Abstract：The health status of railcar coupler system is one of the most important factors to insure the safe operation of rail transit vehicles. Structural health monitoring (SHM) based on Lamb wave can be used to evaluate the health condition and service life of the vehicle to ensure its stable operation. In practice, Lamb wave signal is susceptible to environmental factors, and will fluctuate with the change of environment, which will cause false alarm and affect the accuracy of the system. In order to improve the stability and accuracy of SHM system for railcar coupler, an environmental compensation method is developed to solve this problem. Under laboratory conditions, the environment compensation method to SHM system is used to monitor the health condition of railcar coupler for a long time. The result demonstrates that the compensation can effectively remove impacts of crosstalk and noise, and also reduce the temperature effect to the measurement result.
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