Railway Fatigue Testing: Accelerated Service Conditions on Track Support Systems

Railway Fatigue Testing offered at Exova's Pointe-Claire laboratory is set up to provide laboratory testing of railway track support systems. It is the only lab in North America to provide this type of accelerated test to simulate service load conditions on track support systems. Originally developed as a test for a major North American railway to evaluate tie pads, it became evident this test would be useful to evaluate ties as well.

The accelerated test program was refined to encompass concrete, wood and composite ties, fastening systems and tie life predictions. Exova accelerated test program imposes forces in the same manner as a freight axle set, providing vertical and lateral dynamic loading through the rail and fastening system into the rail seats. This test has recently been incorporated into AREMA (American Railway Engineering and Maintenance of Way Association), Chapter 30 for Concrete ties. AREMA states this test method is an example of how to do wear and abrasion tests on rail seats and components and has been used successfully to improve concrete tie and component design.

What makes the Exova test unique is the method of loading. Most tests of this nature run straight vertical and straight lateral loading alternately, which is theoretically correct and easily reproduced in a lab, but not how it happens in reality. In the Exova accelerated test method, vertical and lateral loads are imposed simultaneously through the gauge corner head radius of the railhead at an angle equal to that of a wheel in a curve, making it a severe test for components.

The competitive advantage of Exova setup is that it runs accelerated dynamic testing to determine if a component will last over a long period of time. Other tests, such as real time testing, would require, for example, one year to impose one year’s worth of cycling in track. Exova can do the same in just 10 to 15 days.

Railway Fatigue Testing – Rail Ties

Furthermore, our lab can test the dynamic strength of your ties and fastening components through fatigue testing such as: severe service load testing, tangent testing, incline load testing, rail seat dynamic testing, and center negative testing. We have two fatigue test frames:

Dynamic Test Frame 110 000 lb

Load cell 20 000 – 120 000 lb

Compression 2 000 lb – 110 000 lb

DAQ (Data acquision): DASYLab

Deflection & Force feedbacks

Frequencies at 60 000 lb

Max: 3 Hz, deflection 0.004 in.

Min: 0.1 Hz, deflection up to 6 in.

Max. sample size: 28’’ wide, 7’ high, 12’ long

Railway Fatigue Testing – Small Components

Both frames may be used for a variety of fatigue testing on parts such as tie pads, abrasion plates, clips, etc. In addition, we conduct dynamic tests on small components that are not related to ties.

Dynamic Test Frame 65 000 lb

Load cell : 20 000 – 60 000 lb

Compression & tension 250 lb – 64 000 lb

Adaptors : 10 – 50 lb

DAQ (Data acquision): DASYLab

Deflection & Force feedback

Frequencies at 60 000 lb

Max: 8 Hz, deflection 0.004 – 0.006 in.

Min: 0.1 Hz, deflection up to 0.5 in.

Max. sample size: 30’’ wide, 40’’ high, 8’ long