The Measuring Method Of High-Frequency Wheel-Rail Contact Force

With the rapid development of Chinese railway, the train speed is from30km/h up to300km/h. The operating mileage is increasing, which has exceeded to100,000km. The far development of the train is met for the national market.At the same time, people also made high demands on the safety and comfort of railway. It’s necessary to detect the wheel-rail train force for studying the derailment mechanism and the comfort of the train. Among the wheel-rail force measurement methods, instrumented wheelset is the most effective and accurate method, which is a kind of continuous measurement. Trains run in the complex environment, so in the actual operation of the train wheels suffered wheel force, which is a piece of a broad spectrum from low frequency to high frequency. According to modal vibration theory, when incentived in some certain frequencies, the wheels will lead to modal resonance. In the simulation mode experiment, it is about to calculate the first-order resonance frequency at270Hz. This modal resonance phenomenon, is inevitably superimposed in the strain of webs, leading to some errors to the instrumented wheelset. According UIC518standards, the highest measured wheel-rail force is90Hz. Generally, the20Hz is the less frequency of measurement. Therefore, this thesis against to the existing Instrumented wheelset’s deficiencies, we propose a high-frequency wheel-rail force measurement method.Firstly, based on the principle of the instrumented wheelset, we not only analyzed the interaction force between the wheel and rail but also brought forward the harmonic of the data form the wheastone bridge. At the same time, wo proposed the analytical equations of wheel-rail force and the state model fo the wheels. Then we described the modal vibration theory. By the use of CAD software for modeling of the wheel and FEM software-PATRAN we analyzed the modal of the wheel and response of some excitation. A kind of reasonable filter is used for compensating the high-frequency wheel-rail forces mixed modal resonances. Finally, we designed a multi-channel high-frequency wheel-rail force collection in order to complete the latter experiment for the actual data measured and in detailed descripted the hardware and software of it.