Dynamic Thermo-mechanical Response of Hastelloy X to Shock Wave Loading

Abstract

A comprehensive series of experiments were conducted to study the dynamic response of rectangular Hastelloy X plates at room and elevated temperatures when subjected to shock wave loading. A shock tube apparatus, capable of testing materials at temperatures up to 900 °C, was developed and utilized to generate the shock loading. Propane gas was used as the heating source to effectively provide an extreme thermal environment. The heating system is both robust and capable of providing uniform heating during shock loading. A cooling system was also implemented to prevent the shock tube from reaching high temperatures. High-speed photography coupled with the optical technique of Digital Image Correlation (DIC) was used to obtain the real-time 3D deformation of the Hastelloy X plates under shock wave loading. To eliminate the influence of thermal radiation at high temperatures, the DIC technique was used in conjunction with bandpass optical filters and a high-intensity light source to obtain the full-field deformation. In addition, a high-speed camera was utilized to record the side-view deformation images and this information was used to validate the data obtained from the high temperature 3D stereovision DIC technique. The results showed that uniform heating of the specimen was consistently achieved with the designed heating system. For the same applied incident pressure, the highest impulse was imparted to the specimen at room temperature. As a consequence of temperature-dependent material properties, the specimen demonstrated an increasing trend in back-face (nozzle side) deflection and in-plane strain with increasing temperature.