Great to have answer from you. Thank you very much for your informations. As I read from the Ansys converter informations page, linear contacts can be transferred to Nastran as you said. But the problem that I'm facing is, I converted my ansys modal analysis model which has only linear contact as Bonded Contact (Formulation = MPC) and joint as Revolute Joint, to Nastran .bdf and couldn't see any contact cards in the .bdf file. There is only RBE2's for the joints if I get it right but they don't work like constrainting the coordinates like TX,TY,TZ,RX,RY = 0 and RZ = free. Can you help me with that where I'm making mistakes or missing details? If you want and let me know how effectively, I can share both the ansys and nastran models with you?