Fracture Mechanics-Based and Continuum Damage Modeling Approach for Prediction of Crack Initiation and Propagation in Integral Abutment Bridges

摘要

Piles in integral abutment bridges (IABs) are prone to fatigue damage crack attributable to cyclic load caused by daily and seasonal temperature variations. Previous research has shown that the fatigue life of these piles can be as low as three decades. It is essential to be able to predict the fatigue-crack initiation site and propagation path and have an accurate estimate of the total time to failure. This research presents a multiscale modeling approach used to accurately determine the local deformation and stresses in the critical pile. A continuum-based damage modeling approach is used to determine the location of the crack and its path as the number of daily cycles increase. The model is then verified using a fracture-based modeling approach, Paris Law, which assumes local plastic deformation at the tip of the crack. Paris Law constants for this case are generated and compared with literature values presented for the steel material used in the piles and show a very good correlation.