8 Replies Latest reply on Apr 12, 2013 11:14 AM by Jared Conway

    Othotropic Properties Not Proper

    Ross Jensen

      So I have been delving into composite analysis and have to do analysis on an aluminum honeycomb core, aluminum skin composite. The honeycomb has orthotropic material properties and I know what they are. It allows me to enter all the data, save and apply it to my composite shell; but when I go to run the analysis it gives an error that the "Othotropic properties are not proper (see output file)". I do not know what would cause this or where to find this output file as well. The skin is an Isotropic material, I don't think that would affect it but I don't really know what SW's capabilities are. Please if you have anything that could help me that would be awesome, all suggestions are welcome.error.PNGMatprop1.PNGmatprop2.PNG

        • Re: Othotropic Properties Not Proper
          Adrian Tayne

          I too have received this error and need assistance.

          • Re: Othotropic Properties Not Proper
            Mitchell Kadel

            I had a similar issue. Poisson ratios in all directions seemed to overdefine the material. I removed the Poisson ratio opposite to the vector with the largest strength, and it resolved my issue.

             

            Remove the Poisson Ratio for you YZ or XY and this should resolve your issue.

            • Re: Othotropic Properties Not Proper
              Jared Conway

              Hi Ross, are you on subscription? There are 2 articles in the solidworks KB that i would suggest looking at. S-025202 and S-019594. The latter describes the reason for the error and the former provides a description of how to check your input values. Basically what I'm reading is that there are certain conditions that must be met by the inputs that you've chosen and if they don't, they throw the error. If you check the .out file it should tell you better what is wrong but otherwise it is up to the user to check the inputs. This is probably why Mitchell's workaround works, he eliminates the checks because he removes some of the values.

               

              If you'd like to post your values I can check it them out based on curiosity.

              • Re: Othotropic Properties Not Proper
                Graeme Hyson

                I've had this error quite a few times. I work in composites so basically everything I simulate contains some form of orthotropic material.

                 

                I've only seen the "Not Proper" error when you've created a material that essentially "doesn't make sense". I.e. it may not actually be possible to reconcile the combination of E, G and nu that you've input. For example, your material is incredibly low stiffness in two directions and a million times higher in the third. You wouldn't expect to see Poisson's ratio of 0.01 in all three directions (is that actually possible?) either.

                 

                I'm guessing you're trying to create a ficitonal material that essentially only 'works' in one axis and is essentially 'invisible' in the other two, hence the very large differences in properties?