PSI - Issue 66

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Alfonso Fernández-Canteli et al. / Procedia Structural Integrity 66 (2024) 296–304 A. Fernández-Canteli et al / Structural Integrity Procedia 00 (2025) 000–000

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Nomenclature cdf

cumulative distribution function

pdf probability density function FCGR fatigue crack growth rate crack size *

modified crack size pre-cracked length 0 location parameter of the three-parameter Weibull distribution, denoting the initial location of the starting crack in the REX model initial test crack size crack size at failure probability of failure specimen thickness Young’s modulus experimental number of cycles number of cycles from the origin of the prospective crack growth � normalized number of cycles for the prospective number of cycles associated with the critical crack size number of cycle from the predicted retrospective crack size, 0 , to the initial test crack size,

maximum stress intensity factor (SIF) , Asymptotic SIF for the threshold region fracture toughness asymptotic SIF to be distinguished from the stress ratio given implicity as / specimen width shape parameter of the three-parameter Weibull distribution scale parameter of the three-parameter Weibull distribution shape parameter of the Gumbel distribution scale parameter of the Gumbel distribution specimen width maximum stress minimum stress 2. Proposed methodology

In this Section, a new methodology, applicable to the whole process related to the determination of the crack growth rate curve, is presented. It represents a unitary procedure, which consists in the successive application of the following steps: 2.1. Analytical definition of the curve based on the REX model The experimentally data, collected from the crack growth monitoring during the test, are assumed to belong to a stochastic sample function [7], which adequately normalized is identified as a Weibull cdf: