Design and development of a test bench for railway coupler testing

Abstract

Accurate modelling and experimental characterization of railway coupling devices are essential to reliably estimate the maximum longitudinal compressive and tensile forces to which a trainset is subjected. These estimates are paramount to ensure safe and efficient operations, particularly for longer and heavier freight trains. However, traditional testing of couplers is based on simple, standardized tests which fail to correctly reproduce their behaviour under realistic conditions. Moreover, these methodologies cannot be easily interfaced with numerical simulation tools. This paper presents the design and development of an innovative test bench for the experimental analysis of several types of railway couplers. The test bench can actuate a moving frame with two translational and one rotational degree of freedom in the horizontal plane, allowing indoor reproduction of relative motions between adjacent wagons. The bench is compatible with both conventional buffer-and-hook systems and Digital Automatic Couplers (DACs) and is equipped with a comprehensive measurement system for forces, moments, and displacements. The effects of uncertainties on the measurement setup are also discussed. The capabilities of the test bench are assessed through an experimental campaign on a standard UIC coupling system assembly, including compression and traction tests up to realistic load levels and an open-loop simulation of a trainset negotiating a double switch. The proposed test bench represents a flexible and effective tool for advanced experimental characterization of railway couplers and a solid basis for future Hardware-in-the-Loop based longitudinal dynamics investigations.