Thesis
Understanding the factors affecting the mechanical properties of marine composites
Washington State University
Master of Science (MS), Washington State University
2009
Handle:
https://hdl.handle.net/2376/100234
Abstract
In order to meet the American Bureau of Shipping (ABS) requirements for speed and weight in the marine vessels, advanced composite materials such as glass fiber reinforced plastics (GFRP) must be incorporated into the hull structure, which is the major component of the vessel. Composite hull design and fabrication are cost and skill intensive techniques. Quality control requires frequent hull design/manufacturing validation tests and continuous process improvement based on objective tests and analysis results. In this study, an investigation of the factors that affect the mechanical properties of marine composites is presented. In particular, the effect of composite fabrication process, material systems, and test methods on mechanical properties of GFRP composite materials was experimentally investigated. For sample fabrication, hand lay-up (HL), vacuum infusion (VI), and hybrid processes were used. For mechanical property testing, tensile, compressive, and ignition loss testing was performed. Results showed that vacuum pressure implemented during composite fabrication did have an effect on mechanical properties. As the vacuum pressure increased, more voids were extracted from the material system, leading to improved properties. Increasing layers of fiber within composite panels did not have significant effect on measured properties. Even though the panels experienced more load before failure, the area also increased giving no improvement in comparison. The panel type was influenced by fabrication method. HL, hybrid (HL+VI), and VI processes showed some increase in properties as fabrication method trended towards the VI procedure. The two standard compressive test methods, ASTM D695 and ASTM D695M, were compared. While the ASTM D 695M testing procedure gave better ultimate strengths, the ASTM D 695 testing procedure indicated better moduli. Finally, it was found that by deviating the end surface of a compressive test specimen negatively influences the outcomes in compressive properties.
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Details
- Title
- Understanding the factors affecting the mechanical properties of marine composites
- Creators
- Kevin Daniel Beavers
- Contributors
- Dave Kim (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
- 99900525182801842
- Language
- English
- Resource Type
- Thesis