Ultrasonic monitoring of insulated block joints

Abstract

Insulated block joints are essential components used in railway tracks. They are divided into circuits and are used for train detection and signalling. However, they also represent a weak point in the track system and have a finite life. Condition monitoring of these components for planning preventative maintenance is currently labour intensive, and can be significantly expensive for the rail operator. In this study, insulated block joints were fatigued via shear load, whilst being condition monitored for degradation using a normally incident ultrasonic technique. Tests were also initially performed on lap-joints and shear specimens to further understand the response of the ultrasonic signal to failure of the adhesive layer under controlled conditions. Dynamic reflection coefficients as well as the applied load were recorded in all tests, and results were compared to failure zones on the specimens. The results showed that the ultrasonic technique was able to determine the onset of failure and de-bonding of the adhesive layer in addition to degradation and wear. The technique was also able to highlight differences in performance between two different liners, pultruded glass reinforced polyester resin and a flexible glass fibre sheet, with the latter showing improved resistance. The outcomes of this study have highlighted the viability of condition monitoring insulated block joints using an ultrasonic approach and have provided a basis for a future field trial.

Keywords

Insulated block joints cyclic shear load fishplates rail ultrasonic reflection

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References

Kerr

Cox

. Analysis and tests of boned insulted rail joints subjected to vertical wheel loads. Int J Mech Sci 1999; 41: 1253–1272.

Beaty P, Lewis R, Temple B, et al. Experimental modelling of rail end lipping in insulated joints. In: Proceedings of World Congress of Railway Research (WCRR), Sydney, Australia, 25–28 November 2013.

Nishihara T. Development of TPC railroad ties for rail joint use. In: Proceedings of World Congress of Railway Research (WCRR), Sydney, Australia, 25–28 November 2013.

Zong

Dhanasekar

. Experimental studies on the performance of rail joints with modified wheel/railhead contact. Proc IMechE, Part F: J Rail and Rapid Transit 2014; 228: 857–877.

Wen

Jin

Zhang

. Contact-impact stress analysis of rail joint region using the dynamic finite element method. Wear 2005; 258: 1301–1309.

Chen

Y-C

Chen

L-W

. Effects of insulated rail joint on the wheel/rail contact stresses under the condition of partial slip. Wear 2006; 260: 1267–1273.

Ekberg

Sandström

. Numerical study of the mechanical deterioration of insulated rail joints. Proc IMechE, Part F: J Rail and Rapid Transit 2009; 223: 265–273.

Mayville

Stringfellow

. Numerical analysis of a railroad bolt hole fracture problem. Theor Appl Fract Mech 1995; 24: 1–12.

Sih

Tzou

. Rail-end bolt hole fatigue crack in three dimensions. Theor Appl Fract Mech 1985; 3: 97–111.

10.

Dhanasekar

Bayissa

. Performance of square and inclined insulated rail joints based on field strain measurements. Proc IMechE, Part F: J Rail and Rapid Transit 2012; 226: 140–154.

11.

Health and Safety Investigation Board. Train Derailment at Potters Bar, UK, Report, 10 May 2002, SMIS Ref. No.: QNE/2002/02/71643, No. 04655675, 2003. pp.1–24.

12.

Rail Accident Investigation Branch. Rail Accident Report – Derailment at Grayrigg 23 February 2007, Department for Transport, Report no. 081023_R202008_Grayringg_v5, pp.123–131.

13.

Peltier DC and Barkan CPL. Modelling the effects of epoxy debonding on bonded insulated rail joints subjected to longitudinal loads. In: Transportation research board 87th annual meeting, Washington, DC, 13–17 January 2008.

14.

Davis DD, Akhtar M, Kohake E, et al. Effects of heavy axle loads on bonded insulated joint performance. In: Proceedings of the 2005 Annual Conferences: AREMA 2005 C & S Technical Conference, Chicago, Illinois, 25–28 September 2005.

15.

Davis

Akhtar

. Improving the performance of bonded insulated joints. Railway Track Struct 2005; 101: 14–17.

16.

Stephen

Marshall

Lewis

. An investigation into contact pressure distribution in bolted joints. Proc IMechE, Part C: J Mechanical Engineering Science 2014; 228: 3405–3418.

17.

Marshall

Lewis

Drinkwater

et al.

An ultrasonic approach for contact stress mapping in machine joints and concentrated contacts. J Strain Anal Eng Des 2004; 39: 339–350.

18.

Stephen J, Marshall M and Lewis R. Relaxation of contact pressure and self-loosening in dynamic bolted joints. Proc IMechE, Part C: J Mechanical Engineering Science. 2016; 231: 3462–3475.

19.

Weight

. New transducers for high-resolution ultrasonic testing. NDT Int 1984; 17: 3–8.

20.

Guyott

CCH

Cawley

. Evaluation of the cohesive properties of adhesive joints using ultrasonic spectroscopy. NDT Int 1988; 21: 233–240.

21.

Titov

Maev

Bogachenkov

. Pulse-echo NDT of adhesively bonded joints in automotive assemblies. Ultrasonics 2008; 48: 537–546.

22.

William

. Engineering tribology, New York, NY: Cambridge University Press, 2005.

23.

Kendall

Tabor

. Ultrasonic study of area of contact between stationary and sliding surfaces. Proc R Soc Lond A-Math Phys Sci 1971; 323: 321–340.

24.

Tattersall

. Ultrasonic pulse-echo technique as applied to adhesion testing. J Phys D-Appl Phys 1973; 6: 819–832.

25.

Drinkwater

Dwyer-Joyce

Cawley

. A study of the interaction between ultrasound and a partially contacting solid–solid interface. Proc R Soc Lond A-Math Phys Eng Sci 1996; 452: 2613–2628.

26.

Hammant

. The use of 4-point loading tests to determine mechanical properties. Composites 1971; 2: 246–249.

27.

The Permanent Way Institution. The railway track as a structure. Report, British Railway Track, Great Britain, 2007, pp.471–486.

28.

Standards Australia. AS1085:12 Railway Track Material Part 12: Insulated Joint Assemblies. Sydney: Standards Australia International Ltd., 2013.