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Static FEA Stress Analysis Error

Question asked by 1-S8I9QM on Jul 7, 2010
Latest reply on Jul 21, 2010 by Keith Parker

Hey guys,  Hope im posting this is the correct spot..Im new to this forum.

 

Anways, I have a question I was hoping to get some answers on:

 

Im running a Static anaylsis test on a Portable Cart we are designing to hold and move Hospital compressor/ventilator systems.

 

I am trying to simulate the stress/displacement/strain and FOS of the cart due to a 200 lb load "basically a nurse pushing down on the handle as hard as she can"  along with the total weight of the ventilator it will be holding.

 

However when I run the simulator, it gets 34% done and says Error:"Equilibrium is Not Achieved" "Results will be saved upto the current iteration."

 

 

Below is a picture of the Cart and the constraints ive added to it.

 

Material:  I cant specify exact material, but its a combination of Steel and aluminum

 

External Loads: I have a 200 lb load normal to the bottom plane, with a 100lb load uniformially distributed over the head of the cart.

 

Connections: I have Threaded Counterbore screws going up through the base into the spine (bottom)  and also connecting the handle to the head (cant see those from this view.)  I set all of the coincident interference as no penetration, and I did a contact set between the welded parts.

 

Fixtures:  (THIS IS WHERE I THINK I AM HAVING ISSUES)  I fixed the bottom left corner of the base completely by selecting the Cylindrical face of the "shaft" where the casters (not shown) will attach.   Next, I selected the other 3 cylindrical shafts and added a vertical constraint.

 

 

*IF anybody can help me out, that would be a huge help...my boss and I have tried several different ways of fixing the bottom to get the results we are looking for but arent having much luck.

FEA.bmp

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