sheetmetal shell contact sets non penetration

PD 2012-03-05

Hi,

I am using sets of non penetration contacts to assess a sheetmetal spot welded locker type structure. I am having trouble getting this to work particularly in the top front corners where a vertical side panel and a vertical top panel intersect. At the corner the folded edges in U/Z/W type shapes intersect with edge/edge; edge/face and face/face - some of which I would like to constrain with non penetration contact sets to prevent them diving through eachother as the locker shell distorts. I don't seem to be able to get this to work, and there is insufficient documentation on a sound approach/methodology that gives some insight into how the underlying code 'thinks' and how to best work with it. (this is a huge drawback from SW and a detailed well indexed technical manual is really needed).

To date its been an experimental/iterative approach which is time consuming with mesh/solve rebuilds as an overhead. In looking through the forum I came across one or two threads that provide some help (below), however I'm still looking for assistance or advice.

Thanks in advance

Brian Zias on 15/12/2011 6:01 AM Re: How to reduce penetration in solid works analysis

and

Bruce Shearer Re: Bonded Connections with Shell Elements

Locker Corner	Penetration from Simulation
	red/white dots are contacts that I wish to constrain. Constraints have been applied but these do not seem to be having an effect. Probably contravening 'good practice' or breaking some rules but not sure what these may be. One difficulty is that sheetmetal parts do not seem to allow shell edge to face constraints. Is it possible/advisable to select a complete tangent surface and then constrain it against the adjacent parts touching edge loop (or other tangent surface ) in one non penetrating contact set. Does this create difficulty for simulation in generating the contacts and/or a huge overhead in processing/solution. There is a 0.25mm gap between some edges/faces to allow for final powder coating thickness.

Locker Corner

Penetration from Simulation

red/white dots are contacts that I wish to constrain. Constraints have been applied but these do not seem to be having an effect. Probably contravening 'good practice' or breaking some rules but not sure what these may be. One difficulty is that sheetmetal parts do not seem to allow shell edge to face constraints. Is it possible/advisable to select a complete tangent surface and then constrain it against the adjacent parts touching edge loop (or other tangent surface ) in one non penetrating contact set. Does this create difficulty for simulation in generating the contacts and/or a huge overhead in processing/solution. There is a 0.25mm gap between some edges/faces to allow for final powder coating thickness.

Solidworks Simulation