Transient dynamic response and failure of composite structure under cyclic loading with fluid structure interaction

• Main Author: Teo, Hui Fen
• Other Authors: Kwon, Young
• Published: Monterey, California: Naval Postgraduate School 2014
• Online Access: http://hdl.handle.net/10945/44014

Approved for public release; distribution is unlimited === With the growing interest in using composites in naval shipbuilding, it is crucial to understand the behavior of structures, especially the Fluid Structural Interaction (FSI) aspect of the composites under dynamic loading, to ensure the survivability of the platform at sea. The objective of this study is to perform displacement-controlled fatigue cyclic loading on quasi-isotropic E-glass laminate, which is commonly used in the shipbuilding industry. The fatigue cyclic loading is performed in both air and water environments with varied frequencies to analyze the structural behavior and failure pattern of composites under FSI. The results of the experiment show significant FSI effects on the fatigue failure life cycle of the composite under high frequency loading of 2 Hz, 5 Hz and 10 Hz. The degree of FSI effect of the 5 Hz and 10 Hz cyclic loading is significantly higher than 2 Hz cyclic loading and the FSI effect varies for 5 Hz and 10 Hz, with 5 Hz loading exhibiting a higher impact on the composite. The knowledge gained from the investigation will benefit ongoing research into understanding the dynamic response and failure mechanism of the composite structures under FSI. The insights and suggestions for follow-on studies will contribute to the development of future life prediction modeling or tools that will help to prevent premature failures in the design of composite vessel—particularly a naval ship—where survivability is vital.