Forming quality of thin-walled rectangular waveguide tube during small-radius rotary draw bending under different push assistant matching conditions

Abstract

In the small-radius rotary draw bending (RDB) process of thin-walled rectangular tubes, push assistant matching consisting of pressure die and booster die is proposed to improve the forming quality of tube in this paper. Based on ABAQUS platform, the reliable 3D-FE models without and with booster die were established, and the cross-sectional deformation and wall thickness variation under different push assistant levels were analyzed. The results show that: (1) Adding the booster die or increasing push assistant level can reduce the cross-sectional deformation and wall thinning ratio of tube during small-radius RDB process. (2) The influence of adding the booster die or increasing push assistant level on the cross-sectional deformation in mandrel support zone (MSZ) is smaller than that in non-mandrel support zone (NMSZ), while the influence of that on wall thickness variation is opposite. (3) Increasing the push assistant level not only results in the variation of deformation degree of tube, but also makes the distribution zone of wall thickness thinning and thickening changed. Besides, the reasonable push assistant matching conditions are obtained.