I'm having problems with an analysis on a can end (like a campbell's soup can top).
The analysis is a non-linear study in which I am trying to first apply 40 psi inside....then 25 psi from the outside. I'm using shell elements and cutting the end in half (symmetry).
The problem (in real life) is that the can end wrinkles when the end is forced back down from the "up" condition.
The analysis seems to work when I lessen the first internal pressure to keep the stresses in the elastic range. However, when I increase the first internal pressure to go into the plastic range the model always chokes where the pressure reverses and the can end wants to buckle from the "up" condition to the "down" condition.
I've tried force, displacement and Arc Length control. I've even tried a Non-Linear dynamic study. Nothing seems to work. The stress and strain plots show nothing of interest (i.e. the start of wrinkling).
Any good ideas out there?
The analysis is a non-linear study in which I am trying to first apply 40 psi inside....then 25 psi from the outside. I'm using shell elements and cutting the end in half (symmetry).
The problem (in real life) is that the can end wrinkles when the end is forced back down from the "up" condition.
The analysis seems to work when I lessen the first internal pressure to keep the stresses in the elastic range. However, when I increase the first internal pressure to go into the plastic range the model always chokes where the pressure reverses and the can end wants to buckle from the "up" condition to the "down" condition.
I've tried force, displacement and Arc Length control. I've even tried a Non-Linear dynamic study. Nothing seems to work. The stress and strain plots show nothing of interest (i.e. the start of wrinkling).
Any good ideas out there?