Sent: Sunday, May 19, 2024 9:20 AM To: XANSYS Mailing List Home Cc: XANSYS Mailing List Home; Grama Bhashyam Subject: [Xansys] Re: [External Email] RE: SHELL181 in Workbench vs APDL This is puzzling to me. Can you share the input with me please? Keyopt3 == 2 shouldn’t be a cause here. Regards Grama Bhashyam Grama.bhashyam@ansys.com ________________________________ From: Mohammad Gharaibeh via Xansys <xansys-temp@list.xansys.org> Sent: Sunday, May 19, 2024 10:12 AM Cc: XANSYS Mailing List Home <xansys-temp@list.xansys.org>; Mohammad Gharaibeh <mgharai1@binghamton.edu> Subject: [Xansys] Re: [External Email] RE: SHELL181 in Workbench vs APDL [External Sender] Thank you, Matt, for the good suggestion. I dug into the DS.DAT and caught the cause. It is a KEYOPT as expected (KEYOP(3)=2 and it should be 0). Thanks again, Mohammad ===================================== Mohammad A Gharaibeh, Ph.D. Associate Professor Department of Mechanical Engineering The Hashemite University P.O. Box 330127 Zarqa, 13133, Jordan Tel: +962 - 5 - 390 3333 Ext. 4771 Fax: +962 - 5 - 382 6348 ===================================== On Wed, 15 May 2024 at 6:45 PM Matthew Ridzon <Matt@prime-engineer.com> wrote: > I would open up DS.DAT from the workbench model. Also open up the APDL > model. I would go through DS.DAT line-by-line to find out what might be > different from the APDL model. It might be a keyopt, but it's hard to tell. > > —Matt > > -----Original Message----- > From: Mohammad Gharaibeh via Xansys <xansys-temp@list.xansys.org> > Sent: May 15, 2024 11:38 AM > To: XANSYS Mailing List Home <xansys-temp@list.xansys.org> > Cc: Mohammad Gharaibeh <mgharai1@binghamton.edu> > Subject: [Xansys] SHELL181 in Workbench vs APDL > > Hi All, > > A student of mine is trying to do modal analysis of a cantilevered plate > (25mm x 50mm x 1mm) using ANSYS. The plate has TB,ANEL properties defined > using stiffness matrix. > > We have experimental results says that the first natural frequency of this > system is 201 Hz. > > First, I had him use ANSYS APDL to learn modeling basics and all about > element types. He used SHELL181 and executed modal analysis and the plate’s > 1st resonance frequency is calculated as 203 Hz. Then tried SOLID185 to get > a result of 204 Hz. Another student did it in ABAQUS and found a frequency > of 204 Hz using S4R element. Till now life is great. > > Going up in the learning ladder, I asked him to do it in WB. SHELL181 is > the element and same mesh properties we used in APDL. Shockingly, the first > natural frequency in WB is 166 Hz. We double checked everything (geometry & > mechanical properties). > > Why are we getting a much lower natural frequencies? I would have to guess > something related to element KEYOPT? Any feedback is greatly appreciated. > > Best, > Mohammad > > ===================================== > Mohammad A Gharaibeh, Ph.D. > Associate Professor > Department of Mechanical Engineering > The Hashemite University > P.O. Box 330127 > Zarqa, 13133, Jordan > Tel: +962 - 5 - 390 3333 Ext. 4771 > Fax: +962 - 5 - 382 6348 > ==================================== > _______________________________________________ > Xansys mailing list -- xansys-temp@list.xansys.org To unsubscribe send an > email to xansys-temp-leave@list.xansys.org If you are receiving too many > emails from XANSYS please consider changing account settings to Digest mode > which will send a single email per day. > > Please send administrative requests such as deletion from XANSYS to > xansys-mod@tynecomp.co.uk and not to the list > _______________________________________________ Xansys mailing list -- xansys-temp@list.xansys.org To unsubscribe send an email to xansys-temp-leave@list.xansys.org If you are receiving too many emails from XANSYS please consider changing account settings to Digest mode which will send a single email per day. Please send administrative requests such as deletion from XANSYS to xansys-mod@tynecomp.co.uk and not to the list _______________________________________________ Xansys mailing list -- xansys-temp@list.xansys.org To unsubscribe send an email to xansys-temp-leave@list.xansys.org If you are receiving too many emails from XANSYS please consider changing account settings to Digest mode which will send a single email per day. Please send administrative requests such as deletion from XANSYS to xansys-mod@tynecomp.co.uk and not to the list

MG

Mohammad Gharaibeh

Wed, May 22, 2024 12:48 PM

Peter,
Wow! You really nailed it. I got back to Dr. Bhashyam off the list. We were
able to figure out what's going on. People should not judge without knowing
the whole situation.

I hope you're happy now.

Best,
Mohammad

---====
Mohammad A Gharaibeh, Ph.D.
Associate Professor
Department of Mechanical Engineering
The Hashemite University
P.O. Box 330127
Zarqa, 13133, Jordan
Tel: +962 - 5 - 390 3333 Ext. 4771
Fax: +962 - 5 - 382 6348

---====

On Wed, May 22, 2024 at 3:37 PM Attar, Peter J. via Xansys <
xansys-temp@list.xansys.org> wrote:

I agree and if the guy was really interested in having his student
understand what's going on (in particular the ins and outs of locking and
when it should/shouldn't occur...) he would get back to you...

Peter

From: Grama Bhashyam via Xansys xansys-temp@list.xansys.org
Sent: Sunday, May 19, 2024 9:20 AM
To: XANSYS Mailing List Home
Cc: XANSYS Mailing List Home; Grama Bhashyam
Subject: [Xansys] Re: [External Email] RE: SHELL181 in Workbench vs APDL

This is puzzling to me. Can you share the input with me please? Keyopt3 ==
2 shouldn’t be a cause here.

Regards

Grama Bhashyam
Grama.bhashyam@ansys.com

From: Mohammad Gharaibeh via Xansys xansys-temp@list.xansys.org
Sent: Sunday, May 19, 2024 10:12 AM
Cc: XANSYS Mailing List Home xansys-temp@list.xansys.org; Mohammad
Gharaibeh mgharai1@binghamton.edu
Subject: [Xansys] Re: [External Email] RE: SHELL181 in Workbench vs APDL

[External Sender]

Thank you, Matt, for the good suggestion. I dug into the DS.DAT and caught
the cause. It is a KEYOPT as expected (KEYOP(3)=2 and it should be 0).

Thanks again,
Mohammad

---====
Mohammad A Gharaibeh, Ph.D.
Associate Professor
Department of Mechanical Engineering
The Hashemite University
P.O. Box 330127
Zarqa, 13133, Jordan
Tel: +962 - 5 - 390 3333 Ext. 4771
Fax: +962 - 5 - 382 6348

---====

On Wed, 15 May 2024 at 6:45 PM Matthew Ridzon Matt@prime-engineer.com
wrote:

I would open up DS.DAT from the workbench model. Also open up the APDL
model. I would go through DS.DAT line-by-line to find out what might be
different from the APDL model. It might be a keyopt, but it's hard to

tell.

—Matt

-----Original Message-----
From: Mohammad Gharaibeh via Xansys xansys-temp@list.xansys.org
Sent: May 15, 2024 11:38 AM
To: XANSYS Mailing List Home xansys-temp@list.xansys.org
Cc: Mohammad Gharaibeh mgharai1@binghamton.edu
Subject: [Xansys] SHELL181 in Workbench vs APDL

Hi All,

A student of mine is trying to do modal analysis of a cantilevered plate
(25mm x 50mm x 1mm) using ANSYS. The plate has TB,ANEL properties defined
using stiffness matrix.

