9 Replies Latest reply on Nov 14, 2018 11:14 AM by Taylor Duran

    stress concentration

    Chuanhu Sun

      Hello,everyone!

       

      recently I encounter an example,and one  the attachments

       

      is the part  used to simulate , the question and requiremnets and  tips  are as follows:

       

      dimensions and load(pressure):A=21mm,B=7mm,D=36mm,(other dimensions unchanged) P=1Mpa;

       

      question:what is the average value  SX of stress concentration area ?(through the whole thickness )unit: Mpa,decimals: two;

       

      tips:

          1. if the displacement is small,the result is not related to the chosen material;
          2. apply appropriate mesh style,boundary conditions and mesh parameters setting  ;
          3. you can use symmetrical fixture or create split curve if you like;
          4. mesh element should be fine to get precise result;

       

       

      I have finished it ,but not sure if I am right (please refer to my finished simulation),if wrong,how can I calculate it ? by the way,my result is 8.77, thanks ! ( note :before simulation,I have converted the solid part to sheet metal)

        • Re: stress concentration
          Cnu Vasu

          the max value SX is 6.959MPa after removing the spurious value, the dispplacement is 7e-04mm

          • Re: stress concentration
            Jose Manuel Delgado

            Hi guys, I running the study and I see the max stress in x direction as 8.77 MPa but the averange stress in x direccion was 0.999 MPa. Who has the correct answer?

            • Re: stress concentration
              Taylor Duran

              This looks oddly like an intro CAE/FEA type homework question.

               

              Read through the link below and see if your simulation is giving an accurate result compared to hand calculations.

              Stresses At Elliptical Holes

               

              Maybe look into using an adaptive mesh? It will refine the mesh through iterative loops until the value converges

              If you aren't taking advantage of symmetry by splitting the model you can put a split line on the face of the hole and probe the entity, export to excel, and get the mean value for the average stress through the thickness.

                • Re: stress concentration
                  Taylor Duran

                  Actually, I forgot it averages the value for you when you probe the split line. So..no need to export to excel

                  My geometry and force applied may not be the same as the "example" so don't use these values to verify your simulation.

                    • Re: stress concentration
                      Jose Manuel Delgado

                      Hello Taylor.

                      Did you apply material at model? Cause I use two normal  forces  with inertial relief. But when I try to run the simulation the program send a massenge that simulation requiere a meterial, and I use steel and I have a result and after this I run an other simulation with aluminum and I have other result but in problem says that the result is not related to the chosen material.

                        • Re: stress concentration
                          Taylor Duran

                          Jose,

                           

                          Why are you using inertial relief with force applied to both ends? Does the example you're working on instruct you to set up the simulation that way? If you're not taking advantage of symmetry, you should be able to fix one end and apply the force to the other like it was a tensile test specimen. You will get different values depending on which way you set up the simulation....But think about the loading scenario you are trying to simulate and what is happening in SolidWorks when you select the inertial relief option.

                           

                           

                          Yes, I think I just used plain carbon steel for the snippet above.

                           

                          Since stress is force/area, and the force and cross sectional area would stay the same regardless of material, then theoretically you should get the same value for the average normal stress in the x-direction right? You will however have a different value for Strain because of different material properties.

                           

                          Make sure you're model is aligned with the coordinate system in the picture and that your stress plot is of SX and not VonMises. VonMises stress is also known as maximum distortion strain energy.

                           

                          Hope this helps!