A micro-scale simulation scheme is developed in this study to evaluate in-situ damage and strength properties of CFRP laminates with various ply thicknesses. To capture both the initiation and propagation of transverse cracks, the microscopic random fiber configuration and the constraint effect from neighboring plies should be carefully considered. This study considers the representative volume element (RVE), consisting of the ‘inhomogeneous’ ply in which the solid elements individually modeled the fiber and matrix, and the ‘homogenized’ plies, homogeneously modeled by the shell elements. Matrix damage and debonding between fiber and matrix were modeled in the inhomogeneous ply to reproduce transverse crack propagation. Furthermore, in the RVE simulation, the key degree of freedom method was incorporated to evaluate the in-situ properties of each ply effectively. The validity of the proposed tool was examined by comparing the predicted cracking behavior with the results of unidirectional tensile tests on cross-ply laminates having different 90º ply thicknesses. The effects of ply thickness on the in-situ damage and strength properties of cross-ply laminates were numerically investigated, and the continuum damage mechanics model for thin-ply laminate was proposed based on the numerical results.

在这项研究中开发了一种微型仿真方案，以评估具有不同层厚度的CFRP层压板的原位损伤和强度特性。为了捕获横向裂纹的萌生和扩展，应仔细考虑微观随机纤维构型和相邻层的约束效应。这项研究考虑了代表性的体积元（RVE），它由“不均匀”层组成，在其中固体元素分别对纤维和基质进行建模，而“均质”层则由壳单元进行均匀建模。在不均匀的层中模拟了纤维与基质之间的基质损伤和脱粘现象，以再现横向裂纹的扩展。此外，在RVE模拟中，结合了关键的自由度方法可以有效地评估每层的原位特性。通过将预测的开裂行为与具有不同90º层厚度的交叉层层压板的单向拉伸测试结果进行比较，检验了所提出工具的有效性。数值研究了层厚度对交叉层板原位损伤和强度性能的影响，并基于数值结果提出了薄层板的连续损伤力学模型。