Non-linear fracture mechanics analyses of part circumferential surface cracked pipes

• Published in: International journal of fracture Vol. 116; no. 4; pp. 347 - 375
• Main Authors: KIM, Yun-Jae, KIM, Jin-Su, LEE, Young-Ze, KIM, Young-Jin
• Format: Journal Article
• Language: English
• Published: Heidelberg Springer 01.08.2002; Springer Nature B.V
• Subjects: Applied sciences; Computational techniques; Deformation; Estimates; Exact sciences and technology; Finite-element and galerkin methods; Fracture mechanics; Fracture mechanics (crack, fatigue, damage...); Fracture mechanics, fatigue and cracks; Fundamental areas of phenomenology (including applications); Influence functions; Internal pressure; Mathematical analysis; Mathematical methods in physics; Mechanical engineering. Machine design; Nonlinear analysis; Parameter estimation; Physics; Pipes; Pipings, valves, fittings; Solid mechanics; Steel design; Structural and continuum mechanics; Surface cracks; J integral; Creep; Circumferential crack; Rupture; Pressure vessel; C integral; Pipe; Modeling; Finite element method; Influence function; Inelasticity; Three dimensional model; Elastoplasticity; Piping; Non linear effect; Internal pressure
• ISSN: 0376-9429; 1573-2673
• DOI: 10.1023/A:1020779611803

This paper provides engineering estimates of non-linear fracture mechanics parameters for pipes with part circumferential inner surface cracks, subject to internal pressure and global bending. Solutions are given in the form of two different approaches, the GE/EPRI approach and the reference stress approach. For the GE/EPRI approach, the plastic influence functions for fully plastic J solutions are tabulated based on extensive 3-D FE calculations using deformation plasticity, covering a wide range of pipe and crack geometries. The developed GE/EPRI-type fully plastic J estimation equations are then re-formulated using the concept of the reference stress approach for wider applications. The proposed reference stress based estimates are validated against detailed 3-D elastic-plastic and elastic-creep FE results. For a total of 26 cases considered in this paper, agreement between the proposed reference stress based J and C* estimates and the FE results is excellent. An important aspect of the proposed estimates is that they not only are simple and accurate but also can be used to estimate J and C* at an arbitrary point along the crack front.