Comprehensive Comparisons of Two-and Three-Dimensional Numerical Estimation of Stress Intensity Factors and Crack Propagation in Linear Elastic Analysis

Abstract

IntroductionReliable structural integrity and reliability assessment of the critical structural components remain an essential process for the safety of engineering structures including crack initiation and propagation. Stress intensity factors are important parameters for failure analysis of cracked structures because it has been used for the prediction of crack initiation and cracks propagation path. Stress intensity factors (SIFs) defines the amplitude of the crack tip singularity. These stresses near the crack tip increase in proportion to SIFs. Moreover, the stress intensity factor completely defines the crack tip conditions; if SIFs are known, it is possible to solve for all components of stress, strain, and displacement. Numerous handbooks of stress intensity factors calculation are available [1,2] for specific geometries and loading. Due to the limitation of the analytical solution of stress intensity factors, the vast majority of fracture problems encountered in engineering practice should be resolved with a numerical analysis method [2]. Stress intensity factors can be computed by various methods, such as the boundary element method (BEM), finite element method (FEM) by [4], both FEM and BEM by [5]. The basic practical problem facing a designer is to make a decision as to the method for determining stress intensities.There exist two categories of commercial FEM programs, finite element programs such as ANSYS [6,7], ABAQUS, NASTRAN, etc. can be used to add elements manually and perform analysis on complex structures. The other type is professional FEM programs, such as NASGROW, AF-GROSS, etc. these are more expensive but provide a high precision calculation [8]. However, there are limitations when it comes to more complicated geometries and Abstract: This paper presents a comprehensive comparison of two finite element software in two and three dimensions. The first is a two-dimensional crack growth simulation program developed as source code by using Visual Fortran Language whereas the second is ANSYS mechanical program (3D structural analysis for fracture mechanic analysis). The procedure consists of computing stress intensity factors (SIFs), the crack growth path and the stresses and strain distributions via an incremental analysis of the crack extension, considering two and threedimensional analysis. Comparisons between this two software were performed for different case studies for stress intensity factors as well as crack growth trajectory. This source code includes the mesh generator based on the advancing front method as well as all the pre and post process for the crack growth simulation under linear elastic fracture mechanics theory with a user-friendly interface. The maximum circumferential stress criterion was used for prediction of the crack growth in isotropic materials under mixed-mode loading. Furthermore, the equivalent domain integral method has been used for calculating the stress intensity factors values during crack growth. Verification of the predicted crack path and stress intensity...

Numerical Simulation of Mixed‐Mode Fatigue Crack Growth for Compact Tension Shear Specimen

“…It has been estimated that 60% to 80% of the failures of mechanical components are associated with fatigue [8]. Various problems concerning fatigue crack growth can be found in the literature using different approaches for simple and complex geometries in two and three dimensions [9][10][11][12][13]. Combined action of tensile stress, cyclic stress, and plastic strain initiates failure due to fatigue phenomena.…”

Fatigue Life of 7005 Aluminum Alloy Cruciform Joint Considering Welding Residual Stress

“…Regarding the cruciform joint residual stress, it has different effects on the crack initiation and propagation. For the former, the crack initiation, the effect of residual stress is mostly noted in the stress concentration [ 39 ], While in the latter, the crack propagation, its effect is mostly found in the stress intensity factor [ 40 , 41 ]. The relationship between the various calculation steps is shown in Figure 1 , it can be seen that the calculation process consists of three parts.…”

Nonplanar Crack Growth Simulation of Multiple Cracks Using Finite Element Method

“…ere exist two categories of commercial FEM programs: finite element programs such as ANSYS [6,7], ABAQUS, and NASTRAN can be used to add elements manually and perform analysis on complex structures. e other type is professional FEM programs such as NASGROW and AF-GROSS, and they are comparatively very accurate in providing a high-precision calculation [8].…”

“…Initial mesh for the plate with a hole and three interacting cracks 6. Advances in Materials Science and Engineering due to the influence of the hole on the crack direction.…”