Automated Structural Health Monitoring of Bolted Joints in Railroad Switches

Author(s):  
Mana Afshari ◽  
Thomas Marquie´ ◽  
Daniel J. Inman

Current switch bolt inspection on rail systems is a labor intensive and sometimes unreliable approach to maintaining the switch integrity. Recent rail accidents in the United Kingdom (Potters Bar in 2002 and Grayrigg in 2007) underscore the need for routine inspections of the switch mechanisms. From the Grayrigg report of 23 February 2007 the main causes of the accident were found to be the loosening and, as a result, the initiation and growth of cracks, and, eventually, rupture of the bolts of the switch bars, especially the one maintaining the switch rails at a correct distance apart. Such findings also resulted from the 2002 crash report but unfortunately frequent visual inspections were not forthcoming. In this paper, an effective method for monitoring the loosening of the switch bolts is described. As the loosening of the bolts further causes the crack formation in the bolted joints, it seems valid to say that the early detection of loosening of bolted joints in railroad switches will be of great importance in eliminating the need for frequent visual inspection by totally automating inspection of the switches’ mechanical condition. The first part of the present paper focuses on the use of smart materials and structures for the health monitoring of bolted joints in railroad switches. It is shown that using the piezoelectric transducers and the impedance-based structural health monitoring technique, the loosening of the bolted joints are detectable. The accuracy in loosening detection is as high as 25 ft-lbs which corresponds to merely 1/10th of a bolt turn. Being able to detect the loosening of the bolted joints in railroad switches, the concept of self-healing bolted joints is applied in the next part in order to automatically retighten the loosened bolts to their prescribed functional conditions.

Sensors ◽  
2020 ◽  
Vol 20 (13) ◽  
pp. 3730 ◽  
Author(s):  
Pengcheng Jiao ◽  
King-James I. Egbe ◽  
Yiwei Xie ◽  
Ali Matin Nazar ◽  
Amir H. Alavi

Recently, there has been a growing interest in deploying smart materials as sensing components of structural health monitoring systems. In this arena, piezoelectric materials offer great promise for researchers to rapidly expand their many potential applications. The main goal of this study is to review the state-of-the-art piezoelectric-based sensing techniques that are currently used in the structural health monitoring area. These techniques range from piezoelectric electromechanical impedance and ultrasonic Lamb wave methods to a class of cutting-edge self-powered sensing systems. We present the principle of the piezoelectric effect and the underlying mechanisms used by the piezoelectric sensing methods to detect the structural response. Furthermore, the pros and cons of the current methodologies are discussed. In the end, we envision a role of the piezoelectric-based techniques in developing the next-generation self-monitoring and self-powering health monitoring systems.


2010 ◽  
Vol 2010 ◽  
pp. 1-13 ◽  
Author(s):  
M. Sun ◽  
W. J. Staszewski ◽  
R. N. Swamy

Structural Health Monitoring (SHM) aims to develop automated systems for the continuous monitoring, inspection, and damage detection of structures with minimum labour involvement. The first step to set up a SHM system is to incorporate a level of structural sensing capability that is reliable and possesses long term stability. Smart sensing technologies including the applications of fibre optic sensors, piezoelectric sensors, magnetostrictive sensors and self-diagnosing fibre reinforced composites, possess very important capabilities of monitoring various physical or chemical parameters related to the health and therefore, durable service life of structures. In particular, piezoelectric sensors and magnetorestrictive sensors can serve as both sensors and actuators, which make SHM to be an active monitoring system. Thus, smart sensing technologies are now currently available, and can be utilized to the SHM of civil engineering structures. In this paper, the application of smart materials/sensors for the SHM of civil engineering structures is critically reviewed. The major focus is on the evaluations of laboratory and field studies of smart materials/sensors in civil engineering structures.


10.29007/qhwp ◽  
2018 ◽  
Author(s):  
Darshan Patel ◽  
C. B. Mishra

Nanotechnologies are a quickly extending territory of research in highway infrastructure. This is due to self-cleaning, self-vibration damping, structural health monitoring and self-healing properties of it. This paper focuses on the advancement of important nanotechnology and its effect on roadway designing practice is presented for widening vision and inspiring the creativity of highway engineeringkeeping in viewpoint safety, durability, financial aspects and maintainability of the transportation framework of India is considered.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Massimo Olivero ◽  
Guido Perrone ◽  
Alberto Vallan ◽  
Daniele Tosi

A comparative study is presented between Bragg grating (FBG) and polarimetric sensors (PS), two of the most promising fiber optic sensing techniques for the structural health monitoring of smart materials based on carbon fiber composites. The paper describes the realization of a test plate equipped with both types of sensors and reports the characterization under static and dynamic conditions, highlighting pros and cons of both technologies. The FBG setup achieves 1.15 ± 0.0016 pm/kg static load response and reproduces dynamic excitation with 0.1% frequency uncertainty; the PS system exhibits a sensitivity of 1.74 ± 0.001 mV/kg and reproduces dynamic excitation with 0.5% frequency uncertainty. It is shown that the PS technology is a good and cheap alternative to FBG for vibration-monitoring of small structures at high frequency.


2006 ◽  
Vol 1 (3) ◽  
pp. 248-256 ◽  
Author(s):  
Simon C. Wong ◽  
Alan A. Barhorst

This research work is in the area of structural health monitoring and structural damage mitigation. It addresses and advances the technique in parameter identification of structures with significant nonlinear response dynamics. The method integrates a nonlinear hybrid parameter multibody dynamic system (HPMBS) modeling technique with a parameter identification scheme based on a polynomial interpolated Taylor series methodology. This work advances the model based structural health monitoring technique, by providing a tool to accurately estimate damaged structure parameters through significant nonlinear damage. The significant nonlinear damage implied includes effects from loose bolted joints, dry frictional damping, large articulated motions, etc. Note that currently most damage detection algorithms in structures are based on finding changed stiffness parameters and generally do not address other parameters such as mass, length, damping, and joint gaps. This work is the extension of damage detection practice from linear structure to nonlinear structures in civil and aerospace applications. To experimentally validate the developed methodology, we have built a nonlinear HPMBS structure. This structure is used as a test bed to fine-tune the modeling and parameter identification algorithms. It can be used to simulate bolted joints in aircraft wings, expansion joints of bridges, or the interlocking structures in a space frame also. The developed technique has the ability to identify unique damages, such as systematic isolated and noise-induced damage in group members and isolated elements. Using this approach, not just the damage parameters, such as Young’s modulus, are identified, but other structural parameters, such as distributed mass, damping, and friction coefficients, can also be identified.


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