Surface Crack Growth in Offshore Metallic Pipes under Cyclic Loads: A Literature Review

Abstract

The surface crack, also known as the partly through-thickness crack, is a serious threat to the structural integrity of offshore metallic pipes. In this paper, we review the research progress in regard to surface crack growth in metallic pipes subjected to cyclic loads from the fracture mechanics perspective. The purpose is to provide state-of-the-art investigations, as well as indicate the remaining challenges. First, the available studies on surface cracked metallic pipes are overviewed from experimental, numerical, and analytical perspectives, respectively. Then, we analyse state-of-the-art research and discuss the insufficiencies of the available literature from different perspectives, such as surface cracks and pipe configurations, environmental influential parameters, the girth welding effect, and numerical and analytical evaluation methods. Building on these surveys and discussions, we identify various remaining challenges and possible further research topics that are anticipated to be of significant value both for academics and practitioners.

Analysis of the Root Causes of Damage to the Edges of Tank Manholes on the Main Deck of Handy-Size Bulk Carriers

“…The authors hypothesized that the main decks cracked around manholes because of very poor-quality welded joints and poor-quality steel used to make manholes, which contain large amounts of non-metallic impurities. These factors were accompanied by excessive mechanical loads associated with hull reactions to waves and operation in a corrosive and low-temperature environment [ 44 , 45 , 46 ]. Another important factor is the influence of residual stresses resulting from welding on the appearance of cracks inside the welds.…”

Finite Element Analysis of Fatigue in Offshore Pipelines with Internal and External Circumferential Cracks

“…The stress intensity factor (SIF) is used in crack growth prediction to assess whether a specific crack causes a structural component to fracture [6,8,11,[14][15][16][17][18]]. Most of the numerical studies on surface cracked offshore metallic pipes readily available in open literature focus on the growth of shallower surface cracks (a/c < 1.0) due to cracks detected at inspection having small aspect ratios [19]. For example, in [8] the SIFs of surface cracks up to aspect ratios of a/c < 1.0 were presented based on contour integral evaluation on each mesh element node along the crack front.…”

“…One of the objectives of this paper is to, therefore, study the circumferential crack growth of surface cracks in an offshore metallic pipe up to an aspect ratio of a/c = 1.6. Furthermore, most of the previous work, for example, [6,[9][10][11][12][13][14][15][16][17][18][19], address either the effects of longitudinal cracks or external circumferential cracks under different loading (e.g., internal pressure, bending, and/or torsion) on SIF estimations. Analytical solutions to calculate the SIFs for circumferential surface cracks in pipes subjected to tension and bending loads were developed by [20] for a/c ratios up to 1.0 and later adopted in flaw assessment guides e.g., [3].…”

“…Results from the analyses were compared with results obtained from previous works [26,28] and showed good agreement. Furthermore, due to the lack of study on circumferential internal surface crack in metallic pipe under tension which is also suggested in [19], analyses on a typical offshore pipeline containing internal and external surface cracks, respectively, are presented herein.…”

Fatigue crack growth studies on welded joints with multiple weld toe cracks

“…Surface cracks in plain plates have been well researched [27,[56][57][58][59][60][61] (Figure 2-2 [62]), as many types of structural components can be simplified to plate elements. The solution by Newman and Raju is the most commonly used, providing SIF solutions for surface cracks with different sizes and shapes in plain plates [26,58,59].…”