scholarly journals Continuing crack-tip deformation and fracture for plane-strain crack growth in elastic-plastic solids

1978 ◽  
Vol 26 (3) ◽  
pp. 163-186 ◽  
Author(s):  
J.R. Rice ◽  
E.P. Sorensen
Keyword(s):  
Crack Growth ◽  
Plane Strain ◽  
Crack Tip ◽  
Elastic Plastic ◽  
Deformation And Fracture ◽  
Plane Strain Crack

Virtual Methods in Creep Crack Growth Predictions in 316H Stainless Steels

2007 ◽  
Author(s):  
Masataka Yatomi ◽  
Kamran M. Nikbin
Keyword(s):  
Crack Growth ◽  
Plane Strain ◽  
Stainless Steels ◽  
Creep Crack Growth ◽  
Crack Propagation Rate ◽  
Creep Model ◽  
Elastic Plastic ◽  
Creep Crack ◽  
Plastic Creep ◽  
Plane Strain Crack

The paper discusses numerically based virtual techniques of creep crack growth predictions in a fracture mechanics component. The material properties used are for 316H stainless steels and the constitutive behaviour of the steel is described by a power law creep model. A damage-based approach is used to predict the crack propagation rate in compact tension (C(T)) specimens and the data are correlated against an independently determined C* parameter. Elastic-plastic-creep analyses are performed using two different crack growth criteria to predict crack extension under plane stress and plane strain conditions. The NSW and NSW-MOD strain exhaustion models are applied to compare to the experimental data and FE predictions. The plane strain crack growth rate predicted from the numerical analysis is found to be less conservative than the plane strain NSW model but more conservative than plane strain NSW-MOD model, for values of C* within the limits of the present creep crack growth testing standards. At higher loads and C* values, the plane strain crack growth rates, predicted using an elastic-plastic-creep material response, approach is considered and compared to the plane strain NSW-MOD model.

The Equivalence of the Final Stretch and Crack Tip Opening Angle Criteria for Plane Strain Crack Growth

1981 ◽  
Vol 103 (2) ◽  
pp. 148-150 ◽  
Author(s):  
E. Smith
Keyword(s):  
Crack Growth ◽  
Plane Strain ◽  
Process Zone ◽  
Crack Tip ◽  
Opening Angle ◽  
Type Model ◽  
Geometrical Parameters ◽  
Crack Tip Opening Angle ◽  
Crack Tip Opening ◽  
Plane Strain Crack

The equivalence of the final stretch and crack tip opening angle criteria, as applied to the Dugdale-Bilby-Cottrell-Swinden type model for Mode I plane strain crack growth, is demonstrated. This equivalence is independent of the plastic zone size, geometrical parameters, and the stress distribution within the fracture process zone, if the yield stress is sufficiently low and the crack growth resistance is sufficiently high. The results therefore provide further support for the viability of crack tip opening angle as a crack growth characterizing parameter.

Plane-Strain Crack-Tip Fields for Pressure-Sensitive Dilatant Materials

1990 ◽  
Vol 57 (1) ◽  
pp. 40-49 ◽  
Author(s):  
F. Z. Li ◽  
J. Pan
Keyword(s):  
Plane Strain ◽  
Effective Stress ◽  
Hydrostatic Stress ◽  
Yield Criterion ◽  
Crack Tip ◽  
Flow Rule ◽  
Pressure Sensitivity ◽  
Crack Tip Fields ◽  
Pressure Sensitive ◽  
Plane Strain Crack

Plane-strain crack-tip stress and strain fields are presented for materials exhibiting pressure-sensitive yielding and plastic volumetric deformation. The yield criterion is described by a linear combination of the effective stress and the hydrostatic stress, and the plastic dilatancy is introduced by the normality flow rule. The material hardening is assumed to follow a power-law relation. For small pressure sensitivity, the plane-strain mode I singular fields are found in a separable form similar to the HRR fields (Hutchinson, 1968a, b; Rice and Rosengren, 1968). The angular distributions of the fields depend on the material-hardening exponent and the pressure-sensitivity parameter. The low-hardening solutions for different degrees of pressure sensitivity are found to agree remarkably with the corresponding perfectly-plastic solutions. An important aspect of the effects of pressure-sensitive yielding and plastic dilatancy on the crack-tip fields is the lowering of the hydrostatic stress and the effective stress directly ahead of the crack tip, which may contribute to the experimentally-observed enhancement of fracture toughness in some ceramic and polymeric composite materials.

The Inelastic Line-Spring: Estimates of Elastic-Plastic Fracture Mechanics Parameters for Surface-Cracked Plates and Shells

1981 ◽  
Vol 103 (3) ◽  
pp. 246-254 ◽  
Author(s):  
D. M. Parks
Keyword(s):  
Fracture Mechanics ◽  
Crack Growth ◽  
Computing Time ◽  
Crack Tip ◽  
J Integral ◽  
Crack Tip Opening Displacement ◽  
Opening Displacement ◽  
Elastic Plastic ◽  
Plates And Shells ◽  
Crack Tip Opening

Recent studies of the mechanics of elastic-plastic and fully plastic crack growth suggest that such parameters as the J-integral and the crack tip opening displacement can, under certain conditions, be used to correlate the initiation and early increments of the ductile tearing mode of crack growth. To date, elastic-plastic fracture mechanics has been applied mainly to test specimen geometries, but there is a clear need for developing practical analysis capabilities in structures. In principle, three-dimensional elastic-plastic finite element analysis could be performed, but, in fact, such analyses would be prohibitively expensive for routine application. In the present work, the line-spring model of Rice and Levy [1-3] is extended to estimate the J-integral and crack tip opening displacement for some surface crack geometries in plates and shells. Good agreement with related solutions is obtained while using orders of magnitude less computing time.

scholarly journals A Numerical Analysis of Selected Elastic-Plastic Fracture Parameters for DEN(T) Plates under Plane Strain Conditions

2017 ◽  
Vol 22 (1) ◽  
pp. 49-80 ◽  
Author(s):  
M. Graba
Keyword(s):  
Numerical Analysis ◽  
Fracture Mechanics ◽  
Plane Strain ◽  
Plastic Material ◽  
Crack Tip ◽  
Limit Load ◽  
Material Model ◽  
Crack Tip Opening Displacement ◽  
Opening Displacement ◽  
Elastic Plastic

Abstract This paper provides a numerical analysis of selected parameters of fracture mechanics for double-edge notched specimens in tension, DEN(T), under plane strain conditions. The analysis was performed using the elastic-plastic material model. The study involved determining the stress distribution near the crack tip for both small and large deformations. The limit load solution was verified. The J-integral, the crack tip opening displacement, and the load line displacement were determined using the numerical method to propose the new hybrid solutions for calculating these parameters. The investigations also aimed to identify the influence of the plate geometry and the material characteristics on the parameters under consideration. This paper is a continuation of the author’s previous studies and simulations in the field of elastic-plastic fracture mechanics [4, 6, 16, 17, 31].

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