
Re: Find largest principal stress difference between two load cases.
James Riddell Sep 28, 2015 6:07 AM (in response to Simon Taber)The only way I know is to set your display to show each principal stress in each load case with both max & min identified. (RMB click on "Results" and select appropriate value under "Stress").

Re: Find largest principal stress difference between two load cases.
Aaron Gradeen Sep 28, 2015 2:43 PM (in response to Simon Taber)Hi Simon,
Sounds like a fatigue study might give you the answer that you're looking for. I would try creating a fatigue study with a loading event that is defined using "find cycle peaks" along with your two static load cases. If you set your fatigue study to compute the alternating stress based on the "Max. absolute principal (P1)", then the node with the largest amount of cumulative damage in your damage results plot should be the node which experiences the largest range of principal stress if I'm thinking about this correctly. Solidworks will actually compute the alternating stress at each node based on the difference between the the maximum absolute principle stress (P1, P2 and P3). It is misleading that the option only says "max. absolute principle (P1)". Hope this helps Below are a couple screenshots to help illustrate my proposed solution.

Re: Find largest principal stress difference between two load cases.
Simon Taber Sep 28, 2015 3:48 PM (in response to Aaron Gradeen)Thank you Aaron for a very good answer!
The result is actually for an fatigue calculation. I am going to try this first thing tomorrow and then i will discuss it with my professor, and give you an reply on his opinion.
My only concern is does this result: "node with the largest amount of cumulative damage" take account for the difference in direction of the principal stress and angle to the surface ?
In the ideal scenario, i would like to use this to locate the node where the largest difference in size between the to studies occurs.
But where it also takes account for the stress to have approximately the same direction, and is close to normal to the surface.
I know that normally this is not a concern but this is kind of a theoretic problem

Re: Find largest principal stress difference between two load cases.
James Riddell Sep 29, 2015 6:14 AM (in response to Simon Taber)That is fairly easy to accomplish using the method I outlined above even if it is a little more work. You can save nodes as sensors to compare from LC to LC in the same model.

Re: Find largest principal stress difference between two load cases.
Simon Taber Sep 30, 2015 6:59 AM (in response to James Riddell)Hi James, i did it as you wrote before, but this only gives me difference between minimum/maximum P1 stress in the load cases.
Note: the possibility, that the largest difference between P1 stress could occur some where else than the max or min node.
I think your method is practical and can be used i practice. But theoretical it don't thinks it gives me the largest possible difference in P1 stress.
I don't know if it makes any sense?
I think that Aarons method is more likely the way to go, for my problem. But i need to read more about it before i can come to any conclusion.


