Sofiane Maachou, Belaïd Mechab and Bel Abbes Bachir Bouiadjra (DOI: 10.24874/jsscm.2025.19.02.04)

 

Abstract

 

This work uses the three-dimensional finite element method to compare three fatigue models (NASGRO, FORMAN, and WALKER) for assessing crack propagation in structures subjected to bending. The impact of several key factors, including material qualities, load ratio (R), and environmental conditions, is investigated. The chance of structural failure is assessed using the Monte Carlo method. Two mathematical functions—a sixth-degree polynomial and a Gaussian function—are analysed to determine the density distribution. This research offers important insights into the fatigue behaviour of cracked structures, enhancing the reliability of failure risk assessments. The study's conclusions emphasise the critical influence of geometric and mechanical parameters on crack propagation, providing a solid foundation for predicting fatigue life in engineering applications. The finite element method results align well with Zahoor's (1988) findings, validating the numerical model with a standard deviation of less than 3%. Environmental conditions significantly influence crack propagation, with ambient conditions enhancing the durability of TP304 compared to humid and dry environments. A higher load ratio (R=0.5) delays crack growth, increasing the number of cycles before failure. TP304 exhibits more excellent crack resistance than TP316, particularly in the NASGRO and FORMAN models, emphasising the importance of selecting an appropriate predictive model. The Gaussian distribution provides an accurate estimate of the mean and a good approximation of the probability density function.

 

Download