Flexible forming of 3-D metal panels

Elghawail, Ali Mohamed (2018). Flexible forming of 3-D metal panels. University of Birmingham. Ph.D.

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Abstract

The process of sheet metal forming is commonly used to create 3-D surfaces in, e.g., aircrafts and automobiles. Stamping is one of most common sheet metal forming processes but traditional forming processes which have been developed for mass production are inflexible and expensive, and economically unsuitable for small-scale production. More appropriate for small-batch and prototype production are flexible forming methods such as multi-point forming (MPF) which have been developed in recent years. A pair of opposed reconfigurable tools containing pin matrices could replace traditional solid stamping tools. Based on this technique, the construction of sheet metal forming tools becomes flexible and fast.

Springback, caused by elastic recovery and release of residual stress, is an unavoidable issue in all sheet metal forming and significantly affects the geometrical precision of the products. Springback is a defect, and if it is beyond permissible tolerance it will adversely affect the assembly process such as distortion of sub-assemblies and poor fit-up during welding. Estimation of springback remains an important and challenging issue for the sheet metal industry.

Based on the ABAQUS software, 3-D finite element models were generated, with the required constraints and boundary conditions described and applied in the simulation. The process of multi-point forming and springback were simulated by combining explicit and implicit algorithms. The influence of some significant working parameters, such as radius of forming curvature, blank holder force and elastic cushion thickness on final product quality (springback, thickness variation and wrinkling) has been investigated.

Type of Work:

Thesis (Doctorates > Ph.D.)

Award Type:

Doctorates > Ph.D.

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