Application of ductile fracture criteria in spin-forming and tube-bending processes

摘要: Abstract As one of the principal failures that occur in metal spin-forming and tube-bending processes, ductile fracturing restricts process forming. It is difficult to predict rupture forming limit for complex processes spin tube bending. Thus, this paper we aim choose reasonable fracture criteria accurately time, position distribution damage occurs these processes. By embedding Lemaitre Cockcroft–Latham (C&L) into VUMAT (user material subroutine ABAQUS/explicit finite element method (FEM) code), models are built validated predicting failure shear spin-forming, splitting The results show criterion better than C&L at which will its both maximum feed ratio varies within a small range with angle roller. There an obvious difference between distribution, variation level can normal bending radius without rupturing, very radius, where there greater risk rupturing. For using mandrel tube, pressure die velocity increases, so flattening area increases some extent, makes it opposite