How to avoid penetration due to joint?

what do you want to do? if you want to do this in SAP2000 i can tell you from define menu then section properties then link properties then chose gap element link define the gap distance and then the stiffness of the spring in the link  

SAP2000 i can tell you from define menu then section properties then link properties then chose gap element link define the gap distance and then the stiffness of the spring in the link