复合材料粘聚区模型的强度参数预测

提出了一种基于周期性代表性单元（RVE）的细观模型，用于预测粘聚区模型的强度参数，以提高基于粘聚区模型的有限元法模拟复合材料分层的精度。模型从复合材料的细观结构出发，采用最大主应力准则判断粘聚层的初始裂纹的萌生，从而建立了粘聚强度与基体强度的关系；并以宏观正交各向异性为假设条件，确定了RVE的周期性位移边界条件。用该模型预测了AS4/PEEK和T700/QY8911层合板不同铺层间的粘聚强度。采用所预测的粘聚强度值对混合模式弯曲（MMB）和六点弯曲试验进行了仿真，仿真结果与实验值具有较好的一致性。

PREDICTION ON THE STRENGTH PARAMETERS OF COHESIVE ZONE MODEL FOR SIMULATION COMPOSITE DELAMINATION

A micromechanical model based on the periodic RVE technique is presented to predict the cohesive strength which is an important parameter in accurately modeling composite delamination via CZM (cohesive zone model) based FEM. By using major principal stress criterion to predict the crack initiation in cohesive layer, a relationship between cohesive and matrix strength is set up. A periodic displacement boundary condition has been presented on the assumption that the RVE is orthotropic in the sense of overall response. The cohesive strength of AS4/PEEK and T700/QY8911 laminates at various fibers cross angles are obtained by this model. The FEM simulations on mixed-mode-bending (MMB) and the six-point bending test are presented by applying CZM with the predicted cohesive strength. The numerical results are in fair agreement with experimental observation.