Numerical analysis of blunting of a crack tip in a ductile material under small-scale yielding and mixed mode loading

1986 ◽  
Vol 1 (1) ◽  
pp. 11-19 ◽  
Author(s):  
M. Saka ◽  
H. Abé ◽  
S. Tanaka
Keyword(s):  
Numerical Analysis ◽  
Mixed Mode ◽  
Crack Tip ◽  
Ductile Material ◽  
Small Scale ◽  
Mixed Mode Loading ◽  
Small Scale Yielding ◽  
Scale Yielding

Small Scale Yielding at a Crack Normal to the Interface Between an Elastic and a Yielding Material

1991 ◽  
Vol 239 ◽  
Author(s):  
Ming Y. He ◽  
R. M. McMeeking ◽  
Ning T. Zhang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Brittle Material ◽  
Crack Tip ◽  
Asymptotic Solutions ◽  
Ductile Material ◽  
Small Scale ◽  
Small Scale Yielding ◽  
Element Analysis ◽  
Scale Yielding

ABSTRACTBy using the elastic singular field as a prescribed loading condition, small scale yielding solutions are obtained for a crack normal to the interface between a brittle and a ductile material. Results for both a crack in the brittle material and one in the ductile material are obtained by finite element analysis. The crack tip fields obtained by the finite element analysis are compared with the asymptotic solutions. It is found that near the tip the stress fields approach the asymptotic solutions. If the crack is in the brittle material, the high triaxial stresses are developed near the interface ahead of the crack tip.

Elastic-Plastic Analysis of Cracks on Bimaterial Interfaces: Part I—Small Scale Yielding

1988 ◽  
Vol 55 (2) ◽  
pp. 299-316 ◽  
Author(s):  
C. F. Shih ◽  
R. J. Asaro
Keyword(s):  
Phase Angle ◽  
Mixed Mode ◽  
Numerical Solutions ◽  
Crack Tip ◽  
Small Scale ◽  
Plastic Behavior ◽  
Small Scale Yielding ◽  
Elastic Plastic ◽  
Crack Problems ◽  
Scale Yielding

Full-field numerical solutions for a crack which lies along the interface of an elastic-plastic medium and a rigid substrate are presented. The solutions are obtained using a small strain version of the J2-deformation theory with power-law strain hardening. In the present article, results for loading causing only small scale yielding at the crack tip are described; in subsequent articles the mathematical structure of the crack-tip fields under small scale yielding and results for contained yielding and fully plastic behavior will be presented. We find that although the near-tip fields do not appear to have a separable singular form, of the HRR-type fields as in homogeneous media, they do, however, bear interesting similarities to certain mixed-mode HRR fields. Under small scale yielding, where the remote elastic fields are specified by a complex stress-concentration vector Q = |Q|eiφ with φ being the phase angle between the two in-plane stress modes, we find that the plastic fields are members of a family parameterized by a new phase angle ξ, ≡ φ + εln(QQ/σ02L), and the fields nearly scale with the well-defined energy release rate as evaluated by the J-integral. Here σ0 is the reference yield stress and L is the total crack length (or a relevant length of the crack geometry). Numerical procedures appropriate for solving a general class of interface crack problems are also presented. A description of a numerical method for extracting the mixed mode stress intensities for cracks at interfaces and in homogeneous isotropic or anisotropic media, is included.

Plastic Stress Intensity Factors for Small Scale Yielding in Antiplane Shear by Caustics

1982 ◽  
Vol 49 (4) ◽  
pp. 754-760 ◽  
Author(s):  
P. S. Theocaris ◽  
C. I. Razem
Keyword(s):  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Crack Tip ◽  
Antiplane Shear ◽  
Elastic Behavior ◽  
Small Scale ◽  
Small Scale Yielding ◽  
Scale Yielding ◽  
Plastic Stress

The KIII-stress intensity factor in an edge-cracked plate submitted to antiplane shear may be evaluated by the reflected caustic created around the crack tip, provided that a purely elastic behavior exists at the crack tip [1]. For a work-hardening, elastic-plastic material, when stresses at the vicinity of the crack tip exceed the yield limit of the material, the new shape of caustic differs substantially from the corresponding shape of the elastic solution. In this paper the shape and size of the caustics created at the tip of the crack, when small-scale yielding is established in the vicinity of the crack tip, were studied, based on a closed-form solution introduced by Rice [2]. The plastic stress intensity factor may be evaluated from the dimensions of the plastic caustic. Experimental evidence with cracked plates made of opaque materials, like steel, corroborated the results of the theory.

Estimation of K in Ductile CT and SENB Specimens under LEFM and SSY Regimes by J Integral Method: A Review

2013 ◽  
Vol 275-277 ◽  
pp. 242-246
Author(s):  
Bhimsen Karadin ◽  
Nilesh Satonkar ◽  
Sunil Bhat
Keyword(s):  
Integral Method ◽  
Crack Tip ◽  
Small Scale ◽  
J Integral ◽  
Small Scale Yielding ◽  
Critical Limit ◽  
Ductile Materials ◽  
Ductile Mode ◽  
Scale Yielding ◽  
Material Fracture

Stress intensity factor (K) is the measure of severity of stress at the crack tip. When K exceeds the critical limit (i.e., the material fracture toughness), the crack grows. K is valid in brittle materials (LEFM) and to some extent in ductile materials also provided there is small scale yielding (SSY) at the crack tip. The paper reviews the numerical methodology to obtain KI of ductile, Mode I cracked, CT and SENB test specimens in LEFM and SSY regimes with the help of J integral method. The numerical values are successfully compared with the theoretical values.

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