Plastic Strain and Anand material model
Dear XANSYS Experts,
I have been recently working on thermo-mechanical modeling of electronic
structure. The electronic package basically is composed of printed circuit
board (PCB), component and solder joints.
The mechanical properties for the PCB and the component are linear elastic.
However, for solder joints the model is rate-dependent plasticity with the
ANAND option in ANSYS Classic 2020 R1.
As you might already know, for one solder alloy there are several published
anand parameters. Well, I am trying to select a bunch of these parameters
to simulate and then compare. I am turning large deformations ON.
The surprising thing is that some constitutive models can provide plastic
strain and some could not. I triple-checked everything to make sure that I
am not doing something terrible in my simulations.
My question here is, why is that happening? Am I missing something? Or,
could that be a good sign that such ANAND parameters are not real?
Your suggestions are much 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 Mohammad,
I cannot speak for the specific cases you are running but one thing I can say is that in the past, we found out that some of the published Anand parameters (published in technical papers) were three orders magnitude off. I am not talking about all 9 parameters but one out of 9 parameters was 3 orders magnitude off; it might have been a typo or it might have been conversion error. We found out about that when we could not get converged solution and had to dig deeper and, fortunately, found out in another technical paper the difference.
So, what I am trying to say is you may want to double check the 9 constants individually as one of the checks...
Best regards, Metin
Metin Ozen, Ph.D., ASME Fellow
Principal/CEO
Ozen Engineering, Inc. - Ansys Elite Channel Partner
America's Channel Partner of the Year: 2015, 2018, 2021
Phone: 800-832-3767 Email: metin@ozeninc.com
1210 E Arques Ave., #207, Sunnyvale, CA 94085
-----Original Message-----
From: Mohammad Gharaibeh via Xansys xansys-temp@list.xansys.org
Sent: Friday, July 22, 2022 9:39 AM
To: XANSYS Mailing List Home xansys-temp@list.xansys.org
Cc: Mohammad Gharaibeh mgharai1@binghamton.edu
Subject: [Xansys] Plastic Strain and Anand material model
Dear XANSYS Experts,
I have been recently working on thermo-mechanical modeling of electronic structure. The electronic package basically is composed of printed circuit board (PCB), component and solder joints.
The mechanical properties for the PCB and the component are linear elastic.
However, for solder joints the model is rate-dependent plasticity with the ANAND option in ANSYS Classic 2020 R1.
As you might already know, for one solder alloy there are several published anand parameters. Well, I am trying to select a bunch of these parameters to simulate and then compare. I am turning large deformations ON.
The surprising thing is that some constitutive models can provide plastic strain and some could not. I triple-checked everything to make sure that I am not doing something terrible in my simulations.
My question here is, why is that happening? Am I missing something? Or, could that be a good sign that such ANAND parameters are not real?
Your suggestions are much 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
Thanks, Dr. Metin! That makes sense! And thank you for the off-the-list
valuable discussion.
One more thing I have to ask the expert here, I see that the unit of Q/R
(activation energy / Universal Gas Constant) is 1/Kelvin in some papers and
it is Kelvin in some others. I believe it should be Kelvin because that in
Arrhenius equation exp(Q/RT), where T is temperature in Kelvin, the
exponent has to be dimensionless, right?
For a closer look:
The unit of the activation energy (Q) is J/mol and that of the universal
gas constant (R) is J/(K.mol), right? So, Q/R gives K which makes much
sense because in the exponent (Q/RT) the unit multiplication is K.(1/K) and
this results in dimensionless value.
I just confirmed that with ANSYS Materials Reference. The Unit of Q is
Energy/Volume and that of R is Energy/(Volume.Temperature). Which makes it
that Q/R is in Temperature units or Kelvin.
Please if you come to review a paper that says the unit of Q/R is 1/K -
please correct them!
Best,
Mohammad
—
On Friday, July 22, 2022, Metin Ozen metin@ozeninc.com wrote:
Hi Mohammad,
I cannot speak for the specific cases you are running but one thing I can
say is that in the past, we found out that some of the published Anand
parameters (published in technical papers) were three orders magnitude off.
I am not talking about all 9 parameters but one out of 9 parameters was 3
orders magnitude off; it might have been a typo or it might have been
conversion error. We found out about that when we could not get converged
solution and had to dig deeper and, fortunately, found out in another
technical paper the difference.
So, what I am trying to say is you may want to double check the 9
constants individually as one of the checks...
