Modelling of Metal Forming Processes: Proceedings of the Euromech 233 Colloquium, Sophia Antipolis, France, August 29–31, 1988

The physical modelling of metal forming processes has been widely used both in University and in Industry for many years. Relatively simple numerical models, such as the Slab Method and the Upper Bound Method, were first used and many such models are implemented in the industry for practical design or regulation of forming processes. These are also under investigation in the University, mainly for treat­ models ments which require low cost calculations or very fast answers for on-line integration. More recently, sophisticated numerical methods have been used for the simulation of metal flow during forming operations. Since the early works in 1973 and 1974, mainly in U. K. and U. S. A. , the applications of the finite element method to metal processing have been developed in many laboratories all over the world. Now the numerical approach seems to be widely re­ cognized as a powerful tool for comprehension oriented studies, for predic­ ting the main technological parameters, and for the design and the optlmi­ zation of new forming sequences. There is also a very recent trend for the introduction of physical laws in the thermo-mechanical models, in order to predict the local evolution of internal variable representing the micro­ structure of the metal. To day more and more practicians of the Industry are asking for compu­ ter models for design of their forming processes.

Table of Contents:
1: MATERIAL BEHAVIOUR.- The description of yield surfaces for cold prestressed metals with the hypothesis of the isotropy centers translation.- Constitutive description and numerical approach in modelling for metal forming processes.- Simulation of impact tension deformation of metals by FEM.- Finite elements analysis of large plastic deformation in metals.- Modelling of structure formation and relation to mechanical properties of nodular cast iron.- 2: NUMERICAL TECHNIQUES.- H and P mesh refinement in the metal forming FEM analysis.- A mixed Eulerian- Lagrangian FEM for simulation of thermo-mechanical forming processes.- A method to reduce cost of mesh deformation in Eulerian- Lagrangian formulation.- Error control, mesh updating schemes and automatic adaptive remeshing for finite element analysis of unsteady extrusion processes.- Modelling of frictional tool surfaces in finite element metalforming analyses.- Numerical modelling of friction for metal forming processes.- 3: SHEET METAL FORMING.- Modelling of deep drawing processes by model testing and dimensional analysis.- A finite difference model as a basis for developing new constitutive equations for the sheet forming process.- Influence of anisotropy in sheet metal forming.- Experience with explicit and implicit finite element programs for sheet forming analysis.- Influence of thickness and curvature on the formability of metal sheets.- Experimental analysis of an axisymmetric deep drawing.- Computer aided design of a progressive die.- Finite element analysis of sheet metal forming problems using a viscous voided shell formulation.- Time stepping schemes for the numerical analysis of superplastic forming of thin sheet.- Thin sheet forming numerical analysis with a membrane approach.- 4: FORGING AND DRAWING.- Comparison of simulation techniques and industrial data in forging applications.- Finite Element calculation of hot forging with continuous remeshing.- Finite element applications in forming billet and P/M preforms.- Three dimensional finite element calculation of the forging of a connecting rod.- numerical identification of forging parameters.- Identification of defect locations in metal forming using a personal computer oriented finite element method.- Modelling of metal forming processes.- Numerical analysis of cold drawing of tubes.- 5: HOT AND COLD ROLLING.- A 3D thermomechanical analysis of steady flows in hot forming processes. Application to hot flat rolling and hot shape rolling.- Thermal-mechanical modelling for hot rolling: experimental substantiation.- Simulation of hot rolling of steel by plasticine or waxes. Comparison between the flow of steel and the flow of plasticine by actual rolling and finite element models.- Simulation of profile and flatness in the cold rolling of steel strip.- Application of a mathematical model for the cold rolling process on six-high mills.- Analysis of plane strain cold rolling using a flow function and the weighted residuals method.- Metallographic verification of computer modelling of hot rolling.- Finite element analysis of two-roll hot piercing.- Modelling the mechanics of the longitudinal tube rolling process.