Rigid-Plastic Finite-Element Analysis of Plastic Deformation in Metal-Forming Processes.
Abstract
Metal-forming processes of extrusion, drawing, ring compression, and closed-die forging were analysed by the rigid-plastic finite-element method. According to the individual problem characteristics, the method was modified in order to deal with the steady-state configurations of the extrusion and drawing problems, the neutral flow point (or region) problems of ring compression, and the complexity in geometric changes of the closed-die forging problems. The present investigation is a complete study of the axisymmetric steady-state extrusion and drawing processes, including multipass extrusion and drawing. Detailed deformation mechanics were revealed, showing the influence of the previous deformation history on the flow pattern in the current pass. To solve the neutral flow problems in ring compression, a variational formulation was developed for the case where the frictional stress is dependent on the relative velocity at the die-workpiece interface. The finite-element solutions of ring compression were then obtained under various friction conditions for several materials. Some of the results were compared with the approximate theoretical solutions and experimental results. It was concluded that this modified finite-element scheme does provide a useful tool for the analysis of neutral flow problems and for industrial applications. The closed-die forging problems are characterized by very complex geometries, large rigid portions, and rapid changes in velocity fields.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1979
- Accession Number
- ADA078987
Entities
People
- C. C. Chen
- Shiro Kobayashi
Organizations
- University of California, Berkeley