Methodologies for Predicting and Testing the Effects of Combat Damage on Flight Envelopes

Abstract

Abstract : Survivability of an aircraft in combat is achieved by not getting hit, or withstanding the effects of any suffered hits. To assess the latter aspect of survivability of a given military aircraft, live-fire tests are performed on its wings. However, these tests may fail to provide accurate and complete vulnerability assessments, because the static and quasi-static ground loading techniques they currently rely on do not replicate the loads encountered during flight, and do not account for changes in structural stiffness and mass after damage infliction. Furthermore, current live-fire tests do not address the damage-induced changes to the flight mechanics and aeroelastic stability of an aircraft; these changes can lead to the abortive impairment of the ability of this aircraft to accomplish its designated mission, or cause its premature failure. For these reasons, the present AFOSR Grant F49620-03-1-0052, entitled Methodologies for Predicting and Testing the Effects of Combat Damage on Flight Envelopes, focuses on developing a numerical simulation technology for predicting the consequences of battle damage on the flight and flutter envelopes of fighters, assessing the impact of several contributors to aircraft survivability, and assisting in the development of new dynamic live-fire ground testing methodologies that may remedy the shortcomings of current static ground-testing techniques.