Learning Forum

[chaymael]

Hello ANSYS users , I am working on nickel titanium shape memory alloy helical spring and I don't know how to get the famous curve of stress-strain shape memory alloys (same in figure 2 bellow)

I don't know where is the problem what should I do?

[peteroznewman]

nPlease read the ANSYS Help, Mechanical APDL, Technology Showcase: Example Problems, Chapter 40: Shape Memory Allow (SMA) with Thermal Effect.n

[chaymael]

I already did, but the probleme is with the curven

[peteroznewman]

It looks like you have a plot of Elastic Strain. That is a straight line.nHave you tried plotting the Equivalent Total Strain? That can show curvature. The problem is to show hysteresis.nThe problem with Equivalent Plastic Strain is that it is always positive, so when you reverse the direction of stress, the plastic strain keeps increasing. See my post under cyclic plasticity. Someone wanted to plot the traditional figure shown in textbooks, but you have to work really hard in Excel to manually assign the sign on the plastic strain as the material cycles.n/forum/discussion/2307/stress-vs-strain-full-hysteresis-loop#comment-00ff2dfe-8c6c-4da0-a76f-a9470021d7f6n

[illiiiilililiii]

I think you should input displacement(strain) value.n