Mesh randomly deforming without any load

[c.heintz.357]

Hi, I am running a 2d axisymetric MES with plastic materials. I am modeling a hardened steel dart piecring a steel plate. The dart has an initial velocity, and the plate is fixed on the outside. Algor Professional 2011, windows 7 x64, core i7 q720, nvidia gforce 310m.

I am having two problems. The first is that the analsys stops if the elements deform too much. This is understandable, and I figured I would just make the mesh finer to mitigate that. So I refined the mesh, and when the analsys begins, both the plate and dart sart out very deformed in the areas with the fine mesh. I'll attach screenshots.

I suppose my questions are:

1. Is there any way to override the solver's decision to stop the simulation because of deformation? I know there is the risk of inaccuracies.

2. Is there any way to avoid the parts deforming when I use a fine mesh?

Thanks for your time,

Chris

[S.LI]

MES won't stop for distorted element, except for convergence problem coming up due to bad element shape.

A larger convergence tolerance might make the simulation go further.

Updated Lagrange method in element definition is helpful to avoid element distortion in finite deformation simulation.

Selective reduced integration method is another way to keep element shape, but it's only available in brick element now.