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Error in calibration of results with experiment for tension test

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abc123ali

Mechanical
Nov 6, 2023
90
Resepected ABAQUS Users, I am performing the tensile test upto the yield point of metallic sintered joint placed betwen the chips to join them. Taking the experimental data and putting into the ABAQUS property module and proceeding towards simulation are not giving the reliable results to match the experimental data. The experimental data is put in form of stress strain uniaxial tension test. The thickness of joint is made 0.4 mm, stress in MPa and the chips thickness is 0.5 mm. To achieve the yield stress which is 27.5 MPa, the strain is applied upto yield point and the yield strain is to be 0.02 according to experimental data which is multiplied by the thickness of 0.4 mm to get the value of deformation required which is 0.008 mm or simply change in length. The area of crossection of the chip is 20mm*5mm.

I am also facing problem of

""1. The applied amplitude for cyclic displacement in the load module is different from the output reaction displacement which should be possible because the model is strain controlled.""

""2. The output results are taken in terms of reaction force and displacement curve which should come out in Newton according to the units set above and the displcement should be in mm. Now the value of reaction force is very low as just 0.6 N and the applied strain peak value is 0.008 mm is not reached but just to 0.007mm why is it so. so if force is 0.6 N then the stress is 0.6/100 equals 0.006 MPa which is wrong and not even a bit near to 27.5Mpa where it should be.""
But he value shown in mises and stress COMPONENTS goes to 37 MPa to 46 Mpa not exact but a bit near

How to solve this calibration problem? The cae file is attached here

Thanks for Cooperation
 
 https://files.engineering.com/getfile.aspx?folder=714f1a1b-bd7d-4696-8062-e741762a8cd6&file=laptensilerealdata.cae
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Are you sure all the input values are correct ? Young's modulus of the plate should be 1000 GPa (Poisson's ratio 0.06) while Young's modulus of the binder is 5 GPa (Poisson's ratio 0.1) ?

Your amplitude ends at 15.1 s while the step time period is 2 s. Is it expected ?

How do you measure the reaction force ?
 
I have checked the modulus for both the materials according to the stress strain curve and changed the modulus of sintered joint ot 1.5 GPa but even then the results are meaningless the output stress values are actually not yielding the specimnen and the results are linear with for the reaction-force and stress-strain curve and not according to the input data. The output Reaction force- displacent is very low and the applied displacement is not executing the same strain as calculated. The cae file is attached here.
If the step time period is short as 2s while amplitude end 15.1 second how it affacts the output results.
Reaction force and displacemet are measured in the direction of applied displacement of 0.008mm at a node. The cae file is attached

Thanks
 
Also a new file making a dog bone specimen is attached here for validation keeping all the properties here the reults are pretty fine and meets the values of stress and applied strain but only upto the yield point. Applying the strain beyond the yield point is not including the plastic points and the output value of tensile stress goes judt to 23MPa but not to 27Mpa according to input data. What is the problem i this simple test.

Secondly this work is done to validate the above problem and the same data is used along with precise calcualtion of applied strain but it gives better results. Please assit me the previous problem of chips and binder for which cae file is attached. Here I am attaching the input file and the nodal reaction response of tensile test and the input file.

Here I have checked the variation in poisons ratio as well as modulus which contributes a very little effect in changing output results.
The reaction for and other results file are uploaded also for a good clarification
Thanks for cooperation
 
 https://files.engineering.com/getfile.aspx?folder=59fe4c74-850d-4856-9783-dca75225515a&file=silvertens.inp
When measuring the reaction force, you should take all nodes with the applied boundary condition and sum their reaction forces. It's much easier when the boundary condition is applied via kinematic coupling or rigid body constraint - then you have just one node (reference point).
 
Respected ABAQUS users, After applying kinematic coupling and making a reference point the force-displacement results are satisfactory in contour plot but how can I get the results at the reference point to get graph as if open the view port just only nodal values or the nodes of the meshed model is just selected and the reference point is not displayed. Kindly assist the way to select reference point to get result there.
Thanks for cooperation
 
The recommended way would be to request history output for the reference point before running an analysis but you can also just use XYData --> Create --> ODB field output --> Unique nodal and select the reference point from the Node sets list in the Elements/Nodes tab.
 
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