Finite element dynamic modeling and vibration reduction analysis of the double-lap bolted thin plate with partially attached constrained layer damping

The double-lap bolted thin plate is widely used, but it is easy to produce vibration. In this paper, the method of attaching H-shaped constrained layer damping (CLD) is adopted to reduce vibration, and the finite element dynamic model of the double-lap bolted thin plate with H-shaped CLD is investigated. The innovations of the modeling method are described as follows. A composite element with four nodes and 28 degrees of freedom (DOFs) is produced by taking into account the interlaminar shear deformation of the CLD structure and employing complex modulus to quantify the damping characteristics of the viscoelastic layer. A series of transition elements are constructed to conduct the assembly of elements with inconsistent dimensions. Complex stiffness spring components and mass elements are presented to simulate the stiffness, damping, and mass characteristics of the double-lap bolt joint based on the crock-shaped stress distribution in the double-lap bolt joint and taking the bolt effect region into account. Finally, a case study is carried out, and the rationality of the finite element model of the bolted structure in solving the natural characteristics and vibration response parameters is verified by the established experimental tests. At the same time, the test and modeling results show that the H-shaped CLD reduces vibration on the double-lap bolted thin plate. Furthermore, based on the established finite element model, the influence of the attaching position of the H-shaped CLD, thicknesses of the viscoelastic layer, and the constraining layer on the vibration characteristics of the bolted structure are analyzed.