内聚力模型参数对不同应力状态下粘接接头失效的影响

Effects of cohesion model parameters on failure of bonded joints under different stress states

内聚力模型参数是影响粘接接头失效仿真分析的主要因素。本文基于内聚力单元建立碳纤维增强基复合材料(CFRP)/铝合金单搭接接头和对接接头的仿真分析模型,并通过试验验证其仿真精度。选取了内聚力单元的六个参数,即杨氏/剪切模量、模式Ⅰ/Ⅱ失效强度和模式Ⅰ/Ⅱ断裂韧性,采用单因素试验方法和正交试验方法设计试验方案,研究了内聚力单元参数对应力状态和失效载荷的影响规律。研究结果表明:内聚力模型单一参数对单搭接接头和对接接头失效载荷的影响呈近似线性关系;单搭接接头的失效载荷主要受模式Ⅰ断裂韧性和模式Ⅱ失效强度影响,对接接头的失效载荷主要受模式Ⅰ失效强度和模式Ⅰ断裂韧性影响;不同内聚力模型参数组合对失效载荷的影响存在一定的耦合作用。

Cohesion model parameters are the main factors that influence the failure simulation analysis of bonded joints.In this paper,the simulation analysis models of carbon fiber reinforced polymer(CFRP)/aluminum alloy single lap joint and butt joint were established based on cohesion unit,and the simulation accuracy was verified through experiments.Six parameters of cohesion element,namely Young’s/shear modulus,modeⅠ/Ⅱfailure strength and modeⅠ/Ⅱfracture toughness were selected.The single factor test method and orthogonal test method were used to design the experiment scheme,and the effects of cohesion element parameters on stress state and failure load were studied.The research results showed that the influence of single parameter of cohesion model on failure load of single lap joint and butt joint were approximately in linear relationship.The failure load of single lap joint was mainly influenced by mode I fracture toughness and modeⅡfailure strength,and the failure load of butt joint was mainly influenced by mode I failure strength and mode I fracture toughness.The combination of different cohesion model parameters had a certain coupling effect on the failure load.