FODDD
Mechanical
- Dec 20, 2013
- 6
Hi, I am modelling a deep drawing process of a thin sheet and am having some issues with the stability of the model. I started my analysis using a step time approx. equal to the lowest mode of the blank (frequency = 290.50s-1 giving a period = 0.0034s and I used 0.003s). This gives reasonable results but if I try to carry out a mesh convergence study the model produces oscillatory type deformation in the deformed blank near the die entrance radius as the mesh is refined. I also get this issue if I try to increase the time step above 0.003, with some elements stretching by a huge amount and the model eventually failing.
Has anyone come across this before or what can be done to rectify it? I've attached an image of these oscillations in case it helps.
Thank you.
Has anyone come across this before or what can be done to rectify it? I've attached an image of these oscillations in case it helps.
Thank you.