L形碳纤维增强复合材料/铝合金胶接复合构件剥离应力建模与分析

针对承受剥离载荷的L形碳纤维增强复合材料(Carbon fiber reinforced plastic/polymer,CFRP)/铝合金胶接复合构件,以微元受力平衡方程为基础,建立胶层平均剥离应力的二维分布方程。在方程中引入基材的弯曲刚度系数,描述背材与基材均为刚性材料的情况下胶层剥离应力的分布规律。其应力分布曲线为拉压应力交替作用的阻尼调和函数,周期与峰值由胶接件构型尺寸与材料性能参数决定。通过CFRP/铝合金剥离试验及三维有限元模拟对理论模型进行对比验证,结果的总体趋势与数值吻合程度较好,并分析不同方法获得的剥离应力分布状态之间的差异及其产生的原因。基于胶接复合构件的理论模型与三维有限元模型,研究基材厚度改变对剥离应力分布的影响,发现伴随着CFRP板厚度的增加,剥离应力的峰值明显下降,在剥离前沿的应力集中现象得到改善。

Peeling Stress Model and Analysis of Single-L Carbon Fiber Reinforced Plastic/Polymer/Al Composite Component

A two-dimensional equation of peeling stress distribution for the single-L peel adhesive joints is established,which consists of carbon fiber reinforced plastic/polymer(CFRP) and Aluminum alloy(Al),under tension,according to balance equations.The substrate bending stiffness coefficient is regarded as an important parameter in this equation to describe the peeling stress distribution,when backing and substrate both are rigid material.The curve is a damping harmonic function,whose period and peak values are decided by the nature of the adhesive,the mechanical properties and geometries of the single-L peel adhesive joint.The correctness of the equation is verified by the peel test and finite element analysis,and analyzing the discrepancy among them.Numerically,the influence of peeling stress distribution by altering the substrate thickness is investigated,and compared to the finite element analysis.It is found that along with the thickness of CFRP increasing,the peak value of peeling stress has decreased.