Finite Element Models of a Benchmark Footbridge

Fiammetta Venuti,Marc Lizana,Marco Domaneschi,Branko Glisic

doi:10.3390/app11199024

Abstract

Modern footbridges are often lively structures, characterized by natural frequencies that fall in the range of pedestrian activities, such as walking, running, and jumping. Therefore, serviceability assessment under human-induced excitation is crucial both at the design stage and during the footbridge lifetime. This paper presents and validates two different FE models of an existing footbridge with very complex geometry: the Streicker Footbridge at the Princeton University Campus. It represents a benchmark in the field as a testbed for vibration serviceability assessments under pedestrian excitation. The real structure is equipped with strain and temperature sensors that are currently used to collect measurements in both static and dynamic modes for research and educational purposes in Structural Health Monitoring (SHM). Based on detailed drawings of the Streicker Footbridge, a three-dimensional beam-based model was developed to represent the complex behavior of the full-scale benchmark bridge. Subsequently, a more refined discretization of the bridge deck adopting shell elements was inserted. The bridge Finite Element models were validated against available SHM data concerning static and dynamic tests. The relevant ANSYS APDL script files along with an example of pedestrian jumping application are available upon request for further research developments on the relationship between pedestrians and the benchmark footbridge.

Highlights

Serviceability assessment of footbridges under human-induced excitation has become a challenging engineering problem since the London Millennium Bridge was closed in 2000 due to unexpected lateral vibrations induced by synchronized pedestrians [1]
The aim of this paper is to make available to the scientific community a new benchmark structure, the Streicker footbridge, which is in service at the Princeton University
This paper presents a new phase of the research on the Streicker Bridge benchmark

Summary

Introduction

Serviceability assessment of footbridges under human-induced excitation has become a challenging engineering problem since the London Millennium Bridge was closed in 2000 due to unexpected lateral vibrations induced by synchronized pedestrians [1]. That episode highlighted a gap in the knowledge and related code provisions concerning pedestrian dynamic loads and their dynamic effect on flexible structures. A great number of studies have been devoted to fill the gap, and significant advancements have been made both in the phenomenological analysis and in the modelling of dynamic loads induced by walking pedestrians (for a review see, e.g., [2,3,4]). There is still lack of an unanimously accepted procedure to assess the dynamic behavior of footbridges under pedestrian excitation. In this context, the current knowledge could be greatly extended by making available experimental data collected on real footbridges, which so far are very scarce.

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