DISPLACEMENT RESPONSE WAVEFORM RESTORATION OF SIMPLY SUPPORT BRIDGE DURING TRAIN PASSAGE BASED ON MEASUREMENT ACCELERATION INTEGRATION

Abstract

 This study proposed a method to restore the displacement waveform from the acceleration waveform when the train passes by utilizing the linear vibration theory. The proposed method replaces only the low frequency region affected by noise with a linear theoretical solution, although utilizes actual measurement data in the vicinity of the natural frequency where non-linearity such as concrete concrete member cracks and the influence of train / bridge interaction can be observed. The method identifies the only parameter of the ratio of uniaxial weight to modal stiffness. Numerical experiments clarified that the method can estimate the maximum displacement of bridge from acceleration in the error of about 5% or less, and the decrease in estimation accuracy was limited even when the dynamic characteristics of the bridge are unknown, when the standard deviation of noise is less than 0.005 m/s² and the train speed is more than 150km/h. Furthermore, the proposed method were applied to the acceleration monitoring data and it was shown that the displacement waveform can be restored from the acceleration waveform.