الفهرس 
AbstractOnly 14 pages are availabe for public view
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Abstract
A good quality product is a product without any defects (no fracture or wrinkle), with good surface finish and with desired dimensions. Manufacturing a good quality product is the ultimate goal of the sheet metal forming industry. This goal can be achieved by many different ways depending on the problem in the sheet metal forming process. One of the most sensitive features of sheet metal forming processes is the elastic recovery during unloading, called springback, which leads to some geometric changes in the product. If the problem is inaccurate dimensions due to the elastic recovery of the part after the load is removed, springback needs to be investigated. Springback can be predicted by utilizing finite element analysis (FEM) and the part can be formed to desired dimensions. In this work springback dependence on the mechanical properties of different materials and tools geometry has been examined numerically and experimentally in sheet metal U- bending test. Finite element simulation of springback using MARC implicit code was conducted to explore the limits regarding process control by boundary values versus material parameters. 2-D finite element modeling was considered in the springback simulations. The computer code MARC was used to simulate the U- bending process under plane strain condition. Experiments were conducted for the U-bending process using three different materials to study the variation of springback due to both process and material parameters such as punch profile radius, die profile radius, strain hardening exponent, and normal anisotropic parameter. The design of experiments was used to evaluate the predominate parameters for a specific lot of sheet metal. Comparison between the experimental and the finite element simulation results were also performed. A complete knowledge of the springback phenomenon and its dependence on material and process variables is strongly required in order to develop effective real time process control systems.