Using Novel Printed Piezoelectric Sensors for Monitoring the Health of a Composite Foreign Object Damage Panel

Abstract

This research focuses on the structural health monitoring (SHM) of a foreign object damage (FOD) composite panel substructure of an aircraft engine fan blade equipped with an architecture array of novel screen printed piezoelectric sensors and is being carried out within the purview of the MORPHO – H2020 project. The state of the art printing technology ensures that architecture network of printed sensor is not only non-intrusive and lightweight but can also be printed during the manufacturing process before the structure goes into service. The FOD panel in this work is made of 3D woven composite, measuring approximately 800 mm x 350 mm, with a stainless-steel leading edge bonded to one of the longer edges and hosts a network of 5 arrays of 5 printed sensors each. The printed sensors can potentially be used in multiple ways to analyse the health of the host structure. Since the fabrication process of the sensors is an on-going research, first the electromechanical behaviour of the sensors is analysed with the help of impedance measurements. It is observed that the printing process ensures repeatability. Secondly, the performance of the printed sensors in case of impact loading is discussed here, as bird impact is one of the leading causes of engine fan blade failure. The impact response measured by the printed sensors is studied to detect the impact location on the FOD panel. Next, the ability of the printed sensors to sense ultrasonic guided wave responses generated by standard ceramic piezoelectric disc actuators is demonstrated. Finally, the health of these printed sensors upon undergoing multi-load multi-cycle bending tests is also discussed here. The ultimate goal of this project is to create diverse diagnostic and prognostic techniques for estimating the remaining lifespan and Structural Health Monitoring (SHM) of the FOD panel based on the range of measurements gathered using the printed sensors.