| Summary: | 博士 === 國防大學理工學院 === 國防科學研究所 === 103 === Over the last decade, the need for a material with more function was increasing; from a single material to composite and from composite to intelligent or functional composite. The application of new materials can improve disadvantage of the use of materials in industry.
In this paper, the design concept of advanced material structure is proposed to enhance the absorption of energy. The smart structure is made of fiber composite and shape memory alloy (SMA). The prestress on SMA will produce shape memory effect (SME), resulting in compression effect on the overall structure. This effect causes the increase of the structural strength under impact, resulting in a smaller deflection and larger energy absorption. The energy absorption of laminates embedded with SMA is investigated.
First, composite materials theory, the laminated plate theory, the first order shear strain theory, strain energy and the minimum energy method are used to analyze the absorbed energy of fiber composite laminates under impact. Second, one-dimensional constitutive equation of SMA is constructed to understand the theory and the highly nonlinear behavior of it. Prestrain, temperature, the phase change and other factors affecting prestress is under examination .
Finally, in analyzing the hybrid laminate structure, the mechanical model of the whole structure and prestress induced overall compressive strain must be derived. The energy absorption of the laminate is calculated by using the derived model and various theory mentioned above.
The results show that in terms of energy absorption, it is better to place SMA on the outer layer than on the inner of the laminate. It is also found in this study that temperature and prestrain are significant factors affecting energy absorption. Overall, the hybrid laminate can effectively reduce deflection and enhance impact resistance capability to achieve the purpose of upgrading energy absorption.
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