Abstract
Noticing the noise reduction effects of the drainage asphalt pavement, the method of estimation of radiation characteristics of automobile tire/road noises and the road design concept of reducing such noises are examined. By using FEM, the tire vibration responses depending on the grain size of road texture are obtained and regarding those responses and the normal acoustic impedance of the finite area simulating road surface as the boundary conditions for acoustic analysis by BEM, the sound pressures radiated from the tire on the both of the dense and porous asphalt pavements are calculated. As a result, it is verified that in the drainage asphalt pavement, the tire/road noise is more reduced than in the dense pavement by the suppression of horn effect in addition to the excess attenuation due to sound absorbing effect of porous asphalt.
