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Imposing tensile stress on an edge of a sheet metal blank is a common condition in many sheet metal forming operations, making edge formability a very important factor to consider. Because edge formability varies greatly among different materials, cutting methods (and their control parameters), it is very important to have access to an experimental technique that would allow for quick and reliable evaluation of edge formability for a given case. In this paper, two existing techniques are compared: the hole expansion test and the tensile test. It is shown that the hole expansion test might not be adequate for many cases, and is prone to overestimating the limiting strain, because the burr on the sheared edge is typically smaller than what is observed in production. The tensile test represents an effective alternative to the hole expansion test. Advantages and disadvantages of each case are discussed.

This study involves the investigation of the sensitivity of the torsional stiffness of a bolt-together heavy truck chassis to variations in tight/loose conditions for various combinations of individual bolts or groups of bolts. The behavior of the chassis, which features several hundred threaded fasteners as the primary means of connecting the cross members to the longitudinal beams, is studied using the Hierarchical Evolutionary Engineering Design System (HEEDS) in connection with the finite element program (ABAQUS) for performing a multiple-run analysis. A novel analysis approach involving a systematic segregation of the bolts is introduced. First, the bolts that are used for connecting the components of the chassis are divided into various sets. Each set represents a number of individual bolts in each joint between the longitudinal beams and the various cross members.