Corrosion Initiation and Crack Propagation in Wires of Cable Suspension Bridges

Columbia University, New York NY

Investigators

Abstract

9901378 This research project stems from the results and conclusions of a previous study on the environmental deterioration of high-strength bridge wires and it focuses on the initiation of the corrosion process and on the subsequent crack formation and propagation mechanism and their interaction with the mechanical stresses. The main purpose of this project is to answer the difficult question of "why are there broken wires in the main cables of suspension bridges in service conditions"? The research project will focus on 1) the initiation and location of the corrosion process in bridge wires, 2) the effects and importance of residual stresses and their superposition with service stresses, 3) the lever of service loads that wires can carry and their interaction with the corrosion process, and on 4) the galvanizing process and wire manufacturing. Particular attention will be given to 1) crack formation and distribution of residual stresses, 2) corrosion initiation and pitting and their relation to microcracks, residual stresses and material flaws, 3) the fundamental interrelation between mechanical stresses, corrosion initiation and propagation and hydrogen embrittlement, and 4) the effects of wire manufacturing on the distribution of residual stresses.