はり理論による低周波空気振動の放射音圧レベルの解析

抄録

Low frequency sound generated from highway bridges at speedy passage of heavy vehicles, has been rising to a new traffic problem. It has, therefore, been an urgent necessity to make clear how it occurs and to calculate the pressure level of a sound regarding bridge vehicle system. In this paper the authors attempt to evaluate the SPL of the bridge vehicle system by an average SPL during the vehicle passage time and over the surface of the bridge. The dynamic response of a bridge under a travelling vehicle, is handled by a beam theory subjected to a sprung mass system and the SPL radiating from bridge is calculated from the particle velocity equation. The effect of the correlated vibration between bridge and vehicle, travelling velocity of the vehicle and randomness of the bridge surface on the SPL radiating from bridge, are shown in numerical results.