We have experimental results says that the first natural frequency of

this

system is 201 Hz.

First, I had him use ANSYS APDL to learn modeling basics and all about
element types. He used SHELL181 and executed modal analysis and the

plate’s

1st resonance frequency is calculated as 203 Hz. Then tried SOLID185 to

get

a result of 204 Hz. Another student did it in ABAQUS and found a

frequency

of 204 Hz using S4R element. Till now life is great.

Going up in the learning ladder, I asked him to do it in WB. SHELL181 is
the element and same mesh properties we used in APDL. Shockingly, the

first

natural frequency in WB is 166 Hz. We double checked everything

(geometry &

mechanical properties).

Why are we getting a much lower natural frequencies? I would have to

guess

something related to element KEYOPT? Any feedback is greatly appreciated.

Best,
Mohammad

---====
Mohammad A Gharaibeh, Ph.D.
Associate Professor
Department of Mechanical Engineering
The Hashemite University
P.O. Box 330127
Zarqa, 13133, Jordan
Tel: +962 - 5 - 390 3333 Ext. 4771
Fax: +962 - 5 - 382 6348

---===

Xansys mailing list -- xansys-temp@list.xansys.org To unsubscribe send

an

email to xansys-temp-leave@list.xansys.org If you are receiving too many
emails from XANSYS please consider changing account settings to Digest

mode

which will send a single email per day.

Please send administrative requests such as deletion from XANSYS to
xansys-mod@tynecomp.co.uk and not to the list

Xansys mailing list -- xansys-temp@list.xansys.org
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If you are receiving too many emails from XANSYS please consider changing
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To unsubscribe send an email to xansys-temp-leave@list.xansys.org
If you are receiving too many emails from XANSYS please consider changing
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xansys-mod@tynecomp.co.uk and not to the list

Peter, Wow! You really nailed it. I got back to Dr. Bhashyam off the list. We were able to figure out what's going on. People should not judge without knowing the whole situation. I hope you're happy now. Best, Mohammad ===================================== Mohammad A Gharaibeh, Ph.D. Associate Professor Department of Mechanical Engineering The Hashemite University P.O. Box 330127 Zarqa, 13133, Jordan Tel: +962 - 5 - 390 3333 Ext. 4771 Fax: +962 - 5 - 382 6348 ===================================== On Wed, May 22, 2024 at 3:37 PM Attar, Peter J. via Xansys < xansys-temp@list.xansys.org> wrote: > I agree and if the guy was really interested in having his student > understand what's going on (in particular the ins and outs of locking and > when it should/shouldn't occur...) he would get back to you... > > > Peter > > ________________________________________ > From: Grama Bhashyam via Xansys <xansys-temp@list.xansys.org> > Sent: Sunday, May 19, 2024 9:20 AM > To: XANSYS Mailing List Home > Cc: XANSYS Mailing List Home; Grama Bhashyam > Subject: [Xansys] Re: [External Email] RE: SHELL181 in Workbench vs APDL > > This is puzzling to me. Can you share the input with me please? Keyopt3 == > 2 shouldn’t be a cause here. > > Regards > > Grama Bhashyam > Grama.bhashyam@ansys.com > > ________________________________ > From: Mohammad Gharaibeh via Xansys <xansys-temp@list.xansys.org> > Sent: Sunday, May 19, 2024 10:12 AM > Cc: XANSYS Mailing List Home <xansys-temp@list.xansys.org>; Mohammad > Gharaibeh <mgharai1@binghamton.edu> > Subject: [Xansys] Re: [External Email] RE: SHELL181 in Workbench vs APDL > > [External Sender] > > Thank you, Matt, for the good suggestion. I dug into the DS.DAT and caught > the cause. It is a KEYOPT as expected (KEYOP(3)=2 and it should be 0). > > Thanks again, > Mohammad > > ===================================== > Mohammad A Gharaibeh, Ph.D. > Associate Professor > Department of Mechanical Engineering > The Hashemite University > P.O. Box 330127 > Zarqa, 13133, Jordan > Tel: +962 - 5 - 390 3333 Ext. 4771 > Fax: +962 - 5 - 382 6348 > ===================================== > > > > > On Wed, 15 May 2024 at 6:45 PM Matthew Ridzon <Matt@prime-engineer.com> > wrote: > > > I would open up DS.DAT from the workbench model. Also open up the APDL > > model. I would go through DS.DAT line-by-line to find out what might be > > different from the APDL model. It might be a keyopt, but it's hard to > tell. > > > > —Matt > > > > -----Original Message----- > > From: Mohammad Gharaibeh via Xansys <xansys-temp@list.xansys.org> > > Sent: May 15, 2024 11:38 AM > > To: XANSYS Mailing List Home <xansys-temp@list.xansys.org> > > Cc: Mohammad Gharaibeh <mgharai1@binghamton.edu> > > Subject: [Xansys] SHELL181 in Workbench vs APDL > > > > Hi All, > > > > A student of mine is trying to do modal analysis of a cantilevered plate > > (25mm x 50mm x 1mm) using ANSYS. The plate has TB,ANEL properties defined > > using stiffness matrix. > > > > We have experimental results says that the first natural frequency of > this > > system is 201 Hz. > > > > First, I had him use ANSYS APDL to learn modeling basics and all about > > element types. He used SHELL181 and executed modal analysis and the > plate’s > > 1st resonance frequency is calculated as 203 Hz. Then tried SOLID185 to > get > > a result of 204 Hz. Another student did it in ABAQUS and found a > frequency > > of 204 Hz using S4R element. Till now life is great. > > > > Going up in the learning ladder, I asked him to do it in WB. SHELL181 is > > the element and same mesh properties we used in APDL. Shockingly, the > first > > natural frequency in WB is 166 Hz. We double checked everything > (geometry & > > mechanical properties). > > > > Why are we getting a much lower natural frequencies? I would have to > guess > > something related to element KEYOPT? Any feedback is greatly appreciated. > > > > Best, > > Mohammad > > > > ===================================== > > Mohammad A Gharaibeh, Ph.D. > > Associate Professor > > Department of Mechanical Engineering > > The Hashemite University > > P.O. Box 330127 > > Zarqa, 13133, Jordan > > Tel: +962 - 5 - 390 3333 Ext. 4771 > > Fax: +962 - 5 - 382 6348 > > ==================================== > > _______________________________________________ > > Xansys mailing list -- xansys-temp@list.xansys.org To unsubscribe send > an > > email to xansys-temp-leave@list.xansys.org If you are receiving too many > > emails from XANSYS please consider changing account settings to Digest > mode > > which will send a single email per day. > > > > Please send administrative requests such as deletion from XANSYS to > > xansys-mod@tynecomp.co.uk and not to the list > > > _______________________________________________ > Xansys mailing list -- xansys-temp@list.xansys.org > To unsubscribe send an email to xansys-temp-leave@list.xansys.org > If you are receiving too many emails from XANSYS please consider changing > account settings to Digest mode which will send a single email per day. > > Please send administrative requests such as deletion from XANSYS to > xansys-mod@tynecomp.co.uk and not to the list > _______________________________________________ > Xansys mailing list -- xansys-temp@list.xansys.org > To unsubscribe send an email to xansys-temp-leave@list.xansys.org > If you are receiving too many emails from XANSYS please consider changing > account settings to Digest mode which will send a single email per day. > > Please send administrative requests such as deletion from XANSYS to > xansys-mod@tynecomp.co.uk and not to the list > _______________________________________________ > Xansys mailing list -- xansys-temp@list.xansys.org > To unsubscribe send an email to xansys-temp-leave@list.xansys.org > If you are receiving too many emails from XANSYS please consider changing > account settings to Digest mode which will send a single email per day. > > Please send administrative requests such as deletion from XANSYS to > xansys-mod@tynecomp.co.uk and not to the list

AP

Attar, Peter J.

