A structural crack monitoring gasket for aircraft bolt-jointed structures with temperature compensation

In order to meet the need of the quantitative monitoring of cracks in critical connection structures of aircraft, aiming at improving the durability of sensors and the reliability of signals, a structural crack monitoring (SCM) gasket, which can be used for the quantitative monitoring of cracks in bolted joints, is developed. The gasket is formed by a gasket substrate and a flexible eddy current sensor integrated to withstand the load, with the capability of temperature compensation. First of all, a new temperature-compensated rosette eddy current array (TC-RECA) sensor is designed and used to study the failure mode of the sensor. According to the failure mode of the sensor, a gasket substrate with load-bearing capacity is developed. Subsequently, the influence of permeability, conductivity and lift-off on the trans-impedance of the sensor is studied. The influence of permeability on the trans-impedance is characterized by conductivity. Based on this, a temperature compensation method for ferromagnetic materials is developed. Then, a temperature influence experiment and a structural crack quantitative monitoring experiment are carried out using a front beam connection structure of an aircraft wing. The temperature effect experimental results show that even if the ambient temperature changes from 60 °C to −40 °C, the characteristic signal ΔC does not change significantly, indicating that the gasket has a temperature compensation capability. The experimental results of the crack monitoring of the front beam connection structure show that the gasket can bear the load and has the capability to quantitatively monitor cracks, and can be used for the quantitative monitoring of cracks in the critical connection structure of aircraft structures.

[1]  J. Schijve.  Fatigue of aircraft materials and structures , 1994 .

[2]  Gaëtan Kerschen,et al.  Structural damage diagnosis under varying environmental conditions—Part I: A linear analysis , 2005 .

[3]  J. Michaels,et al.  A methodology for structural health monitoring with diffuse ultrasonic waves in the presence of temperature variations. , 2005, Ultrasonics.

[4]  Paul D. Wilcox,et al.  Strategies for guided-wave structural health monitoring , 2007, Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences.

[5]  Dennis Patrick Roach,et al.  Real time crack detection using mountable comparative vacuum monitoring sensors. , 2008 .

[6]  Anthony N. Palazotto,et al.  Lamb Wave Propagation in Varying Isothermal Environments , 2008 .

[7]  Y. Sheiretov,et al.  MWM-Array Sensors for In Situ Monitoring of High-Temperature Components in Power Plants , 2009, IEEE Sensors Journal.

[8]  Jochen Moll,et al.  Efficient temperature compensation strategies for guided wave structural health monitoring. , 2010, Ultrasonics.

[9]  C. S. Cai,et al.  Acoustic emission monitoring of bridges: Review and case studies , 2010 .

[10]  Peter Cawley,et al.  Guided wave health monitoring of complex structures by sparse array systems: Influence of temperature changes on performance , 2010 .

[11]  Hoon Sohn,et al.  Reference-free crack detection under varying temperature , 2011 .

[12]  Valder Steffen,et al.  A low-cost electromechanical impedance-based SHM architecture for multiplexed piezoceramic actuators , 2011 .

[13]  Nezih Mrad,et al.  Fiber Optic Sensors for Structural Health Monitoring of Air Platforms , 2011, Sensors.

[14]  Fu-Kuo Chang,et al.  A structural health monitoring fastener for tracking fatigue crack growth in bolted metallic joints , 2012 .

[15]  Edwin Reynders,et al.  Output-only structural health monitoring in changing environmental conditions by means of nonlinear system identification , 2014 .

[16]  Patrice Mégret,et al.  Fiber Bragg Grating Sensors toward Structural Health Monitoring in Composite Materials: Challenges and Solutions , 2014, Sensors.

[17]  Kuldeep Lonkar,et al.  A novel physics-based temperature compensation model for structural health monitoring using ultrasonic guided waves , 2014 .

[18]  Yaghoob Farnam,et al.  Acoustic emission waveform characterization of crack origin and mode in fractured and ASR damaged concrete , 2015 .

[19]  Gerardo Rodríguez,et al.  Cracking assessment in concrete structures by distributed optical fiber , 2015 .

[20]  António Barrias,et al.  A Review of Distributed Optical Fiber Sensors for Civil Engineering Applications , 2016, Sensors.

[21]  Mira Mitra,et al.  Guided wave based structural health monitoring: A review , 2016 .

[22]  James C. Newman,et al.  Fatigue and crack-growth analyses of riveted lap-joints in a retired aircraft , 2016 .

[23]  Gui Yun Tian,et al.  Passive RFID sensor systems for crack detection & characterization , 2017 .

[24]  Shengbo Jiao,et al.  Temperature-compensated rosette eddy current array sensor (TC-RECA) using a novel temperature compensation method for quantitative monitoring crack in aluminum alloys , 2017 .