Health monitoring using distributed sensing of structural power flow

Health monitoring of defective flat plates is achieved through the use of a distributed network of sensors that can map the deflection profile of these plates. The mapped deflection profiles are then used to extract the structural power flow as an effective criterion for identifying the exact location of the defects. In this paper, emphasis is placed on developing the theoretical equations governing monitoring the deflection and localizing the defects using the theory of finite elements. The predictions of the developed theoretical models are validated experimentally using a scanning laser vibrometer as means for monitoring the structural power flow over defective plates. The accuracy and effectiveness of the power flow maps in localizing the defects are demonstrated and compared with conventional modal parameter identification methods that fail to identify small defects. The presented concepts can be easily employed in health monitoring of more complex and critical structures such as aircraft fuselages and bridges where small defects can be detrimental to their safe operation and their locations can not be easily identified by conventional modal identification methods.