Optimizing the Rotary Draw Tube Bending Process to Avoid Wrinkles

Abstract

Large metal deformation and highly nonlinear contact conditions arise during tube bending. Instability conditions like wrinkling and tearing persist in the problem. With the advancement of computational facilities and numerical methods like finite element methods (FEMs), it became viable to model these nonlinearities and instabilities inside the computer. Here a finite element model was developed using commercial package ABAQUS/CAE. The solution of the developed model was obtained using finite element solver, ABAQUS/EXPLICIT, which has capability of handling these nonlinearities and instabilities. The results of the model were validated by comparing the thickness variation with the experimental values. To find out the optimum process parameters for avoiding wrinkle effects, various process parameters like clamping die position, tube-clamp die interaction, wiper die position, tube-wiper die interaction, mandrel position, and tube-mandrel interaction were studied. The model predicts the behaviour of the tube during bending and is sensitive to the various process parameters. It was found that tube-clamping die interaction property, clamping die position, wiper die position, and mandrel position are responsible for the formation of wrinkles, and that optimum selection of these parameters is helpful in avoiding wrinkles during tube bending.