Wed, May 22, 2024 12:53 PM

Care to explain what happened then??

Peter

From: Mohammad Gharaibeh mgharai1@binghamton.edu
Sent: Wednesday, May 22, 2024 7:48 AM
To: XANSYS Mailing List Home
Cc: Grama Bhashyam; Attar, Peter J.
Subject: Re: [Xansys] Re: [External Email] RE: SHELL181 in Workbench vs APDL

Peter,
Wow! You really nailed it. I got back to Dr. Bhashyam off the list. We were able to figure out what's going on. People should not judge without knowing the whole situation.

I hope you're happy now.

Best,
Mohammad

---====
Mohammad A Gharaibeh, Ph.D.
Associate Professor
Department of Mechanical Engineering
The Hashemite University
P.O. Box 330127
Zarqa, 13133, Jordan
Tel: +962 - 5 - 390 3333 Ext. 4771
Fax: +962 - 5 - 382 6348

---====

On Wed, May 22, 2024 at 3:37 PM Attar, Peter J. via Xansys <xansys-temp@list.xansys.org mailto:xansys-temp@list.xansys.org> wrote:
I agree and if the guy was really interested in having his student understand what's going on (in particular the ins and outs of locking and when it should/shouldn't occur...) he would get back to you...

Peter

From: Grama Bhashyam via Xansys <xansys-temp@list.xansys.org mailto:xansys-temp@list.xansys.org>
Sent: Sunday, May 19, 2024 9:20 AM
To: XANSYS Mailing List Home
Cc: XANSYS Mailing List Home; Grama Bhashyam
Subject: [Xansys] Re: [External Email] RE: SHELL181 in Workbench vs APDL

This is puzzling to me. Can you share the input with me please? Keyopt3 == 2 shouldn’t be a cause here.

Regards

Grama Bhashyam
Grama.bhashyam@ansys.com mailto:Grama.bhashyam@ansys.com

From: Mohammad Gharaibeh via Xansys <xansys-temp@list.xansys.org mailto:xansys-temp@list.xansys.org>
Sent: Sunday, May 19, 2024 10:12 AM
Cc: XANSYS Mailing List Home <xansys-temp@list.xansys.org mailto:xansys-temp@list.xansys.org>; Mohammad Gharaibeh <mgharai1@binghamton.edu mailto:mgharai1@binghamton.edu>
Subject: [Xansys] Re: [External Email] RE: SHELL181 in Workbench vs APDL

[External Sender]

Thank you, Matt, for the good suggestion. I dug into the DS.DAT and caught
the cause. It is a KEYOPT as expected (KEYOP(3)=2 and it should be 0).

Thanks again,
Mohammad

---====
Mohammad A Gharaibeh, Ph.D.
Associate Professor
Department of Mechanical Engineering
The Hashemite University
P.O. Box 330127
Zarqa, 13133, Jordan
Tel: +962 - 5 - 390 3333 Ext. 4771
Fax: +962 - 5 - 382 6348

---====

On Wed, 15 May 2024 at 6:45 PM Matthew Ridzon <Matt@prime-engineer.com mailto:Matt@prime-engineer.com>
wrote:

I would open up DS.DAT from the workbench model. Also open up the APDL
model. I would go through DS.DAT line-by-line to find out what might be
different from the APDL model. It might be a keyopt, but it's hard to tell.

—Matt

-----Original Message-----
From: Mohammad Gharaibeh via Xansys <xansys-temp@list.xansys.org mailto:xansys-temp@list.xansys.org>
Sent: May 15, 2024 11:38 AM
To: XANSYS Mailing List Home <xansys-temp@list.xansys.org mailto:xansys-temp@list.xansys.org>
Cc: Mohammad Gharaibeh <mgharai1@binghamton.edu mailto:mgharai1@binghamton.edu>
Subject: [Xansys] SHELL181 in Workbench vs APDL

Hi All,

A student of mine is trying to do modal analysis of a cantilevered plate
(25mm x 50mm x 1mm) using ANSYS. The plate has TB,ANEL properties defined
using stiffness matrix.

We have experimental results says that the first natural frequency of this
system is 201 Hz.

First, I had him use ANSYS APDL to learn modeling basics and all about
element types. He used SHELL181 and executed modal analysis and the plate’s
1st resonance frequency is calculated as 203 Hz. Then tried SOLID185 to get
a result of 204 Hz. Another student did it in ABAQUS and found a frequency
of 204 Hz using S4R element. Till now life is great.

Going up in the learning ladder, I asked him to do it in WB. SHELL181 is
the element and same mesh properties we used in APDL. Shockingly, the first
natural frequency in WB is 166 Hz. We double checked everything (geometry &
mechanical properties).

Why are we getting a much lower natural frequencies? I would have to guess
something related to element KEYOPT? Any feedback is greatly appreciated.

Best,
Mohammad

---====
Mohammad A Gharaibeh, Ph.D.
Associate Professor
Department of Mechanical Engineering
The Hashemite University
P.O. Box 330127
Zarqa, 13133, Jordan
Tel: +962 - 5 - 390 3333 Ext. 4771
Fax: +962 - 5 - 382 6348

---===

Xansys mailing list -- xansys-temp@list.xansys.org mailto:xansys-temp@list.xansys.org To unsubscribe send an
email to xansys-temp-leave@list.xansys.org mailto:xansys-temp-leave@list.xansys.org If you are receiving too many
emails from XANSYS please consider changing account settings to Digest mode
which will send a single email per day.

Please send administrative requests such as deletion from XANSYS to
xansys-mod@tynecomp.co.uk mailto:xansys-mod@tynecomp.co.uk and not to the list

Xansys mailing list -- xansys-temp@list.xansys.org mailto:xansys-temp@list.xansys.org
To unsubscribe send an email to xansys-temp-leave@list.xansys.org mailto:xansys-temp-leave@list.xansys.org
If you are receiving too many emails from XANSYS please consider changing account settings to Digest mode which will send a single email per day.

Please send administrative requests such as deletion from XANSYS to xansys-mod@tynecomp.co.uk mailto:xansys-mod@tynecomp.co.uk and not to the list

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To unsubscribe send an email to xansys-temp-leave@list.xansys.org mailto:xansys-temp-leave@list.xansys.org
If you are receiving too many emails from XANSYS please consider changing account settings to Digest mode which will send a single email per day.

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To unsubscribe send an email to xansys-temp-leave@list.xansys.org mailto:xansys-temp-leave@list.xansys.org
If you are receiving too many emails from XANSYS please consider changing account settings to Digest mode which will send a single email per day.

