Hi ,

 I'm working on simulation of wave propagation in a bar. I'm using
newmark time integration scheme to solve my problem. I have a bae
clamped at one end and under tensile at the other end. when I decrease
my time step ,at the beginning of the loading I see tiny negative
strains which is so weird. I used some numerical damping with the scheme
and I could reduce the time step but still I have this problem in
smaller time steps. Can anyone help me with this?

  Thank you very much!!!

Hi all,

 I am new in the Forum, and I am looking for some informations regarding how to simulate nonlinear material in explicit.

I am tryng to analyse the behaviour of a roller rolling on the sand (or mud), but the results I get with a basic elasto-plastic material are not very accurate, expecially because I cannot set the tension allowed in the sand to be zero.

Other ways to input nonlinearity in Explicit are always refused by ABAQUS. Is there any way to get something more accurate?

I would like to perform a dynamic structural analysis with ansys. How can I include in the analysis a check after each time step about the status of some elements ( check whether they are broken)  "kill" them if need to and continue the analysis. Thanks, Ran 

You are cordially invited to submit an abstract to the symposium on “Emerging Methods To Understand Mechanical Behavior” at 2008 TMS annual meeting, New Orleans, LA, March 9-13, 2008.