Pin-loaded Strength and Stress Distribution of Orthogonal 3-D Composite Materials

• Main Authors: Chen, Jieng Chiang, 陳錦江
• Other Authors: Lin, Chung Hua
• Format: Others
• Language: zh-TW
• Published: 1993
• Online Access: http://ndltd.ncl.edu.tw/handle/75664890246032331364

博士 === 逢甲大學 === 紡織工程研究所 === 81 === The purpose of this dissertation is to study the pin-loaded characteristics of orthogonal three-dimensional composite materials. Firstly, an anisotropic plate theory has been used to analyze the stress concentration and stress distribution of conventional laminated plates (0■-UD, 90■-UD, cross-ply and plain fabric composites) and orthogonal 3-D composite materials. The reflective photoelastic method has been used to obtain isochromatic fringe patterns for each specimen. Tests were also conducted measuring the notched strengths of each plate. Secondly, the photoelastic technique and shear difference methods have been used to analyze the pin-loaded stresses on the the bearing plane, across the net-tension plane, along the shear-out plane for plain fabric, 0■-UD, 90■-UD, cross -ply laminated composite plates and orthogonal 3-D composite plates. Also, typical isochromatic fringe patterns are presented. The influence on the pin-loaded stress distribution of several important parameters such as weave parameters (the amount of carbon filaments in the in-plane directions and in the through-the- thickness direction and yarn spacing) and geometric parameters (hole diameter, ratio of width to hole diameter and ratio of edge distance to hole diameter) are discussed. Finally, tests were also conducted measuring the ultimate pin-loaded strengths and failure modes for each specimen. The effects of weave parameters and geometric parameters on pin-- loaded strength and failure mode in orthogonal 3-D composites have also been discussed. Based on the analytical results and experimental observations, some guidlines are given to choose the optimum weave structures and geometric parameters for the structural application of orthogonal 3-D composite materials.