Empathy List Archives

MG

Mohammad Gharaibeh

Mon, Jan 8, 2024 9:53 PM

On Tue, 9 Jan 2024 at 12:08 AM Gallagher, Keith (GE Aerospace, US) <
Keith.Gallagher@ge.com> wrote:

Distortions are not the issue. Workbench is generating a bad mesh. It
will not solve at all, just errors out right away.

Shells are not an option, unfortunately. These are intended to be
detailed sub-models for local stress.

Well, that is why I prefer the use of ANSYS APDL. I could have complete
control on my model (Keypoints/Lines/Areas/Volumes). When the geometry
construction is controlled, it is easy to control the mesh in so many
aspects. In fact, the smart choice of the number of areas of a specific
volume, could really help in selecting the suitable element type (brick or
else).

Professors are not dinosaurs. They are people care more about the
“fundamentals” rather than mickey mouse CAD geometry, with all due respect.
I cannot teach mechanics of materials without teaching statics first. I
cannot teach mechanical vibrations without teaching ordinary
differential equations. Similarly, I cannot get a student to use ANSYS
without teaching them all about building engineered geometries, element
type, mesh quality.

I have reviewed plenty of papers that incorporated FEA using workbench. The
first thing I ask for is the element type. If they authors got that wrong
(some has stated they used Abaqus element types, imagine?), I immediately
reject the manuscript.

Keith, I hope you’ll get your model fixed!

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 Tue, 9 Jan 2024 at 12:08 AM Gallagher, Keith (GE Aerospace, US) < Keith.Gallagher@ge.com> wrote: > Distortions are not the issue. Workbench is generating a bad mesh. It > will not solve at all, just errors out right away. > > Shells are not an option, unfortunately. These are intended to be > detailed sub-models for local stress. > Well, that is why I prefer the use of ANSYS APDL. I could have complete control on my model (Keypoints/Lines/Areas/Volumes). When the geometry construction is controlled, it is easy to control the mesh in so many aspects. In fact, the smart choice of the number of areas of a specific volume, could really help in selecting the suitable element type (brick or else). Professors are not dinosaurs. They are people care more about the “fundamentals” rather than mickey mouse CAD geometry, with all due respect. I cannot teach mechanics of materials without teaching statics first. I cannot teach mechanical vibrations without teaching ordinary differential equations. Similarly, I cannot get a student to use ANSYS without teaching them all about building engineered geometries, element type, mesh quality. I have reviewed plenty of papers that incorporated FEA using workbench. The first thing I ask for is the element type. If they authors got that wrong (some has stated they used Abaqus element types, imagine?), I immediately reject the manuscript. Keith, I hope you’ll get your model fixed! 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 =====================================

GK

Gallagher, Keith (GE Aerospace, US)

Mon, Jan 8, 2024 10:04 PM

I'm laughing about the element type. You're right, most people these days don't know what ANSYS is using in the background.

I am trying to struggle thru this in workbench, but the geometry for this is very complex. I tried pulling it into APDL and it would not import.
With that said the geometry when it does import seems to be very clean. It's just frustrating that workbench thinks generating a mesh with major errors is acceptable.

I have been able to muddle thru this but it's very very slow progress. Looking to improve this.

It was suggested internally to try the mesher that is built into NX (Unigraphics). I've had fairly good luck with it. Might have to consider that route.

Thanks,
Keith Gallagher
GE Aviation

-----Original Message-----
From: Mohammad Gharaibeh via Xansys xansys-temp@list.xansys.org
Sent: Monday, January 8, 2024 4:54 PM
To: XANSYS Mailing List Home xansys-temp@list.xansys.org
Cc: Mohammad Gharaibeh mgharai1@binghamton.edu
Subject: EXT: [Xansys] Re: [External Email] Re: Jacobian errors on tet elements in Workbench

WARNING: This email originated from outside of GE. Please validate the sender's email address before clicking on links or attachments as they may not be safe.

