Radioss Material M36 Plastic Tab

Altair Forum User

Hi,

 

Could anyone tell me if we use M36 Plastic tab there is a procedure given to represent tear or element deletion.

 I have certain queries 

1) Can I represent tear with M36 Plastic tab like that of  real scenario?

2) When stresses and strains are given has a input in the N func should they be [true stress vs true strain]        or       [Engineering stress vs Engineering Strain]?

3) I tried to generate tear, for this purpose I used Et = 1(strain in the pic) and Em = 1.25 (approximation) when such  a model was used I couldn't reach the maximum ultimate stress, tear occurred much earlier at 250 MPa. Whereas if I don't define Em and let it be a default then I achieved a maximum stress of 350 MPa. So is this procedure correct?

4) Where can I find the literature of Em (maximum failure strain where stress is zero)

 

 

 

 

thanking you,

 

 

yours sincerely,

kartik kanugo

Altair Forum User

Hi Kartik,

1).Yes, you can represent /MAT/LAW36 to represent tear like simulation.

2).The function should be true stress vs true strain.

3).When the material reaches the failure strain (εp_max) the corresponding elements will be deleted from the model. SO i recommend you to provide a higher value of Eps_max and simulate the tear effect. The other option is to use any failure card, like /FAIL/JOHNSON.

4).If the largest principal strain reaches εm value, the stress in the element is reduced to 0, but the element is not deleted.