Please send administrative requests such as deletion from XANSYS to xansys-mod@tynecomp.co.uk mailto:xansys-mod@tynecomp.co.uk and not to the list

Care to explain what happened then?? Peter ________________________________________ From: Mohammad Gharaibeh <mgharai1@binghamton.edu> Sent: Wednesday, May 22, 2024 7:48 AM To: XANSYS Mailing List Home Cc: Grama Bhashyam; Attar, Peter J. Subject: Re: [Xansys] Re: [External Email] RE: SHELL181 in Workbench vs APDL Peter, Wow! You really nailed it. I got back to Dr. Bhashyam off the list. We were able to figure out what's going on. People should not judge without knowing the whole situation. I hope you're happy now. Best, Mohammad ===================================== Mohammad A Gharaibeh, Ph.D. Associate Professor Department of Mechanical Engineering The Hashemite University P.O. Box 330127 Zarqa, 13133, Jordan Tel: +962 - 5 - 390 3333 Ext. 4771 Fax: +962 - 5 - 382 6348 ===================================== On Wed, May 22, 2024 at 3:37 PM Attar, Peter J. via Xansys <xansys-temp@list.xansys.org<mailto:xansys-temp@list.xansys.org>> wrote: I agree and if the guy was really interested in having his student understand what's going on (in particular the ins and outs of locking and when it should/shouldn't occur...) he would get back to you... Peter ________________________________________ From: Grama Bhashyam via Xansys <xansys-temp@list.xansys.org<mailto:xansys-temp@list.xansys.org>> Sent: Sunday, May 19, 2024 9:20 AM To: XANSYS Mailing List Home Cc: XANSYS Mailing List Home; Grama Bhashyam Subject: [Xansys] Re: [External Email] RE: SHELL181 in Workbench vs APDL This is puzzling to me. Can you share the input with me please? Keyopt3 == 2 shouldn’t be a cause here. Regards Grama Bhashyam Grama.bhashyam@ansys.com<mailto:Grama.bhashyam@ansys.com> ________________________________ From: Mohammad Gharaibeh via Xansys <xansys-temp@list.xansys.org<mailto:xansys-temp@list.xansys.org>> Sent: Sunday, May 19, 2024 10:12 AM Cc: XANSYS Mailing List Home <xansys-temp@list.xansys.org<mailto:xansys-temp@list.xansys.org>>; Mohammad Gharaibeh <mgharai1@binghamton.edu<mailto:mgharai1@binghamton.edu>> Subject: [Xansys] Re: [External Email] RE: SHELL181 in Workbench vs APDL [External Sender] Thank you, Matt, for the good suggestion. I dug into the DS.DAT and caught the cause. It is a KEYOPT as expected (KEYOP(3)=2 and it should be 0). Thanks again, Mohammad ===================================== Mohammad A Gharaibeh, Ph.D. Associate Professor Department of Mechanical Engineering The Hashemite University P.O. Box 330127 Zarqa, 13133, Jordan Tel: +962 - 5 - 390 3333 Ext. 4771 Fax: +962 - 5 - 382 6348 ===================================== On Wed, 15 May 2024 at 6:45 PM Matthew Ridzon <Matt@prime-engineer.com<mailto:Matt@prime-engineer.com>> wrote: > I would open up DS.DAT from the workbench model. Also open up the APDL > model. I would go through DS.DAT line-by-line to find out what might be > different from the APDL model. It might be a keyopt, but it's hard to tell. > > —Matt > > -----Original Message----- > From: Mohammad Gharaibeh via Xansys <xansys-temp@list.xansys.org<mailto:xansys-temp@list.xansys.org>> > Sent: May 15, 2024 11:38 AM > To: XANSYS Mailing List Home <xansys-temp@list.xansys.org<mailto:xansys-temp@list.xansys.org>> > Cc: Mohammad Gharaibeh <mgharai1@binghamton.edu<mailto:mgharai1@binghamton.edu>> > Subject: [Xansys] SHELL181 in Workbench vs APDL > > Hi All, > > A student of mine is trying to do modal analysis of a cantilevered plate > (25mm x 50mm x 1mm) using ANSYS. The plate has TB,ANEL properties defined > using stiffness matrix. > > We have experimental results says that the first natural frequency of this > system is 201 Hz. > > First, I had him use ANSYS APDL to learn modeling basics and all about > element types. He used SHELL181 and executed modal analysis and the plate’s > 1st resonance frequency is calculated as 203 Hz. Then tried SOLID185 to get > a result of 204 Hz. Another student did it in ABAQUS and found a frequency > of 204 Hz using S4R element. Till now life is great. > > Going up in the learning ladder, I asked him to do it in WB. SHELL181 is > the element and same mesh properties we used in APDL. Shockingly, the first > natural frequency in WB is 166 Hz. We double checked everything (geometry & > mechanical properties). > > Why are we getting a much lower natural frequencies? I would have to guess > something related to element KEYOPT? Any feedback is greatly appreciated. > > Best, > Mohammad > > ===================================== > Mohammad A Gharaibeh, Ph.D. > Associate Professor > Department of Mechanical Engineering > The Hashemite University > P.O. Box 330127 > Zarqa, 13133, Jordan > Tel: +962 - 5 - 390 3333 Ext. 4771 > Fax: +962 - 5 - 382 6348 > ==================================== > _______________________________________________ > Xansys mailing list -- xansys-temp@list.xansys.org<mailto:xansys-temp@list.xansys.org> To unsubscribe send an > email to xansys-temp-leave@list.xansys.org<mailto:xansys-temp-leave@list.xansys.org> If you are receiving too many > emails from XANSYS please consider changing account settings to Digest mode > which will send a single email per day. > > Please send administrative requests such as deletion from XANSYS to > xansys-mod@tynecomp.co.uk<mailto:xansys-mod@tynecomp.co.uk> and not to the list > _______________________________________________ Xansys mailing list -- xansys-temp@list.xansys.org<mailto:xansys-temp@list.xansys.org> To unsubscribe send an email to xansys-temp-leave@list.xansys.org<mailto:xansys-temp-leave@list.xansys.org> If you are receiving too many emails from XANSYS please consider changing account settings to Digest mode which will send a single email per day. Please send administrative requests such as deletion from XANSYS to xansys-mod@tynecomp.co.uk<mailto:xansys-mod@tynecomp.co.uk> and not to the list _______________________________________________ Xansys mailing list -- xansys-temp@list.xansys.org<mailto:xansys-temp@list.xansys.org> To unsubscribe send an email to xansys-temp-leave@list.xansys.org<mailto:xansys-temp-leave@list.xansys.org> If you are receiving too many emails from XANSYS please consider changing account settings to Digest mode which will send a single email per day. Please send administrative requests such as deletion from XANSYS to xansys-mod@tynecomp.co.uk<mailto:xansys-mod@tynecomp.co.uk> and not to the list _______________________________________________ Xansys mailing list -- xansys-temp@list.xansys.org<mailto:xansys-temp@list.xansys.org> To unsubscribe send an email to xansys-temp-leave@list.xansys.org<mailto:xansys-temp-leave@list.xansys.org> If you are receiving too many emails from XANSYS please consider changing account settings to Digest mode which will send a single email per day. Please send administrative requests such as deletion from XANSYS to xansys-mod@tynecomp.co.uk<mailto:xansys-mod@tynecomp.co.uk> and not to the list

MG

Mohammad Gharaibeh

Wed, May 22, 2024 1:00 PM

The student model coordinate system does not align with his ANEL material
properties directions. Once he figured and fixed that, we matched the APDL
results with the WB and with experiments.

I am thankful for everyone for their assistance on this.

Best,
Mohammad

---====
Mohammad A Gharaibeh, Ph.D.
Associate Professor
Department of Mechanical Engineering
The Hashemite University
P.O. Box 330127
Zarqa, 13133, Jordan
Tel: +962 - 5 - 390 3333 Ext. 4771
Fax: +962 - 5 - 382 6348

---====

On Wed, 22 May 2024 at 3:53 PM Attar, Peter J. peter.attar@ou.edu wrote:

Care to explain what happened then??

