2.5维C/SiC复合材料单胞模型及刚度预测  

Unit cell of 2.5 dimension C/SiC and its stiffness prediction

作　　者：孔春元[1] 孙志刚[1] 高希光[1] 宋迎东[1] 

机构地区：[1]南京航空航天大学能源与动力学院,南京210016

出　　处：《航空动力学报》2011年第11期2459-2467,共9页Journal of Aerospace Power

基　　金：国家自然科学基金(51075204);航空科学基金(2009ZB52028);南京航空航天大学基本科研业务费专项科研项目

摘　　要：通过提取2.5维C/SiC复合材料经纱边界曲线,采用鲁棒最小二乘拟合得到了经纱轴向函数表达式,对拟合后的曲线进行合理简化,建立了参数化的2.5维C/SiC复合材料的有限元模型.采用双尺度模型对2.5维C/SiC复合材料进行刚度预测,分别为考虑纤维/基体/孔隙的微观尺度和考虑经纱/纬纱/孔隙的单胞尺度模型,刚度预测的方法采用刚度平均法和能量法.最后讨论了微观尺度的孔隙率对2.5维C/SiC复合材料弹性模量的影响.结果表明,刚度平均法和能量法的计算结果差异较小,考虑微观孔隙率后,计算结果与试验结果吻合得更好.A kind of unit cell for 2.5 dimension C/SiC composites was established by extracting the boundary of warp, fitting the curve using robust least square and simplifying the fitted curve. The elastic properties of 2.5 dimension C/SiC composites were predicted using dual-scale model; the dual-scale model was micro-scale which considered the scale of matrix/ fiber/pore, and also meso-scale which considered the scale of warp/weft/cavity. The method for predicting the elastic properties of 2.5 dimension C/SiC composites was stiffness average method and energy method; finally the relationship between the porosity in the microscale and the elastic properties of 2.5 dimension C/SiC composites was discussed. Numerical results show that the theoretical results using energy method and stiffness average method have little difference; when considering the micro-scale porosity, the theoretical results can fit the experimental results better.

关 键 词：2.5维C/SiC复合材料 鲁棒最小二乘 双尺度模型 刚度平均法 孔隙率 

分 类 号：V258[一般工业技术—材料科学与工程] TB33[航空宇航科学与技术—航空宇航制造工程]