Asymptotics of the elastic solution of a plane problem near the crack tip terminating at a nonideal bimaterial interface (mode I and II)

1998 ◽  
Vol 34 (5) ◽  
pp. 439-456 ◽  
Author(s):  
G. S. Mishuris
Keyword(s):  
Plane Problem ◽  
Crack Tip ◽  
Elastic Solution ◽  
Bimaterial Interface ◽  
Mode I ◽  
Interface Mode

scholarly journals Analytical corrections for double-cantilever beam tests

2021 ◽  
Author(s):  
T. Chen ◽  
C. M. Harvey ◽  
S. Wang ◽  
V. V. Silberschmidt
Keyword(s):  
Elastic Foundation ◽  
Analytical Solutions ◽  
Data Reduction ◽  
Crack Tip ◽  
Beam Theory ◽  
Dynamic Loads ◽  
Structural Vibration ◽  
Mode I ◽  
Mode I Fracture ◽  
Reduction Methods

AbstractDouble-cantilever beams (DCBs) are widely used to study mode-I fracture behavior and to measure mode-I fracture toughness under quasi-static loads. Recently, the authors have developed analytical solutions for DCBs under dynamic loads with consideration of structural vibration and wave propagation. There are two methods of beam-theory-based data reduction to determine the energy release rate: (i) using an effective built-in boundary condition at the crack tip, and (ii) employing an elastic foundation to model the uncracked interface of the DCB. In this letter, analytical corrections for a crack-tip rotation of DCBs under quasi-static and dynamic loads are presented, afforded by combining both these data-reduction methods and the authors’ recent analytical solutions for each. Convenient and easy-to-use analytical corrections for DCB tests are obtained, which avoid the complexity and difficulty of the elastic foundation approach, and the need for multiple experimental measurements of DCB compliance and crack length. The corrections are, to the best of the authors’ knowledge, completely new. Verification cases based on numerical simulation are presented to demonstrate the utility of the corrections.

Dynamic Analysis of a Mode I Propagating Crack Subjected to a Concentrated Load

2003 ◽  
Vol 70 (5) ◽  
pp. 668-675
Author(s):  
Y.-L. Chung ◽  
M.-R. Chen
Keyword(s):  
Stress Intensity ◽  
Wave Speed ◽  
Complete Solution ◽  
Crack Tip ◽  
Dynamic Effect ◽  
Mode I ◽  
S Wave ◽  
Dynamic Stress Intensity Factors ◽  
Concentrated Load ◽  
Self Similar

This work investigates the phenomenon of mode I central crack propagating with a constant speed subjected to a concentrated load on the crack surfaces. This problem is not a self-similar problem. However, the method of self-similar potential (SSP) in conjunction with superposition can be successfully applied if the time delay and the origin shift are considered. After the complete solution is obtained, attention is stressed on the dynamic stress intensity factors (DSIFs). Analytical results indicate that the DSIF equals the static stress intensity factor if the crack-tip speed is very slow and equal to zero if the crack-tip velocity approaches the Rayleigh-wave speed. However, the dynamic effect becomes obvious only if the crack-tip speed is 0.4 times faster than the S-wave speed. Moreover, the combination of SSP method and the superposition scheme can be applied to the expanding uniformly distributed load acting on a portion of the crack surfaces.

Atomistic Study of Cleavage and Dislocation Emission in NiAl

1994 ◽  
Vol 364 ◽  
Author(s):  
M. Ludwig ◽  
P. Gumbsch
Keyword(s):  
Finite Element ◽  
Mixed Mode ◽  
Crack Tip ◽  
Mode I ◽  
Crack Plane ◽  
Dislocation Emission ◽  
Dislocation Generation ◽  
Embedded Atom ◽  
Atomistic Study ◽  
Eam Potential

AbstractThe atomistic processes during fracture of NiAl are studied using a new embedded atom (EAM) potential to describe the region near the crack tip. To provide the atomistically modeled crack tip region with realistic boundary conditions, a coupled finite element - atomistic (FEAt) technique [1] is employed. In agreement with experimental observations, perfectly brittle cleavage is observed for the (110) crack plane. In contrast, cracks on the (100) plane either follow a zig-zag path on (110) planes, or emit dislocations. Dislocation generation is studied in more detail under mixed mode I/II loading conditions.

The dislocation-free zone at a mode I crack tip

1995 ◽  
Vol 50 (2) ◽  
pp. 165-173 ◽  
Author(s):  
Jianqiao Chen ◽  
Shigeo Takezono
Keyword(s):  
Crack Tip ◽  
Mode I ◽  
Mode I Crack ◽  
Free Zone

scholarly journals An approach to analysis of dynamic crack growth at bimaterial interface

2009 ◽  
Vol 36 (4) ◽  
pp. 299-327 ◽  
Author(s):  
R. Nikolic ◽  
Jelena Djokovic
Keyword(s):  
Asymptotic Analysis ◽  
Strain Field ◽  
Crack Tip ◽  
Optical Data ◽  
Bimaterial Interface ◽  
Dynamic Crack ◽  
New Approach ◽  
Shear Wave Speed ◽  
Propagating Crack

In this paper is presented the new approach to asymptotic analysis of the stress and strain fields around a crack tip that is propagating dynamically along a bimaterial interface. Through asymptotic analysis the problem is being reduced to solving the Riemann-Hilbert's problem, what yields the strain potential that is used for determination of the strain field around a crack tip. The considered field is that of a dynamically propagating crack with a speed that is between zero and shear wave speed of the less stiffer of the two materials, bound along the interface. Using the new approach in asymptotic analysis of the strain field around a tip of a dynamically propagating crack and possibilities offered by the Mathematica programming package, the results are obtained that are compared to both experimental and numerical results on the dynamic interfacial fracture known from the literature. This comparison showed that it is necessary to apply the complete expression obtained by asymptotic analysis of optical data and not only its first term as it was done in previous analyses.

scholarly journals Analysis of Inclined Cracks in Thin-Walled Circular Tube under Mixed-Mode I + II Fracture

Proceedings ◽  
2018 ◽  
Vol 2 (8) ◽  
pp. 517 ◽  
Author(s):  
Boy Raymond Mabuza
Keyword(s):  
Fracture Mechanics ◽  
Mixed Mode ◽  
Crack Tip ◽  
Theoretical Models ◽  
Mode I ◽  
Mixed Mode Fracture ◽  
Shear Stresses ◽  
Inclined Crack ◽  
Mode Fracture ◽  
Thin Walled

This paper provides a study on mixed-mode fracture mechanics in thin-walled tube which is subjected to tension, shear and torsion loading. This type of loading causes an inclined crack to develop and generate a mixture of normal and shear stresses ahead of a crack tip. The stress state ahead of a crack tip is frequently based on mixed-mode type of interactions which designate the amplitude of the crack tip stresses. The analytical expressions for the stress intensity factors for mixed-mode I + II approach are presented. The Paris law for mixed-modes I + II has been discussed. Mixed-mode fracture mechanics is used with theoretical models to predict the path of crack growth when an inclined crack is subjected to a combination of mode I and mode II deformations. The torque at which crack propagation can be expected has been determined. The numerical calculations have been carried out by using MATLAB code. The results are good and could be useful for companies working with thin-walled circular tubes.

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