Stress intensity factor and elastic crack opening displacement solutions of complex cracks in pipe using elastic finite-element analyses

Jae Uk Jeong, Jae Boong Choi, Nam Su Huh, Yun-Jae Kim

Research output: Contribution to journalArticle

7 Citations (Scopus)


In the present paper, the closed-form expressions for the stress intensity factors (SIFs) and the elastic crack opening displacements (CODs) of complex-cracked pipes are derived based on the systematic three-dimensional (3D) elastic finite-element (FE) analyses. The loading conditions that are evaluated include global bending moment, axial tension, and internal pressure. In terms of geometries, the geometric variables affecting the SIFs and the elastic CODs of complex-cracked pipes, i.e., the crack angle of throughwall cracks (TWCs), the crack depth of fully circumferential, internal surface cracks in the inner surface of pipe, and the ratio of pipe mean radius to thickness, are systematically considered in the present FE analyses. The FE analysis procedure employed in the present study has been validated against the existing solutions for the circumferential TWC pipes. Using the present FE results, the shape factors of SIF and elastic COD for complex-cracked pipes are tabulated as a function of geometric variables. The results are applied for closed-form expressions of SIF and elastic COD when the pipe is subjected to simple loading conditions of bending, axial tension, or internal pressure. The proposed closed-form expressions can estimate SIF and elastic COD of complex-cracked pipes within maximum differences of 2.4% and 5.9% with FE results, respectively.

Original languageEnglish
JournalJournal of Pressure Vessel Technology, Transactions of the ASME
Issue number1
Publication statusPublished - 2016 Feb 1



  • complex crack
  • elastic crack opening displacement
  • Finite-element analysis
  • shape factor
  • stress intensity factor

ASJC Scopus subject areas

  • Mechanical Engineering
  • Mechanics of Materials
  • Safety, Risk, Reliability and Quality

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