Paper number 799

COMPOSITE STRUCTURES WITH BUILT-IN DIAGNOSTICS

Fu-Kuo Chang

Dept. of Aeronautics and Astronautics
Stanford University
Stanford, CA 94305

Summary

A built-in diagnostic technique based on a distributed sensor network is presented for composite structures. The technique uses the built-in sensors to measure the response of the structures and process the measured signals to interpret the changes of signals at two different times in terms of physical change of the structures. The development of the technique includes three major items: sensor selection, sensor/structure integration, and signal processing and interpretation. Piezoelectric materials were selected for the technique as sensors for receiving information as well as actuators for generating diagnostic signals. A SMART (Stanford Multi-Actuator Receiver Transduction) Layer Technology has been developed for fabricating a network of distributed piezoelectric elements for both embedding in and surface-mounting on composite structures. Application software has also been developed for the SMART layer to identify impact load in real time and to detect impact damage automatically in composite panels. A prototype of the proposed technique has been developed and successfully applied to composite plates and stiffened panels.

Keywords

smart materials, sensors, signal processing, structural health monitoring.