Evaluation of Structural Responses on Artificial Fatigue Crack for Bulb Rib Orthotropic Deck

Abstract

An orthotropic steel deck is quite susceptible to fatigue cracking at its welded joints depending on the structural stiffness, occurrence of high-magnitude cyclic load stress, and complicated geometric details of the welded joints. This study experimentally and numerically investigated the structural behavior of an orthotropic steel deck with bulb ribs. The behavior of the deck was examined, particularly the warped deformations of the developed fatigue cracks and the uniform stress distributions against moving loads attributed to the deck's asymmetric bulb ribs. An artificial fatigue crack serving as an authentic model of a fatigue crack was developed in the longitudinal bulb rib of an orthotropic steel deck in actual service. The loading tests were conducted on an orthotropic steel deck with artificial fatigue cracks. The test results were evaluated based on the artificial fatigue crack length on the longitudinal bulb ribs and compared with a nonlinear full finite-element analysis model considering the nonlinear contact behavior of artificial fatigue cracks.