By implementing a built-in sensor network on a composite structure, crucial information regarding the condition, damage state, and service environment of the structure can be obtained. In this study, methods for integrating piezoelectric sensor networks into a composite structure during different fabrication processes, including the resin transfer molding (RTM) and filament winding processes, are examined. To integrate sensor networks with different contours of structures, the method to fabricate a three-dimensional (3-D) diagnostic layer is developed. It is demonstrated that a large number of sensors supported on a thin flexible dielectric film, called a SMART Layer, offers a simple and efficient way to integrate a large sensor network onto a complex 3-D structure. The sensor network permanently embedded inside the composite structures can be used with either active sensing or passive sensing to monitor the health condition of a structure throughout its lifetime.

Built-in sensor network for structural health monitoring of composite structure

Advances in the development of built-in diagnostic system for filament wound composite structures

In this paper, the influence of the integration of several sensors in composite structures is investigated. The plates and the structures in simple shapes, composed of laminated and sandwich materials, are considered. The mechanical behaviour, the acoustics activity and the location of damage sources in various structures with and without piezoelectric implant are compared. The analysis of results allowed a better identification of the influence of the impact of piezoelectric implant on the mechanical behaviour of different structures under different loads. Then, the analysis and the observation of Acoustic Emission (AE) signals led to the identification of the main acoustic signatures of different damage modes dominant in each type of composite materials (laminates and sandwich). Viewpoint comparison between integrated and non-integrated structures, acoustic activity is more significant in the case of integrated material. The location of the sources of damage has shown that acoustic events occurred far from the positions of integrated sensors.

Use of piezoelectric as acoustic emission sensor for in situ monitoring of composite structures

Aircraft smart skin technology requires the integration of large-scale, lightweight, and integrative sensor networks with aircraft structural skin, but it is difficult to directly manufacture such ...

A stretchable and large-scale guided wave sensor network for aircraft smart skin of structural health monitoring:

Mechanical behavior and health monitoring by Acoustic Emission of unidirectional and cross-ply laminates integrated by piezoelectric implant

A smart layer module design utilizing a flexible printed circuit process is developed in this paper. The smart layer module, composed of two single-sided flexible polyimide films, piezoelectric sensor/actuator(s) and a pin connector, provides the advantages of convenience, efficiency, and performance when embedded in a smart structure. The problems of the piezoelectric sensor/actuator lead-wires often being easily damaged during fabrication and the short-circuiting of the sensor/actuator by carbon/graphite fibers can be solved. Tensile and modal tests show that the embedded smart layer module increases both the stiffness and strength of a composite laminated smart structure. Experiments of vibration measurement and suppression validate that the smart layer module is effective in engineering applications.

https://iopscience.iop.org/article/10.1088/0964-1726/14/2/003/pdf

K H Chen

Papers

Design and fabrication of a smart layer module in composite laminated structures