Vibration characteristic analysis of opening spherical shell with local active constrained layer damping

Abstract:

To reduce the vibration of the opening spherical shell, this paper proposes a kind of spherical shell with local active constrained layer damping (ACLD). Based on the first-order shear deformation theory and the Donnell shell theory, the strain is expressed as a function of displacement. The spherical shell deformation is represented by the expansions of Jacobian polynomials in latitude direction and Fourier functions in the longitude direction. The system dynamics model is established by use of the energy method and Lagrange equation. The effects of the structure parameters of ACLD, damping layer duty ratio and excitation voltage of piezoelectric layer on modal frequency and damping ratio are studied and the frequency response of the mid-point of the spherical shell is compared under different excitation voltages. The results show that the proper viscoelastic thickness and duty ratio can dissipate the vibration energy of spherical shell effectively. The large size of the piezoelectric layer in the latitude and longitude direction can generate big damping ratio of the system but it will make the mass and modal frequency grow so fast that the performance of the spherical shell is destroyed. The application of excitation voltage can promote the dissipation of vibration energy almost without changing the modal frequency. However, a certain excitation voltage can be effectively only for reduction of the modal amplitude in a specific direction.