Graduate Diploma Thesis, July 2013
Thin-walled tube bending is an advanced technology for producing precision bent tube parts (referred to as “bends” or “elbows” in pipelines, aerospace, aviation and automobiles, etc. With increasing demands of bending tubes with a larger tube diameter and a smaller bending radius, wrinkling instability is a critical issue to be solved urgently for improving the bending limit and forming quality in this process. In this study, using finite element (FE) numerical models in ABAQUS, the Rotary Draw Bending, the most universal approach to produce these kinds of thin-walled bent tubes is simulated, and wrinkling of thin-walled tube bending is predicted. The model simulates in detail the critical wrinkling region, and captures the deformation features of the Rotary Draw Bending process. The study provides an in-depth understanding of the plastic wrinkling instability and the model may be suitable for the wrinkling prediction and optimization of cold bending process.