AN IMPROVED FATIGUE ANALYSIS FOR OFFSHORE STRUCTURES

This paper presents a spectral fatigue damage calculation on offshore structures subjected to non-narrow banded Gaussian stress processes. The calculation is based on use of the Palmgren-Miner's rule and a multilinear S-N fatigue model. In the calculation, an equivalent stress range, which is defined as dependent on the absolute value of stress maxima and a parameter, is used. This parameter is calculated in terms of the spectral bandwidth measure of the stress process and the slope of the S-N line used. For this purpose, the rainflow cycle counting algorithm and the Monte-Carlo procedure are used to determine stress ranges and cycles from time simulations of a number of stress spectra of a monopod structure. A relation between the equivalent stress range parameter and the commonly known damage correction factor is constructed. Cumulative damage arising during a sea state and in a long-term period is presented.

• Supplemental Notes:
  • Marine Structures, v 4 n 4, 1991, p 333 [20 p, 13 ref, 5 tab, 9 fig]
• Authors:
  • Karadeniz, H
• Publication Date: 1991

Language

• English

Subject/Index Terms

• TRT Terms: Fatigue (Mechanics); Offshore structures; Probability density functions; Structural analysis
• Old TRIS Terms: Normal density functions
• Subject Areas: Bridges and other structures; Marine Transportation;

Filing Info

• Accession Number: 00701296
• Record Type: Publication
• Source Agency: British Maritime Technology
• Files: TRIS
• Created Date: Aug 14 1995 12:00AM