Assessing the effects of delamination on the damped dynamic response of composite beamswith piezoelectric actuators and sensors

Abstract

Experimental and analytical studies are presented investigating the effect of delaminationcracks on the low-frequency dynamic response of composite beam specimens with surfaceattached piezoelectric actuators and sensors. Frequency response functions of laminatedbeams with piezoceramic actuators and piezoelectric sensors having single delaminationcracks of various sizes are measured. Comparisons with mechanical actuation–accelerometersensor configurations illustrate the sufficiency and advantages of piezoelectricactuator–sensor pairs in self-monitoring the effects of delamination on the dynamicresponse. Modal frequencies and damping values of the beams are also measured and theirdependence on delamination size is studied. Comparisons with analytically predictedresults are shown. Finally, the sensitivity of damage indices based on changes in modalfrequency, modal damping, and modal peak density to the crack size is quantified.