Cost-Effectiveness of Structural Health Monitoring in Fuselage Maintenance of the Civil Aviation Industry †

Abstract

Abstract:Although structural health monitoring (SHM) technologies using sensors have dramatically been developed recently, their capability should be evaluated from the perspective of the maintenance industry. As a first step toward utilizing sensors, the objective of the paper is to investigate the possibility of using sensors for inspecting the entire fuselage during C-check. First, we reviewed various sensors for their detection range, detectable damage size, and installed weight, which revealed that the piezoelectric wafer active sensor (PWAS) is the most promising sensor for aircraft SHM. Second, we performed a case study of inspecting the fuselage of Boeing-737NG using PWAS. To maintain the same detecting capability of manual inspection in C-check, we estimated the total number of sensors required. It turned out that utilizing sensors can reduce the maintenance downtime and thus, maintenance cost. However, even with a very conservative estimate, the lifetime cost was significantly increased due to the weight of sensor systems. The cost due to the weight increase was an order of magnitude higher than the cost saved by using SHM. We found that a large number of sensors were required to detect damage at unknown locations, which was the main cause of the weight increase. We concluded that to make SHM cost-effective, it would be necessary either to improve the current sensor technologies so that a less number of sensors are used or to modify the aircraft design concept for SHM.

A Brief Review on Structural Health Monitoring Sensor Technology in Civil and Aviation Technology Applications

“…The results show that the FBG embedded technique was applicable for SHM strategies in aerospace-grade composite material. Further comparison on CVM, FBG and Piezoelectric wafer active sensors (PWAS) were conducted to evaluate the ability of the sensors to detect the smallest damage size [23]. CVM was proposed as the best choice due to the capability to detect any damage up to 0.02".…”

“…However, system costing is the most influencing criteria in the SHM implementation. The crucial factors that are calculated in the cost analysis include sensor cost, installation cost, inspection cost, cost caused by extra weight, cost reduction due to less number of labor and discount due to maintenance downtime reduction [23]. The maintenance cost can be reduced significantly, as compared to the current traditional NDT while sustaining the level of risk [40].…”

“…The maintenance cost can be reduced significantly, as compared to the current traditional NDT while sustaining the level of risk [40]. The technology and installation of this system may incur a higher cost due to the increased amount of sensors installed (depends on aircraft size), and well beyond the affordability of many small and medium industries [23]. Besides that, the implementation of SHM in aircraft industry requires authority approval, multiple testing conditions and weight penalty, which could prolong the implementation process in the aircraft industry.…”

“…Besides that, a brief discussion on sensor technology is presented as well. The sensor technology that widely use in SHM such as strain-based method [6], [12], [18], [26], Eddy current [27], guided waves [23], [28]- [32], acoustic emission [33]- [35]. and carbon nanotubes (CNT) [36].…”

Polarization Parameters and Scaling Matter—How Processing Environment and Shape Factor Influence Electroactive Nanocomposite Characteristics

“…Piezoelectric and dielectric materials are ubiquitously used as sensors, actuators and transducers over a wide range of applications including but not limited to process control [1,2], industrial and automotive monitoring systems [3][4][5], medical diagnostics [6,7], aviation and aerospace structural health monitoring [8,9], embedded passive devices [10,11], and resonators and filters in telecommunications [12]. The brittle nature of homogenous ceramic piezoelectric materials limits their operational strains (~0.2% for homogenous lead zirconate titanate, PZT) [13], cycle life, and formability into complex shapes and structures [14].…”