Showing papers by "C.J. Van Tyne published in 2014"
TL;DR: In this article, the expansion at potential necking sites was intentionally restricted in order to reduce the strain gradient at potential necksing sites, which is an effective way to retard the initiation of necking.
Abstract: Bursting in tube hydroforming is preceded by localized deformation, which is often called necking. The retardation of the initiation of necking is a means to enhance hydroformability. Since high strain gradients occur at necking sites, a decrease in local strain gradients is an effective way to retard the initiation of necking. In the current study, the expansion at potential necking sites was intentionally restricted in order to reduce the strain gradient at potential necking sites. From the strain distribution obtained from FEM, it is possible to determine strain concentrated zones, which are the potential necking sites. Prior to the hydroforming of a trailing arm, lead patch is attached to the tube where the strain concentration would occur. Due to the incompressibility of lead, the tube expansion is locally restricted, and the resultant strain extends to adjacent regions of the tube during hydroforming. After the first stage of hydroforming, the lead is removed from the tube, and the hydroforming continues to obtain the targeted shape without the local restriction. This method was successfully used to fabricate a complex shaped automotive trailing arm that had previously failed during traditional hydroforming processing.
5 citations
01 Jan 2014
TL;DR: In this paper, the authors provide pertinent information on how some important material properties are measured, as well as to provide a degree of insight into some developing (i.e., specialized) materials so that manufacturing engineers can begin to meet the challenges of industrial production by taking advantage of the unique properties for these emerging materials.
Abstract: The basic properties of materials play a dominant role in their processing. It is important not only to obtain quantitative values for the behavioral properties of a given material during a process, but also to understand how the properties were measured. The goal of this volume of the work is to provide pertinent information on how some important material properties are measured, as well as to provide a degree of insight into some developing (i.e., specialized) materials so that manufacturing engineers can begin to meet the challenges of industrial production by taking advantage of the unique properties for these emerging materials.
2 citations