Best regards, Metin
Metin Ozen, Ph.D., ASME Fellow
Principal/CEO
Ozen Engineering, Inc. - Ansys Elite Channel Partner
America's Channel Partner of the Year: 2015, 2018, 2021
Phone: 800-832-3767 Email: metin@ozeninc.com
1210 E Arques Ave., #207, Sunnyvale, CA 94085
-----Original Message-----
From: Mohammad Gharaibeh via Xansys xansys-temp@list.xansys.org
Sent: Friday, July 22, 2022 9:39 AM
To: XANSYS Mailing List Home xansys-temp@list.xansys.org
Cc: Mohammad Gharaibeh mgharai1@binghamton.edu
Subject: [Xansys] Plastic Strain and Anand material model
Dear XANSYS Experts,
I have been recently working on thermo-mechanical modeling of electronic
structure. The electronic package basically is composed of printed circuit
board (PCB), component and solder joints.
The mechanical properties for the PCB and the component are linear elastic.
However, for solder joints the model is rate-dependent plasticity with the
ANAND option in ANSYS Classic 2020 R1.
As you might already know, for one solder alloy there are several
published anand parameters. Well, I am trying to select a bunch of these
parameters to simulate and then compare. I am turning large deformations ON.
The surprising thing is that some constitutive models can provide plastic
strain and some could not. I triple-checked everything to make sure that I
am not doing something terrible in my simulations.
My question here is, why is that happening? Am I missing something? Or,
could that be a good sign that such ANAND parameters are not real?
Your suggestions are much 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
--
---====
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
---====
Thanks, Dr. Metin! That makes sense! And thank you for the off-the-list
valuable discussion.
One more thing I have to ask the expert here, I see that the unit of Q/R
(activation energy / Universal Gas Constant) is 1/Kelvin in some papers and
it is Kelvin in some others. I believe it should be Kelvin because that in
Arrhenius equation exp(Q/RT), where T is temperature in Kelvin, the
exponent has to be dimensionless, right?
For a closer look:
The unit of the activation energy (Q) is J/mol and that of the universal
gas constant (R) is J/(K.mol), right? So, Q/R gives K which makes much
sense because in the exponent (Q/RT) the unit multiplication is K.(1/K) and
this results in dimensionless value.
I just confirmed that with ANSYS Materials Reference. The Unit of Q is
Energy/Volume and that of R is Energy/(Volume.Temperature). Which makes it
that Q/R is in Temperature units or Kelvin.
This brings me back to my original doubt thar if the authors can be
mistaken about the parameters units how come they won’t be for the values?
Please if you come to review a paper that says the unit of Q/R is 1/K -
please correct them!
Best,
Mohammad
—
On Friday, July 22, 2022, Metin Ozen metin@ozeninc.com wrote:
Hi Mohammad,
I cannot speak for the specific cases you are running but one thing I can
say is that in the past, we found out that some of the published Anand
parameters (published in technical papers) were three orders magnitude off.
I am not talking about all 9 parameters but one out of 9 parameters was 3
orders magnitude off; it might have been a typo or it might have been
conversion error. We found out about that when we could not get converged
solution and had to dig deeper and, fortunately, found out in another
technical paper the difference.
So, what I am trying to say is you may want to double check the 9
constants individually as one of the checks...
Best regards, Metin
Metin Ozen, Ph.D., ASME Fellow
Principal/CEO
Ozen Engineering, Inc. - Ansys Elite Channel Partner
America's Channel Partner of the Year: 2015, 2018, 2021
Phone: 800-832-3767 Email: metin@ozeninc.com
1210 E Arques Ave., #207, Sunnyvale, CA 94085
-----Original Message-----
From: Mohammad Gharaibeh via Xansys xansys-temp@list.xansys.org
Sent: Friday, July 22, 2022 9:39 AM
To: XANSYS Mailing List Home xansys-temp@list.xansys.org
Cc: Mohammad Gharaibeh mgharai1@binghamton.edu
Subject: [Xansys] Plastic Strain and Anand material model
Dear XANSYS Experts,
I have been recently working on thermo-mechanical modeling of electronic
structure. The electronic package basically is composed of printed circuit
board (PCB), component and solder joints.
The mechanical properties for the PCB and the component are linear elastic.
However, for solder joints the model is rate-dependent plasticity with the
ANAND option in ANSYS Classic 2020 R1.
As you might already know, for one solder alloy there are several
published anand parameters. Well, I am trying to select a bunch of these
parameters to simulate and then compare. I am turning large deformations ON.
The surprising thing is that some constitutive models can provide plastic
strain and some could not. I triple-checked everything to make sure that I
am not doing something terrible in my simulations.
My question here is, why is that happening? Am I missing something? Or,
could that be a good sign that such ANAND parameters are not real?
Your suggestions are much 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
--
---====
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
---====
I agree, (Q/K) should have unit of Kelvin (K).
Many papers say unit (1/K), I see that a recent paper in 2021 from John H. Lau, Fellow ASME (doi.org/10.1115/1.4048037) reported it in correct ( K) unit.
