MCML is awarded a new AFOSR grant
Program Manager: Dr. David Stargel. Aerospace, Chemical and Material Sciences Directorate, Multi-Scale Structural Mechanics and Prognosis Program.
Title: Multiscale-Multiphysics Computational Framework for Damage Prognosis in Hypersonic Structures.
Principal Investigator: Caglar Oskay, Department of Civil and Environmental Engineering, Vanderbilt University.
Abstract
This research aims to generate the fundamental knowledge base and develop a simulation frame- work to accurately and efficiently predict damage accumulation and failure in hypersonic struc- tures, and enable design and sustainment of hypersonic platforms. To achieve these aims, a number of challenges associated with the operating conditions of a hypersonic platform must be overcome: (1) Damage accumulation at hypersonic flight conditions is a coupled multiphysics problem due to high thermo-mechanical loads and environmental degradation induced by sustained exposure to elevated temperatures; (2) This is also a multiscale problem due to the tremendous disparity between the microstructural scale at which failure initiates and damage accumulates and the size of typical structural components; and, (3) Existing structural scale simulation methods do not adequately account for the concurrent presence of, and interactions between, a host of damage mechanisms (e.g., environmental degradation, creep, fatigue) at the extreme conditions associated with hypersonic flight. To meet these challenges, a multiscale computational modeling framework that provides the ability to predict the structural limit states that pertain to the hypersonic environment, including high temperatures, variable and high amplitude pressures, and environmental exposure, will be developed. The performance and validity of the proposed computational framework will be assessed using high-fidelity computational models and experimental data. The proposed computational framework will then be employed to gain fundamental understanding of the response of a critical model material/structure system, namely titanium alloy structures subjected to long- duration, elevated thermal environments, and time varying and combined thermal and mechanical loading. This research is critical for enabling the simulation capability and fundamental understanding necessary to reliably model damage accumulation and failure in structures operating in extreme and combined environments, hence providing the underpinnings of high fidelity life prediction of the hypersonic platforms long sought by the United States Air Force.