Modeling the Effects of a Human Standing on a Structure Using a Closed Loop–Control System

The influence of occupants on the dynamic properties of structures is not totally understood and can lead to overdesign, extreme vibrations, or even the collapse of buildings, stadiums, and other structures subjected to the action of standing large crowds. Several numerical models have been proposed to represent the effects of people on the structure, showing that there is not yet a consensus between the different approaches. Most of the models use masses, springs, and dampers to model the human in a standing position. Arguably, the human model could be more complex. The motor system of the human body is a complex interaction of systems (musculoskeletal, nervous, proprioceptive, etc.), all responding at distinct levels of excitation, a phenomenon that is difficult to model with a spring-mass-damper (SMD) system. This paper proposes the use of a closed-loop controller system to model the interaction of a standing human on a structure. The model is updated in a probabilistic sense using experimental data collected in a laboratory setting. The probabilistic approach allows exploration of dependencies between parameters, as well as a probabilistic estimation of the model parameters. The proposed model obtained is validated by predicting the dynamic characteristics of the combined human–structure interaction system after the mass of the structure has been modified. The closed loop controller model is able to predict the dynamic behavior of the human–structure system for a specific individual more closely than traditional SMD models found in the literature.