Abstract
The mechanical properties of the bellows-type inflatable tube subject to bending load are investigated by FEM analyses. First, the method of FEM analysis is verified by the cylindrical inflatable tube. As for the cylindrical tube, the periodic wrinkles in axial direction emerges at first on compressive side of the inflatable tube as the bending load increased, when the axial stress reaches the buckling stress of cylindrical shell structures. As bending load increases further, some isolated wrinkles occur and the periodic wrinkles disappear. Next, the properties of bending stiffness and the collapse load, wrinkles of bellows-type inflatable tube affected by shape and numbers of bellows are investigated by numerical analyses. As the result, the bending stiffness is decrease by changing shape, and the collapse load is mainly determined by the internal pressure. Especially for the wrinkle mode, the bellows-type inflatable tube indicates the different deformation mode from that of cylindrical tube.
