A Computational Study of an Aerospace Structural Panel Subjected to High Velocity Flow

Abstract

Computational material models for analyzing aerodynamic loads on metallic supersonic and hypersonic aircraft panels rarely include plastic deformation. In this study, the Multi-Yield Surface Plasticity model is introduced as a new technique to the aerodynamic structures community to replace or augment existing techniques for aerodynamic problems that include cyclic loading.

The Multi-Yield Surface Plasticity model is compared to the Johnson-Cook model using experimental data and a finite element analysis (FEA) model of a high-speed aircraft Ti-6242S skin panel. Model inputs for the skin panel are calculated using piston theory to describe the cyclical pressure loads from the unsteady high-speed flow.

This study offers a new and versatile approach for modeling future reusable hypersonic aircraft, under loading conditions that exceed their elastic limit. An analysis matrix of various high temperature test cases is conducted to compare the Multi-Yield Surface Plasticity model with the Johnson-Cook model for Ti-6242S, a titanium alloy similar to those introduced on the X-3 and SR-71, among other high-speed aircraft. The results show the Multi-Yield Surface Plasticity model as a reasonable option, though requiring additional experimental data validation, especially when doing simulations that include plastic deformation in their aerostructures.