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Abstract. To simulate the tread temperature rise of the working subway train in the process of its normal operation and to explore the temperature rise limit of wheel tread during operation, finite element numerical simulation was used in this paper. Based on heat transfer theory and finite element method, a three-dimensional finite element model of the subway wheel was created. According to the braking condition of main line pure air brake, thermal simulation of wheel temperature field was conducted and finally the temp-rising law of the metro wheel was achieved. The results show that the wheel tread temperature first increased rapidly and then slowly decreased until the next brake in a period of "brake, stop, accelerate and coast", with the temperature raised about 110°C in a single brake. At first, the braking heat accumulated in the wheel, with the overall temperature gradually increasing. Then, after several consecutive braking processes, the overall temperature tended to be stable. The tread temperature reached its peak at 3766.5s, with the highest temp reaching 298.9°C during the 31st braking process, not exceeding the limit of temperature rise (400°C ).

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To study the temperature rise of the metro wheel tread, the simulation is conducted, finding that the highest temperature emerges in the tread area during the braking process, up to 350 °C. The range of temperature measurement should include 0∼350 °C. The temperature rise of the tread surface and the temperature near the side of the wheel tread tend to be consistent after the braking. The temperature measurement on the side of the wheel can provide a reference for the tread temperature measurement. Then several kinds of temperature sensors used for testing the tread temp are introduced, the accuracy and influencing factors of the measurement of the tread surface temperature sensor was analyzed. For the temperature measurement of wheel tread, featuring bright surface emission, low and unstable emissivity, a real-time temperature test method with multi-sensor compensation and data fusion is proposed and a more realistic curve of the tread temperature is obtained. Taking the actual line pure-air brake condition as an example, the above method is used to measure the temperature of tread surface. The results show that the measurement accuracy of multi-sensor data compensation and fusion is better than that of using the single infrared thermometer method, up by 15%; The law of temperature rise is consistent with that of transient simulation. reflecting that this testing method can offer important references to the real-time measurement of tread temperature.