VIBRATION ANALYSIS AND CONTROL OF A BRIDGE UNDER VEHICULAR RANDOM EXCITATION

摘要

In this paper, vibration response of a bridge under vehicular loads has been analyzed and consequently been controlled by two actuators using active Neural Network (NN) control strategy. The bridge and the vehicles are modeled as a simply-supported Euler Bernoulli beam possessing a simple support precisely located at the middle and one-DOF vehicles respectively. With that goal, equations of the coupled system of the bridge and the vehicles are derived using Hamilton's principle, and then randomness of vibrations transferred to the bridge due to the alternative velocities of the vehicles added, latterly controlled by the designed NN control algorithm. The randomness includes 10 percent of vehicle initial speed. Deflection of the first quarter-span is considered as the output of the system and tried to be controlled by two symmetric forces whose desirable positions are determined by recent studies. Furthermore the sensitivity of the system response has been investigated by applying the different conditions in which the number of the moving vehicles varies. It is shown that the increment in the number of moving vehicles has led to unsolicited deflection specifically when two or more cars moves concurrently, whereas the NN algorithm could either perfectly or effectively get over the issue.