Material law

Altair Forum User

Hello,

I would like to define a material which behaves as follows: there is an initial linear elastic behavior (with a defined E-modulus). Then there is a perfectly plastic region at a maximal stress until the plastic strain reaches a determined value. Next, there is a strain softening phase with a plastic modulus and ultimately an indefinite perfectly plastic phase begins when a stress(min) is reached. 

How can I implement such a material behavior?

 

Thanks in advance for the help

Altair Forum User

Hi @Marie

 

I think LAW36 can be used for your requirement.

Altair Forum User

Thanks for the fast reply.

I wasn't really able to implement my material behavior (see image) with the suggested law 36. The elements are solids. Do you have an idea of what I could do?

 

 

<?xml version="1.0" encoding="UTF-8"?>

Altair Forum User

Hi @Marie

 

With LAW36, The first point of yield stress functions (plastic strain vs stress) should have a plastic strain value of zero. The elastic part will be calculated in the background.

 

You can try with LAW2 with Iflag set to 1, With this new input, you will need yield stress (σy), Ultimate tensile engineer stress (UTS) and engineer strain (εUTS) at necking point. With this new input, RADIOSS automatically calculates the equivalent value for a, b and n

Altair Forum User

Thanks for the help!