DESIGN AND ANALYSIS OF A TRACK COMPLIANCE MEASUREMENT SYSTEM. PHASE II

This report covers the design of a vehicle for measuring the static and dynamic compliance of railroad track. The static compliance system uses the rail deflections due to different axle loads to calculate the track compliance. The static compliance measurements are taken continuously as the vehicle travels a section of track. The dynamic compliance system utilizes an electrohydraulic excitation system capable of cyclically applying in-service wheel loads simulating a passing train and superimposing either pulse, random, or sinusoidal dynamic excitation on the wheel load to dynamically excite the track structure. The excitation and resulting response of the system are analyzed using a digital Fast Fourier Transform program. From these data, the dynamic characteristics of the track structure can be determined. The information in this report is intended for use by research personnel who have an interest in railroad track performance as related to vehicle/track interaction and track maintenance, and in the measurement of track deflections and dynamic characteristics for developing track analysis models and evaluating track structure condition.