Peter

From: Mohammad Gharaibeh mgharai1@binghamton.edu
Sent: Wednesday, May 22, 2024 7:48 AM
To: XANSYS Mailing List Home
Cc: Grama Bhashyam; Attar, Peter J.
Subject: Re: [Xansys] Re: [External Email] RE: SHELL181 in Workbench vs
APDL

Peter,
Wow! You really nailed it. I got back to Dr. Bhashyam off the list. We
were able to figure out what's going on. People should not judge without
knowing the whole situation.

I hope you're happy now.

Best,
Mohammad

---====
Mohammad A Gharaibeh, Ph.D.
Associate Professor
Department of Mechanical Engineering
The Hashemite University
P.O. Box 330127
Zarqa, 13133, Jordan
Tel: +962 - 5 - 390 3333 Ext. 4771
Fax: +962 - 5 - 382 6348

---====

On Wed, May 22, 2024 at 3:37 PM Attar, Peter J. via Xansys <
xansys-temp@list.xansys.org mailto:xansys-temp@list.xansys.org> wrote:
I agree and if the guy was really interested in having his student
understand what's going on (in particular the ins and outs of locking and
when it should/shouldn't occur...) he would get back to you...

Peter

From: Grama Bhashyam via Xansys <xansys-temp@list.xansys.org<mailto:
xansys-temp@list.xansys.org>>
Sent: Sunday, May 19, 2024 9:20 AM
To: XANSYS Mailing List Home
Cc: XANSYS Mailing List Home; Grama Bhashyam
Subject: [Xansys] Re: [External Email] RE: SHELL181 in Workbench vs APDL

This is puzzling to me. Can you share the input with me please? Keyopt3 ==
2 shouldn’t be a cause here.

Regards

Grama Bhashyam
Grama.bhashyam@ansys.com mailto:Grama.bhashyam@ansys.com

From: Mohammad Gharaibeh via Xansys <xansys-temp@list.xansys.org<mailto:
xansys-temp@list.xansys.org>>
Sent: Sunday, May 19, 2024 10:12 AM
Cc: XANSYS Mailing List Home <xansys-temp@list.xansys.org<mailto:
xansys-temp@list.xansys.org>>; Mohammad Gharaibeh <mgharai1@binghamton.edu
mailto:mgharai1@binghamton.edu>
Subject: [Xansys] Re: [External Email] RE: SHELL181 in Workbench vs APDL

[External Sender]

Thank you, Matt, for the good suggestion. I dug into the DS.DAT and caught
the cause. It is a KEYOPT as expected (KEYOP(3)=2 and it should be 0).

Thanks again,
Mohammad

---====
Mohammad A Gharaibeh, Ph.D.
Associate Professor
Department of Mechanical Engineering
The Hashemite University
P.O. Box 330127
Zarqa, 13133, Jordan
Tel: +962 - 5 - 390 3333 Ext. 4771
Fax: +962 - 5 - 382 6348

---====

On Wed, 15 May 2024 at 6:45 PM Matthew Ridzon <Matt@prime-engineer.com
mailto:Matt@prime-engineer.com>
wrote:

I would open up DS.DAT from the workbench model. Also open up the APDL
model. I would go through DS.DAT line-by-line to find out what might be
different from the APDL model. It might be a keyopt, but it's hard to

tell.

—Matt

-----Original Message-----
From: Mohammad Gharaibeh via Xansys <xansys-temp@list.xansys.org<mailto:

xansys-temp@list.xansys.org>>

Sent: May 15, 2024 11:38 AM
To: XANSYS Mailing List Home <xansys-temp@list.xansys.org<mailto:

xansys-temp@list.xansys.org>>

Cc: Mohammad Gharaibeh <mgharai1@binghamton.edu<mailto:

mgharai1@binghamton.edu>>

Subject: [Xansys] SHELL181 in Workbench vs APDL

Hi All,

A student of mine is trying to do modal analysis of a cantilevered plate
(25mm x 50mm x 1mm) using ANSYS. The plate has TB,ANEL properties defined
using stiffness matrix.

We have experimental results says that the first natural frequency of

this

system is 201 Hz.

First, I had him use ANSYS APDL to learn modeling basics and all about
element types. He used SHELL181 and executed modal analysis and the

plate’s

1st resonance frequency is calculated as 203 Hz. Then tried SOLID185 to

get

a result of 204 Hz. Another student did it in ABAQUS and found a

frequency

of 204 Hz using S4R element. Till now life is great.

Going up in the learning ladder, I asked him to do it in WB. SHELL181 is
the element and same mesh properties we used in APDL. Shockingly, the

first

natural frequency in WB is 166 Hz. We double checked everything

(geometry &

mechanical properties).

Why are we getting a much lower natural frequencies? I would have to

guess

something related to element KEYOPT? Any feedback is greatly appreciated.

Best,
Mohammad

---====
Mohammad A Gharaibeh, Ph.D.
Associate Professor
Department of Mechanical Engineering
The Hashemite University
P.O. Box 330127
Zarqa, 13133, Jordan
Tel: +962 - 5 - 390 3333 Ext. 4771
Fax: +962 - 5 - 382 6348

---===

Xansys mailing list -- xansys-temp@list.xansys.org<mailto:

xansys-temp@list.xansys.org> To unsubscribe send an

email to xansys-temp-leave@list.xansys.org<mailto:

xansys-temp-leave@list.xansys.org> If you are receiving too many

emails from XANSYS please consider changing account settings to Digest

mode

which will send a single email per day.

Please send administrative requests such as deletion from XANSYS to
xansys-mod@tynecomp.co.uk mailto:xansys-mod@tynecomp.co.uk and not to

the list

Xansys mailing list -- xansys-temp@list.xansys.org<mailto:
xansys-temp@list.xansys.org>
To unsubscribe send an email to xansys-temp-leave@list.xansys.org<mailto:
xansys-temp-leave@list.xansys.org>
If you are receiving too many emails from XANSYS please consider changing
account settings to Digest mode which will send a single email per day.

Please send administrative requests such as deletion from XANSYS to
xansys-mod@tynecomp.co.uk mailto:xansys-mod@tynecomp.co.uk and not to
the list

Xansys mailing list -- xansys-temp@list.xansys.org<mailto:
xansys-temp@list.xansys.org>
To unsubscribe send an email to xansys-temp-leave@list.xansys.org<mailto:
xansys-temp-leave@list.xansys.org>
If you are receiving too many emails from XANSYS please consider changing
account settings to Digest mode which will send a single email per day.

Please send administrative requests such as deletion from XANSYS to
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the list

Xansys mailing list -- xansys-temp@list.xansys.org<mailto:
xansys-temp@list.xansys.org>
To unsubscribe send an email to xansys-temp-leave@list.xansys.org<mailto:
xansys-temp-leave@list.xansys.org>
If you are receiving too many emails from XANSYS please consider changing
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Please send administrative requests such as deletion from XANSYS to
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the list

