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Full-Text Articles in Mechanical Engineering
Numerical Evaluation Of Energy Release Rate At Material Interfaces For Fatigue Life Predictions, Robert L. Hendrickson
Numerical Evaluation Of Energy Release Rate At Material Interfaces For Fatigue Life Predictions, Robert L. Hendrickson
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Composite materials are becoming popular in almost all industries. Carbon-fiber and glass-fiber composites are used in aircraft, sports equipment, boats, prosthetics, and wind turbine blades. In all these applications, the composites are subjected to different loads. Loads can take the form of impact or cyclic/fatigue loading, both of which decrease the strength of composites as micro-cracks grow through the composite. Composite laminates are made up of fiber plies (thin layers of fiber) and the fibers are surrounded by a resin like epoxy. It is common for laminates to fail because of delamination growth (plies peeling apart). Small delaminations do not …
Plasticity And Damage In Bimodal Grain Size Al-5083: Microstructural Finite Element, Steven Nelson
Plasticity And Damage In Bimodal Grain Size Al-5083: Microstructural Finite Element, Steven Nelson
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Bimodal and nanocrystalline aluminum alloys are being investigated as stronger replacements for conventional polycrystalline aluminum alloys. Higher strengths are achieved by reducing the grain size of a metal; however, as the grain size is reduced the ductility diminishes. One solution that limits this decrease in ductility is the addition of a few microcrystalline grains into a nanocrystalline alloy, creating a bimodal microstructure that offers a better balance of strength and ductility. Two- and three-dimensional microstructural finite element (FE) simulations of monotonic and fatigue failures in Al-5083 having bimodal grain structures are conducted. To reduce the computational time and facilitate the …
Fatigue Life Analysis Of T-38 Aileron Lever Using A Continuum Damage Approach, James D. Gyllenskog
Fatigue Life Analysis Of T-38 Aileron Lever Using A Continuum Damage Approach, James D. Gyllenskog
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
In a recent investigation conducted by the United States Air Force, the mechanical failure of the aileron lever, manufactured from 2014-T6 aluminum, caused the fatal mishap of a T-38 trainer aircraft. In general the locations of cracks are unknown and must be determined by simulation. In this study we propose to use a continuum damage modeling approach to determine the degradation and damage in a material as the number of cycles of loading increases. This approach successfully predicts the location of crack initiation, propagation path, and propagation rate. A stress-based model in conjunction with the successive initiation technique is utilized. …