Learning Forum

[albin.linderstam]

Hello,

I want to perform a analysis of a component using Plasticity.

I’ve have a stress-strain curve from MMPDS, see attached image. According to MMPDS, the curve is a Engineering Stress-Strain.

We have used similar analysis a long time ago, but that was in Ansys R15.0. However, in that version, the Total Strain was entered instead of Plastic Strain, see attached image.

I’ve some questions regarding this; especially about preparding the correct table to input in Ansys

1. Ramberg-Osgood Equation: I have E, Fty and n (see attached image), so I simply try to create a lot of stress-strain values from this equation using this parameters, but I don’t get the correct values. Is the method correct? In the second attached image, I show my values from this equation and parameters. According to the graph, 169ksi should give ~0.011, but I get ~0.085, so I’m way off. Cannot find out why.

2. According to [https://www.youtube.com/watch?v=rCFmcNWRds4], True Stress-Strain is required; should I convert from Engineering to True stress-strain using the equations in attached image and then subtract the elastic strain (s/E) to only get the plastic strain?

3. According to [https://www.youtube.com/watch?v=rCFmcNWRds4], the first point should be (0, yield strength), but how should I then include 0.2% plastic strain at yield point? There is a parameter called Offset, but I cannot modify the values. Should this parameter be used somehow?

Regards,

Albin

 

[Erik Kostson]

Hi Albin since you are a supported user plese create a support request (https://support.ansys.com/) and we will help you there with all these questions.

Closing this one here

All the best

 

Erik Kostson

[Erik Kostson]

 

@Peteroznewman this one is closed – supported user will recieve support via a proper channel.

 

[Erik Kostson]

Closed.