Sensor deployment over damage-containing plates: A topology optimization approach

Health monitoring systems for composite laminates should detect in real-time if damage, typically consisting of delamination (i.e. debonding between adjacent laminae), is incepted or growing under the external actions. To avoid detrimental effects on the overall structural strength induced by embedded sensors, we recently proposed a surface-mounted monitoring scheme adopting microelectromechanical systems (MEMS) devices. We already investigated the capability of this methodology to detect the inception/growth of delamination in a standard test geometry; in this article, we instead focus on the optimization of sensor deployment over flexible plates, so as to maximize the sensitivity of the monitoring system to damage/delamination. This is achieved through a topology optimization approach. For a square thin plate, either supported or clamped along its boundary, we present optimal distributions of MEMS sensors to detect a damage of known or unknown position. We show that, no matter what the location, size, and shape of the damaged area are, a trivial solution consisting of an array of evenly spaced sensors does not represent the optimal one to monitor the structural health.