Interaction effects in combined arrays of radial and longitudinal semi-elliptical surface cracks in pressurized thick-walled cylinder

Conference · Sun Dec 01 00:00:00 EST 1996

OSTI ID:404295

Perl, M ^[1]; Levy, C; Wang, 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

In two previous papers, the interaction effects for two separate cases of large arrays of semi-elliptical, internal, surface cracks in a thick-walled, cylindrical pressure vessel were studied. First, arrays of radial cracks were considered followed by the study of longitudinal-coplanar crack arrays. Radial crack density and longitudinal crack spacing were found to have opposing effects on the prevailing stress intensity factors (SIFs). Consequently, in the present paper combined arrays of both radial and longitudinal cracks are considered, and their interaction effects are studied. The mode I stress intensity factor (SIF) distribution for numerous configurations of combined semi-circular and semi-elliptical crack arrays are evaluated. The 3-D analysis is performed by the finite element (FE) method and the submodeling technique, employing singular elements along the crack front. The effects of crack density in the radial direction and relative spacing in the longitudinal direction on the SIFs are studied for combined arrays of up to 32 radial cracks and having longitudinal relative spacing of 2c/d of 0.25 to .99; for a wide range of crack depth to wall thickness ratios, a/t, from 0.05 to 0.4; and for various ellipticities of the crack, i.e., the ratio of crack depth to semi-crack length, a/c, from 0.2 to 1.5. The results clearly indicate that the SIFs are considerably affected by the interaction among the cracks, and that the SIF values depend upon the radial density and longitudinal spacing, the crack depth and ellipticity, as well as the three dimensional nature of the problem.

• OSTI ID: 404295
• Report Number(s): CONF-960706--; ISBN 0-7918-1785-7
• Resource Type: Conference proceedings
• Conference Information: American Society of Mechanical Engineers (ASME) pressure vessels and piping conference, Montreal (Canada), 21-26 Jul 1996; Is Part Of Pressure vessels and piping codes and standards: Volume 1. PVP-Volume 338; Esselman, T.C. [ed.] [Altran Corp., Boston, MA (United States)]; Adams, T.M. [ed.] [Stevenson and Associates, Cleveland, OH (United States)]; Bhavnani, D. [ed.] [Public Service Electric and Gas Co., Hancock`s Bridge, NJ (United States)]; Cofie, N.G. [ed.] [Structural Integrity Associates, Inc., San Jose, CA (United States)]; Jones, D.P. [ed.] [Westinghouse Electric Corp., West Mifflin, PA (United States)]; Olson, D.E. [ed.] [Sargent and Lundy, Chicago, IL (United States)]; Thailer, H.J. [ed.] [Pacific Gas and Electric Co., San Francisco, CA (United States)]; PB: 295 p.
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
CRACKS
FATIGUE
NUMERICAL ANALYSIS
ORIENTATION
PRESSURE VESSELS
STRESS INTENSITY FACTORS
THREE-DIMENSIONAL CALCULATIONS