Numerical modeling of mounting of plate-like elements on sound insulation

摘要

In the laboratory measurement of sound insulation performance of plate-like elements, aspecimen is normally mounted inside an aperture in a thick concrete wall between coupledrooms. In a special case where a specimen is mounted flush with the wall surface, aprojecting box frame is sometimes installed around it. In both cases, the so-called “nicheeffect” must be involved as a bias error in transmission loss measurement, but thedifference between the two types of niches is not fully clarified. In this paper, a recessingniche and a projecting niche are numerically modeled in vibro-acoustic simulation, and theeffects on the transmission loss for an elastic plate are examined with changing the depth ofniches. Additionally, on the modeling of the edge support system for plates, a lumpedspring model is compared with an elastic body model in transmission loss calculation.