Active vibration control of a three-dimensional embedded piezoelectric braided composite structure

In this paper, a 3-D embedded braided piezoelectric composite structure (3-D EBPCS) is designed by embedding piezoelectric patches inside the beam of three-dimensional (3-D) braided composite material (BCM). Compared with the pasted piezoelectric composite structure, the 3-D EBPCS has the advantage of power-off self-locking, and can provide protection for the piezoelectric patches to prolong service life of the 3-D BCM in harsh environments. The representative volume element (RVE) based on hybrid mesh partitioning strategy is studied, and the mechanical parameters of the 3-D BCM are determined. The piezoelectric sensor and actuator based on the 3-D EBPCS are theoretically analyzed, and the kinematic equation and state-space model are established. The modal of the 3-D EBPCS and the effect of changes in material parameters on the natural frequency are evaluated. The proportional-integral-derivative (PID) control is applied as a piezoelectric active vibration control (AVC) method to investigate the vibration effect of the 3-D EBPCS. Finally, the effect of different embedded depth, braided angle, and piezoelectric patch position on vibration control performance is investigated. The results show that the vibration amplitude of the 3-D EBPCS effectively is greatly reduced when the proportional gain is 25, the integral gain is 1, and the differential gain is 0.1. Compared with the piezoelectric actuator in the farthest position from the fixed end, the control time is shortened by 1.82 s and the peak voltage is reduced by about 16.5% when the piezoelectric actuator is arranged in the nearest position from the fixed end. When the braided angle is increased from 20° to 40°, the vibration control time is reduced by about 11% and the peak voltage is reduced by about 2.5%. The optimal embedded depth of piezoelectric patches is 3.5 mm, with the control time of 0.71 s and the peak voltage of 145.50 V.