Aerospace Applications ofSMARTLayer Technology

Abstract

Structural health monitoring (SHM) is increasingly being considered by the aerospace industry as a new and innovative technique to enhance the safety and reliability of structures, maximize structure operational efficiency, and minimize their operational cost. This article summarizes the latest developments in SHM systems based on SMART Layer technology in aerospace‐related applications. The systems consist of three major components: sensor/actuator network, integrated hardware, and diagnostic software. Two types of SHM systems in terms of their applications are introduced: one is the onboard system and the other is the off‐board system. The onboard SHM system has all components integrated with the host structures, and data can be automatically taken and processed. However, the off‐board system requires only the sensor network to be integrated with the structures, while the hardware and software are detached from the structures and form a portable stand‐alone unit. Data are taken only when the unit is reconnected to the sensor network. A variety of applications of both onboard and off‐board systems are discussed, including monitoring damage in composite pressure vessels and large composite barrels, cracks in the pipes of liquid rocket engines, multisite damage in riveted joints, bondlines in composite repairs, detection of impacts on the thermal protection systems (TPS) of space vehicles, and monitoring composite rocket motor cases.

Piezoelectric Sensing Techniques in Structural Health Monitoring: A State-of-the-Art Review

“…It is composed of the SMART layer shown in Figure 4 a and the SMART suitcase TM . The technology has been tested for its effect on structural integrity [ 62 ]. The feasibility of fabricating SMART layers into 3D shapes, their surface mounting, and implantation within composite and integration into a filament-wound structure has been investigated [ 63 , 64 ].…”

“…The feasibility of fabricating SMART layers into 3D shapes, their surface mounting, and implantation within composite and integration into a filament-wound structure has been investigated [ 63 , 64 ]. Several studies have been conducted to evaluate the effects of loading, temperature, moisture, and aggressive chemical environments on SMART technology [ 62 , 63 , 64 , 65 , 66 , 67 , 68 ]. The SMART layer is fabricated based on the flexible printed circuit technique.…”

Damage quantification using smart patch system for hot spot monitoring

“…Many different types of sensors are used today. But after careful study and extensive research it has been found that piezoelectric (PZT) sensors [6] are more effective for hot spot monitoring in real time. PZT sensors are able to efficiently generate Lamb Wave modes in structures and the interaction of the lamb waves with fatigue cracks causes changes in the wave signals.…”

“…Hence, the complete system would be an efficient early alarm system which, will only be able to quantify the damage if direct measurement are provided to the algorithm. The damage index (DI) representing the j-th file after a certain number of cycles can then be calculated using equation (6). Hypothetically, the damage entropy of a damaged system should be increased compared to that of an undamaged system because number of different possibilities of reorganizing the system increase with occurrence of the damage.…”

Random demodulation for structural health monitoring excited by the five-cycle sine burst

“…According to the different functions of the system, there are two types of monitoring. One is active monitoring, the other is passive monitoring [1][2]. In this paper, the research is on the active monitoring.…”