Simulating a bending rod

David_Cranor

Hello, I am learning the simulations module and trying to evaluate what happens when i apply force to a steel rod spanning some fixed blocks.  The rod is simply resting on the blocks, not fastened. 

How should I set this up in simulation?  I watched the tutorial videos and see that tangent mate does not work in simulations.  But, if I simulate with mates and touching faces, the ends of the bar don't fold upwards, they act like they are bonded to the face of the blocks.

Thank you!

Thanks!

S1mon

As far as I could tell you'll need to set up some helper parts that are allowed to pivot on the edge of the support parts, and slide along the part you're trying to test. It's a bit weird, but it's the only way I could figure to do this basic sort of analysis.

GregBrown

The problem with simple analyses are they are rarely simple...

I'll attach a public doc here with one approach, but you'll have to decide for yourself what it is you are trying to simulate. Do you intend those ends of the rod to be fused to the blocks? or a simple (pinned constraint like the text books might show) What are you most interested in? Overall max deflection. or something else? These questions need to be answered first, as they will influence your modeling approach (Obligatory inclusion of George Box's quote "All models are wrong, some are useful"). For many (all?) cases you'll be best to start off with a first principles hand calculation. It's interesting how much you can glean from a simple beam representation of whatever you have.... especially in your case here!

Without going into the full discourse here, I'll leave my example for your examination. Also, be sure to look at the part studio - I have included hand calcs (in the form of variables/expressions). Note the max displacement, then compare this with the simulation. 

https://cad.onshape.com/documents/8c08753040e2ea7fda115f7f/w/dca4e69d2813d5fab088af1d/e/65f18b52351394d349d458b4