Application of the weight function method for determining stress intensity factors of semi-elliptical cracks

1987 ◽  
Vol 35 (3) ◽  
pp. 175-186 ◽  
Author(s):  
V. A. Vainshtok ◽  
I. V. Varfolomeyev
Keyword(s):  
Stress Intensity ◽  
Weight Function ◽  
Stress Intensity Factors ◽  
Function Method ◽  
Intensity Factors ◽  
Weight Function Method ◽  
Elliptical Cracks

scholarly journals Calculation of Stress Intensity Factors for Elliptical Cracks in Finite Bodies by Using the Boundary Weight Function Method

1999 ◽  
Vol 121 (2) ◽  
pp. 181-187 ◽  
Author(s):  
C.-C. Ma ◽  
I-K. Shen
Keyword(s):  
Stress Intensity ◽  
Weight Function ◽  
Stress Intensity Factors ◽  
Arbitrary Shape ◽  
Function Method ◽  
Weight Functions ◽  
Mode I ◽  
Intensity Factors ◽  
Weight Function Method ◽  
Arbitrary Loading

In this study, mode I stress intensity factors for a three-dimensional finite cracked body with arbitrary shape and subjected to arbitrary loading is presented by using the boundary weight function method. The weight function is a universal function for a given cracked body and can be obtained from any arbitrary loading system. A numerical finite element method for the determination of weight function relevant to cracked bodies with finite dimensions is used. Explicit boundary weight functions are successfully demonstrated by using the least-squares fitting procedure for elliptical quarter-corner crack and embedded elliptical crack in parallelepipedic finite bodies. If the stress distribution of a cut-out parallelepipedic cracked body from any arbitrary shape of cracked body subjected to arbitrary loading is determined, the mode I stress intensity factors for the cracked body can be obtained from the predetermined boundary weight functions by a simple surface integration. Comparison of the calculated results with some available solutions in the published literature confirms the efficiency and accuracy of the proposed boundary weight function method.

scholarly journals Weight Function Method for Stress Intensity Factors of Semi-Elliptical Surface Cracks on Functionally Graded Plates Subjected to Non-Uniform Stresses

Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3155
Author(s):  
Kun-Pang Kou ◽  
Jin-Long Cao ◽  
Yang Yang ◽  
Chi-Chiu Lam
Keyword(s):  
Stress Intensity ◽  
Weight Function ◽  
Stress Intensity Factors ◽  
Function Method ◽  
Functionally Graded ◽  
Weight Functions ◽  
Surface Cracks ◽  
Functionally Graded Plates ◽  
Intensity Factors ◽  
Weight Function Method

In this paper, a weight function method based on the first four terms of a Taylor’s series expansion is proposed to determine the stress intensity factors of functionally graded plates with semi-elliptical surface cracks. Cracked surfaces that are subjected to constant, linear, parabolic and cubic stress fields are considered. The weight functions for the surface, deepest and general points on the crack faces of long and deep cracked functionally graded plates are derived, which has never been done before in the literature. The accuracy of the method in this study is then validated by comparing the results with those of finite element modeling. The numerical results indicate that the derived weight functions are highly accurate and robust enough to predict the stress intensity factors for cracked functionally graded plates subjected to non-uniform stress distributions. The weight function method is therefore a time-saving technique and suitable for handling non-uniform stress fields.

Stress Intensity Factors and Weight Function for Internal Surface Faults in Cylindrical Vessels

2013 ◽  
Vol 705 ◽  
pp. 209-215
Author(s):  
Yan Ling Ni ◽  
Shang Tong Yang ◽  
Chun Qing Li
Keyword(s):  
Stress Intensity ◽  
Aspect Ratio ◽  
Weight Function ◽  
Stress Intensity Factors ◽  
Function Method ◽  
Stress Singularity ◽  
Weight Functions ◽  
Intensity Factors ◽  
Weight Function Method ◽  
Aspect Ratios

Failure of cylindrical vessels can be caused by stress singularity at pitting corrosion induced cracks. Literature suggests that most of research focuses on how to determine stress intensity factors for surface cracks with low aspect ratios, i.e.,a/c1.0. Situation may well arise where the aspect ratio of cracks is larger than one. This paper attempts to propose a weight function method to determine stress intensity factors for high aspect ratio semi-elliptical cracks in cylindrical vessels. The weight functions are derived based on three dimensional finite element analysis. The proposed weight function method is verified numerically. It is found that the higher the aspect ratio of cracks the larger the stress intensity factors, and that the aspect ratio of cracks may alter the failure mode of cylindrical vessels.

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