考虑界面阻尼和刚度等效的螺栓连接结构有限元敏捷建模方法

To balance accuracy and efficiency in the dynamic modeling of bolted joint structures, this paper proposes an equivalent modeling method based on a variable spring stiffness-damping surface model. The method accounts for the stiffness characteristics of the joint interface and, more importantly, incorporates an equivalent representation of interface damping. A quantitative relationship was established among the contact pressure distribution governed by bolt preload, the frictional energy dissipation mechanism, and the evolution of interface stiffness and damping. Accordingly, a set of equivalent interface stiffness-damping parameter identification procedures suitable for finite element modeling was developed. To improve modeling efficiency, an automated finite element modeling plugin based on the Python scripting interface of Abaqus had been developed, enabling agile model construction and parametric adjustments for complex bolted joint structures. Using a standardized bolted beam structure (Brake-ReuB model) and a multi-bolt lap-joint plate structure as case studies, modal tests were conducted and compared with traditional modeling approaches. The results show that the proposed method predicts the modal frequencies of the Brake-ReuB model with errors below 3.00%, and the MAC values exceed 0. 94. Compared with conventional modeling approaches—such as full tie constraints (errors up to 11. 24%) and partial tie constraints (errors up to 6.77%)—the proposed method significantly improves prediction accuracy and effectively captures the stiffness and damping variations under different preload levels. Additionally, the method achieves modal frequency prediction errors below 4. 00% for the multi-bolt lap-joint structure. Overall, the proposed method enables efficient and accurate finite element modeling of bolted joints while maintaining high fidelity, offering a feasible and broadly applicable solution for the dynamic analysis of complex engineering structures.