Ansys help manual link says below says below
https://ansyshelp.ansys.com/account/Secured?returnurl=/Views/Secured/corp/v221/en/ans_mat/rate.html%23matanandoption
C2 =Q/R
Q = Activation energy [Energy / Volume]
R = Universal gas constant [Energy / Volume temperature]
From this one can arrive the C= Q/R has unit of Temperature that is [K]
I too recently ran into this confusion from different papers.
Some papers report (Q/R);
Where Q is Activation Energy with unit J/mol. For solder typical range is 40,000-70,000 J/mol
R is Universal Gas Constant unit [ J/(K.Mol ] = 8.314 [ J/(K.Mol ]
Some papers report (Q /k):
Where Q is Activation Energy with unit eV . Typical value for SAC305 ~ 0.56 eV
K is Boltzmann constant ~ 8.6173e-5 eV/K
Depending on the units (Q/K) should be equal to (Q/R) in value. When stress is in Mpa unit system, the value of (Q/R) for solder is in the range of 5000-11000.
Some papers report Ansys Anand Viscoelasticity constant C2 value as (Q/R), some paper report only Q value either in J/mol or eV.
One need to be very care full. Fortunately, the each these values are very different, by looking the (Q/R) or C2 values reported in the paper one need to guess whether the reported number is Q in J/mol or eV or (Q/K)
Regards,
Santhosh M
ANSYS India / Bangalore.
-----Original Message-----
From: Mohammad Gharaibeh via Xansys xansys-temp@list.xansys.org
Sent: 22 July 2022 11:54 PM
To: xansys-temp@list.xansys.org
Cc: Mohammad Gharaibeh mgharai1@binghamton.edu
Subject: [Xansys] Plastic Strain and Anand material model
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[External Sender]
Thanks, Dr. Metin! That makes sense! And thank you for the off-the-list valuable discussion.
One more thing I have to ask the expert here, I see that the unit of Q/R (activation energy / Universal Gas Constant) is 1/Kelvin in some papers and it is Kelvin in some others. I believe it should be Kelvin because that in Arrhenius equation exp(Q/RT), where T is temperature in Kelvin, the exponent has to be dimensionless, right?
For a closer look:
The unit of the activation energy (Q) is J/mol and that of the universal gas constant (R) is J/(K.mol), right? So, Q/R gives K which makes much sense because in the exponent (Q/RT) the unit multiplication is K.(1/K) and this results in dimensionless value.
I just confirmed that with ANSYS Materials Reference. The Unit of Q is Energy/Volume and that of R is Energy/(Volume.Temperature). Which makes it that Q/R is in Temperature units or Kelvin.
This brings me back to my original doubt thar if the authors can be mistaken about the parameters units how come they won't be for the values?
Please if you come to review a paper that says the unit of Q/R is 1/K - please correct them!
Best,
Mohammad
On Friday, July 22, 2022, Metin Ozen metin@ozeninc.com wrote:
Hi Mohammad,
I cannot speak for the specific cases you are running but one thing I
can say is that in the past, we found out that some of the published
Anand parameters (published in technical papers) were three orders magnitude off.
I am not talking about all 9 parameters but one out of 9 parameters
was 3 orders magnitude off; it might have been a typo or it might have
been conversion error. We found out about that when we could not get
converged solution and had to dig deeper and, fortunately, found out
in another technical paper the difference.
So, what I am trying to say is you may want to double check the 9
constants individually as one of the checks...
Best regards, Metin
Metin Ozen, Ph.D., ASME Fellow
Principal/CEO
Ozen Engineering, Inc. - Ansys Elite Channel Partner America's Channel
Partner of the Year: 2015, 2018, 2021
Phone: 800-832-3767 Email: metin@ozeninc.com
1210 E Arques Ave., #207, Sunnyvale, CA 94085
-----Original Message-----
From: Mohammad Gharaibeh via Xansys xansys-temp@list.xansys.org
Sent: Friday, July 22, 2022 9:39 AM
To: XANSYS Mailing List Home xansys-temp@list.xansys.org
Cc: Mohammad Gharaibeh mgharai1@binghamton.edu
Subject: [Xansys] Plastic Strain and Anand material model
Dear XANSYS Experts,
I have been recently working on thermo-mechanical modeling of
electronic structure. The electronic package basically is composed of
printed circuit board (PCB), component and solder joints.
The mechanical properties for the PCB and the component are linear elastic.
However, for solder joints the model is rate-dependent plasticity with
the ANAND option in ANSYS Classic 2020 R1.
As you might already know, for one solder alloy there are several
published anand parameters. Well, I am trying to select a bunch of
these parameters to simulate and then compare. I am turning large deformations ON.
The surprising thing is that some constitutive models can provide
plastic strain and some could not. I triple-checked everything to make
sure that I am not doing something terrible in my simulations.
My question here is, why is that happening? Am I missing something?
Or, could that be a good sign that such ANAND parameters are not real?
Your suggestions are much 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
--
---====
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
Thanks Santhosh for confirming that and for the good discussion.
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
---====