中文摘要：

首先利用均匀化理论并结合有限元法研究了三维编织复合材料的粘弹性效应,根据松弛模量的计算结果研究了材料热膨胀系数随时间的变化关系,在此基础上,给出了编织结构和工艺参数（编织角、纤维体积比）对材料初始热膨胀系数的影响规律,计算结果与实验值吻合较好.论文工作为深入研究三维编织复合材料的热粘弹性能提供了基础.

英文摘要：

The viscoelastic properties of 3D braided composites were obtained using the homogenization method with combination FEM,and then the variation of thermal expansion coefficients with time was studied based on the numerical results of relaxation moduli of materials.The influence of braided structures and processing parameters including braided angles、fiber volume fractions on initial thermal expansion coefficients was presented,and the numerical results agreed well with the experimental data.The research work in the paper furnishes the basis for further investigating the thermo-viscoelastic properties of 3D braided composites.