平纹编织C/SiC复合材料热残余应力的模拟和分析

通过对平纹编织C/SiC复合材料SEM照片精确测量,获取了纤维束的几何参数,并以四参数正弦函数为拟合方程,得到了RVE的建模曲线方程,并建立了RVE的三维有限元模型。采用间接耦合的降温法,模拟计算了C/SiC复合材料的轴向热残余应力,其计算结果与理论值接近;并分析了制备温度以及纤维体积含量对热残余应力的影响。

Simulation and analysis of the thermal residual stress of plain weave C/SiC composites

The geometrical parameters of fiber bundle are obtained by accurate measuring the scanning electron microscope （SEM） picture of plain weave C/SiC composites. Parametric equation of longitudinal and transverse section of fiber bundles is fitted based on sine function with four paramenters. The three-dimensional finite element model of RVE is established by using MSC.PATRAN. The axial thermal residual stress （TRS） of plain weave C/SiC composites is simulated by cooling method with indirect coupling, the results is close to the theoretical value. The influences of preparation temperature and fiber volume fraction on the TRS are also analyzed. For plain weave C/SiC composites, the TRS of SiC matrix increased with the increase of prepatation temperature and with the decrease of the fiber volume fraction. The effective thermal expansion coefficients related to the fiber volume fraction are the major factors which can detemine the changing trend of the TRS.