ABSTRACT In this paper, a combined experimental-numerical method was proposed to study the effect of adhesive thickness on mode I fracture energy of the adhesive layer, using Double Cantilever Beam (DCB) testing and Cohesive Zone Modelling (CZM). A Trapezoidal Cohesive Zone Model (TCZM) was introduced in tabular form into commercial Finite Element (FE) package to simulate the crack propagation behaviour in the adhesive layer and include the ductile characteristics of the selected adhesive. In order to overcome the difficulty in the accurate monitoring and measurement of crack length during loading, the Compliance-Based Beam Method (CBBM) was adopted to deduce the mode I strain energy release rate data. The load–displacement curve, Resistance curve (R curve), and mode I fracture energy data obtained from both experiment and simulation were analysed to validate the established FE model. It was observed that adhesive thickness has a significant influence on the ductile fracture behaviour of adhesive under mode I loading. The mode I fracture energy increases initially, and then decreases with the increase of adhesive layer thickness in the selected thickness range, while obvious transition was also observed in the perspective of micro-scale failure mechanism of the fracture surface through Scanning Electron Microscopy (SEM).

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关于粘合剂厚度对 I 型断裂能的影响 - 使用梯形内聚区模型的实验和建模研究

摘要 在本文中，使用双悬臂梁 (DCB) 测试和内聚区建模 (CZM)，提出了一种结合实验-数值方法来研究粘合剂厚度对粘合剂层 I 型断裂能的影响。梯形内聚区模型 (TCZM) 以表格形式引入商业有限元 (FE) 包中，以模拟粘合剂层中的裂纹扩展行为并包括所选粘合剂的延展特性。为了克服加载过程中裂纹长度精确监测和测量的困难，采用基于柔量的梁法（CBBM）推导出I型应变能释放率数据。载荷-位移曲线，阻力曲线（R曲线），分析了从实验和模拟中获得的 I 型断裂能量数据，以验证所建立的有限元模型。观察到胶粘剂厚度对胶粘剂在模式 I 加载下的韧性断裂行为有显着影响。I型断裂能在选定的厚度范围内随着胶层厚度的增加先增大后减小，同时通过扫描电子显微镜（SEM）观察断裂面微观破坏机理也观察到明显的转变。 ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? .