Probabilistic Models of Uncertainties in Fatigue and Fracture Reliability Analysis

Abstract

Probabilistic methods enable the modelling of the uncertainties associated with the integrity assessment of structures containing defects to be taken into account. This paper presents a critical review of recent developments in the probabilistic modelling of the uncertainties associated with fatigue and fracture reliability assessment. A number of probabilistic models for the principal parameters in the S-N curve, fatigue crack growth functions and fracture analysis are presented and discussed with particular emphasis on the identification of future needs for the development of suitable code procedures for offshore structures.

Weld defect frequency, size statistics and probabilistic models for ship structures

“…In engineering critical assessment (ECA), when reliable data over the whole range of possible values are not available, it is common to treat one or all of these parameters deterministically by assuming (an) upper/lower bound value(s). In reliability analyses, however, accurate and realistic defect size distributions is a vital input [32]. The choice of distribution type depends on two factors: 1. the nature of the physical phenomena modelled and 2: the goodness of fit of the data to distribution.…”

Calibration of Design Fatigue Factors for Offshore Wind Turbine Support Structure Based on Fatigue Test Database

“…Zhao et al [11] found that the CoV varies from case to case, and recommends a log normal distribution with mean 𝜇 = 1 and CoV = 0.45 based on averaging results from a number of tests/models, as shown in…”

Bi-Linear Fatigue and Fracture Approach for Safety Analysis of an Offshore Structure

“…Letting D = Ap, the basic damage expression of Eq. (10) can be expressed in terms of the time to failure T = (12) Log (Stress intensity factor range, K)…”

“…Risk assessment is essential to regulate the design so that the resulting structure is safe, serviceable, and economical, ensuring satisfactory performance during its design life period. As evidenced from similar applications in offshore structures [5][6][7][8] and other steel structures [9][10][11][12], one possible avenue for meeting these objectives is the implementation of the fracture mechanics approach, in light of the load and response uncertainties, probabilistic modeling, and reliability analysis. The work described in this paper is aimed at the development of a probabilistic methodology for the assessment of marine structures using the bilinear S-N curve and fracture mechanics approaches.…”