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

Author(s):  
Abdulnaser M. Alshoaibi ◽  
1979 ◽  
Vol 101 (1) ◽  
pp. 12-17 ◽  
Author(s):  
T. E. Kullgren ◽  
F. W. Smith

A linear elastic analysis using the finite element-alternating method is conducted for problems of single semi-elliptical and double quarter-elliptical cracks near fastener holes. Mode-one stress intensity factors are presented along the crack periphery for cases of open and loaded holes and crack opening displacements are calculated. Results are shown for a variety of crack geometries and loading conditions and for two ratios of hole diameter to plate thickness.


2017 ◽  
Vol 754 ◽  
pp. 145-148
Author(s):  
J. Li ◽  
C. Shi ◽  
Pi Hua Wen

The finite block method (FBM) is developed to determine stress intensity factors with orthotropic functionally graded materials under static and dynamic loads in this paper. The higher order derivative matrix for two and three dimensional problems can be constructed directly. For linear elastic fracture mechanics, the COD and J-integral techniques to determine the stress intensity factors are applied. Several examples are given and comparisons have been made with both analytical solutions and the finite element method in order to demonstrate the accuracy and convergence of the finite block method.


Author(s):  
Pei Gu ◽  
R. J. Asaro

For mixed-mode loading at a crack tip under small-scale yielding condition, mode I, mode II and mode III stress intensity factors control the crack propagation. This paper discusses three-dimensional mode separation to obtain the three stress intensity factors using the interaction integral approach. The 2D interaction integral approach to obtain mode I and mode II stress intensity factors is derived to 3D arbitrary crack configuration for mode I, mode II and mode III stress intensity factors. The method is implemented in a finite element code using domain integral method and numerical examples show good convergence for the domains around the crack tip. A complete solution for the three stress intensity factors is obtained for a bar with inclined crack face to the cross-section from numerical calculations. The solution for the bar is plotted into curves in terms of a set of non-dimensional parameters for practical engineering purpose. From the solution, mode mixity along the crack front and its implication to the direction of crack propagation is discussed.


2013 ◽  
Vol 3 (5) ◽  
pp. 506-510
Author(s):  
A. Boulenouar ◽  
N. Benseddiq ◽  
M. Mazari

When the loading or the geometry of a structure is not symmetrical about the crack axis, rupture occurs in mixed mode loading and the crack does not propagate in a straight line. It is then necessary to use kinking criteria to determine the new direction of crack propagation. The aim of this work is to present a numerical modeling of crack propagation under mixed mode loading conditions. This work is based on the implementation of the displacement extrapolation method in a FE code and the strain energy density theory in a finite element code. At each crack increment length, the kinking angle is evaluated as a function of stress intensity factors. In this paper, we analyzed the mechanical behavior of inclined cracks by evaluating the stress intensity factors. Then, we presented the examples of crack propagation in structures containing inclusions and cavities.


Author(s):  
Xian-Kui Zhu

Crack assessments for pressure vessels often need to quantify the crack driving force — stress intensity factor K with the linear-elastic fracture mechanics methods. Different numerical methods have been developed to calculate the stress intensity factors for complex cracks. Of which, four typical methods, i.e., the displacement extrapolation method, the virtual crack closure technique (VCCT), the J-integral conversion method, and the direct K output method are selected and evaluated in this paper using the finite element analysis (FEA) and ABAQUS software. The evaluations are performed based on the benchmark FEA calculations in the linear-elastic conditions for the central-cracked panel (CCP) specimen in the two-dimensional (2D) plane strain conditions. The “best method” is then determined and used to calculate the stress intensity factor for the CCP specimen with a through-thickness crack in the three-dimensional (3D) conditions. The results show that ABAQUS can simply determine very accurate K values for both 2D and 3D cracks.


2020 ◽  
Author(s):  
Ondrej Slávik ◽  
Pavel Hutař ◽  
Michael Berer ◽  
Anja Gosch ◽  
Tomáš Vojtek ◽  
...  

1988 ◽  
Vol 110 (3) ◽  
pp. 408-413 ◽  
Author(s):  
L. J. Ghosn

Crack propagation in a rotating inner raceway of a high-speed roller bearing is analyzed using the boundary integral method. The model consists of an edge plate under plane strain condition upon which varying Hertzian stress fields are superimposed. A multidomain boundary integral equation using quadratic elements was written to determine the stress intensity factors KI and KII at the crack tip for various roller positions. The multidomain formulation allows the two faces of the crack to be modeled in two different subregions making it possible to analyze crack closure when the roller is positioned on or close to the crack line. KI and KII stress intensity factors along any direction were computed. These calculations permit determination of crack growth direction along which the average KI times the alternating KI is maximum.


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