47 Replies Latest reply on Apr 18, 2016 12:53 PM by David Vue

    how to apply load onto an assembly

    David Vue

      hello everyone,

        new to the forum and new to solidworks simulation.

       

      I'm trying to determine if a gate assembly will be able to handle a certain amount of pound force. this is what I've done so far. all my knowledge on solidworks is from online searches and forums such as this one, so bare with me.

       

      first I simplified the part by removing all the fillets. Then I looked for gaps and edited the individual parts to close the gaps (do I need to set Contact settings here, all I did was edit the dimensions).   From what I've read, I needed to save the assembly as a part, and I did that. Now, I have about 58 solid bodies in the new part file.  I then used the solidworks Features/combine to combine most parts, and reduced it down to 6 solid bodies. this is where I'm stuck. I looked at the part and found the inside door is not making contact with the outside frame.  I guess I will have to fix that.

       

      so my question is, is it possible to apply a load on to an assembly? or do I have to save it as a part?

      and

      is my approach correct?  or how would a professional solidworks user go about doing FEA on a gate.

      also,

      will I need to set my Contact settings on the inside door and the frame as well as the hinges and other parts that are capable of moving? I think after combining the 58 solid bodies into 1 would make it a bonded contact right, and it will act as one solid piece.

       

      hope I make sense...

       

      thanks!

      David

        • Re: how to apply load onto an assembly
          James Riddell

          We do assembly FEAs all the time.  If you have the simulation package and not SWX then it is fairly easy.

           

          Usually fully contacting parts come in as bonded (not always).  If you have some moving/non-contacting parts then you'll have to set up contact sets based on your desired result.

           

          Set up your boundary conditions, loads and gravity then mesh & run, easy-peasy.

          • Re: how to apply load onto an assembly
            David Vue

              I have access to sw simulation premium.

             

            This is what I tried to do last Saturday before saving the assembly as a part.

             

            I selected the front plane.  Drew a circle for testing.   But when in assemble mode.  I do not have the option for curve/split line.  Maybe I am doing something wrong.

             

            I am able to do split line in assembly when I go to edit feature on a particular part of the assembly.  But this will only give me the option of selecting the faces on that part only and not the area of interest on the gate.

             

            Any idea what I'm doing wrong?

            • Re: how to apply load onto an assembly
              David Vue

              Riddell,

              I ran into a problem. what i did was i clicked the front face of the part i am wanting to sketch on.  right-clicked. edit sketch. i drew a simple rectangle to test the load projection. when i try to do a split line I get the message "Please select from the solid body you are editing".   so it is asking me to only select the faces on the part that i am editing.  i'm looking to project this force over a certain area which would include multiple parts.. i'm doing all this in assembly mode.  take a look at the screen shot below.  I selected the top bar's face to do the edit sketch but looking to project the load on the two bars for example...

               

              projection error.jpg

              • Re: how to apply load onto an assembly
                David Vue

                So I was able to combine the solid bodies down to 4 parts.  Those extra parts I can exclude from the analysis because they are just covers and a hinge with a pin which I can replace with a fixture...that should leave me with 1 whole body for the entire gate. I was able to mesh it but haven't gotten the time to run yet.   I tried first to let the bodies that are not initially touching have contact settings with surface to surface but the time to run took too long.  40 min and 20% done.  So I terminated that run and did more simplification...which was what I described above.

                 

                I also tried to do split line in assembly mode again. This time. I added a plain. Sketch an area for the force to be projected. My plan was to go in and edit each part with the same area project from the plain I just created.  The problem now is, because the horizontal bars that are hit with the projection are the same part but used 6 times, if I edit one, all 6 will have the same split line. .. any way to work around this?  Or would I have to bring in 6 bars of the same part but with different file name to let the program know that it is 6 different parts?  I guess an example would be a picture.jpg.  but I can have picture1.jpg, picture2.jpg. picture3.jpg, etc...but they are all the same picture still...  I hope I make sense

                 

                I'll run my single body part later when I get home.. hopefully  it works..

                  • Re: how to apply load onto an assembly
                    James Riddell

                    If you want split surfaces on different locations (only) for each part then you are stuck with part1, part2, etc.  If it is no big deal, you can have multiple split surfaces on a part used in many areas.  The only downside to this that I have noticed is if the boundary causes a point to show high stress that isn't really there.

                  • Re: how to apply load onto an assembly
                    David Vue

                    I didn't build this model and I'm just trying to learn to do fea on it. 

                    I guess I'm a little confused.  Let's say I want to project a circle.  In assembly mode, I edit the top bar which is a part that is used 6 times down a column.  If I created a split on that bar,  the split at the same location would then be automatically be applied to the other 5 bars because it's the same part...  And that is not what I want.  I want it to show just one full circle projection after I get done splitting the other bars using an outline from an inserted plain....

                     

                    I think I'm just confused..

                      • Re: how to apply load onto an assembly
                        James Riddell

                        From what you are describing you have instances of the identical part which may (or may not) be oriented/mated the same way every time - it could even be flipped end-to-end.  Each surface of the part has a 'name' and if you split the one, all the others will automatically show up.  This can be a (small) problem if you have an assembly with properly mated parts, however, it probably won't impact your FEA, you'll just see some added geometry.

                         

                        If you truly want only one part with a split circle you could copy the part into a new file, substitute the new part in for the one you need the surface on and then do your split operation in the assembly.

                         

                        In practice, I will many times, set up a part with the surfaces I need for constraints/loads and add it to the assembly.

                      • Re: how to apply load onto an assembly
                        David Vue

                        When I ran the simulation.  It says large displacement was found.  Click yes to proceed with flag for large displacements no to continue with small displacement...

                         

                        What does this mean.  Currently searching Google for answers..

                        • Re: how to apply load onto an assembly
                          David Vue

                          Hi james. Been awhile since I've been on this forum.  Been running different simulations trying to get my part to pass.  Unfortunately, the load is too much.

                           

                          Now I am wanting to know how much force magnitude will cause the material or gate to yield.

                           

                          Is there an option in solidworks simulation to find this automatically, or will I have to keep running simulations at different load to find its yielding magnitude?