Impact Damage Identification of Composite Structures with Built-in Piezoelectric Sensor/Actuator Networks
Abstract
An investigation was performed to develop a self-diagnostic technique using a built-in piezoelectric wafer network to detect damage and to identify the extent of the damage in fiber-reinforced composite plates resulting from foreign-object impact. The principle of the technique was to use built-in piezoelectric wafers as actuators to generate stress waves and also use the neighboring piezoelectric wafers as sensors to receive the propagating waves. The difference in sensor measurements before and after the introduction or impact damage, referred to as scatter, contains information about the location and size of site impact damage. Accordingly, the proposed technique. consists of signal generation, signal processing, and damage identification. In the first part of the study, focus was on thin to moderately thick composites where identifying damage in the thickness direction was ignored and only a single piezoelectric wafer network through the composite plates was used. Diagnostic signals were selected for built-in piezoelectric actuators to generate appropriate Lamb waves to enhance the sensitivity of the sensor measurement to damage and to minimize signal noises due to environments. A signal-processing scheme composed of a smooth filtering and a joint time-frequency analysis was utilized to overcome noise interference and convert sensor measurements into sensor and scatter spectrograms in the time-frequency domain.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1999
- Accession Number
- ADA412408
Entities
People
- Calvin S. Wang
- Fu-Kuo Chang
- J. H. Park
Organizations
- Stanford University