A Treatment of Interfacial Cracks in the Presence of Friction

1999 ◽  
pp. 205-214
Author(s):  
C. T. Sun ◽  
W. Qian
Keyword(s):  
Interfacial Cracks

scholarly journals An Improved Cohesive Zone Model for Interface Mixed-Mode Fractures of Railway Slab Tracks

2021 ◽  
Vol 11 (1) ◽  
pp. 456
Author(s):  
Yanglong Zhong ◽  
Liang Gao ◽  
Xiaopei Cai ◽  
Bolun An ◽  
Zhihan Zhang ◽  
...  
Keyword(s):  
Interface Crack ◽  
Cohesive Zone ◽  
Mixed Mode ◽  
Cohesive Zone Model ◽  
Complex Loading ◽  
Bending Test ◽  
Mixed Mode Fracture ◽  
Zone Model ◽  
Slab Track ◽  
Interfacial Cracks

The interface crack of a slab track is a fracture of mixed-mode that experiences a complex loading–unloading–reloading process. A reasonable simulation of the interaction between the layers of slab tracks is the key to studying the interface crack. However, the existing models of interface disease of slab track have problems, such as the stress oscillation of the crack tip and self-repairing, which do not simulate the mixed mode of interface cracks accurately. Aiming at these shortcomings, we propose an improved cohesive zone model combined with an unloading/reloading relationship based on the original Park–Paulino–Roesler (PPR) model in this paper. It is shown that the improved model guaranteed the consistency of the cohesive constitutive model and described the mixed-mode fracture better. This conclusion is based on the assessment of work-of-separation and the simulation of the mixed-mode bending test. Through the test of loading, unloading, and reloading, we observed that the improved unloading/reloading relationship effectively eliminated the issue of self-repairing and preserved all essential features. The proposed model provides a tool for the study of interface cracking mechanism of ballastless tracks and theoretical guidance for the monitoring, maintenance, and repair of layer defects, such as interfacial cracks and slab arches.

Fatigue Crack Growth Tests on Glass Fibre Reinforced Polymer Matrix Composite

2005 ◽  
Vol 473-474 ◽  
pp. 189-194
Author(s):  
Zilia Csomós ◽  
János Lukács
Keyword(s):  
Cyclic Loading ◽  
Crack Opening Displacement ◽  
Matrix Composite ◽  
Glass Fibre ◽  
Crack Opening ◽  
Loading Conditions ◽  
Opening Displacement ◽  
Interfacial Cracks ◽  
Glass Fibre Reinforced ◽  
Number Of Cycles

E-glass fibre reinforced polyester matrix composite was investigated, which was made by pullwinding process. Round three point bending (RTPB) specimens were tested under quasi-static and mode I cyclic loading conditions. Load vs. displacement (F-f), load vs. crack opening displacement (F-v) and crack opening displacement range vs. number of cycles (ΔCOD-N) curves were registered and analysed. Interfacial cracks were caused the final longitudinal fracture of the specimens under quasi-static and cyclic loading conditions.

Fatigue crack growth simulations of interfacial cracks in bi-layered FGMs using XFEM

2013 ◽  
Vol 52 (4) ◽  
pp. 799-814 ◽  
Author(s):  
S. Bhattacharya ◽  
I. V. Singh ◽  
B. K. Mishra ◽  
T. Q. Bui
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Interfacial Cracks

scholarly journals Verification of Brittle Fracture Criteria for Bimaterial Structures

2014 ◽  
Vol 8 (1) ◽  
pp. 44-48
Author(s):  
Grzegorz Mieczkowski ◽  
Krzysztof Molski
Keyword(s):  
Experimental Data ◽  
Composite Materials ◽  
Cyclic Loading ◽  
Brittle Fracture ◽  
Axial Loading ◽  
Loading Conditions ◽  
Fracture Criteria ◽  
Interfacial Cracks ◽  
Theoretical Results ◽  
Brittle Fracture Criteria

Abstract The increasing application of composite materials in the construction of machines causes strong need for modelling and evaluating their strength. There are many well known hypotheses used for homogeneous materials subjected to monotone and cyclic loading conditions, which have been verified experimentally by various authors. These hypotheses should be verified also for composite materials. This paper provides experimental and theoretical results of such verifications for bimaterial structures with interfacial cracks. Three well known fracture hypotheses of: Griffith, McClintock and Novozhilov were chosen. The theoretical critical load values arising from each hypotheses were compared with the experimental data including uni and multi-axial loading conditions. All tests were carried out with using specially prepared specimens of steel and PMMA.

scholarly journals Finite-Element Simulation of Residual Stresses During the Processing of Lumped Burnable Absorber Fuel

