Vibration isolation of a self-powered piezoelectric pipe conveying fluid composed of laminated fiber-reinforced composites

Based upon the wave manipulating characteristics of phononic crystals (PCs), this paper aims to isolate flexural vibration of laminated composite pipes conveying fluid by introducing a self-powered periodic piezoelectric design. The pipe is composed of three layers of fiber-reinforced composites along the thickness, and is periodically attached with a number of shunted piezoelectric sensor/actuator pairs along the axis. A negative proportional feedback strategy is adopted to amplify the sensing voltage to the actuators, which can generate periodic active stiffness to the pipe and thus enable tunable wave propagation and frequency band gap (BG). The dynamical equation of motion for a single piezoelectric laminated pipe conveying fluid is deduced from classical laminated beam theory as well as one-dimensional piezoelectric constitution. The BG distribution and amplitude transmission of topological structure are obtained by the spectral element method (SEM). Numerical results demonstrate that the present self-powered piezoelectric PC design can achieve excellent vibration isolation effect for the laminated composite pipe conveying fluid. Major parameter regulations including cross-ply angle, lamina sequence, feedback control gain, geometry of piezoelectric layers and fluid effect are examined. Free vibration and stability of the system are also discussed to perfect the vibration isolation design.