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Functioning as an introduction to modern mechanics principles and various applications that deal with the science, mathematics and technical aspects of sheet metal forming, Mechanics Modeling of Sheet Metal Forming details theoretically sound formulations based on principles of continuum mechanics for finite or large deformation, which can then be implemented into simulation codes. The forming processes of complex panels by computer codes, in addition to extensive practical examples, are recreated throughout the many chapters of this book in order to benefit practicing engineers by helping them better understand the output of simulation software.

Present models and methods for simulations of sheet metal forming processes are reviewed in this paper. Because of rapid progress of computer hardware, complex computations, formerly impossible to perform due to high computational cost, are now feasible. Therefore, more realistic and computational intensive models are suggested for finite elements, materials, and frictional forces. Also, simulation methods suitable for sheet metal forming processes are recommended. Four numerical examples at the end of the paper are presented to support the recommendations.

This paper is concerned with the use of solid elements in sheet metal forming simulation, particularly springback prediction for flanging when the flanging radii are comparable with the metal thickness. It is demonstrated that appropriate solid elements must be used instead of shell elements in order to obtain adequate results. Numerical difficulties associated with development of suitable solid elements are discussed in detail, with emphasis on the volumetric locking and transverse shear locking phenomena respectively. The transverse shear locking arises from the incompatible deformation modes when the element is used for thin structure bending analysis. A four point bending testing problem is used to study the performances of different solid elements. A locking-free solid element based on assumed strain formulation is developed in Ford in-house program MTLFRM for accurate springback prediction, and a flanging example is given to demonstrate its application.

This paper is concerned with the development of a finite element method for the elasto-plastic analysis of a gas turbine wheel under severe thermal and mechanical loads. A computer program based upon this development has been written and checked by running sample problems for which the solutions exist in the literature. The output of the computer program gives the transient displacements and stresses for a specified set of discrete points in the structure. As an illustration of an actual application, one power turbine wheel has been analyzed by using the developed method and running the checked computer program. The method developed in this paper should serve as a useful tool in turbine wheel design and should result in improved wheel designs and extended engine durability.

This paper presents an analytical treatment of a mechanical-mathematical model of an air bag inflation process integrated with a model for the interaction between the air bag and a standing child dummy. The inflation model consists of a one-dimensional gas dynamics analysis of the flow system which delivers the gas to inflate the bag. The interaction model then provides a method for calculating the forces exerted by the inflating bag on the standing child. The results show that the unacceptably high contact forces recorded in standing-child air bag tests are due to impact of the unopened portion of the bag on the standing child. A single-membrane concept is thus suggested to reduce this impact severity.