界面应力传递重新分析及Cohesive模型参数的确定

在经典剪滞理论中引入双线性cohesive模型表征纤维/基体之间的非理想界面,重新分析了纤维增强复合材料中的应力传递机理,得到了考虑界面因素的应力分布。用上述结果解释了单丝段裂实验过程中的现象,讨论了界面参数和材料性能对应力分布的影响。基于上述理论,建立了用cohesive单元表征界面的模拟单丝段裂实验的三维有限元模型,结合单丝段裂实验结果,提出了一种估测cohesive界面刚度参数的新方法。数值和理论分析结果与实验结果对比,吻合良好,可以为材料的界面性能分析和材料设计提供参考依据。

Re-analysis of Interface Stress Transfers and Parameter Evaluation for Cohesive Zone Model

Based on the classical shear lag model,the bilinear cohesive zone model (CZM) was introduced by taking imperfect interfacial factors into consideration to reanalyze the interface stress transfer mechanism of fiber-reinforced composite materials.New stress distribution results of the fiber reinforced composite materials are obtained.Some phenomena that occurred in single fiber fragmentation experiments can be explained by these results.Effect of different interfacial parameters and material properties on the result of stress distribution was discussed.Based on the theoretical analysis,interface of cohesive element was introduced to establish a three dimensional finite element model that simulated the single fiber fragmentation experiment.Thereafter,a new method of estimating interfacial CZM parameter was put forward combining with experimental result of single fiber fragmentation.Theoretical analysis results and the FEM results are in good agreement with the result of experiment.Some support can be provided for research of interfacial properties and design of composite by these results.