基于接触分析的螺栓连接刚度计算及模态验证

Stiffness calculation and modal verification of bolted connectionsbased on contact analysis

在考虑螺栓预紧力和连接界面接触的情况下,将连接结构分成螺栓预紧力作用的主区域和界面因螺栓连接而发生接触效应的接触面副区域两部分,然后结合赫兹接触理论和M-B分形模型,分别建立了两部分区域螺栓连接的法向刚度和切向刚度计算模型。该刚度计算模型结合薄层单元可应用于结构的有限元建模。通过对不同螺栓连接形式的梁和板模型以及舱段圆筒模型进行有限元建模及动力学仿真,仿真模态分析结果与实测模态实验结果对比,最大误差小于6%。验证结果表明了该螺栓连接刚度计算模型的有效性。

Considering the bolt preload and the contact of the connection interface,the connection structure is divided into two parts.The main area of the bolt preload and the sub area of the contact surface with the contact effect of the interface due to the bolt connection.Then,combined with the Hertz contact theory and M-B fractal model,the calculation models of the normal stiffness and tangential stiffness of the bolt connection in the two parts are established respectively.The stiffness calculation model combined with thin-layer element can be applied to the finite element modeling of structure.Through the finite element modeling and dynamic simulation of beam and plate models and cabin cylinder models with different bolt connection forms,the maximum error between the simulation modal analysis results and the measured modal experimental results is less than 6%.The verification results show the effectiveness of the bolt connection stiffness calculation model.