Learning Forum

[douk.van.werven]

Hi,

I'm using WB 2024R1 and want to simulate a drop test with plastic parts. I have my non linear material data, but it is not clear to me what material model to use. Does anyone know how to best input my (true) stress strain curve?

[Armin]

 

 

Hi Douk,

If you have your stress-strain curve available, I would suggest you to employ the Multilinear Isotropic Hardening model available in Engineering Data (picture below) and then proceed to more complex models if necessary. Once you select this model, you can input your stress-strain data in the form of tabular data.
Note that this plasticity model uses the *MAT_PIECEWISE_LINEAR_PLASTICITY model of LS-DYNA that is based on isotropic von Mises plasticity and isotropic hardening, and you can refer to the help documentation for the available options and more details about this model.

 

 

[douk.van.werven]

Hi Armin, thanks for this input. I would like to use this model for my simulation. Where can I find information how to input my engineering stress strain curve into this model? If I understand correctly, I have to break it up into true stress and plastic strain. Is that correct? Is there any documentation on how to convert the experimental data so that it can be input for the material model? Is there information available how to determine the end of linear part? 

[Armin]

No problem Douk.
You are correct. You need to convert your engineering stress-strain data into true stress - plastic strain and then input it into the model. Check the paper below and the references therein where this topic is discussed in more detail. The end of the linear region is typically determined using the 0.2% offset rule (you can look up 0.2% offset rule online and you'll be able to find relevant information).

https://www.sciencedirect.com/science/article/pii/S2666359722000208