三维编织复合材料孔边特性的工程计算及分析

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

三维编织复合材料的研究中,实际工程常用的带孔结构缺乏理论分析方法。在分析三种不同制孔工艺的基础上,研究了三维编织复合材料的孔边特性,提出了一种工程计算方法。先根据孔边纱线几何构型分析计算出制孔影响范围,再进行孔边单元体物理性能计算,然后用有限元方法对孔边区域进行建模计算。用此种方法对典型件进行分析计算,并做试验验证,试验结果与理论分析的规律性一致。在此研究基础上,提出了一些设计、制造三维编织带孔件的工程建议。

The physical performances of the three-dimensionally braided composite structure around a hole were discussed. Three types of holes were analyzed including braided hole, compressed hole and drilled hole. The geometrical model and physical model used in the analysis are based on the braided unit-cell. Firstly, according to the making procedure of the three kinds of holes, the calculation of the unit-cell＇s geometrical parameters was performed. Then, the unit-cell＇s physical parameters could be obtained by using the inclined-plate model and classic laminate theory. After gaining physical parameters of each unit-cell around holes, the finite-element method was used to analyze the properties around this area. Some typical 3-D braided composite plates with a hole were analyzed using the method produced above. The experiment on a typical structure was performed, and the results agreed well with the theoretical calculation. Some rules were concluded from the analysis result, which can guide the design and manufacture of 3-D braided composite structures with holes.