Experimental verification of relaxation of stress concentrations in an adaptive plate with a circular hole using piezoelectric actuators

Using piezoelectric actuators which have the capability to induce various amounts of strain upon activation, it is possible to reduce stress concentrations under varying external load conditions by distributing them in high stress regions in advance. In this paper, we verify experimentally the relaxation of stress concentrations in an adaptive plate with a circular hole using piezoelectric actuators. The adaptive plate is a simple actuator/substrate system in which the substrate is an acrylic acid resin plate with a circular hole and actuators are PZT piezoelectric ceramics bonded to the plate surfaces around the hole. The optimal voltage calculated to minimize maximum stresses in the substrate subjected to uniaxial tensile load was applied to each piezoelectric actuator. The experimental results of circumferential stress distributions on the circular hole boundary were compared with the numerical ones. Both results appeared in agreement and the relaxation of stress concentrations in the adaptive plate was verified.