Thesis
Computational modeling of fracture and associated wave propagation in precipitate-hardened aluminum alloys
Master of Science (M.S.), Drexel University
Jun 2018
DOI:
https://doi.org/10.17918/z3j5-hp52
Abstract
The identification of early stages of damage is an important consideration for determining remaining useful life in critical structures such as aircrafts. In this context, previous experimental investigations on precipitate-hardened aluminum alloys, which is a widely used class of aerospace materials, confirmed the acoustic emission resulting from fracture of second phase particles, which in fact occurs early in the deformation process so that it can be considered a damage precursor. The experiments also identified correlations between crystallographic (e.g. grain boundaries) and property mismatches (e.g. of elastic modulus and hardness) at the microscale with fracture initiation sites. Motivated by these findings, the research work presented in this thesis develops a computational modeling approach targeting the investigation of fracture at the microscale of aluminum alloys. In addition, the resulting wave propagation occurring because of the acoustic emission following the fracture events at that scale, is explicitly modeled using the finite element method. Specifically, a crystal plasticity model is employed to model strain localizations near particles in the aluminum matrix. Then a numerical approach is developed to transfer the crystal plasticity results to an enriched continuum domain. Finally, the resulting wave propagation is investigated by linking implicit and explicit analysis. The results from this investigation confirmed the effect of the fracture initiation sites on the resulting wave characteristics while they also provide theoretical validation on the related experimental investigations of recording acoustic emission at the microscale.
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Details
- Title
- Computational modeling of fracture and associated wave propagation in precipitate-hardened aluminum alloys
- Creators
- Vignesh Inbashekhar Perumal - DU
- Contributors
- Antonios Kontsos (Advisor) - Drexel University (1970-)
- Awarding Institution
- Drexel University
- Degree Awarded
- Master of Science (M.S.)
- Publisher
- Drexel University; Philadelphia, Pennsylvania
- Number of pages
- xii, 87 pages
- Resource Type
- Thesis
- Language
- English
- Academic Unit
- College of Engineering (1970-2026); Mechanical Engineering (and Mechanics) (1970-2026); Drexel University
- Other Identifier
- 8307; 991014632245404721