Tacoma Bridge Failure-- a Physical Model

TL;DR

This paper presents a physics-based feedback model explaining the Tacoma Narrows Bridge collapse, emphasizing negative damping and positive feedback mechanisms supported by computational, experimental, and historical evidence.

Contribution

It introduces a novel feedback model derived from fundamental physics that explains the bridge's instability phenomena.

Findings

The model accounts for observed oscillation features.

Supported by computational and experimental data.

Aligns with historical collapse evidence.

Abstract

The cause of the collapse of the Tacoma Narrows Bridge has been a topic of much debate and confusion since the day it fell. Many mischaracterizations of the observed phenomena have limited the widespread understanding of the problem. Nevertheless, there has always been an abundance of evidence in favour of a negative damping model. Negative damping, or positive feedback, is responsible for many large amplitude oscillations observed in many applications. In this paper, we will explain some well-known examples of positive feedback. We will then present a feedback model, derived from fundamental physics, capable of explaining a number of features observed in the instabilities of many bridge decks. This model is supported by computational, experimental and historical data.