ITER (International Thermonuclear Experimental Reactor) Cryostat has interfaces with many systems which are connected with ITER machine. In which it has one interface with VS (Vertical Stability) coil feeder. To absorb the relative displacement between the interfaces expansion joint is used. Present work deals with the design and analysis of oblong bellow for VS coil feeder. The theoretical design has been done on the basis of EJMA standard by taking it as combination of circular and rectangular bellow. ANSYS workbench 13.0 software has been used to cross check the EJMA results. As after yield point (in plastic region) material shows the nonlinear variation, so nonlinear structural analysis is performed on ANSYS workbench 13.0 software to get the true value of stress and to verify the fatigue life cycle of bellows, which is calculated as per the EJMA standards.

Keywords: Bellows, ITER cryostat, EJMA, ANSYS, Nonlinear analysis, Coffin- Manson.