Shock Tube Based Forming of Sheets

Abstract

During the automotive structure design, it is important to have a better understanding about the plastic deformation of the material. Most of the sheet materials are strain rate dependent above a threshold limit. Therefore, it is necessary to evaluate the material properties and the forming behavior at different ranges of strain rate. Universal testing machine, and Split Hopkinson Pressure Bar are generally utilized for the purpose. High energy rate forming devices such as electromagnetic forming, electrohydraulic forming and explosive forming are mostly used to study the forming behavior of the material at high strain rates. Besides several advantages, the major limitation of these processes are higher capital cost, complexities in handling, and instrumentation. To avoid such limitations, nowadays, the shock tube facility is utilized as a laboratory device to study the dynamic behavior of the sheets. In the present chapter, in the first section, the existing methods of testing of sheets at high strain rates are described with their merits and demerits. In the second section, shock tube facility and characterization of formability of sheets are presented with instrumentation details. Finally, some recent case studies on shock tube formability testing of Aluminum sheets are included.