Fatigue failures in engineering structures occur predominately at component connections, even in those structures that have been designed, fabricated, and inspected according to Code. Connections refers to those locations in a structure where elements are joined to reconcile changes in geometry and/or accommodate fabrication or service requirements.For example, fatigue cracking in bridges, ships, offshore structures, pressure vessels, and buildings occurs, almost without exception, at the welded or bolted connections and attachments such as cover plate fillet weld terminations, stiffeners, backing bars, and seam and girth weld toes (Refs. 1-1 to 1-3).