抄録
In order to study the effects of the tube length on the deformation behavior for free bulged electric resistance welded tubes, the finite element analyses changing the ratio of the tube length to its outside diameter from L/D=1 to L/D=8 were performed. Consequently, it is confirmed that those effects depend on the boundary conditions of tube edges. In the condition not loading axially compressive force to the tube edge, the deformation behavior in the central part of the tube is almost equal between L/D=2 and L/D=8. And, the effects of the plastic anisotropy to the reduction of the tube thickness at L/D=4 depend on the boundary conditions as same as at L/D=2.
