Hello XANSYS Experts,
I am performing a thermo-mechanical simulation of a an electronic system
with sintered silver is the die attach material. I am using experimental
stress-strain data (at 3 temperatures). For defining the sintered silver
material model, I used TB command with the options of EXPE and UNITENSION.
The data points are then defined using TBPT. Prior TBPT, Temperatures are
set using TBTEMP.
The model solved just fine and I want to see the stress-strain results from
this simulation. I wonder what strain type (not component) is available in
/POST26 for this kind of material modeling? Elastic, plastic, or else? Or,
am I doing something wrong? Any advice would be greatly appreciated!
Thank you very much,
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
---====
Well, let me try to rephrase my question.
Using ANSYS Classic APDL, I am performing a thermo-mechanical simulation of
an electronic system with sintered silver as the die attach material. I am
using experimental stress-strain data (at 3 temperatures) for modeling the
silver. For defining its material model, I used the TB command with the
options of EXPE and UNIAXIAL (and UNITENSION). The stress-strain data
points are then defined using TBPT. Prior TBPT, Temperatures are set using
TBTEMP. Please see the APDL snippet at the end of this email for more
details.
I am doing this because I have fitted Norton Creep parameters (strain_rate
= A * (stress^n) * exp(-Q/RT)) and want to compare between the actual test
stress-strain data simulation results with those of this fitting empirical
model. Does it make sense?
The model solved just fine and I want to see the stress-strain results from
this simulation. There were no strain values stored except the "Elastic
Strains". I believe plastic strains should be also available. Am I missing
something? should I, at some point, define the initiation of plastic
deformation in my material model definition? Please advise!
Best Regards,
Mohammad
APDL:
! Die Attach
MPTEMP,1,25,100,200
MPDATA,EX,2,1,61E3,53E3,49e3
MP,PRXY,2,0.28
MP,CTEX,2,21.7e-6
!
TB,expe,2,3,50,uniaxial ! Could be UNITENSION
TBTEMP,25 ! Define first temperature
!tbpt , , 0.000000 , 0.000000
tbpt , , 0.000280 , 17.794428
tbpt , , 0.000548 , 38.414079
tbpt , , 0.000938 , 63.728864
tbpt , , 0.001343 , 87.815119
tbpt , , 0.001721 , 107.134180
tbpt , , 0.002000 , 128.129020
tbpt , , 0.002255 , 145.976007
tbpt , , 0.002498 , 158.901011
tbpt , , 0.002824 , 176.915343
tbpt , , 0.003188 , 199.353776
tbpt , , 0.003590 , 224.233568
tbpt , , 0.004019 , 248.443674
tbpt , , 0.004445 , 269.039227
tbpt , , 0.004869 , 286.479704
tbpt , , 0.005337 , 310.925911
TBTEMP,100 ! Define second temperature
!tbpt , , 0.000000 , 0.000000
tbpt , , 0.001571 , 73.745654
tbpt , , 0.002005 , 100.639202
tbpt , , 0.002398 , 117.823746
tbpt , , 0.002894 , 140.088412
tbpt , , 0.002969 , 142.336910
tbpt , , 0.002979 , 142.243919
tbpt , , 0.003135 , 151.278902
tbpt , , 0.003891 , 198.233721
tbpt , , 0.004704 , 233.552649
tbpt , , 0.005568 , 264.700466
tbpt , , 0.006054 , 282.188126
tbpt , , 0.006365 , 292.063758
TBTEMP,200 ! Define third temperature
!tbpt , , 0.000000 , 0.000000
tbpt , , 0.001311 , 49.591660
tbpt , , 0.001723 , 67.973589
tbpt , , 0.002206 , 86.082534
tbpt , , 0.002670 , 99.968976
tbpt , , 0.003016 , 109.822132
tbpt , , 0.003361 , 116.975289
tbpt , , 0.003684 , 122.554393
tbpt , , 0.003876 , 127.105099
tbpt , , 0.004258 , 130.714321
tbpt , , 0.004336 , 133.297749
tbpt , , 0.004672 , 134.854808
tbpt , , 0.004738 , 135.597108
tbpt , , 0.005075 , 135.935566
tbpt , , 0.005196 , 136.365141
tbpt , , 0.005440 , 137.314378
tbpt , , 0.005550 , 139.029876
tbpt , , 0.005707 , 141.543198
tbpt , , 0.006137 , 144.719815
tbpt , , 0.006495 , 148.316230
tbpt , , 0.006940 , 151.872619
---====
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, Aug 9, 2023 at 8:09 PM Mohammad Gharaibeh mgharai1@binghamton.edu
wrote:
Hello XANSYS Experts,
I am performing a thermo-mechanical simulation of a an electronic system
with sintered silver is the die attach material. I am using experimental
stress-strain data (at 3 temperatures). For defining the sintered silver
material model, I used TB command with the options of EXPE and UNITENSION.
The data points are then defined using TBPT. Prior TBPT, Temperatures are
set using TBTEMP.
The model solved just fine and I want to see the stress-strain results
from this simulation. I wonder what strain type (not component) is
available in /POST26 for this kind of material modeling? Elastic, plastic,
or else? Or, am I doing something wrong? Any advice would be greatly
appreciated!
Thank you very much,
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
---====
Dear Prof,
TB,EXPE is meant to provide experimental stress strain data for Response Function material model for Hyperelastic materials.
Refer below video for more details.
