Formulation of human–structure interaction for vibration serviceability of steel–concrete composite floors

In this paper, an analytical model representing the human–structure interaction (HSI) system of steel–concrete composite floors under human vibrations is described and discussed. In the theoretical analysis, the human and composite floor are idealized as the subsystems represented by a linear oscillator model and the anisotropic rectangular plate, respectively. The analytical formula for the natural frequency and acceleration response of a steel–concrete composite floor with various boundary conditions and HSI is proposed. For analyzing the natural frequencies, the human subsystem can be treated as a structural system with added mass, damping, and stiffness. The proposed analytical solution on the acceleration response is based on the combined weighted residual and perturbation method, which is simple to be implemented and can avoid the cumbersome numerical calculations. The theoretical solutions are validated with the experimental results. A sensitivity study utilizing the analytical solution was also conducted to investigate the effects of walking frequency, occupant weight, sprung mass, equivalent damping ratio, occupant natural frequency, and occupant spacing on the natural frequency and peak acceleration.