Aaron Hayden

Grab bag of questions regarding a study

Discussion created by Aaron Hayden on May 4, 2008
Ok, there's plenty of questions here to go around. Everyone feel free to reach in a grab one for yourself. ;-P I'm running a study with a sliding wedge not to dissimilar to a side action cam on a die. This wedge has a jack screw with a shoulder. I am running a study to see what the effects are on the cap plate (yellow) and jack screw (red) if a load is place on the wedge (it's inside the assy). Please see picture. I have used bolted connections for the cap plate. The global contact is set to no penetration. I have created a bonded contact set between the O.D. of the threaded portion of the jack screw and the hole that it is threaded into in the wedge. So, the load will push the slide (maroon I guess) in which forces the wedge up and pushes the shouldered jack screw against the cap plate.

My questions are as follows:

I have run the study several times and only gotten results once without an error. Most of the time I get "Equilibrium is not achieved". On one or two occasions I got "large displacement detected do you want to turn on large displacement mode?" I think I even got an error about convergence... Not 100% on that one.

What do I do about not reaching equilibrium? I sorta understand the large displacement error except the one time I got results the max displacement was .0007 (m) which equates to .027" That certainly doesn't seem very large. Also, does Cosmos tell you if your bolted connector fails? You have to input the material data for the bolted connection but does it report on the simulated bolt itself or do I have to model the bolt if I want those results?

Thanks in advance,