7 Replies Latest reply on May 25, 2014 3:27 PM by Jerry Steiger

    problem of Imported  3D model meshing ...

    Pouya Aghabeygi

      hi everyone

       

      I have a 3D model on solidworks and i wnat to imprt to ansys or abaqus and generate mesh and analyze but when i try to generate mesh some part of it wont get meshed the problem is on boss extrude 24 if I delete this part many of the other parts get deleted and i dont want this ...how can i fix it ???!

       

      001.jpg

      and this is the area that wont get mesh ...

      002.jpg

      thanks for your helping ...

        • Re: problem of Imported  3D model meshing ...
          Jerry Steiger

          Pouya,

           

          The first thing I would do is check your model in SolidWorks. Use the Check tool to make sure that the model doesn't have some unseen problems. Since it looks like one of the ANSYS error messages is talking about surfaces that intersect other surfaces, I would check to make sure that you don't have unexpected interferences.

           

          Jerry S.

            • Re: problem of Imported  3D model meshing ...
              Pouya Aghabeygi

              Hi jerry

               

              thanks for your attention

               

              I checked my model it look like I have one Under define sketch I tried to make it fully define from tools>dimension>Fully define sketch but it couldnt fix the problem ... i reduced boss extrude 24 thickness to 170 mm and mesh problem get solved but anaysis is still unacceptable .... some of my results :

              003.jpg

              004.jpg

              005.jpg

              006.jpg

              Thanks for your help ... if u want i can upload the solid file next time ...

                • Re: problem of Imported  3D model meshing ...
                  Jerry Steiger

                  Pouya,

                   

                  I'm not sure what kind of problems you are having with the model and the analysis. The warnings may mean something is terribly wrong, or they may just indicate something that sometimes causes problems, but may not be an issue for this particular analysis. In the bottom results picture, it looks like your flat roof structure is not properly bonded to or contacting the walls underneath. On the other hand, I see that the results defrormations are scaled 58X and that can often give you a very distorted idea of what the real model is doing.

                   

                  Sorry I can't be of much more help. I'm under some very tight time constraints at work and have very little time to spend on the forums.

                   

                  Jerry S.

                    • Re: problem of Imported  3D model meshing ...
                      Pouya Aghabeygi

                      thanks alot Jerry ... I try alot ... redraw my project again and again with test in each step and finally get the true model ... i appreciate u so much for ur help ... i need to limit analysis and time history with failure analysis on this model in ansys or abaqus .. if can help me on this matter with any tutorial or book i will be very thanksful ...

                       

                      thanks again

                        • Re: problem of Imported  3D model meshing ...
                          Jerry Steiger

                          Pouya,

                           

                          I'm afraid I can't be of much help. I'm a designer who uses ANSYS to do fairly simple analyses, not an analyst who really understands ANSYS. If you are using solid elements, I may be able to help a bit, but I hardly ever do analyses with shell elements and have never used beams. I have never done a mixed solid/shell analysis.

                           

                          You may need to add split lines in your SolidWorks model where the various parts meet one another. This will help you define the contacts between the parts. All the contacts have to be defined properly in ANSYS; the mates in SolidWorks don't get translated into ANSYS.

                           

                          Jerry S.

                            • Re: problem of Imported  3D model meshing ...
                              Pouya Aghabeygi

                              Jerry,

                               

                              i drew my model in just single part and no mate ... because of ansys ... and i can just have a tet mesh because of complex geometry .. i use solid elements .. i need to calculate the failure of this masonry and historic structure under seismic load ... is there any way to do this ? i need crack pattern to perform limit analysis ... any book or tutorial if u have .. i appreciate u again ...

                                • Re: problem of Imported  3D model meshing ...
                                  Jerry Steiger

                                  Pouya,

                                   

                                  I'm guessing from some of the screen shots that your structure is a multi-body part. You have to be sure that the connections between the bodies are correct.

                                   

                                  The usual rule of thumb is that you need to have at least two elements through the thickness of any volumes that are structurally significant. That will require much smaller elements than are shown in your screen shots. But I would suggest that you keep the element sizes large until you get the analysis running well, since adding elements makes the model run more slowly (the run time typically goes up as the square of the number of elements, so doubling the number of elements usually quadruples the run time and quadrupling the number of elements makes the run time 16 times as long).

                                   

                                  To get useful results for seismic loading on a masonry structure with pre-existing cracks seems like a very ambitious undertaking. You need some experts involved. Maybe you can talk one into working with you without charge.

                                   

                                  Jerry S.