Numerical Investigation on the Natural Frequency of RC Slab Reinforced with Cambered Steel Beam for Reducing Heavy-Weight Impact Noise

Abstract

In an apartment building, inter-floor noise occurs due to the residents' movements. The floor impact noises are divided into light and heavy-weight impact sounds depending on the impact source. This study proposed cambered steel beam reinforcement technology installed under floor slab to reduce heavy-weight impact noise. The beam for stiffness reinforcement is supported by both side of the walls in the ceiling structure, and it reduces inter-floor noise by applying upward force to the bottom surface of the slab and controlling the slab vibration characteristics. In order to verify the effectiveness of the proposed technology and investigate the natural frequency of the floor, finite element analysis model was developed for the 84m2 type apartment plan with bearing wall structure. From the eigenvalue analysis, it is known that the first natural frequency increased by 0.37~12.67% depending on the cross-section size of the cambered steel beam. Based on the first natural frequency, as a result of evaluating the vibration standards of residential buildings presented in DIN 4150-2, the vibration characteristics of the slab were improved by reducing the vibration value KB by up to 75.20%. Therefore, this study indicated that in an apartment building reinforced with cambered steel beams, inter-floor noise caused by heavy-weight impact sound was reduced.