# Geometry Selection Tips for No Penetration Contact Set in SolidWorks Simulation

Article by Irfan Zardadkhan, PhD, CSWE updated April 29, 2014

###### Article

When creating No Penetration Contact Sets in SolidWorks Simulation, the selected geometrical entities can be used either as Source (Set 1, indicated by a blue colour) or Target (Set 2, indicated by a pink colour) for the defined contact set. When you define a contact between Face 1 and Face 2, you can make Face 1 the source and Face 2 the target or you can make Face 2 the source and Face 1 the target. But which is best?

Contact Sets PropertyManager

### About the Contact Sets PropertyManager

• For Free condition and Bonded with Compatible mesh condition, Source or Target choice has no effect. It is the same for No penetration with Node to node contact.
• For all other contact conditions, involving either Shrink fit, Node to surface or Surface to surface contact or Bonded with Incompatible mesh condition, Source and Target choice can be critical.
• Source and Target sets have been renamed Set 1 and Set 2 respectively.

### Recommendations for No Penetration Contact Sets

• You shouldn’t create many No Penetration contact sets with only one Source and one Target. Instead, you should create fewer No Penetration contact sets. In each of them, include all the faces that make physical sense to group together. This will be the case for instance for contiguous faces on the same part. Also, if a part A touches simultaneously parts B and C, then is probably makes sense to define a single contact set for it.
• When defining local contact between faces that belong to components with considerably different moduli of elasticity, use the surface with the higher modulus of elasticity as the Target. In general the stiffer face should be the Target.
• In general, the Source entities can be faces, edges, and vertices except for the Node to Node and Surface to Surface option which allows faces only for the Source. Target can only be a face.
• Since SolidWorks Simulation 2006, entities in the Source and Target sets can belong to the same component, body, or shell (self contact is allowed). This was not the case in previous releases.
• Target face(s) should be flatter, larger than Source entities.
• Target face(s) can be meshed coarser than Source entities.
• There is no need to cut Target faces with split lines to make them smaller. Doing so doesn’t increase analysis speed.
• There should be no 90° angle on Target faces if contact is expected in or around the corner area. If that is the case and you can’t switch Source and Target entities, you should create a reasonably large round to cut the sharp angle. A very small round would create more problems. An alternative is to create two sets. (See image below)
• Although possible, it is not generally recommended to define an entity as Source in a contact set and as a Target in another contact set. In complex models, it may lead to contact failure.