Cosmos Motion Impact Issue

[goldenshemesh]

I am simulating a head-on train collision between 2 rail cars.
I am currently using distance limit mate along with a 3-D contact for the impact faces. The distance limit mate restricts one train to go through the other.
The current simulation behaves like it should but because there is no way for me to figure out real values to compare the crash with, I am not sure if the values I am recieving are correct.

Now my question is would using the limit mate affect the results I obtain in the end?
And if yes, how would I set up the impact force property poperly to work in this situation?
(think of it as one block with constant velocity running into the other block)

 

[cbrn]

Hi,
as CosmosMotion, based on ADAMS engine, is a RIGID multi-body motion simulator, there is a very easy way to double-check your results: hand-calc !!!
Now, as for examining what the impact forces really do on your cars, CosmosMotion will tell you absolutely nothing: you will have to pass the results of the crashing time-step to CosmosWorks (direct transfer) or to another FE ambient (via neutral file).

Regards

 

[cbrn]

... sorry, I forgot:
as in reality two crashing cars don't "bounce back" as if they were bowling balls, the best formulation for hand-approaching this problem is the anelastic shock (so you assume that all the impact energy is absorbed in deformation by the two bodies). This is not totally true, but better than the "elastic impact" formulation. By triggering the settings inside CosmosMotion, you can adjust your problem to be "somewhere" in between.

Regards