Abstract
In this paper, an effective numerical method to solve a transient dynamic and acoustic problem for railway structures due to the impact forces is presented. After the dynamic response of the structure is obtained by FEM and the velocity response of the surface of the structure is transformed to the frequency domain, the sound pressure in the air outside the structure is obtained by BEM using the velocity boundary condition at each frequency. The transient sound pressure at the arbitrary points outside the structure is obtained by the superposition of the sound pressure in the frequency domain. In the superposition, the inadequate higher frequency decided from the element size of boundary mesh is omitted to get a reasonable solution and save computation time. The submodel in the whole structure is employed to get a transient acoustic solution effectively for an actual railway structure. Based on the present method, a transient dynamic and acoustic analysis program, ASA/ACOUSTICS, has been developed. Numerical examples are demonstrated.
