RESPONSE MOMENTS OF AN ELASTIC BEAM SUBJECTED TO POISSONIAN MOVING LOADS

Abstract

The problem of vibration of engineering structures resulting from the passage of different types of loads is of great importance. Vibrations of this type occur in bridges and railways excited by vehicles, piping systems subjected to two-phase flow, and machining operations where high axial speed is employed, and beams subjected to pressure waves. This paper is concerned with higher order moments of a simply supported elastic beam subjected to a stream of random moving loads of Poissonian type in the transient and steady states. These higher response moments should enable better reliability predictions than those obtained by using the assumption of Gaussian responses. The stream of loads is assumed to move with a time varying velocity and the beam is subjected to different axial forces. The effect of the arrival rate of the stream of loads, the effect of the beam damping, and the effect of deterministic axial forces are investigated and compared with known solutions for constant velocity of the passage of the stream of loads. It is shown that the distribution of the response is sensitive to the arrival rate of the stream of moving loads, the damping of the beam, the speed and the type of motion of the moving loads, and the axial force acting on the beam. The results are verified by simulation.