Stress Fields Along Semi-Elliptical Interfacial Crack Front with Yield-Strength-Mismatch

2003 ◽  
Vol 27 (1) ◽  
pp. 126-137
Keyword(s):  
Yield Strength ◽  
Crack Front ◽  
Interfacial Crack ◽  
Stress Fields

scholarly journals Universal characterization of three-dimensional creeping crack-front stress fields

2018 ◽  
Vol 152-153 ◽  
pp. 104-117 ◽  
Author(s):  
Wanlin Guo ◽  
Zhiyuan Chen ◽  
Chongmin She
Keyword(s):  
Crack Front ◽  
Three Dimensional ◽  
Stress Fields

Stress Field of Semi-Infinite Interface Crack Tip of Double Dissimilar Orthotropic Composite Materials

2010 ◽  
Vol 97-101 ◽  
pp. 1223-1226
Author(s):  
Jun Lin Li ◽  
Shao Qin Zhang
Keyword(s):  
Composite Material ◽  
Composite Materials ◽  
Interface Crack ◽  
Interfacial Crack ◽  
Crack Tip ◽  
Stress Fields ◽  
Displacement Fields ◽  
Orthotropic Composite ◽  
Stress Functions ◽  
Secular Equations

The problem of orthotropic composite materials semi-infinite interfacial crack was studied, by constructing new stress functions and employing the method of composite material complex. In the case that the secular equations’ discriminates the and theoretical solutions to the stress fields and the displacement fields near semi-infinite interface crack tip without oscillation and inter-embedding between the interfaces of the crack are obtained, a comparison with finite element example was done to verify the correction of theoretical solution.

The detachment of an inclined micro-pillar adhered to a dissimilar substrate

2021 ◽  
pp. 1-22
Author(s):  
Nitish Kumar ◽  
Syed Nizamuddin Khaderi
Keyword(s):  
Stress Intensity ◽  
Axial Load ◽  
Interfacial Crack ◽  
Axial Loading ◽  
Stress Fields ◽  
Singular Stress ◽  
Elastic Mismatch ◽  
Bending Loads ◽  
Singular Stress Fields ◽  
The Moment

Abstract We investigate the mechanics of the detachment of an inclined micro-pillar adhered to a dissimilar substrate when subjected to a combination of an axial load and end moment. When the micro-pillar has adhered to the substrate, singular stress fields exist at the bi-material corners. The order of singularity is estimated using asymptotic analysis. The first two terms in the asymptotic expansion lead to singular stress fields. The magnitude of the singularity is evaluated in terms of the elastic mismatch between the pillar and substrate and the micro-pillar inclination. The asymptotic stress due to the moment loading is more sensitive to the micro-pillar inclination when compared to that due to the axial loading. They are insensitive to the micro-pillar inclination when the micro-pillar is rigid when compared to the substrate. A short interfacial crack is further assumed to exist at the bi-material corner. This crack is embedded in the corner singularity region and is loaded by the singular fields due to axial and bending loads. A boundary layer analysis is performed on the singular zone to estimate the stress intensity factor when a short crack embedded in it is subjected to the singular fields. The stress intensity factors are also calculated for a long interfacial crack at the bi-material corner, which extends beyond the singular zone. Using the above results, we investigate the detachment of the inclined micro-pillar under the combination of an axial load and end moment.

A computational tool for estimating stress fields along a surface crack front

2014 ◽  
Vol 38 (2) ◽  
pp. 180-189 ◽  
Author(s):  
A. S. Chernyatin ◽  
Y. G. Matvienko ◽  
I. A. Razumovsky
Keyword(s):  
Crack Front ◽  
Surface Crack ◽  
Stress Fields ◽  
Computational Tool

scholarly journals Avalanches and extreme value statistics in interfacial crackling dynamics

2018 ◽  
Vol 377 (2136) ◽  
pp. 20170394 ◽  
Author(s):  
S. Santucci ◽  
K. T. Tallakstad ◽  
L. Angheluta ◽  
L. Laurson ◽  
R. Toussaint ◽  
...  
Keyword(s):  
Power Law ◽  
Crack Front ◽  
Statistical Physics ◽  
Random Medium ◽  
Interfacial Crack ◽  
Maximum Amplitude ◽  
Extreme Value Statistics ◽  
Power Law Distribution ◽  
Extreme Statistics ◽  
Average Crack

