Related Experiment Video
Updated: May 5, 2026
10:52
Simulation of Human-induced Vibrations Based on the Characterized In-field Pedestrian Behavior
Published on: April 13, 2016
8.1K
Theoretical mechanics: crowd synchrony on the Millennium Bridge
Steven H Strogatz1, Daniel M Abrams, Allan McRobie
1Department of Theoretical and Applied Mechanics, Cornell University, Ithaca, New York 14853-1503, USA. strogatz@cornell.edu
Nature
|November 4, 2005
Summary
Pedestrians on London's Millennium Bridge synchronized their steps, amplifying its sway. This study models the phenomenon using biological oscillator principles to aid bridge stabilization against crowd-induced vibrations.
Area of Science:
- Civil Engineering
- Physics
- Applied Mathematics
Background:
- The Millennium Bridge in London experienced significant lateral vibrations upon opening due to pedestrian footfalls.
- Initial theories attributed the sway to the bridge's innovative design, but this was later disproven.
Purpose of the Study:
- To model the phenomenon of pedestrian-induced bridge sway.
- To understand the collective synchronization of pedestrians as a contributing factor.
- To provide engineers with methods to stabilize crowded footbridges.
Main Methods:
- Adapted mathematical models originally developed for the collective synchronization of biological oscillators (e.g., neurons, fireflies).
- Applied these models to analyze pedestrian-induced vibrations on the Millennium Bridge.
Main Results:
- The study successfully modeled the notorious side-to-side swaying of the Millennium Bridge.
- Pedestrian synchronization with the bridge's natural frequency was identified as the primary cause, not the design.
- The model provides a framework for understanding and predicting such phenomena.
Conclusions:
- Crowd synchronization is a critical factor in the dynamic response of footbridges.
- The adapted modeling approach offers a valuable tool for engineers to design effective damping systems.
- This research helps prevent future occurrences of excessive bridge vibrations caused by pedestrian collective behavior.
Related Concept Videos
01:07Static Equilibrium - II
8.0K
Static equilibrium is a special case in mechanics that is very important in everyday life. It occurs when the net force and the net torque on an object or system are both zero. This means that both the linear and angular accelerations are zero. Thus, the object is at rest, or its center of mass is moving at a constant velocity. However, this does not mean that no forces are acting on the object within the system. In fact, there are very few scenarios on Earth in which no forces are acting upon...
8.0K
01:09Torsional Pendulum
6.9K
A torsional pendulum involves the oscillation of a rigid body in which the restoring force is provided by the torsion in the string from which the rigid body is suspended. Ideally, the string should be massless; practically, its mass is much smaller than the rigid body's mass and is neglected.
As long as the rigid body's angular displacement is small, its oscillation can be modeled as a linear angular oscillation. The amplitude of the oscillation is an angle. The role of mass is played...
As long as the rigid body's angular displacement is small, its oscillation can be modeled as a linear angular oscillation. The amplitude of the oscillation is an angle. The role of mass is played...
6.9K
01:29Wheatstone Bridge
3.1K
An ohmmeter is a resistance-measuring device. It works by applying a voltage to a resistor of unknown resistance and measuring the current across the resistor. The resistance value is deduced using Ohm's law. Usually, the standard configuration of an ohmmeter comprises a voltmeter or an ammeter. However, such configurations are limited in accuracy because the meters alter the voltage applied to the resistor and the current that flows through it.
Thus, for accurate resistance measurements, a...
Thus, for accurate resistance measurements, a...
3.1K
01:28An Introduction to Mechanics
7.2K
Humans have been making ships, shelters, pyramids, weapons, agricultural equipment, and many more items without recording the process or theory behind them for centuries. It would be challenging to document the evolution of mechanics from its origin to the present.
According to records, the history of mechanics starts with Aristotle (384–322 BC). He related mechanics to physical theory, aiming for a universal synthesis.
Newton defined mechanics as the branch of physical science that...
According to records, the history of mechanics starts with Aristotle (384–322 BC). He related mechanics to physical theory, aiming for a universal synthesis.
Newton defined mechanics as the branch of physical science that...
7.2K
01:15Design Example: Strain Gauge Bridge or Wheatstone Bridge
1.3K
The utilization of strain gauges as transducers for converting mechanical strain into electrical signals is a common practice in various engineering applications. These strain gauges are frequently integrated into Wheatstone bridge circuits to accurately measure parameters such as force or pressure. Within this context, each element within the circuit exhibits a resistance that undergoes subtle variations when subjected to mechanical strain. The primary objective is to convert minuscule...
1.3K
01:12Classical Mechanics
175
Classical mechanics provides a mathematical description of the motion of bodies under the influence of forces. A key principle within this field is the work-energy theorem, which establishes a bridge between the net work done on an object and its kinetic energy.The work-energy theorem states that the net work done on a particle by all the forces acting on it equals the change in its kinetic energy.In simple terms, the work-energy theorem is a method to analyze the effects of forces on an...
175