Free vibration of co‐curing damping sandwich composites with different lay‐up angles

Abstract

In this article, the dynamic characteristics of Co‐curing Damping Sandwich Composites with Different Lay‐up Angles (CDSCDLA) are studied by means of modal analysis and numerical simulation to optimize the structure of co‐curing composites. The vibration equilibrium equation of CDSCDLA is derived according to first order shear deformation theory and Hamilton equation. The dynamic model of the structure is established by finite element simulation to verify the accuracy of the theoretical calculation. The influence of different lay‐up angle and the damping film thickness on the free vibration of CDSCDLA is explored under the condition of constant skin thickness. The theoretical derivation and finite element simulation results reveals that the overall dynamic characteristic of damping sandwich composite with a lay‐up angle of 45° is optimal when the damping film thickness is constant. In particular, when the thickness of the damping film is 0.1 mm, the first‐order mode damping and mode frequency of composite plate with a lay‐up angle of 45° reach the maximum value of 0.1495 and 747.9 Hz, respectively. The first order damping loss factor of the CDSCDLA with different layup angles is maximum when the damping film thickness is 0.3 mm. However, blindly increasing the damping layer thickness can not always improve the damping performance of the composite structure, but will greatly reduce the stiffness of the composite. The work provides a reference for dynamic performance optimization and structural design of sandwich plate with high strength and large damping loss factor.Highlights Free vibration of sandwich composites with lay‐up angles is investigated. The dynamic analytical model of the structure is established. The validity of the derived theory is verified by numerical simulation.