基于各向同性本构关系薄层单元的螺栓连接参数识别

摘要

针对螺栓连接建模与参数识别问题开展研究。基于各向同性本构关系薄层单元理论，提出螺栓连接结构接触面力学性能识别方法。对单个螺栓搭接及多个螺栓搭接两种结构分别进行有限元建模，忽略螺栓质量、螺孔影响，搭接界面采用各向同性本构关系的薄层单元模拟。根据试验模态参数构造优化问题，识别搭接界面薄层单元材料参数。结果表明，两种螺栓连接结构前四阶弯曲模态频率计算精度较高，薄层单元能准确反映接触界面力学性能。该方法适用于单个螺栓及螺栓较密集工况动力学精确模拟。%The finite element modeling and parameter identification of bolted joints were concerned.According to the basic theory of thin-layer element with isotropic constitutive relationship,a parameter identification method for recognizing the mechanical characteristics of contact surface in bolted structures was proposed.The finite element modeling methods for single and multiple bolted structures were investigated respectively,ignoring the hole and the mass of the bolt,and modeling the contact surface by using thin-layer elements.Experimental modal data were used for identifying the constitutive parameters of thin-layer element with an optimization procedure.Applying the identified parameters in the finite element model,the maximum error between the computational and experimental modal frequencies was reduced reasonably.It is shown that thin layer element with identified parameters can be used for accurately simulating the normal and tangential stiffness of contact surface.The proposed approach is available for precisely simulating the single and multiple bolted structures.