Stress Analysis

[Anonymous]

Hi

I am currently performing a stress analysis for a university project on a gimble ring using inventor 2010. In the gimble ring there are 4 holes in the cricumferance of the ring, 90 degrees appart in the centre of the width of the ring. To perform the stress analysis we are told to use fixed constraints at the holes, where in 2 holes, i.e north south holes, we are told to fix the x co-ordinate and leave y and z free, and in the west east holes, we are told to fix the y co-ordinate and leave x and z free. Then we applied forces at the holes. The forces in the north south holes act in opposite directions to the forces in the west east holes and all forces act parrallel to the ring centre axis. These forces will cause a twisting of the ring. I then run the stress analysis, which should highlight max stesses in 4 areas, 45 degrees to the holes on the ring circumference. However it warns of forces being used at fixed constraints and then says not enough constraints. I then go into 'edit simulation properties' and select 'detect and eliminate rigid body modes'. I then run the simulation again, and this time it gives a result, but it shows the max stresses to be in the holes, which is not right according to the way the ring deforms due the twisting action caused by the forces. I then take the same part and apply the same constraints and forces in inventor 2009, and run the simulation. It then gives me the max stresses to be at 4 points, 45 degrees to each hole, which is what I am looking for, and displays a message that weak springs had to be put into place to get a result.

Can anyone help me acheive the same results in 2010 as I obtained in 2009? Is there a setting I must change, besides playing around with 'contact defaults' under 'stress analysis settings', or has there been a change in the ansys programme for 2010 that will not allow me to get the same result as in 2009?

[JDMather]

Attach your ipt file here.

It would be useful to have the instruction sheet as well - so that it can be determined that you followed the instructions.