A hybrid piezoelectric/fiber optic diagnostic system for structural health monitoring

Abstract

A hybrid piezoelectric/fiber optic diagnostic system has been developed for quick non-destructive evaluation and long term health monitoring of aerospace vehicles and structures. The hybrid diagnostic system uses piezoelectric actuators to input a controlled excitation to the structure and fiber optic sensors to capture the corresponding structural response. The system consists of three major parts: a diagnostic layer with a network of piezoelectric elements and fiber gratings to offer a simple and efficient way to integrate a large network of transducers onto a structure; diagnostic hardware consisting of an arbitrary waveform generator and a high speed fiber grating demodulation unit together with a high speed data acquisition card to provide actuation input, data collection, and information processing; and diagnostic software to determine the condition of the structure. This paper presents key development issues related to the manufacturing of the hybrid piezoelectric/fiber optic diagnostic layer and integration of a highly portable diagnostic hardware. Validation and proof testing of this integrated diagnostic system are also presented.

A Review of Vibration-based Structural Health Monitoring with Special Emphasis on Composite Materials

“…A very interesting conclusion stated by these authors is that the proposed model allows evaluating the Young modulus of the adhesive, which is very difficult to determine experimentally. Qing et al (2005) develop a hybrid piezoelectric/fibre optic (HyPFO) diagnostic system for quick non-destructive evaluation and long term health monitoring of aerospace vehicles and structures. Piezoelectrics are used as actuators and fibre gratings as sensors.…”

Structural Health Monitoring for Composite Materials

“…However, these NDT methods, merely allowing the off-line testing in a local manner with complicated and heavy equipments, are labor-extensive and time-consuming especially for large-scale structures. Meanwhile, disassembling the tested structures may be required to ensure the inspection area accessible, which can increase the maintenance costs [6][7].…”

“…The benefits from the layers are [20]: a) rapidly and consistently arranging a large number of sensors is allowed; b) connecting wires are avoid to reduce EMI; c) the layers can be surface-mounted on existing structures or embeded as extra layers in composites during manufacturing. Besides the PZT-array layer, known as SMART Layer [21], the PZT-FOS hybrid array layer [6] and HELP (Hybrid Electromagnetic Performing) layer [22] have also emerged, as shown in figure 5. …”

Design of a robust SHM system for composite structures

“…The maturity and networking capability of the various sensor types depends on the conditions of usage and structural application. Acellent Technologies has integrated several different types of sensors onto the SMART Layer, but primarily use piezoelectric transducers for their ability to be used as both an actuator and a sensor [6][7][8][9][10][11]. Because of this, the SMART Layer technology has both active and passive sensing capabilities via the embedded piezoelectric transducers (Figure 1).…”