| Summary: | 碩士 === 國立臺灣科技大學 === 工程技術研究所 === 78 ===
Traditional two-dimensional (2-D) laminate composites offer the highest properties in the plane of reinforcement, so get poor through-the-thickness strength. In order to raise the interlaminar shear strength and impact strength of convensional 2-D composites, the structural variety of text-lie was applied, to provide the reinforcement of through-the-thickness. An unique characteristic of three-dimensional fabric composites is the through-the-thickness reinforcement which is responsible for reducing interlaminar failure, often occuring in laminar composites. In this study, the BMI resin is reinforced by three-dimensional fabrics. The purpose of this pater is to investigate the effects of various structures on physical properties, such as the measurement of tensile strength , short beam shear strength, flexural strength, impact strength, and the obserbation of SEM were discussed. Experimental results show that the tensile strength and flexural strength of three-dimensional fabric composites increase with the increasing of the spacing between two Z-directional yarn bundle, and the strength of 3D structures are greater than those of 5D structures. Since the Z-directional fibers have the resistant effect of crack propagation, the short beam shear strength of three-dimensional composites is more greater than two-dimensional composites. The impact properties of three-dimensional composites are better than two-dimensional composites. The failure mode changes from the predominant delamination type in the 2-D laminates to other modes such as interfacial debonding, fiber buckling, and shear kink failure in the three-dimensional composites.
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