| 摘要 |
PROBLEM TO BE SOLVED: To provide an FEM (Finite Element Method) modeling method that makes it possible to implement FEM from the standpoint of calculation time in a way that takes into account the presence of soundproofing material in a relatively large-scale sound field, such as vehicle interior space. SOLUTION: When FEM is applied to a sound field in a structure where a member with the function of absorbing or isolating sound is disposed between a structural body that can vibrate and the sound field, the member is modeled as a frequency-dependent spring-mass-damper model disposed between the structural body and a nodal point of the sound field. The spring constant of the spring-mass-damper model, its mass, and the frequency characteristic of its damper damping constant are calculated on the basis of the surface impedance and the vibration transmissibility of the member both of which are determined either experimentally or through simulations. When FEM is applied to a vehicle, the structural body, the sound field, and the member correspond to a body panel, the vehicle interior space, and interior material including the soundproofing material, respectively. COPYRIGHT: (C)2006,JPO&NCIPI
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