Identification of walking human model using agent-based modelling

Erfan Shahabpoor,Vitomir Racic,Aleksandar Pavic

doi:10.1016/j.ymssp.2017.10.028

Abstract

Abstract The interaction of walking people with large vibrating structures, such as footbridges and floors, in the vertical direction is an important yet challenging phenomenon to describe mathematically. Several different models have been proposed in the literature to simulate interaction of stationary people with vibrating structures. However, the research on moving (walking) human models, explicitly identified for vibration serviceability assessment of civil structures, is still sparse. In this study, the results of a comprehensive set of FRF-based modal tests were used, in which, over a hundred test subjects walked in different group sizes and walking patterns on a test structure. An agent-based model was used to simulate discrete traffic-structure interactions. The occupied structure modal parameters found in tests were used to identify the parameters of the walking individual’s single-degree-of-freedom (SDOF) mass-spring-damper model using ‘reverse engineering’ methodology. The analysis of the results suggested that the normal distribution with the average of μ = 2.85Hz and standard deviation of σ = 0.34Hz can describe human SDOF model natural frequency. Similarly, the normal distribution with μ = 0.295 and σ = 0.047 can describe the human model damping ratio. Compared to the previous studies, the agent-based modelling methodology proposed in this paper offers significant flexibility in simulating multi-pedestrian walking traffics, external forces and simulating different mechanisms of human-structure and human-environment interaction at the same time.

Highlights

Over the past three decades, investigations into a considerable number of vibration serviceability problems of structures [1,2], both in the vertical and horizontal directions, have highlighted the inability of the current design methods to reliably estimate the vibration response of structures to walking pedestrians
It should be noted here that in deriving values presented in Table 3 it was assumed that the mass of the human SDOF is the same as the physical mass of the whole of the human body
It is unlikely that this consideration would have changed significantly the overall frequency response function (FRF) simulation results as it would yield the combined human-structure FRFs which are of similar shape as those identified following the process described in this paper

Summary

Introduction

Over the past three decades, investigations into a considerable number of vibration serviceability problems of structures [1,2], both in the vertical and horizontal directions, have highlighted the inability of the current design methods to reliably estimate the vibration response of structures to walking pedestrians. This is mainly due to the methods ignoring the natural inter- and intra- subject variability of people and their interaction with vibrating structures [2,3,4,5].

Methods

Results

Conclusion