Experimental and finite element simulation methods for metal forming and cutting processes
Abstract
Experimental procedures and finite element simulation methods for metal forming and cutting processes are developed. The development includes the formulation of a tangential stiffness matrix for plane-strain and axisymmetric solid finite elements with four node, eight degree-of-freedom, and quadrilateral cross-section. The effects of elasticity, viscoplasticity, temperature, friction, strain rate, and large strain are included in this formulation. The solution procedure is based on a Newton-Raphson incremental-iterative method which solves the nonlinear equilibrium equations and gives temperatures and incremental stresses and strains. For the metal forming processes, finite element simulation for the upsetting of a cylindrical workpiece between two perfectly rough dies is first performed and the results are compared with alternative finite element solutions. Both experimental and finite element methods are then conducted for the upsetting of a cylindrical billet and the forging of a ball. The orthogonal metal cutting experiments are set-up on a shaper, and the distributions of residual stresses of the annealed 1020 carbon steel sample are measured using the x-ray diffraction method. Under nominally the same cutting conditions are the experiment, the cutting processes are also simulated using the finite element method. Comparisons of the results for the forming forces, deformed configurations, and the distributions of residual stresses between the experimental and finite element methods indicate a fairly reasonable level of agreement. The versatility of the present finite element simulation method allows for displaying detailed results and knowledge during the metal forming and cutting processes, such as the distributions of temperature, yield stress, effective stress, plastic strain, plastic strain rate, hydrostatic stress, and deformed configuration, etc. Such knowledge is useful to provide physical insights into the metal forming and cutting processes as well as to better design the processes for engineering components with improved performance.
Degree
Ph.D.
Advisors
Yang, Purdue University.
Subject Area
Aerospace materials|Mechanical engineering
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