An experimental evaluation of the structural health monitoring capability of piezoelectric wafer active sensors on composite structures at cryogenic temperatures is presented. The piezoelectric wafer active sensor–based electromechanical impedance and the pitch–catch methods were first qualified for cryogenic temperatures using piezoelectric wafer active sensor–instrumented composite specimens ...

This paper addresses the problem of repairing multiple cracked beams subjected to static load using piezoelectric patches. First, is formulated and solved analytically for case two cracks that results in ratio restoring moments produced by employed Since dependent only on crack positions but not their depth, result obtained has been extended cracks. proposition then validated finite element sim...

This paper presents a new approach to vibration reduction of flexible spacecraft during attitude control by using Pulse Width Pulse Frequency (PWPF) Modulator for thruster firing and smart materials for active vibration suppression. The experiment was conducted on the Naval Postgraduate School (NPS) 's Flexible Spacecraft Simulator (FSS) , which consists of a central rigid body and an L-shape f...

In this study, a PID controller was designed for the active vibration suppression of a smart beam equipped with PZT (Lead-Zirconate-Titanate) patches. The smart beam is a cantilever aluminium beam having eight symmetrically located surface-bonded piezoelectric patches. In this particular application, a group of PZT patches closed to the root of the beam was used as actuators and from the remain...

1. Abstract This paper addresses the problem of elastic and piezoelectric parameter estimation in active laminated structures with surface bonded sensors and actuators. The proposed technique is non destructive as the only experimental data it uses are natural frequencies of free vibration of the structure. Emphasis is placed on the influence on the estimated parameters of the adhesive material...