Shanghai Jiaotong Daxue xuebao (Apr 2022)
Influence of Structural Pseudo-Static Components on Seismic Responses of Low-Medium Speed Maglev Vehicle-Bridge System
Abstract
Unlike the traditional seismic analysis on bridge engineering which mainly concerns the relative motion, the seismic analysis of vehicle-bridge system focuses more on the absolute motion of the vehicle system, where the pseudo-static components need to be considered. In order to study the effect of structural pseudo-static components on the seismic responses of low-medium speed maglev vehicle-bridge system, the discussion relying on a typical low-medium speed maglev line was implemented. Considering the vehicle-bridge coupling relationship based on the proportional integral derivative (PID) active suspension control, two dynamic models for the low-medium speed maglev vehicle-bridge system subjected to earthquake were relatively established in the relative coordinate and the absolute coordinate, and the seismic forces were correspondingly solved by employing the relative motion method and the direct solution method. A case study was subsequently conducted, where the effect of structural pseudo-static components on dynamic responses of the vehicle-bridge system, including the maglev gap, the vehicle system and the bridge was further analyzed. The results show that the influence of pseudo-static components on the dynamic responses of the vehicle system is quite significant. Ignoring the pseudo-static components could seriously undervalue the dynamic responses of the vehicle system, of which the difference could be as high as 447%. Compared to the vehicle system, the influence of pseudo-static components on the vertical and transversal displacement responses of the bridge is fairly limited. Therefore, it is suggested that the absolute displacement method which takes the pseudo-static components into account should be adopted to deal with the seismic excitation in the maglev vehicle-bridge system.
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