Modeling Dynamic Occupant Loads

Abstract

Spectators and participants performing various maneuvers produce transient and harmonic dynamic occupant loads. Individuals and groups performed prescribed impulsive and continuous actions on a large force platform. Periodic loads are modeled with Fourier Series and exponentially decaying functions are used to describe impulsive loads. The descriptive load parameters obtained from the modeling procedures, which are functions of several independent random variables, are envisioned as random variables. Multivariate regression analysis is used to model individual loads and group loads are modeled by shifting individual loadtime histories by random‐time phase lags and superimposing the results. The time phase lag values are exponentially distributed. Periodic and transient loads for groups of four people are generated using random simulation. The simulated results correlate with the measured data; measured and simulated frequency spectra compare well for periodic loads. We suggest simplified periodic design values using a load intensity per person considering the number of active people in the crowd.