Mechanical property prediction methods for composites are very important as theoretical tools for engineering structural design. To more accurately capture the transverse mechanical properties of composites, a multiscale analysis method is developed in this paper. The multiscale analysis method includes three scales: (1) At the microscale, a microscopic cohesive model based on atomic potential energy is established for the interface; (2) At the mesoscale, a unit cell model is established for the fibre, matrix and interface; and (3) At the macroscale, the homogenization method, failure criteria and damage degradation models are used for predicting the transverse mechanical properties. Subsequently, the transverse mechanical properties and the damage evolution process are simulated with the multiscale analysis method. A comparison between the simulations and experiments shows that the maximum error of the predicted transverse modulus and transverse strength is −4.45 % and −12.05 %, respectively. Finally, the effects of the interfacial strength on the macroscopic transverse mechanical properties and the damage onset are analysed. The following conclusions are drawn from the simulation results: (1) The interfacial strength has a more significant effect on the transverse strength and ultimate strain than on the transverse modulus; (2) Decreasing the interfacial strength has a greater effect on the transverse modulus, strength and ultimate strain than increasing the interfacial strength; and (3) The interfacial strength can change the damage onset.

复合材料的力学性能预测方法作为工程结构设计的理论工具非常重要。为了更准确地捕获复合材料的横向力学性能，本文开发了一种多尺度分析方法。多尺度分析方法包括三个尺度：（1）在微观尺度上，建立了基于原子势能的微观内聚模型。（2）在中尺度上，建立纤维，基质和界面的晶胞模型；（3）在宏观上，采用均质化方法，破坏准则和破坏退化模型来预测横向力学性能。随后，采用多尺度分析方法模拟了横向力学性能和损伤演化过程。仿真和实验之间的比较表明，预测的横向模量和横向强度的最大误差分别为-4.45％和-12.05％。最后，分析了界面强度对宏观横向力学性能和损伤开始的影响。从仿真结果可以得出以下结论：（1）界面强度对横向强度和极限应变的影响大于对横向模量的影响。（2）降低界面强度比增加界面强度对横向模量，强度和极限应变的影响更大；（3）界面强度可以改变损伤的开始。分别为45％和-12.05％。最后，分析了界面强度对宏观横向力学性能和损伤开始的影响。从仿真结果可以得出以下结论：（1）界面强度对横向强度和极限应变的影响大于对横向模量的影响。（2）降低界面强度比增加界面强度对横向模量，强度和极限应变的影响更大；（3）界面强度可以改变损伤的开始。分别为45％和-12.05％。最后，分析了界面强度对宏观横向力学性能和损伤开始的影响。从仿真结果可以得出以下结论：（1）界面强度对横向强度和极限应变的影响大于对横向模量的影响。（2）降低界面强度比增加界面强度对横向模量，强度和极限应变的影响更大；（3）界面强度可以改变损伤的开始。（1）界面强度对横向强度和极限应变的影响比对横向模量的影响更大；（2）降低界面强度比增加界面强度对横向模量，强度和极限应变的影响更大；（3）界面强度可以改变损伤的开始。（1）界面强度对横向强度和极限应变的影响比对横向模量的影响更大；（2）降低界面强度比增加界面强度对横向模量，强度和极限应变的影响更大；（3）界面强度可以改变损伤的开始。