Off-Set Roller Bending of Aluminium Space-Frame

Abstract:

In the proto-type bending machine reported in the previous paper, the Bending Roller was fixed in the same position during bending. Therefore, almost uniform curvature in longitudinal direction was obtained. We improved the machine as the Bending Roller can be moved by a servo motor. By this improvement, we can bend aluminium space-frame into varied curvature in longitudinal direction. The curvature of a bent aluminium space frame is different from the setting curvature calculated from the moving position of the bending roller, because so called spring back occurs. We found out that the abrupt increase of objective curvature causes collapse of the specimen and we cannot obtain the objective curvature. And the sudden decrease of the objective curvature by sudden decrease in position of bending roller cannot be realized because of the outbreak of gap between the bending roller and the bent space-frame. If we avoid the abrupt change of the objective curvature, we can compensate the spring-back and we can get the objective curvature.