2021 ◽  
Vol 9 ◽  
Author(s):  
Qusai Mistarihi ◽  
Ho Jin Ryu
Keyword(s):  
Finite Element ◽  
Threshold Stress ◽  
Initial Density ◽  
Interfacial Stress ◽  
Spherical Particles ◽  
Stabilized Zirconia ◽  
Interfacial Cracks ◽  
Element Simulation ◽  
Shielding Factor ◽  
Burnable Absorber

UO2–Gd2O3 fuel is mostly used as a burnable absorber fuel in the form of a homogenous mixture of Gd2O3 and UO2. More effective reactivity control can be achieved by lumping Gd2O3 within the UO2 because this enhances the spatial self-shielding factor of the burnable absorber fuel. The fabrication of lumped burnable absorber fuel containing lumped Gd2O3 spherical particles or compacts has been experimentally demonstrated using yttrium-stabilized zirconia (YSZ) as a UO2 fuel surrogate. Interfacial cracks or gaps forming under the interfacial stress that develops during the fabrication of the fuel can be eliminated by controlling the initial density of the lumped Gd2O3. In this study, this interfacial stress during the fabrication process was simulated using finite element methods. The effect of the size, shape, and initial density of the lumped Gd2O3 on the distribution and magnitude of the interfacial stress was investigated. The addition of Gd2O3 spherical particles resulted in a lower and more uniform interfacial stress distribution than the addition of cylindrical Gd2O3 compacts. The interfacial stress was increased with increasing Gd2O3 size and initial density. The calculated interfacial stress was compared with experimental results to estimate the threshold stress for crack development in a lumped burnable absorber fuel.

scholarly journals Effect of interfacial slippage on the near-tip fields of an interface crack between a soft elastomer and a rigid substrate

2014 ◽  
Vol 470 (2170) ◽  
pp. 20140497 ◽  
Author(s):  
T. H. Lengyel ◽  
Rong Long ◽  
P. Schiavone
Keyword(s):  
Interface Crack ◽  
Wedge Angle ◽  
The Body ◽  
Far Field ◽  
Cauchy Stress ◽  
Rigid Substrate ◽  
Interfacial Cracks ◽  
Friction Surfaces ◽  
Interfacial Slippage

We consider the role of interfacial slippage in the deformation and stress fields near the tip of a plane interface crack occurring between a compressible hyperelastic material and a rigid substrate. Specifically, we draw comparisons between the two limiting cases of ‘no-slip’ (infinitely high friction) and ‘frictionless’ (zero friction) surfaces by performing corresponding asymptotic analyses in the crack-tip region. Our results indicate that for the no-slip case, when the body is subjected to far-field loading, the crack deforms to a wedge-like shape consistent with experimental observations reported in the literature. Moreover, in this case, the wedge angle is shown to be directly related to ratios of various Cauchy stress components on the bonded surface in the near-tip region. Finite-element simulations reveal that the wedge angle also depends on material compressibility and the far-field loading conditions. By contrast, the analysis of the frictionless case reveals that the crack consistently opens into a smooth parabolic shape with a right wedge angle and near-tip stress field dominated by the normal stress at the surface. The results established here can be used as a basis for the understanding of the role of varying degrees of slippage on interfacial cracks.

Analysis of Interface Cracking in Flip Chip Packages With Viscoplastic Solder Deformation

2003 ◽  
Author(s):  
M. J. Heffes ◽  
H. F. Nied
Keyword(s):  
Flip Chip ◽  
Strain Energy Release ◽  
Solder Material ◽  
Elastic Plastic ◽  
Linear Elastic ◽  
Interfacial Cracks ◽  
Fracture Parameters ◽  
Solder Bumps ◽  
Interface Cracking ◽  
Semiconductor Packages

This paper examines the modeling of viscoplastic solder behavior in the vicinity of interfacial cracking for flip chip semiconductor packages. Of particular interest is the relationship between viscoplastic deformation in the solder bumps and any possible interface cracking between the epoxy underfill layer and the silicon die. A 3-D finite element code, developed specifically for the study of interfacial fracture problems, was modified to study how viscoplastic solder material properties would affect fracture parameters such as strain energy release rate and phase angle for nearby interfacial cracks. Simplified two-layer periodic symmetry models were developed to investigate these interactions. Comparison of flip chip results using different solder material models showed that viscoplastic models yielded lower stress and fracture parameters than time independent elastic-plastic simulations. It was also found that adding second level attachment greatly increases the magnitude of the solder strain and fracture parameters. As expected, the viscoplastic and temperature dependent elastic-plastic results exhibited greater similarity to each other than results based solely on linear elastic properties.

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