Active Control of Crack Propagation in Laminated Composite Plate Embedded with Piezoelectric Material

The concept of using piezoelectric materials with structural elements is to monitor the behavior of the structure when it is subjected to a load. This paper describes a kind of self repairing structures by integrating the piezoelectric patch with laminated composite plate. The coupled character of mechanical and electrical behavior of piezoelectric material will be used to sense the deformation in the material and actuate it to resist the deformation when subjected to a load. The fatigue behavior of the laminated composite plate is studied for the cyclic bending load by experiment. Mathematical simulation is carried out using finite element method. The test specimen is prepared from a glass/epoxy laminated composite plate. The laminate is constructed as cross-ply with 50:50 fiber/matrix. The alternating stresses are derived from the tensile and three point flexure tests. The fatigue behavior is studied for the constant amplitude displacement at three different stress levels. Based on the fatigue characteristics observed from the experiments, the laminate without and with piezoelectric patch are simulated using finite element method. The simulation results for laminated composite plate with piezoelectric patch has shown a considerable increase in the fatigue life cycles.