通过对平纹编织C/SiC复合材料经向和纬向截面的扫描电子显微镜(Scanning Electron Microscope,SEM)照片的精确测量,获取了纤维束的几何参数和波动曲线,以四参数正弦函数为拟合函数,得到了纤维束纵、横截面的参数化曲线方程。并通过建立的代表特征体元(representative volume element,RVE)得到纤维体积含量的计算值与试验测定值相比较,来检验模型的精确性。以MSC.PATRAN为平台,采用六面体单元进行分网,得到了RVE的三维有限元模型。通过在RVE模型中预制孔洞的方法,计算了平纹编织C/SiC复合材料的有效弹性模量,其中轴向拉伸模量与轴向剪切模量的计算值与试验值吻合较好,其它3个有效弹性模量还有待试验值的检验。
The geometrical parameters and wave curve of fiber bundle are obtained by measuring the warp and across direction of scanning electron microscope(SEM) pictures of plain weave C/SiC composites. Geometrical parameter and wave curve of fiber bundles are obtained. Parameter curve equation of longitudinal and transverse section of fiber bundles is fitted based on sine function with four parameters. The accuracy of the model is verified by comparing the calculated values of fiber volume fraction by the established representative volume element(RVE) with the measured values. The three dimensional finite element model of RVE is gotten by using hexahedral element to mesh on the MSC.PATRAN platform. The effective elastic modulus of plain weave C/SiC composites are calculated by the method of precasting porosity of RVE. The calculated values of axial tensile modulus and axial shear modulus are close to the test values. The other three effective elastic modulus are still to be tested.