scholarly journals The crack kinking out of an interface

2005 ◽  
Vol 32 (3) ◽  
pp. 209-221 ◽  
Author(s):  
Jelena Veljkovic
Keyword(s):  
Energy Release Rate ◽  
Energy Release ◽  
Release Rate ◽  
Interfacial Crack ◽  
Intensity Factors ◽  
Elastic Materials ◽  
Kinked Cracks ◽  
Compliant Material ◽  
Stiff Material ◽  
Plane Strain Crack

Kinking of a plane strain crack out of an interface between the two dissimilar isotropic elastic materials is analyzed. Analysis is focused on the initiation of kinking and thus the segment of the crack leaving the interface is imagined to be short compared to the segment in the interface. The analysis provides the stress intensity factors and energy release rate of the kinked cracks in terms of the corresponding quantities for the interfacial crack. The energy release rate is enhanced if the crack heads into the more compliant material and is diminished if the crack kinks into the stiff material.

scholarly journals Kinking of a Crack Out of an Interface

1989 ◽  
Vol 56 (2) ◽  
pp. 270-278 ◽  
Author(s):  
Ming-Yuan He ◽  
John W. Hutchinson
Keyword(s):  
Stress Intensity ◽  
Energy Release Rate ◽  
Energy Release ◽  
Release Rate ◽  
Intensity Factors ◽  
Elastic Solids ◽  
Kinked Crack ◽  
Compliant Material ◽  
Stiff Material ◽  
Plane Strain Crack

Kinking of a plane strain crack out of the interface between two dissimilar isotropic elastic solids is analyzed. The focus is on the initiation of kinking and thus the segment of the crack leaving the interface is imagined to be short compared to the segment in the interface. Accordingly, the analysis provides the stress intensity factors and energy release rate of the kinked crack in terms of the corresponding quantities for the interface crack prior to kinking. Roughly speaking, the energy release rate is enhanced if the crack heads into the more compliant material and is diminished if it kinks into the stiff material. The results suggest a tendency for a crack to be trapped in the interface irrespective of the loading when the compliant material is tough and the stiff material is at least as tough as the interface.

Analysis of a Kinked Interfacial Crack Under Out-of-Plane Shear

1994 ◽  
Vol 61 (1) ◽  
pp. 38-44 ◽  
Author(s):  
S. R. Choi ◽  
K. S. Lee ◽  
Y. Y. Earmme
Keyword(s):  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Energy Release Rate ◽  
Energy Release ◽  
Release Rate ◽  
Interfacial Crack ◽  
Limit Case ◽  
Plane Shear ◽  
Out Of Plane ◽  
Compliant Material

A kinked interfacial crack under out-of-plane shear is analyzed where a straight interfacial crack is kinked into material 1 out of the interface. Employing the Wiener- Hopf technique, the solution is obtained in a closed form. Discontinuity in the stress intensity factor as the kink angle to approaches zero is found, while the energy release rate is shown to be continuous at ω = 0. The limit case of the kinked length b approaching zero is also investigated. The result shows that the stress field has 1/r singularity and the energy release rate at b = 0+ is enhanced at some ω if the crack kinks into the more compliant material.

scholarly journals Effect of Substrate Compliance on Measuring Delamination Properties of Elastic Thin Foil

2018 ◽  
Vol 85 (5) ◽  
Author(s):  
C. Liu
Keyword(s):  
Energy Release Rate ◽  
Energy Release ◽  
Release Rate ◽  
Model Problem ◽  
Hot Isostatic Pressing ◽  
Interfacial Crack ◽  
Interfacial Strength ◽  
Thin Foil ◽  
Bulge Test ◽  
Thin Elastic Plate

Through the analysis of a model problem, a thin elastic plate bonded to an elastic foundation, we address several issues related to the miniature bulge test for measuring the energy-release rate associated with the interfacial fracture of a bimaterial system, where one of the constituents is a thin foil. These issues include the effect of the substrate compliance on the interpretation of the energy release rate, interfacial strength, and the identification of the boundary of the deforming bulge or the location of the interfacial crack front. The analysis also suggests a way for measuring the so-called foundation modulus, which characterizes the property of the substrate. An experimental example, a stainless steel thin foil bonded to an aluminum substrate through hot-isostatic-pressing (HIP), is used to illustrate and highlight some of the conclusions of the model analysis.

scholarly journals Analytical Energy Release Rate of Interfacial Crack in Composite Laminates

2019 ◽  
Vol 37 (1) ◽  
pp. 137-142
Author(s):  
Weiling Zheng ◽  
Longxi Zheng
Keyword(s):  
Finite Element ◽  
Energy Release Rate ◽  
Energy Release ◽  
Release Rate ◽  
Composite Laminates ◽  
Interfacial Crack ◽  
Crack Tip ◽  
Beam Theory ◽  
Three Point Bending ◽  
The Right

In order to study whether the interfacial crack will grow or not in the composite laminates, the energy release rate of a crack in three-point bending model was obtained by using the Timoshenko beam theory and local generalized forces. The results of energy release rate were validated by the finite element results. The results indicate that the energy release rate of left crack tip is equal to that of the right crack tip when the crack before the crack goes cross the loading point; after the crack goes cross the loading point, the energy release rate of the left crack tip increases and then decreases gradually, while the energy release rate of right crack tip decreases first and increases later; the energy release rate of left crack tip is equal to that of the right crack tip again when the crack is symmetric with the loading point.

The energy release rate for hygrothermal coupling elastic materials

2006 ◽  
Vol 22 (1) ◽  
pp. 28-33 ◽  
Author(s):  
Fan Yang ◽  
Jun Wang ◽  
Dapeng Chen
Keyword(s):  
Energy Release Rate ◽  
Energy Release ◽  
Release Rate ◽  
Elastic Materials

Study of Interfacial Delamination by Considering the Effect of Temperature and Moisture during Solder Reflow for QFN Package

2005 ◽  
Vol 2 (3) ◽  
pp. 197-207
Author(s):  
Fu-Mauh Wong ◽  
K.N Seetharamu
Keyword(s):  
Energy Release Rate ◽  
Energy Release ◽  
Release Rate ◽  
Strain Energy ◽  
Strain Energy Release Rate ◽  
Interfacial Crack ◽  
Strain Energy Release ◽  
Geometrical Parameters ◽  
High Tendency ◽  
Solder Reflow

Experiment has been conducted to measure the solubility Csat of mold compound and to obtain the moisture weight loss curves at various temperature. Moisture desorption modeling has been conducted to calculate the moisture diffusivity for desorption D(T) by matching with the experimental results. Finite Element Analysis (FEA) has also been conducted to calculate the transient development of strain energy release rate (ERR) at the interfacial crack tip due to thermal stress only (Gt), hygrostress only (Gh), and the combined effect (Gtotal) during solder reflow. ERR is computed based on the Virtual Crack Closure Technique (VCCT). It is found that Gh is significantly smaller than Gt, however the effect of hygrostress significantly increases the total strain energy release rate when combined with the thermal effect. The maximum Gtotal occurs at the peak of the solder reflow profile. The effects of crack size and geometrical parameters have been studied. The result imply that the interfacial crack is unstable and has a high tendency of growing to a significant extent. ERR is strongly influenced by the thickness of the package while length between the edge of die and pad has a moderate affect on the ERR.

scholarly journals Analytical Fracture Mechanics Analysis of the Pull-Out Test Including the Effects of Friction and Thermal Stresses

2000 ◽  
Vol 9 (6) ◽  
pp. 096369350000900 ◽  
Author(s):  
John A. Nairn
Keyword(s):  
Energy Release Rate ◽  
Energy Release ◽  
Release Rate ◽  
Thermal Stresses ◽  
Interfacial Crack ◽  
Single Fibre ◽  
Finite Elements Analysis ◽  
Accurate Analysis ◽  
Pull Out ◽  
Microbond Test

The energy release rate for propagation of a debond in a single-fibre pull out test was derived analytically. The key finding was that an accurate analysis can be derived by a global energy analysis that includes effects of residual stresses and interfacial friction but does not need to include the details of the stress state at the interfacial crack tip. By comparison to finite elements analysis, it was verified that the analytical results are very accurate provided the debond tip is not too close to either end of the specimen. By casting the results in terms of net-specimen stress, it was possible to derive a general energy release rate result that applies to both the pull-out test and the related microbond test. The energy release rate expressions can be used to determine interfacial fracture toughness from single-fibre pull-out tests or microbond tests.

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