三维四向碳/碳复合材料力学性能预测与试验验证

Prediction and experimental verification of mechanical properties of 3D four-directional carbon/carbon composites

针对三维四向碳/碳复合材料力学性能预测问题,基于参数传递多尺度分析方法建立微结构模型,并结合细观力学方法实现了基本力学性能的预测。首先在微观尺度采用随机扰动算法构造出纱线体积代表单元(RVE)模型,预测得到纤维束有效性能参数。同时,采用观察试验法构建三维四向碳/碳复合材料细观RVE模型。最后通过均匀化理论准确预测了复合材料弹性性能参数,并讨论了纱线填充因子对三维四向碳/碳复合材料弹性性能参数的影响,开展了相关试验。结果表明:建立的多尺度有限元模型的拉伸模拟预测结果与试验结果误差在5.5%左右;复合材料弹性性能参数对纱线填充因子的敏感度各不相同。

Aiming at the prediction of mechanical properties of 3D four-directional carbon/carbon composites,a microstructure model was established based on the multi-scale analysis method of parameter transfer,and the pre-diction of basic mechanical properties was realized by combining micromechanics.Firstly,the yarn representative volume element(RVE)model was constructed by using the random disturbance algorithm at the microscopic scale,and the effective performance parameters of the fiber bundle were predicted.At the same time,the 3D four-direc-tional carbon/carbon composite meso-RVE model was constructed by observational test method.Finally,the elastic performance parameters of composites were accurately predicted by homogenization theory,and the influence of yarn filling factor on the elastic performance parameters of 3D four-directional carbon/carbon composites was discussed.The results show that the error between the tensile simulation prediction results and the experimental results of the multi-scale finite element model established in this paper is about 5.5%;the sensitivity of elastic properties of com-posites to yarn filling factor is different.