Vibration behaviour of steel-timber composite floors, part (1): Experimental & numerical investigation

Abstract

This paper is the first part of a comprehensive experimental and numerical study on the vibration behaviour of innovative steel-timber composite (STC) floors under service loading conditions. Due to the lighter weight and lower inherent damping of STC floors compared to conventional steel-concrete composite floors, vibration performance is a major serviceability concern that should be addressed to ensure that the dynamic characteristics of the system are within the range of human comfort. Extensive modal testing and numerical analysis were carried out on six STC beams and the acceleration response, natural frequencies, damping ratios and mode shapes were extracted. A 3D finite element (FE) model of the STC beams was generated and calibrated/updated by the Genetic Algorithm to minimise the difference between the experimentally measured and the numerically predicted natural frequencies, mode shapes and dynamic flexibility matrix. It is shown that the updated FE models can predict the vibration response of the idealised STC floors with reasonable accuracy. In Part 2 of the paper, the validated FE model in conjunction with the available guidelines in BS EN 1995-1-1 (EC5), AISC Design Guide 11 and the ECCS reports are utilised to assess the performance of STC floors subject to human-induced vibrations.