Shock Response and Dynamic Failure of Spatially Tailored Aero-Thermal Structures.

摘要

A comprehensive study was conducted to evaluate the performance of spatially tailored aero-thermal structures under thermo-mechanical loadings. Starting from the first principles, analytical analyses were conducted to develop thermo-mechanical stress fields for mixed mode dynamic curving cracks in functionally graded materials (FGMs) under steady-state and transient loading conditions. Asymptotic analysis was used in conjunction with displacement potentials to develop the stress fields around propagating cracks in FGMs. The effect of crack path curvature, transient parameters, temperature and gradation on various components of stresses were evaluated and discussed. Experimental studies were then conducted to evaluate two different materials, namely, Hastelloy X and Nanolayered Titanium Aluminum Carbide (a MAX phase material) under varying rates of loading and at different temperatures. The Johnson-Cook parameters were determined for Hastelloy X to predict its dynamic plastic response at different temperatures and strain rates.