1 Reply Latest reply on Sep 27, 2018 10:05 AM by Bill McEachern

    Evaluate stress range for all nodes, or selection of nodes, between several load cases...?

    Mats Lindqvist

      Dear SW Simulation users,

       

      I have a structure with complex geometry, and a load that is rotating 360 degrees. As the load rotates, the stress in various locations will change. I want to extract the maximum of the maximum principal stress as the load rotates (or for a selection of nodes, or for all nodes) and then, go through all other loading directions (in my case 11 directions, 30 degrees between each direction) to extract the minimum of the minimum principal stress, so as to calculate the stress range in the structure, as the load rotates.

       

      The rotation of the load is defined as a design study. The load direction not only rotates, it's application point also moves 360 degrees. 

       

      It is a very tedious task to manually go through all 12 load cases to extract the mininum of the minimum principal stress, for all loading directions.

       

      This is typically a task suitable for programming, but I'm not sure which is the best way forward here. Is there an API where you can do this?

       

      I recall that I did this in a matlab script in Creo Simulate some years ago. Then I had to request Creo to output ASCII result files (large files), and write a matlab script that extracted the proper numbers to do this evaluation. For large models, it became time&disk space consuming, but at least it worked.  And there are tweaks you can do, to simplify the process, although I did not go down that path. You can add a "skin" with thin shell elements onto the solid's external surfaces, that don't add to the structure's stiffness, and only post-process those shell elements. That way, you can significantly reduce the number of nodes to check (only surface nodes need to be evaluated). 

       

      /Mats Lindqvist

        • Re: Evaluate stress range for all nodes, or selection of nodes, between several load cases...?
          Bill McEachern

          Not that I fully understand how the load application point moving and the load rotating all works but maybe instead of a sequence of static studies you do a dynamic study with the load moving and since you are not particularly interested in dynamic effects then the time steps could just match the spatial descretization you had in the series of static studies. Then maybe a set of sensors would work to extract the min and max you are looking for. Are you only interested in the global min and max or the spatially distributed min and max for each element? If you think this has any merit I would do a small experiment on something simple to see if would get you what you want. You can get the field output from the list results options.