Spectral analysis of human-structure interaction during crowd jumping

Modern slender structures such as cantilever stands and long-span floors are quite sensitive to vibrations induced by crowd jumping. Existing human-structure interaction models cannot consider human body parameter variabilities and apply to jumping-induced vibration analysis of structures with closely-spaced and complex vibration modes and passive crowd. This paper herein aims to derive the equation of motion and its spectral analysis solution of an advanced model for the crowd-structure coupled system. Each person on a structure is treated as a separate spring-mass-damper, and the structure is treated as a multi-degree-of-freedom system. Each person is classified as active crowd or passive crowd according to whether he/she exerts dynamic forces on the structure. Then, the equation of motion of the crowd-structure coupled system is derived, and its spectral analysis solution is established by the stochastic vibration theory and the state space method. The frequency response function is adopted to analyze dynamic properties of the coupled system. With a previously-proposed random field model for crowd jumping loads, vibration responses of the coupled system are analyzed. Comparisons between the simulations and the results from two experiments demonstrate the feasibility of the proposed spectral analysis method.