How can i do a motion analysis having a ''3D CONTACT'' in catia v5r20....?????
Sorry,,catia only deals with kinematics that's generated by constrains & dimensions.
unigraphics deals with kinematics & dynamics, so that it have 3d contact motion against bodies.
Dassault Systemes offers two types of software for solving contact problems. Abaqus FEA which has an associativ interface to CATIA V5: https://www.3ds.com/products-services/simulia/products/abaqus/add-ons/cad-associative-interfaces/
and the multibody dynamics software called Simpack. However, I highly suggest looking into the 3DEXPERIENCE platform as all of this technology is coming together there.