The student model coordinate system does not align with his ANEL material properties directions. Once he figured and fixed that, we matched the APDL results with the WB and with experiments. I am thankful for everyone for their assistance on this. Best, Mohammad ===================================== Mohammad A Gharaibeh, Ph.D. Associate Professor Department of Mechanical Engineering The Hashemite University P.O. Box 330127 Zarqa, 13133, Jordan Tel: +962 - 5 - 390 3333 Ext. 4771 Fax: +962 - 5 - 382 6348 ===================================== On Wed, 22 May 2024 at 3:53 PM Attar, Peter J. <peter.attar@ou.edu> wrote: > Care to explain what happened then?? > > Peter > > ________________________________________ > From: Mohammad Gharaibeh <mgharai1@binghamton.edu> > Sent: Wednesday, May 22, 2024 7:48 AM > To: XANSYS Mailing List Home > Cc: Grama Bhashyam; Attar, Peter J. > Subject: Re: [Xansys] Re: [External Email] RE: SHELL181 in Workbench vs > APDL > > Peter, > Wow! You really nailed it. I got back to Dr. Bhashyam off the list. We > were able to figure out what's going on. People should not judge without > knowing the whole situation. > > I hope you're happy now. > > Best, > Mohammad > ===================================== > Mohammad A Gharaibeh, Ph.D. > Associate Professor > Department of Mechanical Engineering > The Hashemite University > P.O. Box 330127 > Zarqa, 13133, Jordan > Tel: +962 - 5 - 390 3333 Ext. 4771 > Fax: +962 - 5 - 382 6348 > ===================================== > > > > > On Wed, May 22, 2024 at 3:37 PM Attar, Peter J. via Xansys < > xansys-temp@list.xansys.org<mailto:xansys-temp@list.xansys.org>> wrote: > I agree and if the guy was really interested in having his student > understand what's going on (in particular the ins and outs of locking and > when it should/shouldn't occur...) he would get back to you... > > > Peter > > ________________________________________ > From: Grama Bhashyam via Xansys <xansys-temp@list.xansys.org<mailto: > xansys-temp@list.xansys.org>> > Sent: Sunday, May 19, 2024 9:20 AM > To: XANSYS Mailing List Home > Cc: XANSYS Mailing List Home; Grama Bhashyam > Subject: [Xansys] Re: [External Email] RE: SHELL181 in Workbench vs APDL > > This is puzzling to me. Can you share the input with me please? Keyopt3 == > 2 shouldn’t be a cause here. > > Regards > > Grama Bhashyam > Grama.bhashyam@ansys.com<mailto:Grama.bhashyam@ansys.com> > > ________________________________ > From: Mohammad Gharaibeh via Xansys <xansys-temp@list.xansys.org<mailto: > xansys-temp@list.xansys.org>> > Sent: Sunday, May 19, 2024 10:12 AM > Cc: XANSYS Mailing List Home <xansys-temp@list.xansys.org<mailto: > xansys-temp@list.xansys.org>>; Mohammad Gharaibeh <mgharai1@binghamton.edu > <mailto:mgharai1@binghamton.edu>> > Subject: [Xansys] Re: [External Email] RE: SHELL181 in Workbench vs APDL > > [External Sender] > > Thank you, Matt, for the good suggestion. I dug into the DS.DAT and caught > the cause. It is a KEYOPT as expected (KEYOP(3)=2 and it should be 0). > > Thanks again, > Mohammad > > ===================================== > Mohammad A Gharaibeh, Ph.D. > Associate Professor > Department of Mechanical Engineering > The Hashemite University > P.O. Box 330127 > Zarqa, 13133, Jordan > Tel: +962 - 5 - 390 3333 Ext. 4771 > Fax: +962 - 5 - 382 6348 > ===================================== > > > > > On Wed, 15 May 2024 at 6:45 PM Matthew Ridzon <Matt@prime-engineer.com > <mailto:Matt@prime-engineer.com>> > wrote: > > > I would open up DS.DAT from the workbench model. Also open up the APDL > > model. I would go through DS.DAT line-by-line to find out what might be > > different from the APDL model. It might be a keyopt, but it's hard to > tell. > > > > —Matt > > > > -----Original Message----- > > From: Mohammad Gharaibeh via Xansys <xansys-temp@list.xansys.org<mailto: > xansys-temp@list.xansys.org>> > > Sent: May 15, 2024 11:38 AM > > To: XANSYS Mailing List Home <xansys-temp@list.xansys.org<mailto: > xansys-temp@list.xansys.org>> > > Cc: Mohammad Gharaibeh <mgharai1@binghamton.edu<mailto: > mgharai1@binghamton.edu>> > > Subject: [Xansys] SHELL181 in Workbench vs APDL > > > > Hi All, > > > > A student of mine is trying to do modal analysis of a cantilevered plate > > (25mm x 50mm x 1mm) using ANSYS. The plate has TB,ANEL properties defined > > using stiffness matrix. > > > > We have experimental results says that the first natural frequency of > this > > system is 201 Hz. > > > > First, I had him use ANSYS APDL to learn modeling basics and all about > > element types. He used SHELL181 and executed modal analysis and the > plate’s > > 1st resonance frequency is calculated as 203 Hz. Then tried SOLID185 to > get > > a result of 204 Hz. Another student did it in ABAQUS and found a > frequency > > of 204 Hz using S4R element. Till now life is great. > > > > Going up in the learning ladder, I asked him to do it in WB. SHELL181 is > > the element and same mesh properties we used in APDL. Shockingly, the > first > > natural frequency in WB is 166 Hz. We double checked everything > (geometry & > > mechanical properties). > > > > Why are we getting a much lower natural frequencies? I would have to > guess > > something related to element KEYOPT? Any feedback is greatly appreciated. > > > > Best, > > Mohammad > > > > ===================================== > > Mohammad A Gharaibeh, Ph.D. > > Associate Professor > > Department of Mechanical Engineering > > The Hashemite University > > P.O. Box 330127 > > Zarqa, 13133, Jordan > > Tel: +962 - 5 - 390 3333 Ext. 4771 > > Fax: +962 - 5 - 382 6348 > > ==================================== > > _______________________________________________ > > Xansys mailing list -- xansys-temp@list.xansys.org<mailto: > xansys-temp@list.xansys.org> To unsubscribe send an > > email to xansys-temp-leave@list.xansys.org<mailto: > xansys-temp-leave@list.xansys.org> If you are receiving too many > > emails from XANSYS please consider changing account settings to Digest > mode > > which will send a single email per day. > > > > Please send administrative requests such as deletion from XANSYS to > > xansys-mod@tynecomp.co.uk<mailto:xansys-mod@tynecomp.co.uk> and not to > the list > > > _______________________________________________ > Xansys mailing list -- xansys-temp@list.xansys.org<mailto: > xansys-temp@list.xansys.org> > To unsubscribe send an email to xansys-temp-leave@list.xansys.org<mailto: > xansys-temp-leave@list.xansys.org> > If you are receiving too many emails from XANSYS please consider changing > account settings to Digest mode which will send a single email per day. > > Please send administrative requests such as deletion from XANSYS to > xansys-mod@tynecomp.co.uk<mailto:xansys-mod@tynecomp.co.uk> and not to > the list > _______________________________________________ > Xansys mailing list -- xansys-temp@list.xansys.org<mailto: > xansys-temp@list.xansys.org> > To unsubscribe send an email to xansys-temp-leave@list.xansys.org<mailto: > xansys-temp-leave@list.xansys.org> > If you are receiving too many emails from XANSYS please consider changing > account settings to Digest mode which will send a single email per day. > > Please send administrative requests such as deletion from XANSYS to > xansys-mod@tynecomp.co.uk<mailto:xansys-mod@tynecomp.co.uk> and not to > the list > _______________________________________________ > Xansys mailing list -- xansys-temp@list.xansys.org<mailto: > xansys-temp@list.xansys.org> > To unsubscribe send an email to xansys-temp-leave@list.xansys.org<mailto: > xansys-temp-leave@list.xansys.org> > If you are receiving too many emails from XANSYS please consider changing > account settings to Digest mode which will send a single email per day. > > Please send administrative requests such as deletion from XANSYS to > xansys-mod@tynecomp.co.uk<mailto:xansys-mod@tynecomp.co.uk> and not to > the list >

AP

Attar, Peter J.

