Title: AN ULTRASONIC GUIDED WAVE BASED IMPACT AND BOND LINE SHM OF STIFFENED COMPOSITE STRUCTURES
Abstract: In the recent years the use of advance composite has increased significantly in state-of-the-art aircraft and aerospace structures. In spite of their many advantages composite structures are highly susceptible to hidden defects and if remain undetected may cause sudden and catastrophic failure of the entire structure. In this paper two key components of the defects are being studied namely damage due to impact and weak bond-line between the skin and the stiffener. An ultrasonic based real-time real time health monitoring of composite stiffened panel is proposed. The waves are launched into the specimen using a PZT patches and are detected by a distributed array of identical sensors located on the surface of the specimen. The guided wave components of the ultrasonic waves are shown to be strongly influenced by the presence of a defect in the composite structure. The experimentally observed results are used to develop an autonomous scheme to locate the defects due to impact and weak bond-line. The damage foot print predicted from guided wave based approach showed good comparison with commercially used C-Scan techniques. The results should be very useful in model-based understanding of ultrasonic data collected during nondestructive inspection and evaluation (NDI/NDE) of advanced aircraft and aerospace structure and in the development of reliable health monitoring systems in the structures.
Authors: Harsh Baid, Daniel Sutton, and Frank Abdi
Conference: CAMX 2017 –Orlando