An analytical solution for the evaluation of residual stresses in coiling of metal sheets

Abstract

The coiling process is widely used in the manufacturing industry for the compact storage and transportation of metal sheets. However, this process can induce residual stress in the material, which significantly affects the mechanical properties and performance of the final product. This paper presents a closed-form analytical solution for predicting residual stresses in steel sheets resulting from coiling before cold forming into sections. The study models the coiling process as an elastic-plastic plane-strain pure-bending problem, assuming that the steel obeys the Von Mises yield criterion and the Prandtl-Reuss flow rule. This paper explores the impact of coiling radius and steel yield stress on residual stresses, emphasizing the nonlinear variations in residual stresses across the thickness of steel sheets. The analytical predictions of residual stress were experimentally validated using X-ray diffraction, demonstrating close agreement with the finite element analysis (FEA) results. The impact of coiling radius and yield stress on the final residual stresses was also examined. The developed analytical method provides solutions for developed residual stresses during the coiling of metal sheets with higher accuracy, zero cost, and less time-consuming than current available experimental methods for measuring residual stresses.

Keywords

• Residual stress
• Coiling
• Plastic bending
• Finite element simulation
• X-ray diffraction method