一种复合材料螺栓连接结构非线性刚度模型及应用
A Composite Bolted Joints Non-Linear Stiffness Model and its Application

针对复合材料螺栓连接结构挤压破坏及钉载分配规律，提出一种非线性刚度模型。基于单钉连接结构试验获得的应力-应变曲线，将连接结构挤压破坏过程分为：线性无损伤阶段、非线性损伤扩展阶段和线性退化阶段，并将连接结构等效为弹簧系统模型。模型在线性阶段考虑了层合板间摩擦力的影响；在非线性阶段考虑了层合板面内剪切非线性并定义了非线性损伤函数；在线性退化阶段基于能量吸收原理，对结构失效后力学行为进行了表征。最后，将单钉弹簧模型引入多钉连接结构进行分析，通过多钉连接结构试验验证表明，模型计算结果与试验曲线吻合良好，钉载分配计算误差小，符合工程要求。
The paper presents a nonlinear stiffness model on the bearing damage and bolt-load distribution rule of composite bolted joints. Based on the experimental stress-strain curves of composite single-bolted joints, the bearing damage process of structures can be divided into:linear non-damage stage; nonlinear damage propagation stage and linear degeneration stage. In this paper, the composite bolted joints are represented by a system of springs in which the static friction effects between laminates are considered in the linear stage, the non-linear interlaminate shear behavior and the nonlinear damage function for composite are defined and failure behavior based on the energy abortion principle is simulated in the linear degeneration stage. At last, the multi-fasters spring model is analyzed by importing the single-faster spring model.Comparing with the experimental data of multi-fasters shows the numerical result is in good agreement with experimental curves and has little error on the bolt-load distribution, which satisfies to the requirements in the engineering