Influence of Production and Environmental Parameters on the Behavior of Hybrid Piezo/Temperature Sensors for Production and Structural Health Monitoring of Composite Structures

Abstract

During the last years the authors developed a novel hybrid multi-functional piezo / temperature sensor concept for flow front, cure and structural health monitoring of composite parts thus allowing monitoring of the production and the usage with the same sensor type. The sensors and the overall monitoring concept was validated on different composite parts like flat plates, a PAX door edge-member and a helicopter component. During the production of the sensors and the validation of the different composite parts slight differences in the behavior of the different sensors was observed. Within this paper the authors present the effect of imperfections in the production of the sensors and the effect of the production and usage environment on the sensor behavior. Both FE simulation based and experimental results were used to assess the influence of a variety of parameters such as: geometric variations during sensor production, misalignment of the piezo disk, the effect of temperature dependent behavior of the electric components such as piezo disk and PT100 or the effect of temperature and pressure on the sensor characteristic and subsequent performance during production and usage monitoring.