Onset of localization in heterogeneous interfacial failure

Stormo, Arne; Gjerden, Knut Skogstrand; Hansen, Alex

doi:10.1103/physreve.86.025101

Cited by 27 publications

(35 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Hence, changing e without changing k is equivalent to changing L-and hence the linear size of the system-while keeping the elastic properties of the system constant [32]. This is a central point in what follows.…”

Section: Model and Methodsmentioning

confidence: 99%

Local dynamics of a randomly pinned crack front: a numerical study

2014

Self Cite

View full text Add to dashboard Cite

We investigate numerically the dynamics of crack propagation along a weak plane using a model consisting of fibers connecting a soft and a hard clamp. This bottom-up model has previously been shown to contain the competition of two crack propagation mechanisms: coalescence of damage with the front on small scales and pinned elastic line motion on large scales. We investigate the dynamical scaling properties of the model, both on small and large scale. The model results compare favorable with experimental results on stable crack propagation between sintered PMMA plates.

show abstract

Section: Model and Methodsmentioning

confidence: 99%

Local dynamics of a randomly pinned crack front: a numerical study

2014

Self Cite

View full text Add to dashboard Cite

show abstract

“…When the distances are measured in units of the discretization size dl, the relative influence of the elastic interactions with respect to the global loading has been found to be described by a single parameter named the reduced Young modulus [35] e = Edl N .…”

Section: Modelmentioning

confidence: 99%

Soft-Clamp Fiber Bundle Model and Interfacial Crack Propagation: Comparison Using a Non-linear Imposed Displacement

et al. 2016

Self Cite

View full text Add to dashboard Cite

We compare experimental observations of a slow interfacial crack propagation along an heterogeneous interface to numerical simulations using a soft-clamped fiber bundle model. The model consists of a planar set of brittle fibers between a deformable elastic half-space and a rigid plate with a square root shape that imposes a non-linear displacement around the process zone. The non-linear square-root rigid shape combined with the long range elastic interactions is shown to provide more realistic displacement and stress fields around the crack tip in the process zone and thereby significantly improving the predictions of the model. Experiments and model are shown to share a similar self-affine roughening of the crack front both at small and large scales and a similar distribution of the local crack front velocity. Numerical predictions of the Family-Viscek scaling for both regimes are discussed together with the local velocity distribution of the fracture front.

show abstract

“…Completely ductile failure gives a b-value of 0.63, while for brittle fractures, b = 1.2. A recently developed bottom-up model of fracture by Stormo et al (2013) has shown to have similar diffuse to localized damage distribution transition. This model can address the competition between elastic stress redistribution and damage development related to geological heterogeneity.…”

Section: Introductionmentioning

confidence: 98%

“…This model can address the competition between elastic stress redistribution and damage development related to geological heterogeneity. Here, we refine and expand the model proposed by Stormo et al (2013) with the attempt to describe fracture development along a pre-existing weak interface. We observe in our model a similar effective ductile to brittle transition at large scale as observed by previous authors.…”

Section: Introductionmentioning

confidence: 99%

Mechanical origin of b-value changes during stimulation of deep geothermal reservoirs

2015

Self Cite

View full text Add to dashboard Cite

Background:The distribution of induced-earthquake magnitudes in deep geothermal reservoirs is a classical tool for monitoring reservoirs. It typically shows some important fluctuations through time and space. Despite being a very crude information (i.e., a scalar quantity) of very complex mechanical stress evolution, understanding these variations could still give us insights into the mechanics of the reservoir. Here, we analyze the output of a simple quasi-static physical model of a single fault and propose a new way to describe bursts that could be compared to seismic events. Methods: Our model is an elastic fiber bundle model describing multiple ruptures along a single major fault of the reservoir. It consists of a set of fibers with various strengths, arranged in a planar L × L two-dimensional array, linking together two elastic half-spaces. It mimics a fault zone with various asperities. During load, the fibers break quasi-statically according to a stress threshold distribution. Contrary to classical fiber bundle model, here, when a fiber breaks, it redistributes the load on the surviving fibers through long range elastic interactions. Interestingly, the elasticity of the half-spaces which changes the range of the stress distribution, characterizes two distinct regimes. In a stiff regime, we find an effective ductile deformation regime at large scale since the damage distribution is very difuse. Conversely in softer systems, the distance between two consecutive breaking fibers gets smaller and failure of the interface is localized, exhibiting an effective brittle regime. Results: We analyze two types of burst distributions: a classical one built from the statistics of the broken bonds during each failure step and a new one defines from a waiting time matrix of the fracture front propagation. The first one reproduces several known results for this type of model. The new one evidences the existence of effective creeping advances of the front with statistics that follow a Gutenberg-Richter distribution, in particular, in the ductile regime (stiff systems). Conclusions:We proposed a new definition of bursts in a fault model, based on the local fracture front velocity. We find that b v -values for the distribution of the velocity clusters are very consistent with Gutenberg-Richter distribution of induced seismicity. We link the b v -value fluctuations in the reservoirs to the influence of the velocity threshold level that could be related to recording limitation. b b -values obtained from the broken bond statistics are hardly comparable to seismic events because of the lack of space contiguousness of broken fibers during bursts. In the light of our results, we discuss the implications of b-value changes in geothermal reservoir in terms of fault asperities and normal stress evolution.

show abstract

Onset of localization in heterogeneous interfacial failure

Cited by 27 publications

References 24 publications

Local dynamics of a randomly pinned crack front: a numerical study

Local dynamics of a randomly pinned crack front: a numerical study

Soft-Clamp Fiber Bundle Model and Interfacial Crack Propagation: Comparison Using a Non-linear Imposed Displacement

Mechanical origin of b-value changes during stimulation of deep geothermal reservoirs

Contact Info

Product

Resources

About