9 Replies Latest reply on Jul 14, 2011 9:09 PM by Geoff Crocker

    Orthotropic materials for composite analysis

    Paul Bassler

      Hello,

       

      Just wondering if anyone is having trouble using orthotropic materials with the composites analysis feature.

       

      I'm working on a composite cylinder buckling study and am having some odd behaviour with material definition and the resulting analysis.  Even though I have defined my custom material as Linear Orthotropic and assigned all the properties, my material library still shows certain properties in red, as if they have not been defined.  When I would save the library, I received a message stating that "Not all mandatory references have been selected".  I'm wondering if this is because I have not input a value for yield strength (which is not applicable for carbon fiber lamina) or because I have not selected a reference geometry (the help files say this is not necessary for composite shells).

       

      Most recently when I try to edit this material I get a new error message stating that saving the database failed and that the previous database has been restored.  Now I'm thinking the material database has somehow been corrupted and I need to delete it and start over.  Any suggestions on how to proceed?

       

      Paul

        • Re: Orthotropic materials for composite analysis
          Paul Bassler

          According to my VAR, the SW Simulation team has identified this as a bug and has issued an SPR.  Release date...unknown.

            • Re: Orthotropic materials for composite analysis
              Fortino Lopez

              Any updates on a solution or work around?

               

              I get the same error when attempting to apply SN curves to materials for Fatigue studies:

               

              Saving following database(s) failed, restoring the previous database. Recent edits may be missing.

              Custom Materials.sldmat

               

              This error only occurs for assemblies, so it's a bit puzzling as to the source of the issue.

                • Re: Orthotropic materials for composite analysis
                  Dan Wilson

                  Fortino,

                   

                  Do you have the density defined in your material properties?  I have seen this a few times in the past and that we the fix

                   

                  The other possibility is that you down have permissions to write to the folder that your material database is stored at

                    • Re: Orthotropic materials for composite analysis
                      Fortino Lopez

                      I re-checked and density was defined for the materials, along with permission for write access to the local directories.

                       

                      Looking further into the problem, the individual bodies inherit the material properties of the part, even though I manually assign different materials to the bodies within the part. Currently I am attempting to use a secondary materials library by copying the default one and adding fatigue values via notepad. So far the results are mixed when using fatigue studies.

                        • Re: Orthotropic materials for composite analysis
                          Fortino Lopez

                          It seems I may have found a work-around, albeit a lengthy one, for saving custom materials.

                           

                          1) Create a new directory somewhere on your hard drive, e.g. "materials"

                          2) Navigate to your SolidWorks installation directory and into the following folder:

                           

                          \SolidWorks\lang\english\sldmaterials

                           

                          3) Copy "solidworks materials.sldmat'" to the newly created "materials" directory and rename the file, say ,"XYZ materials.sldmat"

                          4) Open the re-named file with Notepad to view the syntax structure for material properties. Some include stress-strain data/curve values and others include fatigue SN data/curve values.

                          5) Alter the existing material data values with your own values or create new materials by following the syntax structure and assigning unique names to the new materials. Save the file.

                          6) Launch SolidWorks and go to Tools->Options to view the "Systems Options" dialogue box. Select "File Locations" on the left and choose "Material Databases" from the drop-down list. Add the location of the new "materials" directory you created.

                          7) When assigning materials to parts/bodies, the "XYZ materials" library will appear underneath the default SolidWorks material library. Select your materials from the new custom library.

                           

                          So far, this solution appears to work since the added material values propagate from Static studies to Fatigue studies. Also, I exclusively use the new material library since the default SolidWorks materials are also included.

                            • Re: Orthotropic materials for composite analysis
                              Blake Larson

                              I have this problem, too.  Unfortunately, I have no other orthotropic materials in any of my SolidWorks libraries.  Anyone care to share?  I can take an XML snippet if that's easiest to post...

                                • Re: Orthotropic materials for composite analysis
                                  Eric Christison

                                  After about a week of trying I was able to generate a linear elastic orthotropic material with temperature dependent moduli of elasticity, ie. what you need to accurately model an injection moulding. I've attached the file.

                                   

                                  If you struggle then please start bugging your VAR until they concede that there are issues with the interface. SW don't seem to want to accept this at the moment.

                                   

                                  Note, once you assign a graph to a property you can't delete it even if you think you have. I loaded a graph of Modulus vs temp for under the density tag by mistake and no matter how many times I tried it wouldn't delete. However we came to the conclusion that it probably was ignoring it and picking up the constant value that we wanted it to.

                      • Re: Orthotropic materials for composite analysis
                        Eric Christison

                        " Even though I have defined my custom material as Linear Orthotropic and assigned all the properties, my material library still shows certain properties in red, as if they have not been defined."

                         

                        If I interpret you correctly the colours don't mean what you think they mean.

                         

                        Here's a cut and paste from a long and useful email from my VAR on materials:

                         

                             Depending upon the different studies set up, you will need to define certain values, e.g. a static study does not need to know the CTE but a thermal does! For a custom material the dialog shows the necessary properties for that study in red, and properties that may also be used but are not absolutely necessary in blue.

                         

                              So you can see that for the static study above the software must know the Elastic Mod, Poisson's ratio, Density, and Yield. The CTE is given in blue because you   might have added a thermal load too.

                         

                        Red mandatory, blue useful.

                         

                        Why don't they say that somewhere rather than make us ask?

                        • Re: Orthotropic materials for composite analysis
                          Geoff Crocker

                          Thanks everyone for the info!

                           

                          I was having the same problem and got a linear elastic orthotropic material into a part by deleting the entries in the "Custom Material" folder while in the material dialog box.  You can copy out any materials you might have in there if needed.

                           

                          Then I was able to apply the material without getting:

                           

                          Saving following database(s) failed, restoring the previous database. Recent edits may be missing.

                          Custom Materials.sldmat

                           

                          You can confirm you have an orthotropic material by right-clicking the part in the simulation tree and selecting "Details..." to ensure there is a reference plane identified.  If your material has ortho properties filled out but you don't have a reference plane then ortho props will show up in the details tab but the simulation will run with isotropic properties.