We study the avalanche and extreme statistics of the global velocity of a crack front, propagating slowly along a weak heterogeneous interface of a transparent polymethyl methacrylate block. The different loading conditions used (imposed constant velocity or creep relaxation) lead to a broad range of average crack front velocities. Our high-resolution and large dataset allows one to characterize in detail the observed intermittent crackling dynamics. We specifically measure the size S , the duration D , as well as the maximum amplitude of the global avalanches, defined as bursts in the interfacial crack global velocity time series. Those quantities characterizing the crackling dynamics follow robust power-law distributions, with scaling exponents in agreement with the values predicted and obtained in numerical simulations of the critical depinning of a long-range elastic string, slowly driven in a random medium. Nevertheless, our experimental results also set the limit of such model which cannot reproduce the power-law distribution of the maximum amplitudes of avalanches of a given duration reminiscent of the underlying fat-tail statistics of the local crack front velocities. This article is part of the theme issue ‘Statistical physics of fracture and earthquakes’.

Residual Stress Effects on the Crack-Front Constraints for Surface Cracks in Pipes

2010 ◽  
Author(s):  
Xudong Qian ◽  
Tieping Li
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Wall Thickness ◽  
Crack Front ◽  
Heat Input ◽  
Crack Depth ◽  
Geometric Parameters ◽  
Stress Fields ◽  
Surface Cracks ◽  
Linear Elastic

This paper investigates the effect of residual stresses on the linear-elastic KI-T fields along the front of circumferential surface cracks in pipelines. The numerical procedure simulates three typical patterns of residual stresses through a modified eigenstrain approach, which combines a thermal loading with a mechanical traction imposed on the heat-affected zone. The three residual stress profiles considered correspond to the high-heat input, the medium-heat input and the low heat input welding processes for circumferential butt welds in pipes outlined in BS 7910. The linear-elastic KI-T stresses, computed from the interaction-integral approach, characterize the constraints along the front of the circumferential flaw. The numerical investigation, covering a comprehensive matrix of geometric parameters, shows that different residual stress fields impose substantial effects on the KI-T stresses along the front of the surface crack in the wall of a pipeline. The deepest point along the crack-front often experiences low crack-front constraints characterized by the computed negative T-stresses for all three residual stress fields considered. The magnitudes of the KI-values and T-stresses show pronounced variations with the change in the ratio of the crack depth over the wall thickness of the pipe (a/t). The variation in the crack aspect ratio (the crack depth over the crack length, a/c) introduces marginal variation in the computed T stresses. The ratio of the outer diameter to the wall thickness of pipe imposes very little effect on the linear-elastic crack-front constraints for the geometric parameters considered.

Scaling and dynamics of an interfacial crack front

2003 ◽  
Vol 121 (1/2) ◽  
pp. 9-22 ◽  
Author(s):  
Knut JØrgen MÅLØY ◽  
Jean SCHMITTBUHL ◽  
Alex HANSEN ◽  
G. George BATROUNI
Keyword(s):  
Crack Front ◽  
Interfacial Crack

Mixed Mode Effects on the Interfacial Crack Propagation

2004 ◽  
Vol 261-263 ◽  
pp. 357-362 ◽  
Author(s):  
B.S. Choi ◽  
Chia Yen Lee ◽  
Young Suck Chai
Keyword(s):  
Crack Initiation ◽  
Crack Propagation ◽  
Crack Front ◽  
Mixed Mode ◽  
Crack Opening ◽  
Interfacial Crack ◽  
Bimaterial Interface ◽  
Negative Mode ◽  
Initiation And Propagation ◽  
Positive Mode

Initiation and propagation of interfacial crack along bimaterial interface are considered in this study. A series of interfacial crack initiation and propagation experiments are conducted using the biaxial loading device for various mixed modes. Normal crack opening displacement (NCOD) is measured near crack front by a crack opening interferometry and used for extracting fracture parameters. From mixed mode interfacial crack initiation experiments, large increase in toughness with shear components is observed. Initial velocity of crack propagation is very dependent upon the mode-mixes. It increased with positive mode-mix due to the increase of stress singularities ahead of crack front and decreased with negative mode-mix resulting from the increase of the degree of compressive stress behind the crack front. Crack propagation was less accelerated with positive mode-mix than the negative mode-mix.

Sign in / Sign up

Export Citation Format

Share Document