1 Reply Latest reply on May 3, 2017 5:23 PM by Ryan Dark

    No penetration - component contacts vs contact sets

    Aaron Hayden

      When using the no penetration contact condition there are a few different approaches one could take to create them. If we have to two parts each with multiple surfaces that interact between the adjacent part (but not bonded) one option would be to use a no penetration component contact and select part A and part B. Another option would be to use one no penetration contact set where we select all interacting faces of component A in face set 1 and all of interacting faces of component B in face set 2. Yet another option would be to use multiple no penetration contact sets where one contact set would be created for each pair of adjacent interacting faces.

       

      Of course, there are many factors that affect accuracy of results and solve time. So, for talking purposes on a given study and all things being equal except for the manner in which no penetration is applied my questions are:

      Would Simulation analyze/solve these approaches differently?

      Would you expect to see significant differences in the results (significant is relative, so let's say greater than 10%)?

      Is there a significant difference in solve time between the different approaches?

        • Re: No penetration - component contacts vs contact sets
          Ryan Dark

          Hi Aaron,

          In my experience with No Penetration contacts this is what I have observed:

          1. Global and Component No Penetration contacts will, at times, have trouble recognizing contacts if gaps are involved.  For this reason, when gaps are involved, I always use contact sets to define the No Penetration contact.

          2. If the contacts for Global/Component No Penetration are recognized I would not expect that there would be a significant difference in the results.  I'd expect they be well within 10% of each other.

          3. There can be a fairly significant difference in solve times when using Global/Component contact vs a Contact Set for No Penetration.  This is due largely to the fact that you can use a Contact Set to define only specific areas of interaction.  For example, if you have a study which portions will compress and other portions will lift off it would not be necessary to define No Penetration at the locations lifting off.  However, if the Global/Component contact definition picks up those area to define for No Penetration it can lead to longer solve times.  A Contact Set definition gives you latitude to ignore these areas.

           

          This all being said, if you create one No Penetration contact set with multiple faces or many contact sets with singular pairs of faces I would expect the computation times and results to be similar.