Wed, May 22, 2024 1:02 PM

See, that makes more sense than just assuming that an element option that has to do with locking would effect the first bending mode of a thin plate... Thank you.

Peter

From: Mohammad Gharaibeh mgharai1@binghamton.edu
Sent: Wednesday, May 22, 2024 8:00 AM
To: Attar, Peter J.
Cc: Grama Bhashyam; XANSYS Mailing List Home
Subject: Re: [Xansys] Re: [External Email] RE: SHELL181 in Workbench vs APDL

The student model coordinate system does not align with his ANEL material properties directions. Once he figured and fixed that, we matched the APDL results with the WB and with experiments.

I am thankful for everyone for their assistance on this.

Best,
Mohammad

---====
Mohammad A Gharaibeh, Ph.D.
Associate Professor
Department of Mechanical Engineering
The Hashemite University
P.O. Box 330127
Zarqa, 13133, Jordan
Tel: +962 - 5 - 390 3333 Ext. 4771
Fax: +962 - 5 - 382 6348

---====

On Wed, 22 May 2024 at 3:53 PM Attar, Peter J. <peter.attar@ou.edu mailto:peter.attar@ou.edu> wrote:
Care to explain what happened then??

Peter

From: Mohammad Gharaibeh <mgharai1@binghamton.edu mailto:mgharai1@binghamton.edu>
Sent: Wednesday, May 22, 2024 7:48 AM
To: XANSYS Mailing List Home
Cc: Grama Bhashyam; Attar, Peter J.
Subject: Re: [Xansys] Re: [External Email] RE: SHELL181 in Workbench vs APDL

Peter,
Wow! You really nailed it. I got back to Dr. Bhashyam off the list. We were able to figure out what's going on. People should not judge without knowing the whole situation.

I hope you're happy now.

Best,
Mohammad

---====
Mohammad A Gharaibeh, Ph.D.
Associate Professor
Department of Mechanical Engineering
The Hashemite University
P.O. Box 330127
Zarqa, 13133, Jordan
Tel: +962 - 5 - 390 3333 Ext. 4771
Fax: +962 - 5 - 382 6348

---====

On Wed, May 22, 2024 at 3:37 PM Attar, Peter J. via Xansys <xansys-temp@list.xansys.org mailto:xansys-temp@list.xansys.org<mailto:xansys-temp@list.xansys.org mailto:xansys-temp@list.xansys.org>> wrote:
I agree and if the guy was really interested in having his student understand what's going on (in particular the ins and outs of locking and when it should/shouldn't occur...) he would get back to you...

Peter

From: Grama Bhashyam via Xansys <xansys-temp@list.xansys.org mailto:xansys-temp@list.xansys.org<mailto:xansys-temp@list.xansys.org mailto:xansys-temp@list.xansys.org>>
Sent: Sunday, May 19, 2024 9:20 AM
To: XANSYS Mailing List Home
Cc: XANSYS Mailing List Home; Grama Bhashyam
Subject: [Xansys] Re: [External Email] RE: SHELL181 in Workbench vs APDL

This is puzzling to me. Can you share the input with me please? Keyopt3 == 2 shouldn’t be a cause here.

Regards

Grama Bhashyam
Grama.bhashyam@ansys.com mailto:Grama.bhashyam@ansys.com<mailto:Grama.bhashyam@ansys.com mailto:Grama.bhashyam@ansys.com>

[External Sender]

Thank you, Matt, for the good suggestion. I dug into the DS.DAT and caught
the cause. It is a KEYOPT as expected (KEYOP(3)=2 and it should be 0).

Thanks again,
Mohammad

---====
Mohammad A Gharaibeh, Ph.D.
Associate Professor
Department of Mechanical Engineering
The Hashemite University
P.O. Box 330127
Zarqa, 13133, Jordan
Tel: +962 - 5 - 390 3333 Ext. 4771
Fax: +962 - 5 - 382 6348

---====

On Wed, 15 May 2024 at 6:45 PM Matthew Ridzon <Matt@prime-engineer.com mailto:Matt@prime-engineer.com<mailto:Matt@prime-engineer.com mailto:Matt@prime-engineer.com>>
wrote:

I would open up DS.DAT from the workbench model. Also open up the APDL
model. I would go through DS.DAT line-by-line to find out what might be
different from the APDL model. It might be a keyopt, but it's hard to tell.

—Matt

Hi All,

A student of mine is trying to do modal analysis of a cantilevered plate
(25mm x 50mm x 1mm) using ANSYS. The plate has TB,ANEL properties defined
using stiffness matrix.

We have experimental results says that the first natural frequency of this
system is 201 Hz.

First, I had him use ANSYS APDL to learn modeling basics and all about
element types. He used SHELL181 and executed modal analysis and the plate’s
1st resonance frequency is calculated as 203 Hz. Then tried SOLID185 to get
a result of 204 Hz. Another student did it in ABAQUS and found a frequency
of 204 Hz using S4R element. Till now life is great.

Going up in the learning ladder, I asked him to do it in WB. SHELL181 is
the element and same mesh properties we used in APDL. Shockingly, the first
natural frequency in WB is 166 Hz. We double checked everything (geometry &
mechanical properties).

Why are we getting a much lower natural frequencies? I would have to guess
something related to element KEYOPT? Any feedback is greatly appreciated.

Best,
Mohammad

---====
Mohammad A Gharaibeh, Ph.D.
Associate Professor
Department of Mechanical Engineering
The Hashemite University
P.O. Box 330127
Zarqa, 13133, Jordan
Tel: +962 - 5 - 390 3333 Ext. 4771
Fax: +962 - 5 - 382 6348

