Influence of different mandrels on cross-sectional deformation of the double-ridge rectangular tube in rotary draw bending process

Abstract

Cross-sectional deformation of the double-ridged rectangular tube inevitably occurs in the rotary draw bending process. It has serious effect on the characteristic of microwave transmission and restricts the quality and performance of tube. Different mandrels play different roles in the bending process, so the rigid and polyvinyl chloride (PVC) mandrels are applied in the E-typed and H-typed rotary draw bending of double-ridged rectangular tube to study their influence on the cross-sectional deformation. Based on the platform of ABAQUS/Explicit, the three-dimensional finite element models for E-typed and H-typed rotary draw bending of H96 brass double-ridged rectangular tube with rigid and PVC mandrels have been established and validated by experiment. Results show that whether in the E-typed or H-typed bending, the PVC mandrel has better inhibitory effect on the cross-sectional long-side deformation δL, short-side deformation δW, and spacing deformation between the bottom of ridge grooves δw of the tube. And the PVC mandrel can be more helpful to reduce the width deformation of ridge grooves of the tube in H-typed bending. The rigid mandrel can restrain the width expansion deformation of outer ridge groove of the tube more effectively in E-typed bending. However, whether using the rigid or PVC mandrel, the width shrinkage deformation of inner ridge groove of the tube in E-typed bending is less affected by the type of mandrels. And the width of two ridge grooves on sidewalls of the tube in H-typed bending also has the obvious shrinkage deformation.