Smart structures, structural health monitoring and crack detection

Smart materials, or active materials, offer a host of new solutions to engineering problems in control and identification. In addition they offer new modeling and analysis challenges. Here we examine the use of smart materials in structural applications, called smart structures, focusing on their use in damage detection and structural health monitoring. Identification and parameter estimation are at the root of the structural health monitoring problem. Both identification and monitoring are generally improved with increased numbers of sensors and actuators. Hence smart materials, which allow almost distributed arrays of sensing and actuation form a natural tool for structural health monitoring. A summary of the issues and problems of structural health monitoring using smart materials is presented. The chapter concludes with some thoughts on open problems in smart structures and structural health monitoring.