FINITE ELEMENT METHOD AND ARTIFICIAL INTELIGENCE BASED MODELING OF MIXED- MODE CRACK PROPAGATION IN THIN STRUCTURAL STEEL SHEET

Abstract

In fracture mechanics, one of the key factors in predicting crack propagation path is the value of the crack initiation angle. crack propagation phenomenon is highly dependent on the state of the stress in the vicinity of the crack tip, therefore the stress intensity factor is consider as the most significant parameter in predicting the crack propagation path. The knowledge of the crack initiation angle is an important issue in arresting the crack. In addition SIF completely characterized the crack tip stress condition in linear elastic material. The main objective of this study is to predict the crack initiation angle for mixed mode fracture using numerical techniques. The FE code ANSYS is used to estimate the SIF numerically and estimated value of the SIF is going to be incorporated into crack initiation criterion to predict the crack initiation angle. Six criterions will be considered in this analysis and these are the maximum tangential stress (MTS) criterion, the minimum strain energy density (S)'-criterion, the maximum dilatational strain (T) criterion, the maximum triaxial stress (M) criterion, the modified MTS criterion (M.MTS) and the (R) criterion. Mild steel sheet of 1mm thickness will be used for manufacturing single edge crack specimen. All specimens have the different length and angle of inclination. In the experimental analysis, the specimen will be loaded on until the crack initiated and the angle is measured to validate both techniques.There are experimental error while finding critical stress intensity factor sothat neuro-fuzzy technique also used to determine the critical stress intensity factor which give the more accurate result.