Analysis of the States of Deformation and Stress in the Surface Layer of the Product after the Burnishing Cold Rolling Operation

Abstract

The article presents the results of computer modelling and numerical simulations the deformation and stresses occurring in the surface layer of the product after the burnishing cold rolling operation. Technological processes were considered as a geometrical and physical boundary and initial value problem, with unknown boundary conditions in the contact zone. An incremental model of the contact problem between movable rigid or elastic body (tool) and elastic/visco-plastic body (object) in updated Lagrange formulation, for spatial states (3D) was considered. The incremental functional of the total energy and variational, non-linear equation of motion and deformation of object on the typical step time were derived. This equation has been discretized by finite element method, and the system of discrete equations of motion of objects was received. For solution of these equations the explicit methods was used. The applications were developed in the ANSYS/LS-Dyna system, which makes possible a complex time analysis of the states of displacements, strains and stresses, in the workpieces in fabrication processes. Application of this method was showed for examples the modelling and the analysis of the asperities with apex angles θ = 85°, 120° and 156°. The Bielajew point using finite elements methodology was indicated. The simulation results were verified experimentally.