Proposed rail pad sensor for wheel-rail contact force monitoring

Abstract

A non-intrusive method is proposed in this study with details showing the steps to convert rail pad into a load sensor for train wheel damage detection applications. The fabrication process is simple, requiring only the addition of a thin PVDF-based multilayered sensing device (approximately 0.7 mm) beneath the rail pad. An alternating-strip configuration is adopted in the multilayered sensing device, comprising active strips for sensing the vertical forces acting on the rail pad and dummy strips for resisting the potential lateral forces together with the baseplate shoulder. To validate the performance of the proposed rail pad sensor, both laboratory and field tests have been conducted. The tests results highlight the feasibility and potential of the rail pad sensor for train wheel condition monitoring. Unlike conventional strain gauge-based wheel load monitoring system, the rail pad sensor does not have blind zone problem.