Contact Force results are generated only where contact is defined between two adjacent parts of a model. Contact force results are computed for all contact types (including Bonded, Separation, Rough, and Sliding).
Contact force is defined as the force acting along the contact interface. The force acting on one part is equal in magnitude and opposite in direction relative to the contact force on the adjacent part. You typically have to hide one part to provide visibility of one of the contact surfaces in the pair.