中文摘要：

针对考虑细观构造特性的纳米复合陶瓷材料宏观强度预测问题，开发基于序列图像的多相材料细观构造有限元重构方法，建立可以准确反映Al2O3／（WTi）C纳米复合陶瓷材料细观构造的三维有限元模型，并且利用统一强度理论建立可考虑线性硬化的弹塑性本构模型，编写用于强度预测的有限元程序。假设各组分相均为刚塑性材料，考虑统一强度理论各种退化模型（6=0，b=0．5，b=1．0）数值预测材料宏观抗弯强度的上下限，并且发现计算模型参数b=0．5时所得结果与试验结果吻合很好。假设材料增强相具有硬化效应，研究它对材料宏观抗弯强度的影响。研究材料组分相体积分数比与A1，O，／（W，Ti）c纳米复合陶瓷材料宏观抗弯强度之间的关系，为今后材料设计、优化提供参考。

英文摘要：

To consider the influence of material＇s microstructure on macro-bending strength of A12O3/（W, Ti）C ceramic composite, a method for automatically reconstruct FE mesh models of materials is developed based on X-ray tomography image, and a calculation program considering the material＇s strain-hardening for strength prediction is complied by using unified strength theory（UST）. Then the upper and lower limit of the bending strength of AI2O3/（W, Ti）C ceramic composite is forecasted based on the rigid-plastic assumption with UST. The predicted strength is proved to be accurate compared with the experimental result when the parameter b, in UST, is chosen to be 0.5. Utilizing linear-hardening elastic-plastic constitutive model based on UST, the relationship between hardening effect of reinforcing phase and macro-bending strength of AI2O3/（W, Ti）C ceramic composite is studied. Considering different volume fraction of compositions in A12O3/（W, Ti）C, bending strength of A12O3/（W, Ti）C ceramic nano-composite is forecast, which can be used for reference of research and development ofA12O3/（W, Ti）C ceramic composite.