The output of this material model is only elastic strain in True Stress Strain format. But the input stress strain should be in Engineering stress strain format.
Also, it is not possible to combine Hyper elastic model with Creep model, valid material combinations are given below
If you see a nonlinear stress strain curve for Sintered Silver, if there is some irrecoverable plastic strain, i doubt applicability of Response Function material model to model this material.
Regards,
Santhosh M
-----Original Message-----
From: Mohammad Gharaibeh via Xansys xansys-temp@list.xansys.org
Sent: Thursday, August 10, 2023 2:20 PM
To: XANSYS Mailing List Home xansys-temp@list.xansys.org
Cc: Mohammad Gharaibeh mgharai1@binghamton.edu
Subject: [Xansys] Re: What Strain to see when using Experimental data
[External Sender]
Well, let me try to rephrase my question.
Using ANSYS Classic APDL, I am performing a thermo-mechanical simulation of an electronic system with sintered silver as the die attach material. I am using experimental stress-strain data (at 3 temperatures) for modeling the silver. For defining its material model, I used the TB command with the options of EXPE and UNIAXIAL (and UNITENSION). The stress-strain data points are then defined using TBPT. Prior TBPT, Temperatures are set using TBTEMP. Please see the APDL snippet at the end of this email for more details.
I am doing this because I have fitted Norton Creep parameters (strain_rate = A * (stress^n) * exp(-Q/RT)) and want to compare between the actual test stress-strain data simulation results with those of this fitting empirical model. Does it make sense?
The model solved just fine and I want to see the stress-strain results from this simulation. There were no strain values stored except the "Elastic Strains". I believe plastic strains should be also available. Am I missing something? should I, at some point, define the initiation of plastic deformation in my material model definition? Please advise!
Best Regards,
Mohammad
APDL:
! Die Attach
MPTEMP,1,25,100,200
MPDATA,EX,2,1,61E3,53E3,49e3
MP,PRXY,2,0.28
MP,CTEX,2,21.7e-6
!
TB,expe,2,3,50,uniaxial ! Could be UNITENSION
TBTEMP,25 ! Define first temperature
!tbpt , , 0.000000 , 0.000000
tbpt , , 0.000280 , 17.794428
tbpt , , 0.000548 , 38.414079
tbpt , , 0.000938 , 63.728864
tbpt , , 0.001343 , 87.815119
tbpt , , 0.001721 , 107.134180
tbpt , , 0.002000 , 128.129020
tbpt , , 0.002255 , 145.976007
tbpt , , 0.002498 , 158.901011
tbpt , , 0.002824 , 176.915343
tbpt , , 0.003188 , 199.353776
tbpt , , 0.003590 , 224.233568
tbpt , , 0.004019 , 248.443674
tbpt , , 0.004445 , 269.039227
tbpt , , 0.004869 , 286.479704
tbpt , , 0.005337 , 310.925911
TBTEMP,100 ! Define second temperature
!tbpt , , 0.000000 , 0.000000
tbpt , , 0.001571 , 73.745654
tbpt , , 0.002005 , 100.639202
tbpt , , 0.002398 , 117.823746
tbpt , , 0.002894 , 140.088412
tbpt , , 0.002969 , 142.336910
tbpt , , 0.002979 , 142.243919
tbpt , , 0.003135 , 151.278902
tbpt , , 0.003891 , 198.233721
tbpt , , 0.004704 , 233.552649
tbpt , , 0.005568 , 264.700466
tbpt , , 0.006054 , 282.188126
tbpt , , 0.006365 , 292.063758
TBTEMP,200 ! Define third temperature
!tbpt , , 0.000000 , 0.000000
tbpt , , 0.001311 , 49.591660
tbpt , , 0.001723 , 67.973589
tbpt , , 0.002206 , 86.082534
tbpt , , 0.002670 , 99.968976
tbpt , , 0.003016 , 109.822132
tbpt , , 0.003361 , 116.975289
tbpt , , 0.003684 , 122.554393
tbpt , , 0.003876 , 127.105099
tbpt , , 0.004258 , 130.714321
tbpt , , 0.004336 , 133.297749
tbpt , , 0.004672 , 134.854808
tbpt , , 0.004738 , 135.597108
tbpt , , 0.005075 , 135.935566
tbpt , , 0.005196 , 136.365141
tbpt , , 0.005440 , 137.314378
tbpt , , 0.005550 , 139.029876
tbpt , , 0.005707 , 141.543198
tbpt , , 0.006137 , 144.719815
tbpt , , 0.006495 , 148.316230
tbpt , , 0.006940 , 151.872619
---====
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, Aug 9, 2023 at 8:09 PM Mohammad Gharaibeh <mgharai1@binghamton.edumailto:mgharai1@binghamton.edu>
wrote:
Hello XANSYS Experts,
I am performing a thermo-mechanical simulation of a an electronic
system with sintered silver is the die attach material. I am using
experimental stress-strain data (at 3 temperatures). For defining the
sintered silver material model, I used TB command with the options of EXPE and UNITENSION.
The data points are then defined using TBPT. Prior TBPT, Temperatures
are set using TBTEMP.
The model solved just fine and I want to see the stress-strain results
from this simulation. I wonder what strain type (not component) is
available in /POST26 for this kind of material modeling? Elastic,
plastic, or else? Or, am I doing something wrong? Any advice would be
greatly appreciated!
Thank you very much,
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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