---===

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See, that makes more sense than just assuming that an element option that has to do with locking would effect the first bending mode of a thin plate... Thank you. Peter ________________________________________ From: Mohammad Gharaibeh <mgharai1@binghamton.edu> Sent: Wednesday, May 22, 2024 8:00 AM To: Attar, Peter J. Cc: Grama Bhashyam; XANSYS Mailing List Home Subject: Re: [Xansys] Re: [External Email] RE: SHELL181 in Workbench vs APDL The student model coordinate system does not align with his ANEL material properties directions. Once he figured and fixed that, we matched the APDL results with the WB and with experiments. I am thankful for everyone for their assistance on this. Best, Mohammad ===================================== Mohammad A Gharaibeh, Ph.D. Associate Professor Department of Mechanical Engineering The Hashemite University P.O. Box 330127 Zarqa, 13133, Jordan Tel: +962 - 5 - 390 3333 Ext. 4771 Fax: +962 - 5 - 382 6348 ===================================== On Wed, 22 May 2024 at 3:53 PM Attar, Peter J. <peter.attar@ou.edu<mailto:peter.attar@ou.edu>> wrote: Care to explain what happened then?? Peter ________________________________________ From: Mohammad Gharaibeh <mgharai1@binghamton.edu<mailto:mgharai1@binghamton.edu>> Sent: Wednesday, May 22, 2024 7:48 AM To: XANSYS Mailing List Home Cc: Grama Bhashyam; Attar, Peter J. Subject: Re: [Xansys] Re: [External Email] RE: SHELL181 in Workbench vs APDL Peter, Wow! You really nailed it. I got back to Dr. Bhashyam off the list. We were able to figure out what's going on. People should not judge without knowing the whole situation. I hope you're happy now. Best, Mohammad ===================================== Mohammad A Gharaibeh, Ph.D. Associate Professor Department of Mechanical Engineering The Hashemite University P.O. Box 330127 Zarqa, 13133, Jordan Tel: +962 - 5 - 390 3333 Ext. 4771 Fax: +962 - 5 - 382 6348 ===================================== On Wed, May 22, 2024 at 3:37 PM Attar, Peter J. via Xansys <xansys-temp@list.xansys.org<mailto:xansys-temp@list.xansys.org><mailto:xansys-temp@list.xansys.org<mailto:xansys-temp@list.xansys.org>>> wrote: I agree and if the guy was really interested in having his student understand what's going on (in particular the ins and outs of locking and when it should/shouldn't occur...) he would get back to you... Peter ________________________________________ From: Grama Bhashyam via Xansys <xansys-temp@list.xansys.org<mailto:xansys-temp@list.xansys.org><mailto:xansys-temp@list.xansys.org<mailto:xansys-temp@list.xansys.org>>> Sent: Sunday, May 19, 2024 9:20 AM To: XANSYS Mailing List Home Cc: XANSYS Mailing List Home; Grama Bhashyam Subject: [Xansys] Re: [External Email] RE: SHELL181 in Workbench vs APDL This is puzzling to me. Can you share the input with me please? Keyopt3 == 2 shouldn’t be a cause here. Regards Grama Bhashyam Grama.bhashyam@ansys.com<mailto:Grama.bhashyam@ansys.com><mailto:Grama.bhashyam@ansys.com<mailto:Grama.bhashyam@ansys.com>> ________________________________ From: Mohammad Gharaibeh via Xansys <xansys-temp@list.xansys.org<mailto:xansys-temp@list.xansys.org><mailto:xansys-temp@list.xansys.org<mailto:xansys-temp@list.xansys.org>>> Sent: Sunday, May 19, 2024 10:12 AM Cc: XANSYS Mailing List Home <xansys-temp@list.xansys.org<mailto:xansys-temp@list.xansys.org><mailto:xansys-temp@list.xansys.org<mailto:xansys-temp@list.xansys.org>>>; Mohammad Gharaibeh <mgharai1@binghamton.edu<mailto:mgharai1@binghamton.edu><mailto:mgharai1@binghamton.edu<mailto:mgharai1@binghamton.edu>>> Subject: [Xansys] Re: [External Email] RE: SHELL181 in Workbench vs APDL [External Sender] Thank you, Matt, for the good suggestion. I dug into the DS.DAT and caught the cause. It is a KEYOPT as expected (KEYOP(3)=2 and it should be 0). Thanks again, Mohammad ===================================== Mohammad A Gharaibeh, Ph.D. Associate Professor Department of Mechanical Engineering The Hashemite University P.O. Box 330127 Zarqa, 13133, Jordan Tel: +962 - 5 - 390 3333 Ext. 4771 Fax: +962 - 5 - 382 6348 ===================================== On Wed, 15 May 2024 at 6:45 PM Matthew Ridzon <Matt@prime-engineer.com<mailto:Matt@prime-engineer.com><mailto:Matt@prime-engineer.com<mailto:Matt@prime-engineer.com>>> wrote: > I would open up DS.DAT from the workbench model. Also open up the APDL > model. I would go through DS.DAT line-by-line to find out what might be > different from the APDL model. It might be a keyopt, but it's hard to tell. > > —Matt > > -----Original Message----- > From: Mohammad Gharaibeh via Xansys <xansys-temp@list.xansys.org<mailto:xansys-temp@list.xansys.org><mailto:xansys-temp@list.xansys.org<mailto:xansys-temp@list.xansys.org>>> > Sent: May 15, 2024 11:38 AM > To: XANSYS Mailing List Home <xansys-temp@list.xansys.org<mailto:xansys-temp@list.xansys.org><mailto:xansys-temp@list.xansys.org<mailto:xansys-temp@list.xansys.org>>> > Cc: Mohammad Gharaibeh <mgharai1@binghamton.edu<mailto:mgharai1@binghamton.edu><mailto:mgharai1@binghamton.edu<mailto:mgharai1@binghamton.edu>>> > Subject: [Xansys] SHELL181 in Workbench vs APDL > > Hi All, > > A student of mine is trying to do modal analysis of a cantilevered plate > (25mm x 50mm x 1mm) using ANSYS. The plate has TB,ANEL properties defined > using stiffness matrix. > > We have experimental results says that the first natural frequency of this > system is 201 Hz. > > First, I had him use ANSYS APDL to learn modeling basics and all about > element types. He used SHELL181 and executed modal analysis and the plate’s > 1st resonance frequency is calculated as 203 Hz. Then tried SOLID185 to get > a result of 204 Hz. Another student did it in ABAQUS and found a frequency > of 204 Hz using S4R element. Till now life is great. > > Going up in the learning ladder, I asked him to do it in WB. SHELL181 is > the element and same mesh properties we used in APDL. Shockingly, the first > natural frequency in WB is 166 Hz. We double checked everything (geometry & > mechanical properties). > > Why are we getting a much lower natural frequencies? I would have to guess > something related to element KEYOPT? Any feedback is greatly appreciated. > > Best, > Mohammad > > ===================================== > Mohammad A Gharaibeh, Ph.D. > Associate Professor > Department of Mechanical Engineering > The Hashemite University > P.O. Box 330127 > Zarqa, 13133, Jordan > Tel: +962 - 5 - 390 3333 Ext. 4771 > Fax: +962 - 5 - 382 6348 > ==================================== > _______________________________________________ > Xansys mailing list -- xansys-temp@list.xansys.org<mailto:xansys-temp@list.xansys.org><mailto:xansys-temp@list.xansys.org<mailto:xansys-temp@list.xansys.org>> To unsubscribe send an > email to xansys-temp-leave@list.xansys.org<mailto:xansys-temp-leave@list.xansys.org><mailto:xansys-temp-leave@list.xansys.org<mailto:xansys-temp-leave@list.xansys.org>> If you are receiving too many > emails from XANSYS please consider changing account settings to Digest mode > which will send a single email per day. > > Please send administrative requests such as deletion from XANSYS to > xansys-mod@tynecomp.co.uk<mailto:xansys-mod@tynecomp.co.uk><mailto:xansys-mod@tynecomp.co.uk<mailto:xansys-mod@tynecomp.co.uk>> and not to the list > _______________________________________________ Xansys mailing list -- xansys-temp@list.xansys.org<mailto:xansys-temp@list.xansys.org><mailto:xansys-temp@list.xansys.org<mailto:xansys-temp@list.xansys.org>> To unsubscribe send an email to xansys-temp-leave@list.xansys.org<mailto:xansys-temp-leave@list.xansys.org><mailto:xansys-temp-leave@list.xansys.org<mailto:xansys-temp-leave@list.xansys.org>> If you are receiving too many emails from XANSYS please consider changing account settings to Digest mode which will send a single email per day. Please send administrative requests such as deletion from XANSYS to xansys-mod@tynecomp.co.uk<mailto:xansys-mod@tynecomp.co.uk><mailto:xansys-mod@tynecomp.co.uk<mailto:xansys-mod@tynecomp.co.uk>> and not to the list _______________________________________________ Xansys mailing list -- xansys-temp@list.xansys.org<mailto:xansys-temp@list.xansys.org><mailto:xansys-temp@list.xansys.org<mailto:xansys-temp@list.xansys.org>> To unsubscribe send an email to xansys-temp-leave@list.xansys.org<mailto:xansys-temp-leave@list.xansys.org><mailto:xansys-temp-leave@list.xansys.org<mailto:xansys-temp-leave@list.xansys.org>> If you are receiving too many emails from XANSYS please consider changing account settings to Digest mode which will send a single email per day. 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