Title

Correlation of Stress Intensity Range with Deviation of the Crack Front from the Primary Crack Plane in both Hand and Die Forged Aluminum 7085-T7452

Date of Award

1-1-2019

Degree Name

M.S. in Mechanical Engineering

Department

Department of Mechanical and Aerospace Engineering and Renewable and Clean Energy

Advisor/Chair

Advisor: David Myszka

Abstract

Experimental study accomplished the characterization of fatigue crack growth rates and mechanisms in both hand and die forged Aluminum 7085-T7452. Testing was conducted at various positive and negative loading ratios, primarily focused on L-S and T-S orientations to discover a correlation between crack tip branching or turning mechanisms and stress intensity. Interior delaminations were found to originate in the interior of the specimen and propagate outward to the surface and manifested as splitting cracks parallel to the loading direction. Stress intensity ranges have been correlated with the onset of crack deviation from the primary crack plane, as well as, the transition to branching dominated fatigue crack growth.

Keywords

Aerospace Materials, Engineering, Mechanical Engineering, Materials Science, Al 7085-T7452, Al 7085, aluminum alloys, crack branching, delamination, crack arrest, crack splitting, crack delamination, L-S, T-S, fatigue, fatigue crack growth, fracture mechanics, crack deviation, aerospace structures, fracture mechanisms, branching

Rights Statement

Copyright 2019, author

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