LAUSR

This paper studies the vertical dynamic properties of a beam-like bridge attached with standing people. A purpose-built lively bridge was constructed. Model properties of the empty structure are obtained using ambient vibration testing method. Experimental tests of the bridge attached with standing people were also conducted covering a variety of densities of occupants and different postures. The considerable number of participants and repetitions makes it possible to take into account inter- and intrasubject variability. To illustrate the variations of dynamic properties of the structure, a mathematic model of standing people-structure interaction system is developed employing the single degree-of-freedom (SDOF) human body model. It is shown that the model developed herein can effectively illustrate the experimental observations. Based on the model, the effect of damping and natural frequency of the human body on dynamic properties of the occupied structure is scrutinized. Results show that the modal properties of the human body contribute remarkably to the structural damping but little to the structural natural frequencies.