A Study of Fatigue Crack Propagation Paths at U-Rib Welds in Orthotropic Bridge Decks using a Phased-Array Imaging Technique

Abstract

In this paper, the fatigue failure mode of single- and double-sided welded joints in orthotropic bridge decks is innovatively investigated with the phased-array imaging technique for verifying the fatigue failure path defined using the traction structural stress method. The full-scale fatigue specimen tests are conducted, and the fatigue depth and length are imaged and sized for the completeness of fatigue crack propagation law. It can be concluded that the fatigue failure mode of single- and double-sided welded joints is proven to be the thickness-through mode, which is consistent with the fatigue failure path defined in the traction structural stress method. The analysis method for calculating the main characters is first proposed, and the fatigue crack propagation law of the crack length and depth in the through-thickness mode is determined for completeness.