螺栓结合部接触区域非线性动态特征的凝聚建模方法

Condensation Modeling of Nonlinear Dynamics in Contact Region of Bolted Joint

为研究非线性接触力的影响,提出一种新型螺栓结合部接触区域动态特征的建模方法。基于混合坐标模态缩减技术,将螺栓联接模型中线性自由度的特征模态进行截断,仅保留接触区域的非线性动态特征模态。通过引入可等效表征非线性特征的接触耦合凝聚点,利用坐标变换将接触区域耦合面的非线性接触力凝聚到该作用点上,使得对螺栓结合部的非线性界面接触力转化为凝聚作用点的非线性刚度,从而在保证计算精度的前提下有效降低非线性耦合结合部求解的自由度数,节约计算资源。通过理论计算与试验对比,验证结合部耦合凝聚建模方法的有效性与可行性,这将为精准、高效地预测结构联接体的动态特征与性能评价奠定基础。

In order to study the influence of nonlinear contact force, a new method for modeling the dynamic characteristics of the contact region of bolted joint is proposed. Based on hybrid coordinate modal reduction technique, the characteristic modes of the linear degree of freedom in the bolt connection model are truncated, and only the nonlinear dynamic characteristics of the contact region are retained. After introducing the contact coupling condensation point which can equivalently take the place of nonlinear characteristic, the nonlinear contact force of the contact area can be condensed to the point by using the coordinate transformation. The nonlinear force of the bolt contact area will be transformed into the nonlinear stiffness of the condensation point. Therefore, it can effectively reduce the number of degrees of the nonlinear coupling and the computing resources. Through theoretical calculation and experimental comparison, the effectiveness and feasibility of the proposed method is verified. This will lay the foundation for the accurate and efficient prediction of dynamic characteristics and performance evaluation of structural joints.