Analysis of Stress Singularity near the Tip of Artificial Crack

2012 ◽  
Vol 525-526 ◽  
pp. 445-448
Author(s):  
You Tang Li ◽  
Huai Qing Li
Keyword(s):  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Key Words ◽  
Stress Singularity ◽  
Extrapolation Method ◽  
Uniform Tension ◽  
Eigen Value ◽  
Singularity Function

A generalized expression of the stress-singularity function at the tip of artificial crack is proposed, and a formula to calculate the stress intensity factor of artificial crack is obtained in the paper. The solutions of stress singularity of a cracked bi-materials beam under uniform tension and bending were computed. The results show that the degree of stress-singularity is determined by the exponent λ at the tip of artificial crack, and the exponent λ is, not only determined by materials parameter of artificial crack but also by angle. Key words: artificial crack; bi-material; stress singularity; eigen value; stress extrapolation method

Relation between Stress Intensity Factor of a Small Edge Interface Crack and Intensity of Free-Edge Stress Singularity of Bonded Dissimilar Materials

2004 ◽  
Vol 261-263 ◽  
pp. 351-356
Author(s):  
Seiji Ioka ◽  
Shiro Kubo
Keyword(s):  
Stress Intensity Factor ◽  
Free Surface ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Edge Crack ◽  
Stress Singularity ◽  
Dissimilar Materials ◽  
Free Edge ◽  
Edge Stress ◽  
The Relationship

When two materials are bonded, the free-edge stress singularity usually develops near the intersection of the interface and the free-surface. Fracture in bonded dissimilar materials may therefore occur from an interface crack which develops at the intersection of interface and free-surface. Free-edge stress singularity is very important in the evaluation of strength of bonded dissimilar materials. In this study, the relationship between the stress intensity factor of a small edge crack on interface of bonded dissimilar materials and the intensity of free-edge stress singularity of bonded dissimilar materials with no crack under external mechanical loading was investigated numerically by using the boundary element method. The relationship was also investigated theoretically by using the principle of superposition. The results of numerical analyses were compared with those of theoretical analyses. It was found that stress intensity factors of small edge crack on interface K1 and K2 were proportional to the intensity of free-edge stress singularity of bonded dissimilar materials Kσ without crack irrespective of the combination of materials. The numerically determined proportional coefficient between K1 and Kσ agreed well with the theoretical one, and was not affected by crack length when proper normalizations were applied. From these results, it is suggested that stress intensity factor of small edge crack on interface can be used as a strength criterion of interface of bonded dissimilar materials.

scholarly journals Applicability of Continuum Fracture Mechanics in Atomistic Systems

2011 ◽  
Author(s):  
Shao-Huan Cheng ◽  
C. T. Sun
Keyword(s):  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Fracture Mechanics ◽  
Intensity Factor ◽  
Stress Singularity ◽  
Critical Stress Intensity Factor ◽  
Singular Stress ◽  
Virial Stress ◽  
Atomistic Systems ◽  
Definition Of

Stress intensity factor is one of the most significant fracture parameters in linear elastic fracture mechanics (LEFM). Due to its simplicity, many researchers directly employed this concept to explain their results from molecular simulation. However, stress intensity factor defines the amplitude of the singular stress, which is the product of continuum elasticity. Under atomistic systems without the stress singularity, the concept of stress intensity factor must be examined. In addition, the difficulty of studying the stress intensity factor in atomistic systems may be traced back to the ambiguous definition of the local atomistic stress. In this study, the definition of the local virial stress is adopted. Subsequently, through the consideration of K-dominance, the approximated stress intensity factor based on the atomistic stress can be projected within a reasonable region. Moreover, the influence of cutting interatomic bonds to create traction free crack surfaces and the critical stress intensity factor is also discussed.

Influence of the V-Notch Opening Angle on Critical Applied Force Values for the Crack Initiation from the Sharp V-Notch

2014 ◽  
Vol 627 ◽  
pp. 165-168
Author(s):  
Kateřina Štegnerová ◽  
Luboš Náhlík ◽  
Pavel Hutař
Keyword(s):  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Crack Initiation ◽  
Stress Singularity ◽  
Applied Force ◽  
Opening Angle ◽  
Generalized Stress Intensity Factor ◽  
Singularity Exponent ◽  
Notch Tip

The aim of this paper is to estimate a value of the critical applied force for a crack initiation from the sharp V-notch tip. The classical approach of the linear elastic fracture mechanics (LELM) was generalized, because the stress singularity exponent differs from 0.5 in studied case. The value of the stress singularity exponent depends on the V-notch opening angle. The finite element method was used for a determination of stress distribution in the vicinity of the sharp V-notch tip and for the estimation of the generalized stress intensity factor depending on the V-notch opening angle. Critical value of generalized stress intensity factor was obtained by using stability criterion based on the tangential stress component averaged over a critical distancedfrom the V-notch tip. Calculated values of the critical applied force were compared with experimental data taken from the literature.

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