Optimized design of size adjusted freight rail vehicle for the vibration attenuation of railway bridges

Movements of the wheel loads and their sequential entry onto the bridges are known as the two root causes for the vibrations of the railway bridges. It is possible to reduce the levels of the unwanted bridge deck oscillations by introducing one or more size adjusted (the so called anti-resonance) wagon(s) in the train arrangement. The added wagon(s) are of different size(s) compared with the other cars in the train arrangement. This can disturb the periodicity in the wheel loading. Consequently, it can interfere with the resonance phenomena and prevent the bridge from excessive vibrations. It is the purpose of this research to calculate the proper sizes for the anti-resonance rail vehicles. Such vehicles need to fulfill the requirements for the controlled excitation of the bridge dynamic response. The bridge is subjected to series of moving loads. A computer aided analytical method is used in order to calculate the bridge dynamic response. The in-house concept of time matrix method is used to facilitate the calculations procedures. It is attempted to extract from the huge number of calculations, a criteria that can be used for the assessment of the dynamic response of all railway bridges. It is also attempted to manage the levels of the bridge vibrations. This is achieved by simultaneously working on the vital parameters such as the size of the anti-resonance vehicle, the vehicle axle load and the placement and the distribution of the loads throughout the train. Variety of the train speed of travel is considered . Eventually, the optimized sizes for the anti-resonance vehicle are obtained and its effectiveness in reducing the levels of the bridge vibrations is calculated.

کلیدواژه ها:

Anti-resonance wagon ، bridge vibrations ، optimization ، freight fleet