RELIABILITY BASED INSPECTION PLANNING OF A JACK-UP RIG

A reliability based inspection planning of the spud-can-chord connections in a jack-up structure were performed as these have shown to be prone to fatigue cracking. A non-linear dynamic stress range distributions is established and the effect of non-linearity in the inspection planning is thereby included. The non-linearities and dynamic amplifications of the wave loads are determined in the stochastic seaway by a consistent procedure, based on the theory of diffusion processes. The dynamic stress range is multiplied by a correction factor, derived from finite element calculations and measurements, to obtain the hot-spot stress range needed in the fatigue calculations. The fatigue crack growth is calculated for a two- dimensional semi-elliptical surface crack, and used for the reliability based inspection procedure to obtain suitable inspection times. A numerical example illustrates the procedure.

• Supplemental Notes:
  • BOSS '94, 7th Intl Conf on the Behaviour of Offshore Structures; 12-15 July 1994; Massachusetts, USA. Procs. Publ by Pergamon, ISBN 0 08 041915 1. Vol 3, p 377 [23 p, 21 ref, 1 tab, 13 fig]
• Authors:
  • Nielsen, L P
  • Hansen, P F
• Publication Date: 1994

Language

• English

Subject/Index Terms

• TRT Terms: Fatigue (Mechanics); Inspection; Reliability; Structural analysis
• Uncontrolled Terms: Fatigue life; Structural reliability
• Old TRIS Terms: Jackup platforms
• Subject Areas: Marine Transportation;

Filing Info

• Accession Number: 00717060
• Record Type: Publication
• Source Agency: British Maritime Technology
• Files: TRIS
• Created Date: Mar 4 1996 12:00AM