Thesis
The influence of ply orientation on the open-hole tension strength of composite laminates
Washington State University
Master of Science (MS), Washington State University
2008
Handle:
https://hdl.handle.net/2376/102435
Abstract
Composite laminates can be tailored for a specific loading scenario by varying the ply orientation. In open-hole tension, a circular area is removed from the center of the composite specimen to simulate the stress concentration that occurs during the introduction of a bolt or rivet. This stress concentration leads to a decrease in the strength of the specimen, and is likely to be the location of crack initiation in an engineering structure. Increases in first ply failure and ultimate tensile strength have been found by tailoring the ply orientation for open-hole tension. The strain fields of the tailored laminates have been characterized using the digital image correlation method (DICM), Moiré interferometry (MI), and finite element analysis (FEA). Results indicate that DICM is a useful tool for measuring the first ply failure of the laminate. DICM accurately characterized the strain around the hole throughout damage progression, and was verified using MI and FEA. The failure criteria examined in the current study include Maximum Strain, Maximum Stress, Tsai-Wu, Tsai-Hill, Hoffman, Hashin, and Yamada-Sun. The first ply failure predictions of these criteria were compared to those experimentally measured by DICM. The Maximum Strain and Maximum Stress failure criteria most accurately predicted first ply failure. Eight non-traditional laminates were optimized to reduce the stress concentration and increase the first ply failure. The influence of the ply orientation on the open-hole tension strength of these laminates was examined. Significant increases in strength were found by varying the ply orientation of the secondary load bearing plies (±45º and 90º), with relatively small material property trade-off for some laminates. Thus, improvements in strength were found for the tailored laminates in the open-hole tension loading scenario.
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Details
- Title
- The influence of ply orientation on the open-hole tension strength of composite laminates
- Creators
- Daniel Paul Stone
- Contributors
- Lloyd V. Smith (Degree Supervisor)
- Awarding Institution
- Washington State University
- Academic Unit
- Mechanical and Materials Engineering, School of
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University; Pullman, Wash. :
- Identifiers
- 99900525018801842
- Language
- English
- Resource Type
- Thesis