Date of Award

Spring 2005

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Mechanical & Aerospace Engineering

Program/Concentration

Engineering Mechanics

Committee Director

Chuh Mei

Committee Member

Osama A. Kandil

Committee Member

Gene J.-W. Hou

Abstract

Shape Memory Alloy (SMA) has a unique ability to recover large prestrain (up to 8∼10% elongation for Nitinol, a typical SMA material) completely when the alloy is heated (e.g. aerodynamic heating) above the austenite finish temperature Af. An innovative concept is to utilize the large recovery stress by embedding the prestrained SMA in a traditional fiber-reinforced laminated composite plate, which is called SMA hybrid composite (SMAHC) plate. In this research, static thermal and aerothermal deflections, dynamic panel flutter and random response are investigated for traditional composite plates and SMAHC plates under combined aerodynamic, random and thermal loads by employing nonlinear finite element method. System equations are derived and based on classical laminated plate theory, von Karman nonlinear strain-displacement relation, first-order piston theory aerodynamics and quasi-steady thermal stress theory. Newton-Raphson iterative method is adopted for solving the static thermal and aerothermal buckling deflections. Both normal modes and new proposed aeroelastic modes are employed separately in solution procedures to transform the equations of motion in structural node degree-of-freedom (DOF) into modal equations of motion. Time domain numerical integration technique is adopted for the dynamic analysis under the combined aerodynamic, random and thermal loads.

Numerical results of isotropic, traditional composite plates and SMAHC plates are determined, compared and discussed. Various plate behaviors are studied in detail. It is demonstrated that SMAHC plates can greatly suppress or reduce thermal buckling and panel flutter as compared with the traditional composite plates. While the SMAHC plates exhibit better performance at low levels of acoustic excitations, however, the SMAHC plates do not effectively suppress random response at high levels of acoustic excitations.

DOI

10.25777/3snn-5r47

ISBN

9780542189166

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