Mechanical Behavior of Steel Pipe Bends: An Overview

Abstract

An overview of the mechanical behavior of steel pipe (elbows) is offered, based on previously reported analytical solutions, numerical results, and experimental data. The behavior of pipe bends is characterized by significant deformations and stresses, quite higher than the ones developed in straight pipes with the same cross section. Under bending loading (inplane and outofplane), the main feature of the response is crosssectional ovalization, which influences bending capacity and is affected by the level of internal pressure. Bends subjected to cyclic inplane bending exhibit fatigue damage, leading to base metal cracking at the elbow flank. Using advanced finiteelement tools, the response of pipe elbows in buried pipelines subjected to groundinduced actions is also addressed, with emphasis on soil–pipeline interaction. Finally, the efficiency of specialpurpose finite elements for modeling pipes and elbows is briefly discussed.