Dynamic modeling and frequency-dependent parameter identification of double-lap bolted plates with constrained layer damping

The double-lap bolted thin plates are widely adopted in the aerospace field, but are prone to vibration due to low stiffness and damping. This study establishes the finite element dynamic model for such plates with constrained layer damping (CLD). The 4-node, 36-degree-of-freedom (DOF) composite element is developed for CLD structures, which simultaneously incorporates the higher-order shear deformation and frequency-dependent mechanical properties of the viscoelastic layer. The bolted joints are simulated by artificial springs. According to the experimental frequency response functions (FRFs) of the thin plate with CLD, the inverse method based on the response surface method is used to identify the frequency-dependent elastic modulus and loss factor of the viscoelastic damping. Finally, the FRFs and modal shapes obtained by the inverse iteration method and the modal test data are compared. The results verify the rationality of the finite element model and identification results.