Learning Forum

[tiwari15abhinav]

Hello Everyone.

I was doing a simulation on hyperelastic material by curve fitting. I only have biaxial test data. Here, I put the test data including lateral strain. Further I am curve fitting it to find the respective constants for the material model. The problem is that when I see the curve as shown in figure below. The curve is plotted for stress (m m^-1) and strain (C). The units are wrong. Can anyone help me what it is trying to represent or is there something wrong with my setup?

Thanks in Advance

[1shan]

It looks like you have added your strain values in the temperature column (hence Celsius) and stress in the strain column (hence m m -1). Leave the temperature field blank and insert just the stress strain data. This https://www.youtube.com/watch?v=K0rIwPEi0mg tutorial will help you with the curve fitting process.

Regards Ishan.

[tiwari15abhinav]

Thanks for the quick reply.
I have put the data in their respective columns as i imported .csv file. I took care that all stress and strains values are correctly marked with correct units as shown in the figure below.
I am still getting the curve as shown below.

Regards Abhinav Tiwari

[Sandeep Medikonda]

A few recommendations.
Use the latest version of Ansys Mechanical. As of the day of writing this post that is v2021R1.
Use projected units and reset your settings if needed i.e., go to Workbench and try 'Reset Workspace' and 'Reset Window Layout', then re-start WB and see if this fixes it?
If that doesn't work as well and if you are using Windows, close WB, open up file explorer and reset your appdata:
%appdata%\ansys
and rename the folder of the version you are using, i.e., v211 to v211.old if using v2021R1. Reopen your model and see if it fixes your issue.

[tiwari15abhinav]

Thank you for your quick response.
I have tried all the mentioned points as you told but none of them helped.
Further I figured out that when I use biaxial test data with "Has lateral strain" option set to no the graph becomes correct as shown below
But when I use Biaxial test data with lateral strain the as shown in above post the units of the axis are wrong. Can you please tell me why I am getting the wrong graph with biaxial test data with lateral strain. I have also attached the archive file for the reference.

Regards Abhinav Tiwari