Three-dimensional interaction effects in internally multicracked pressurized thick-walled cylinder. Part 1: Radial crack arrays

Journal Article · Thu Aug 01 00:00:00 EDT 1996 · Journal of Pressure Vessel Technology

DOI:https://doi.org/10.1115/1.2842200· OSTI ID:390220

Perl, M ^[1]; Levy, C; Pierola, J ^[2]

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1. Ben-Gurion Univ. of the Negev, Beer-Sheva (Israel)
2. Florida International Univ., Miami, FL (United States). Dept. of Mechanical Engineering

Under certain conditions, numerous internal surface cracks develop in pressurized thick-walled cylinders, both in the radial and longitudinal directions. For fatigue life assessment of such vessels, the 3-D interaction effects among these cracks on the prevailing stress intensity factors (SIFs) need evaluation. In Part 1 of this paper, radial crack arrays are considered exclusively. The mode 1 SIF distribution for a wide range of semi-circular and semi-elliptical cracks are evaluated. The 3-D analysis is performed via the finite element method with the submodeling technique, employing singular elements along the crack front. SIFs are evaluated for arrays of up to n = 180 cracks; for a wide range of crack depth to wall thickness ratios, a/t, from 0.05 to 0.6; and, for various ellipticities of the crack, i.e., the ratio of crack depth to semicrack length, a/c, from 0.2 to 2. Using a least-squares fit, two simple expressions for the most critical (n = 2) SIFs are obtained for sparse and dense crack arrays. The formulas, which are functions of a/t and a/c, are of very good engineering accuracy. The results clearly indicate that the SIFs are considerably affected by the interaction among the cracks in the array as well as the three-dimensionality of the problem. In Part 2 of this paper, the interaction effects between longitudinal coplanar cracks will be analyzed.

• Sponsoring Organization: USDOE
• OSTI ID: 390220
• Journal Information: Journal of Pressure Vessel Technology, Journal Name: Journal of Pressure Vessel Technology Journal Issue: 3 Vol. 118; ISSN 0094-9930; ISSN JPVTAS
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
CRACK PROPAGATION
CRACKS
FATIGUE
PRESSURE VESSELS
SERVICE LIFE
STRESS INTENSITY FACTORS
THEORETICAL DATA
THREE-DIMENSIONAL CALCULATIONS