螺栓结合部静态迟滞行为分析及刚度和阻尼辨识

获得螺栓结合部的静态迟滞行为并开展刚度、阻尼辨识，对于螺栓结合部设计以及装配工艺制定十分重要.利用三维有限元模型预测螺栓结合部迟滞特性，并给出了螺栓联接接触参数的设置方法.针对获得的迟滞曲线，采用最小二乘多项式拟合推导确定了结合部刚度及阻尼参数的辨识公式.以一个简单的螺栓搭接梁为对象进行了实例研究，试验证明了该搭接梁有限元模型及获得的迟滞曲线的合理性，利用获得的迟滞曲线辨识了该螺栓结合部的时变刚度、平均刚度和损耗因子等参数.研究表明:随着预紧力的增加，螺栓结合部的刚度增加而损耗因子(阻尼参数)减小.

Static Hysteresis Behavior Analysis and Stiffness and Damping Identification of Bolted Joints

Obtaining the static hysteresis behavior of bolted joints and identifying their stiffness and damping are of great significance for the design of bolt joints and the formulation of the assembly process. A three-dimensional finite element model is used to predict the hysteresis characteristics of bolted joints， and the setting method of the bolt contact parameters is given. Finally， a simple example of the bolted lap beam is chosen to present the developed method. The rationality of the finite element model of the bolted lap beam and the obtained hysteresis loop are validated by experiments. The time-varying stiffness， mean stiffness and loss factor of the bolted joint are identified by the obtained hysteresis loop. The results show that the stiffness of the bolted joint increases and the loss factor(damping parameter)decreases with the increase of the preload force.