Finite Element Method for Active Vibration Suppression of Smart Composite Structures using Piezoelectric Materials

摘要

Adaptive or intelligent structures which have the capability for sensing and responding to their environment promise a novel approach to satisfy the stringent performance requirements of future space missions.Analytical,numerical,and experimental results are employed to verify the performance of piezoelectric stacks and patches as well as to determine the natural frequencies of typical strut and panel structures.A strut model with a piezoelectric stack actuator for axial vibration suppression and a composite beam with surface-mounted piezoelectric patch actuator for lateral vibration suppression are considered to model an active composite strut (ACS)and an active composite panel (ACP),respectively.These ACS and ACP are employed to develop an actuator optimum voltage (OV)for active vibration suppression using modal,harmonic,and transient finite element analyses for a range of frequency encompassing a natural frequency.The ACP model demonstrates that the actuator vibration suppression capability depends on the modal shape and location of the actuator.The OV,in this work,is determined by increasing the level of actuator voltage gradually and generating a vibration with same frequencies as the external vibration but 180 deg out-of-phase,and observing the increasing level of active vibration suppression until an optimum/threshold actuator voltage is reached.Beyond the optimum voltage level,the actuator increased the level of vibration 180 deg out-of-phase.Modal,harmonic,and transient finite element analyses are performed to verify the results.Selected axial and lateral vibration suppression experiments are also performed to verify the numerical results.The analytical,numerical,and experimental results obtained in this work are in excellent agreements.This work also presents a systematic guideline for the use of piezoelectric stack and monolithic patch smart materials in intelligent structures using the finite element method.