Effectiveness of Linear Notch Mechanics under the Condition of Small Scale Yielding

2010 ◽  
Vol 452-453 ◽  
pp. 21-24
Author(s):  
T. Teranishi ◽  
Hironobu Nisitani

The linear notch mechanics (LNM) was proposed by H. Nisitani in 1983. The concept of LNM can assure the occurrence of the same phenomena in a notched specimen and a real object. The effectiveness of LNM under the condition of small scale yielding has not been confirmed sufficiently. In this paper, the effectiveness of LNM under the condition of small scale yielding is discussed based on the results of FEM elastic-plastic analyses.

1976 ◽  
Vol 98 (2) ◽  
pp. 146-151 ◽  
Author(s):  
D. M. Tracey

The subject considered is the stress and deformation fields in a cracked elastic-plastic power law hardening material under plane strain tensile loading. An incremental plasticity finite element formulation is developed for accurate analysis of the complete field problem including the extensively deformed near tip region, the elastic-plastic region, and the remote elastic region. The formulation has general applicability and was used to solve the small scale yielding problem for a set of material hardening exponents. Distributions of stress, strain, and crack opening displacement at the crack tip and through the elastic-plastic zone are presented as a function of the elastic stress intensity factor and material properties.


2005 ◽  
Vol 32 (3) ◽  
pp. 193-207
Author(s):  
Ruzica Nikolic ◽  
Jelena Veljkovic

In this paper are presented solutions for the stress and dis?placement fields for a crack that lies along the interface of an elastic and elastic - plastic material and for a crack between two different elastic - plastic materials. These solutions are obtained using the J2-deformation theory with the power - law strain hardening. In this paper results are described for a small scale yielding at the crack tip. The near tip fields do not have a separable singular form, of the HRR type fields, as in homogeneous media, they do, however bare interesting similarities to certain mixed -mode HRR fields. Under the small scale yielding the elastic fields are specified by a complex stress intensity factor and phase angle loading, while plastic field is characterized by a new phase angle. The size of plastic zone in plane strain and plane stress and displacement fields at the crack tip for the new phase angle are obtained. The crack tip opens smoothly and the crack opening displacement is scaled by the J-integral. The whole analysis is performed by application of the Mathematica symbolic programming routine.


1988 ◽  
Vol 55 (2) ◽  
pp. 299-316 ◽  
Author(s):  
C. F. Shih ◽  
R. J. Asaro

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.


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