Shape and vibration control of a smart composite plate with matrix cracks

This paper addresses the interaction between the health monitoring and control functions of a smart structure. A finite element model is developed for a composite plate with surface mounted piezoceramic actuators and matrix cracks by integrating a classical laminate plate theory approach with a matrix crack model. The effect of matrix cracks in a cantilevered smart composite plate with different electrical and mechanical loadings is studied for several different laminate types and ply angles. It is observed that matrix crack saturation depends on the loading conditions, applied voltage, laminate type, and ply angles. It is found that the static and dynamic behavior of the plate changes significantly due to matrix cracking. Changes in deflection caused by loss of stiffness due to matrix cracks can be compensated by applied voltage. A negative velocity feedback control algorithm is used for active control of damping, and it is found that there is a change in the decay rate of the response due to matrix cracks and that this change can be compensated by increasing the control gain of the active damping algorithm. Different applied voltages and control gains can be used to interrogate the structure at varying loading conditions, which creates more data for structural damage detection. The model developed in this work is useful for structural health monitoring applications.