NUMERICAL SIMULATION OF THE STRESS-STRAIN DURING CONSTRAINED GROOVE PRESSING PROCESS

Abstract

In the case of plane deformation, the stress-strain of the workpiece can be calculated analytically with some simplifications without losing the generality of the problem. Numerical simulation by DEFORM software  can be used to analyze most thermo-mechanical forming processes, and many heat treatment processes. The sequentially simulate each process that is to be applied to the workpiece of Constrained Grooved Pressing (CGP) plastic deformation process by finite element method allows to determine technological parameters such as pressure force, stress field, strain field and risk of failure or destruction. The stress-strain has been analyzed at the characteristic points of the plastic deformation region including on the surface, at the center of the workpiece and at the transition regions, the results are consistent with the theoretical study. The unique feature of CGP technology compared to other types of severe plastic deformation (SPD) is that the plastic deformation zone is not in a direct contact with the mold surface, but subjected to indirect forces, and has a small hydrostatic stress. The hydrostatic force and stress parameters only come into play at the end of the back elastic compression stroke. Through numerical simulation, it is possible to visually determine the state of stress and strain on the entire workpiece at all times of the stroke. Therefore, it is possible to determine the stress in the principle axis system.