Effect of shape factor on structural reliability analysis of a surface cracked pipeline-parametric study

Abstract

The variation of crack shape factor (a/c) during propagation has an important role on calculation of the stress intensity factor (SIF), where imprecise estimation of this latter can lead us to an inaccurate prediction of failure probabilities. For the case of external cracked surface pipeline carried oil and gas products, such estimation can results undesired fault decisions like excessive repairs action or inspection planning. In this paper, the structural integrity analysis of pipeline with semi elliptical crack on the external surface is evaluated. Reliability calculations expressed in term of reliability index β are carried out based on Monte Carlo simulation and First Order reliability Method (FORM). The crack shape factors are varied to cover a variety of geometries from shallow to deep cracks while fatigue crack growth is assumed in depth direction. For SIF estimation, surface and deep point are considered. Results of the analysis indicate that for a constant crack depth a/t, the reliability index is strongly affected by a/c ratio and the trend is not similar in deep and surface point for different crack shapes.

The optimum use of high-strength steel in the construction of gas transmission pipeline

“…Various approaches are used to estimate failure probability; the most widely accepted one is the probabilistic method. This approach has the advantage of taking into account the uncertainties of the inspection tools, human errors and manufacturing defects (Guillal et al. , 2019).…”

“…Various approaches are used to estimate failure probability; the most widely accepted one is the probabilistic method. This approach has the advantage of taking into account the uncertainties of the inspection tools, human errors and manufacturing defects (Guillal et al, 2019). The probabilistic method is based on the limit state function (LSF), which is the difference between the resistance of the structure presented as the burst pressure of the corroded pipe and the applied load equal to the operating pressure.…”

Influence of Heavy Weight Drill Pipe Material and Drill Bit Manufacturing Errors on Stress State of Steel Blades

“…Design, technological and operational methods are used to increase drilling tool performance [26,27]. Design methods include improving threaded joint tightness [28][29][30]; preventing self-unscrewing [31]; rational choice of materials by studying structural changes; conducting corrosion studies of metals [32][33][34][35], and studying the processes of destruction [36,37], including different types of coatings (if present) [38][39][40][41]; substantiation of the stress state of pipes [42]; optimization of armaments, supports and units for drill bit washing [43,44], etc. The works of [45][46][47][48] present new approaches to strength and optimization estimates according to the operational criteria of rotating bearing elements for mining machines.…”

Novel hybridized adaptive neuro‐fuzzy inference system models based particle swarm optimization and genetic algorithms for accurate prediction of stress intensity factor

“…Ensuring correct estimation of the failure probability for structures that contain crack defects resulted from the surrounded environment loads is the major critical task 6,7 . Remaining fatigue life assessment (RFLA) is usually employed to evaluate the reliability analysis of structures with crack defect propagation.…”