Single body sensor for calibration of Spring-Mass-Damper parameters in biodynamic pedestrian modelling

Abstract

For structural design and vibration monitoring purposes, several simplified equivalent-force models or more complex computational strategies are available to describe Human-Structure Interaction (HSI) phenomena on pedestrian systems, and in particular the vertical reaction forces induced by walking occupants. Among others, various Spring-Mass-Damper (SMD), Single Degree of Freedom (SDOF) biodynamic models of literature can be used to mechanically describe a single pedestrian in the form of equivalent body mass m, spring stiffness k and viscous damping coefficient c. Basically, existing SMD formulations are characterized by specific theoretical assumptions and (often complex) experimental methods for the calibration of m, k, c. Usually, SMD parameters can be optimally quantified when multiple sensors (on pedestrian’s body and on the structure) are used to capture motion features and the corresponding reaction force. In this paper, body accelerations of a pedestrian are tracked by means of a single Centre of Mass (CoM) sensor and are elaborated to derive basic input parameters for an alternative, newly optimized SMD model. Experimental registrations from a total of 30 random walks and more than 300 gaits (on rigid floor) are taken into account, and fitting expressions for m, k, c are proposed. The present SMD formulation (SMD-0) is validated towards a selection of literature proposals (SMD-1 to SMD-4), based on parametric numerical dynamic analyses (100 in total), which are carried out by taking into account various pacing frequencies (fp = 1.5–2 Hz the explored range) and four different pedestrian structures / floors (F#1 to F#4). The comparison of classical performance indicators for human-induced structural vibrations proves the efficiency and potential of current SMD-0 approach, and suggests further investigations in support of optimized protocols.