Experimental and numerical study on transfer force characteristics and sound pressure in air layer of dry-type double floor system

Abstract

The dry-type double floor system is a floor finishing structure that is mainly composed of floor panels and support legs, and widely installed for apartment buildings and offices in Japan. In this paper, an experimental study is conducted firstly. Several small specimens composed of ten support legs and floor panels are made, and the elastic properties of floor panels are determined by using the impact hammer in advance. In the experiment, two boundary conditions of the air layer are examined where the periphery of the specimen is fully open or closed by wooden frames. The transfer force of each support leg, the sound pressure of the air layer and the displacements of floor panels are measured while impacted by the standard rubber ball. Then, a numerical study is conducted by finite element analysis. The support legs and floor panels are built as Kelvin-Voigt model and plate element respectively. The vibro-acoustic analysis is conducted to investigate the influence of the air layers. It is shown that the gravity of floor panels and the contact condition of support legs on the concrete slab should be modelled to improve the accuracy of numerical analysis.