Evaluation of a Complex Stress Intensity Factor of Interface Cracks: A Perturbation Approach

1993 ◽  
Vol 60 (1) ◽  
pp. 221-222
Author(s):  
C. Y. Hui ◽  
Y. C. Chen
Keyword(s):  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Complex Stress ◽  
Perturbation Approach ◽  
Interface Cracks ◽  
Complex Stress Intensity Factor

scholarly journals Stress Intensity Factor for Interface Cracks in Bimaterials Using Complex Variable Meshless Manifold Method

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Hongfen Gao ◽  
Gaofeng Wei
Keyword(s):  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Complex Variable ◽  
Interfacial Crack ◽  
Dissimilar Materials ◽  
Complex Stress ◽  
Interface Cracks ◽  
Interfacial Cracks ◽  
Crack Problems

This paper describes the application of the complex variable meshless manifold method (CVMMM) to stress intensity factor analyses of structures containing interface cracks between dissimilar materials. A discontinuous function and the near-tip asymptotic displacement functions are added to the CVMMM approximation using the framework of complex variable moving least-squares (CVMLS) approximation. This enables the domain to be modeled by CVMMM without explicitly meshing the crack surfaces. The enriched crack-tip functions are chosen as those that span the asymptotic displacement fields for an interfacial crack. The complex stress intensity factors for bimaterial interfacial cracks were numerically evaluated using the method. Good agreement between the numerical results and the reference solutions for benchmark interfacial crack problems is realized.

Numerical Computation of Complex Stress Intensity Factors of Interface Cracks in Bi-Materials Based on Photoelastic Theory

2013 ◽  
Vol 444-445 ◽  
pp. 50-54
Author(s):  
Peng Cheng Li ◽  
Bang Cheng Yang
Keyword(s):  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Numerical Method ◽  
Fringe Pattern ◽  
Complex Stress ◽  
Theoretical Solution ◽  
Isochromatic Fringe ◽  
Complex Stress Intensity Factor ◽  
Raphson Iteration

This paper presents a new numerical method for obtaining the complex stress intensity factor with an interface crack in bi-materials using photoelastic isochromatic fringe numbers N. The theoretical solution of stress field at the crack tip was deduced from Muskhelishvilis stress function and an undetermined term σ0 which is a function of material properties was added to this theoretical solution. A partial differential iterative equation with fast convergence was formed by applying the photoelastic theory. The complex stress intensity factor K=K1+iK2 and σ0 were obtained by Newton-Raphson iteration method and K domain was discussed. The simulant photoelastic isochromatic fringe pattern could be generated through image processing and numerical calculation according to K and σ0. The simulant isochromatic fringe pattern accords with experimental photoelastic isochromatic fringe pattern, so it is practicable for this numerical method of obtaining the complex stress intensity factor.

Photoelastic Determination of Stress Intensity Factor of an Interfacial Crack in a Bi-material

1993 ◽  
Vol 60 (1) ◽  
pp. 93-100 ◽  
Author(s):  
Hua Lu ◽  
F. P. Chiang
Keyword(s):  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Radial Distance ◽  
Interfacial Crack ◽  
Complex Stress ◽  
Phase Changes ◽  
Complex Vector ◽  
Complex Stress Intensity Factor

The stress intensity factor of an interfacial crack in a bi-material can be represented by a complex vector whose phase changes as a function of r, the radial distance from a crack tip. Two photoelasticity approaches are proposed for the determination of both the magnitude and the phase angle of this complex vector. It is shown that within the K-dominated zone the complex stress intensity factor can be determined at any r and then converted to any other r. The case of an interfacial crack under remote tension is used as an example for the illustration of the proposed techniques.

A Numerical Procedure for Estimating the Stress Intensity Factor of a Crack in a Finite Plate

1964 ◽  
Vol 86 (4) ◽  
pp. 681-684 ◽  
Author(s):  
A. S. Kobayashi ◽  
R. D. Cherepy ◽  
W. C. Kinsel
Keyword(s):  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Intensity Factor ◽  
High Speed ◽  
Linear Equations ◽  
Infinite Plate ◽  
Numerical Procedure ◽  
Complex Stress ◽  
Theory Of Elasticity ◽  
Finite Plate

The advantages of the complex variable method are combined with the numerical procedure of collocation for estimating the stress intensity factors in finite, cracked plates subjected to in-plane loadings. In this approach, the complex stress functions for an infinite plate problem are modified to meet the boundary conditions for a finite plate with identical crack configuration. This procedure produces a system of linear equations which can be programmed readily on high-speed computers. The procedure is used to find the elastic stress intensity factor at the crack tip in a centrally notched plate in uniaxial tension. The resulting values are nearly identical to the stress intensity values determined analytically by the theory of elasticity. This numerical procedure should be useful for designers and analysts working in the fields of fracture mechanics and fail-safe concepts.

Analytical Solutions and Tools for Assessment of Surface Cracks in Cylindrical Components

2008 ◽  
Author(s):  
Igor Varfolomeyev ◽  
Dieter Beukelmann
Keyword(s):  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Fatigue Loading ◽  
Complex Stress ◽  
Radial Coordinate ◽  
Cylinder Wall ◽  
Crack Plane ◽  
Surface Cracks ◽  
Inner Radius

The paper reviews some advanced stress intensity factor solutions derived for analyses of axial and circumferential surface cracks in cylindrical components subjected to variable stress fields. The solutions are examined considering their validity ranges with respect to the crack and cylinder geometry, ability to account for a complex stress distribution in the pipe wall, as well as their accuracy. A method for estimating errors in numerical stress intensity factor solutions is introduced and applied to a particular set of data. Examples of a leak-before-break assessment and crack growth calculations under thermal fatigue loading are included to demonstrate the solutions performance. The considered analytical stress intensity factor solutions yield close results provided that the stress field in the prospective crack plane is described by a smooth function of the radial coordinate. For two-dimensional stress profiles as well as for variable ratios of the cylinder wall thickness to the inner radius, a selective use of the solutions is recommended considering their specific features and validity ranges.

Macrocrack-Microdefect Interaction

1986 ◽  
Vol 53 (3) ◽  
pp. 505-510 ◽  
Author(s):  
A. A. Rubinstein
Keyword(s):  
Stress Intensity Factor ◽  
Integral Equation ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Numerical Technique ◽  
Finite Size ◽  
Numerical Procedure ◽  
Complex Stress ◽  
Elastic Interactions ◽  
Crack Tip Geometry

Elastic interactions (in terms of the stress intensity factor variation) of the macrocrack (represented as semi-infinite crack) with microdefects such as finite size, arbitrarily positioned crack, circular hole or inclusion are considered. A solution for the problem of the interaction with dilational inclusion is also given. The influence of the crack tip geometry on the surrounding stress field is studied by analyzing the case of crack-hole coalescence. Problems are considered in terms of complex stress potentials for linear elasticity and formulated as a singular integral equation on the semi-infinite interval. A stable numerical technique is developed for the solution of such equations. In a particular case, in order to evaluate the accuracy of the numerical procedure, results obtained through the numerical procedure are compared with the available analytical solution and found to be in excellent agreement.

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