Engineering calculation and analysis for properties near the hole edge of 3D braided composites

The physical performances of the three-dimensionally braided composite st ructure around a hole werediscussed. Three types of holes were analyzed including braided hole , compressed hole and drilled hole. The geomet rical model and physical model used in the analysis are based on the braided unit-cell. Firstly , according to themaking procedure of the three kinds of holes , the calculation of the unit-cellps geomet rical parameters was performed. Then , the unit-cellps physical parameters could be obtained by using the inclined-plate model and classiclaminate theory. Af ter gaining physical parameters of each unit-cell around holes , the finite-element method wasused to analyze the properties around this area. Some typical 3-D braided composite plates with a hole were analyzedusing the method produced above. The experiment on a typical st ructure was performed , and the result s agreed wellwith the theoretical calculation. Some rules were concluded f rom the analysis result , which can guide the design andmanufacture of 3-D braided composite st ructures with holes.