On Tue, 9 Jan 2024 at 12:08 AM Gallagher, Keith (GE Aerospace, US) < Keith.Gallagher@ge.com> wrote:

Distortions are not the issue. Workbench is generating a bad mesh.
It will not solve at all, just errors out right away.

Shells are not an option, unfortunately. These are intended to be
detailed sub-models for local stress.

Well, that is why I prefer the use of ANSYS APDL. I could have complete control on my model (Keypoints/Lines/Areas/Volumes). When the geometry construction is controlled, it is easy to control the mesh in so many aspects. In fact, the smart choice of the number of areas of a specific volume, could really help in selecting the suitable element type (brick or else).

Professors are not dinosaurs. They are people care more about the “fundamentals” rather than mickey mouse CAD geometry, with all due respect.
I cannot teach mechanics of materials without teaching statics first. I cannot teach mechanical vibrations without teaching ordinary differential equations. Similarly, I cannot get a student to use ANSYS without teaching them all about building engineered geometries, element type, mesh quality.

I have reviewed plenty of papers that incorporated FEA using workbench. The first thing I ask for is the element type. If they authors got that wrong (some has stated they used Abaqus element types, imagine?), I immediately reject the manuscript.

Keith, I hope you’ll get your model fixed!

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

I'm laughing about the element type. You're right, most people these days don't know what ANSYS is using in the background. I am trying to struggle thru this in workbench, but the geometry for this is very complex. I tried pulling it into APDL and it would not import. With that said the geometry when it does import seems to be very clean. It's just frustrating that workbench thinks generating a mesh with major errors is acceptable. I have been able to muddle thru this but it's very very slow progress. Looking to improve this. It was suggested internally to try the mesher that is built into NX (Unigraphics). I've had fairly good luck with it. Might have to consider that route. Thanks, Keith Gallagher GE Aviation -----Original Message----- From: Mohammad Gharaibeh via Xansys <xansys-temp@list.xansys.org> Sent: Monday, January 8, 2024 4:54 PM To: XANSYS Mailing List Home <xansys-temp@list.xansys.org> Cc: Mohammad Gharaibeh <mgharai1@binghamton.edu> Subject: EXT: [Xansys] Re: [External Email] Re: Jacobian errors on tet elements in Workbench WARNING: This email originated from outside of GE. Please validate the sender's email address before clicking on links or attachments as they may not be safe. On Tue, 9 Jan 2024 at 12:08 AM Gallagher, Keith (GE Aerospace, US) < Keith.Gallagher@ge.com> wrote: > Distortions are not the issue. Workbench is generating a bad mesh. > It will not solve at all, just errors out right away. > > Shells are not an option, unfortunately. These are intended to be > detailed sub-models for local stress. > Well, that is why I prefer the use of ANSYS APDL. I could have complete control on my model (Keypoints/Lines/Areas/Volumes). When the geometry construction is controlled, it is easy to control the mesh in so many aspects. In fact, the smart choice of the number of areas of a specific volume, could really help in selecting the suitable element type (brick or else). Professors are not dinosaurs. They are people care more about the “fundamentals” rather than mickey mouse CAD geometry, with all due respect. I cannot teach mechanics of materials without teaching statics first. I cannot teach mechanical vibrations without teaching ordinary differential equations. Similarly, I cannot get a student to use ANSYS without teaching them all about building engineered geometries, element type, mesh quality. I have reviewed plenty of papers that incorporated FEA using workbench. The first thing I ask for is the element type. If they authors got that wrong (some has stated they used Abaqus element types, imagine?), I immediately reject the manuscript. Keith, I hope you’ll get your model fixed! 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

KD

Keith DiRienz

Tue, Jan 9, 2024 2:28 AM

How about using a snippet to run the TIMP command ?

On Jan 8, 2024, at 2:06 PM, Gallagher, Keith (GE Aerospace, US) Keith.Gallagher@ge.com wrote: