Computation of Stress Intensity Factor for Multiple Cracks Using Singular Finite Element

2011 ◽  
Vol 214 ◽  
pp. 75-79 ◽  
Author(s):  
Ruslizam Daud ◽  
Ahmad Kamal Ariffin ◽  
Shahrum Abdullah ◽  
Al Emran Ismail ◽  
A. Zulkifli
Keyword(s):  
Stress Intensity Factor ◽  
Finite Element ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Analytical Solution ◽  
Crack Width ◽  
Width Ratio ◽  
Multiple Cracks ◽  
Two Dimensional ◽  
Interval Ratio

The simplification of two dimensional approaches in singular finite elements has promoted the method to be used in the formulation of stress intensity factor (SIF) of multiple cracks in finite body. The effect of shielding and amplification are considered in defining the SIF. As been observed, the current available analytical approximations are more restricted to several assumptions. The more accurate and less restricted method has motivated this study. This paper presents the investigation of singular finite elements applied in two dimensional finite element models subjected to different crack-width ratio and cracks interval ratio. The newly finite element formulations are resulted with good agreement with theoretical statement compared to analytical solution. The weak points of presented analytical solution are discussed regards to the influence of crack width ratio and cracks interval ratio.

Stress Intensity Factors for Unequal Longitudinal-Radial Cracks in Thick-Walled Cylinders

1991 ◽  
Vol 113 (1) ◽  
pp. 22-27 ◽  
Author(s):  
J. L. Desjardins ◽  
D. J. Burns ◽  
R. Bell ◽  
J. C. Thompson
Keyword(s):  
Stress Intensity Factor ◽  
Finite Element ◽  
Stress Intensity ◽  
Finite Elements ◽  
Intensity Factor ◽  
Stress Intensity Factors ◽  
Two Dimensional ◽  
Intensity Factors ◽  
Radial Cracks ◽  
Good Agreement

Finite elements and two-dimensional photoelasticity have been used to analyze thick-walled cylinders which contain arrays of straight-fronted, longitudinal-radial cracks of unequal depth. The stress intensity factor K1 has been computed for the dominant crack and for some of the surrounding cracks. Cylinders with 2, 4, 6, 8, 16, 36 and 40 cracks have been considered. Good agreement has been obtained between the experimental and the numerical results and, for cylinders with 2 or 4 cracks, with previously published predictions. The results for all of the foregoing cases are used to develop simple, approximate techniques for estimating K1 for the dominant crack, when the total number of cracks is different from those that have been considered herein. Estimates of K1 obtained by these techniques agree well with corresponding finite element results.

Stresses near narrow rectangular notches, with rounded corners, in beams in bending

1992 ◽  
Vol 27 (4) ◽  
pp. 227-234 ◽  
Author(s):  
T H Hyde ◽  
A Yaghi
Keyword(s):  
Stress Intensity Factor ◽  
Finite Element ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Analytical Solution ◽  
Shape Factor ◽  
Peak Stress ◽  
Notch Width ◽  
Finite Element Calculations ◽  
Tip Radius

The results of finite element calculations have been used to show that an analytical solution for the stresses in the vicinity of crack-like notches with elliptical and hyperbolic shaped ends gives accurate results for narrow, semi-circular ended notches. It is also shown that the peak stresses can be obtained from the stress intensity factor for an equivalent crack and the notch tip radius. Finite element solutions for narrow, rectangular notches with rounded corners, have also been used to show that the peak stresses in such notches can be obtained by using a notch shape factor to modify the peak stress values for semi-circular notches. The shape factor depends only on the notch width to corner radius ratio.

scholarly journals Nonplanar Crack Growth Simulation of Multiple Cracks Using Finite Element Method

2020 ◽  
Vol 2020 ◽  
pp. 1-12 ◽  
Author(s):  
Yahya Ali Fageehi ◽  
Abdulnaser M. Alshoaibi
Keyword(s):  
Stress Intensity Factor ◽  
Finite Element ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Crack Growth ◽  
Source Code ◽  
Circumferential Stress ◽  
Adaptive Mesh ◽  
Propagation Mechanism ◽  
Multiple Cracks

This work deals with a 2D finite element simulation of nonplanar multiple cracks using fracture and crack propagation analysis. This analysis was performed by using the developed source code software written by Visual Fortran Language. This source code includes the adaptive mesh generation utilizing the advanced front method and also the mesh refinement process. In order to correctly represent the field singularity, the quarter-point singular elements are constructed around the tip of the crack. The crack growth criteria are used to predict the crack growth direction by utilizing the circumferential stress factor in calculating the yielding stress in elastic fracture assumptions. The stress intensity factor determination is one of the most critical procedures as it determines the crack initiation and propagation mechanism. Moreover, the stress intensity factor histories during the crack growth are measured with the use of equivalent domain integral methods. The crack path simulation and stress intensity factor calculations are compared with the literature and revealed that the results are in agreement with research carried in this domain.

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