Wireless Sensor Network for Structural Health Monitoring by Means of Lamb-Waves

摘要

A wireless measurement system for structural health monitoring of Fiber-Reinforced-Polymers (FRP) using Piezo-Wafer-Active-Sensors (PWAS) combined with inductive Wireless Power Transfer (WPT) is reported. This system allows a reduction of total system weight as well as a better integration to the structure compared to traditional Lamb-wave based systems. Wireless Power Transmission is achieved by means of inductive coils at low frequencies (LF), while data transfer is done using high frequency (HF). Aquasi-isotropicCarbon-Fiber-Reinforced-Polymer (CFRP) plate with sensor and actuator nodes was made to measure the quality of transmission and the necessary energy to stimulate the actuator-sensor system. In order to produce baselines, measurements were prepared from a heathy plate under specific temperature and humidity specifications. The signals were evaluated to verify the functionality in presence of defects in the CFRP. For instance progress has been achieved detecting the presence of failure in the form of drill holes introduced to the structure. This work shows a complete set of experimental results of different sensor/-actuatornodes.