Probabilistic Stress Intensity Factor Prediction of Surface Crack Using Bootstrap Sampling Method

Fatigue cracks commonly occur for in-service engineering structures. The main parameter for fatigue crack is the stress intensity factor (SIF). The SIF is an indicator of the fatigue crack growth and remaining life of a structure. Nonetheless, a problem was raised when determining the remaining life since the SIF could not be presented in physical phenomena. Thus, a technique is required to predict the range of SIF. Maximum and minimum bounds of SIF help estimate the range of remaining life. This paper aims to predict a structure's safe and failure region during the fracture process based on the SIFs. The primary tool is S-version Finite Element Model (S-FEM). Yet, S-FEM unable to compute random variables in analysis. Thus, the Bootstrap is developed and embedded into S-FEM for computing random variables in the analysis. The random variables are utilised to predict a range of SIFs. The SIFs are generated based on one hundred samples. The samples are randomly generated based on the distribution of material properties. A lognormal distribution is used to generate the material properties. The sampling process is computed based on the bootstrap method. The embedded Bootstrap in S-FEM was introduced as BootsrapS-FEM. When the samples exceed the fracture toughness of 29 MPa.√m, the failure region is indicated at the angle 2ϕ/π = 0.627 to 1 with 6% of failure samples. The safe region is observed at angle 2ϕ/π = 0 to 0.626 with 94% of the samples. The failure region is essential in this analysis to prevent unstable crack growth

Probabilistic Stress Intensity Factor Prediction of Surface Crack Using Bootstrap Sampling Method

Fatigue cracks commonly occur for in-service engineering structures. The main parameter for fatigue crack is the stress intensity factor (SIF). The SIF is an indicator of the fatigue crack growth and remaining life of a structure. Nonetheless, a problem was raised when determining the remaining life since the SIF could not be presented in physical phenomena. Thus, a technique is required to predict the range of SIF. Maximum and minimum bounds of SIF help estimate the range of remaining life. This paper aims to predict a structure's safe and failure region during the fracture process based on the SIFs. The primary tool is S-version Finite Element Model (S-FEM). Yet, S-FEM unable to compute random variables in analysis. Thus, the Bootstrap is developed and embedded into S-FEM for computing random variables in the analysis. The random variables are utilised to predict a range of SIFs. The SIFs are generated based on one hundred samples. The samples are randomly generated based on the distribution of material properties. A lognormal distribution is used to generate the material properties. The sampling process is computed based on the bootstrap method. The embedded Bootstrap in S-FEM was introduced as BootsrapS-FEM. When the samples exceed the fracture toughness of 29 MPa.√m, the failure region is indicated at the angle 2ϕ/π = 0.627 to 1 with 6% of failure samples. The safe region is observed at angle 2ϕ/π = 0 to 0.626 with 94% of the samples. The failure region is essential in this analysis to prevent unstable crack growth

Retracted: Weighting methods in the construction of area deprivation indices

This article was withdrawn and retracted by the Journal of Fundamental and Applied Sciences and has been removed from AJOL at the request of the journal Editor in Chief and the organisers of the conference at which the articles were presented (www.iccmit.net). Please address any queries to [email protected]