7 Replies Latest reply on Sep 24, 2014 8:06 PM by Jared Conway

    General doubts

    Raghav S
    Raghav S Sep 22, 2014 11:12 AM

      Hi all, I have a couple of questions:

      1. I was just wondering why we use von Misses stress theory in Solidworks while performing FEA? Are there any particular advantages of using this particular theory as compared to principal stress/ principal strain theory?

      2. Solidworks is one of the most user friendly softwares that i have come across but I am not so sure about how Solidworks is as compared to Ansys when it comes to static analysis of simple components? Are the results comparable to the ones obtained in Ansys? Thanks!

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        • Re: General doubts
          Michael Spens
          Michael Spens Employee Sep 22, 2014 11:32 AM (in response to Raghav S)

          Hello Raghav

          Von Misses failure criteria is a good representation of failure in ductile material.  It is widely used and easy to interpret since it is a simple scalar quantity.  Since most FEA in mechanical design is done for metals, it is an excellent default.  Maximum principal stress is suited for brittle material.  SOLIDWORKS provides several different failure criterion and reporting methods so you can adjust to your material and load cases as needed.

           

          Regarding accuracy, assuming mesh, loading and restraints are set up similarly, you will get nearly identical results for common mechanical component and assembly stress.  There are academic whitepapers available that show the commonality of results between many FEA solvers.  As you mentioned, the biggest difference between tools is the ease of setup of problems and the ease of reviewing and interpreting results.

           

          Mike

          • Re: General doubts
            Rohit Choudhary
            Rohit Choudhary Sep 22, 2014 6:36 PM (in response to Raghav S)

            Hi Raghav,

            Mike is absolutely right, further, in order to answer your question on comparison with capability of Solidworks Simulation and Ansys there are two things I would suggest, firstly - You can set up a simple problem in FEA, for eg a cantilever beam problem and solve it both the software - provided the Meshing parameters and Boundary conditions are maintained the same in both the softwares, the result will be right in front of your eyes.

            secondly - I would like to share with you a paper which compares some FEA softwares/codes, and outcome was that the results had very insignificant variations

            • Re: General doubts
              Jared Conway
              Jared Conway Sep 23, 2014 8:04 PM (in response to Raghav S)

              1. could you elaborate on your question here? there are several methods for evaluation of stress in solidworks simulation. how and which one you use is up to you.

               

              2. like ansys and other FE software, solidworks has put their software to multiple tests against theory and physical tests to make sure that it is accurately predicting what happens. otherwise it would not be safe for them to put out a software that has a claim to provide results to help make design decisions. and similar to other programs, most inaccuracies come from lack of understanding of the user on the assumptions and approximations made and how to setup the problem. so my opinion is that it is as good as ansys, it comes down to interface and features. solidworks has many features and the interface is great like you said. so it lets you get through many iterations and try lots of different things to help reduce your physical tests and prototypes. but like any other tool, it isn't meant to be a replacement for engineering and testing.