Discrete softening-damage model for fracture process representation with embedded strong discontinuities

Abstract. Floating ice shelves exert a stabilizing force onto the inland ice sheet. However, this buttressing effect is diminished by the fracture process, which on large scales effectively softens the ice, accelerating its flow, increasing calving, and potentially leading to ice shelf breakup. Here, we explore how the application of a continuum damage model (CDM) to the prognostic ice sheet model BISICLES can account for the effects of fracture processes on viscous ice dynamics. Damage is created by the local stress field and advects downstream. This continuum damage model is coupled to the dynamical ice flow model by decreasing the effective viscosity proportional to the damage field. To evaluate the physical role of the fracture process on large-scale ice sheet dynamics and also discern the relative importance of the parameters used in the damage model, we carry out a suite of numerical experiments based on the MISMIP+ (Marine Ice Sheet Model Intercomparison Project) marine ice sheet geometry. We find that behavior of the simulated marine ice sheet is sensitive to fracture processes on the ice shelf. In the case of a geometry that produces strong lateral stress, the stiffness of ice around the grounding line is essential to ice sheet evolution, with softer or more damaged ice leading to thinning and grounding line retreat.

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Size effect analysis of quasi-brittle fracture with localizing gradient damage model

International Journal of Damage Mechanics ◽

10.1177/1056789520983872 ◽

2021 ◽

pp. 105678952098387

Author(s):

Yi Zhang ◽

Amit S. Shedbale ◽

Yixiang Gan ◽

Juhyuk Moon ◽

Leong H. Poh

Keyword(s):

Brittle Fracture ◽

Size Effect ◽

Fracture Process ◽

Fracture Process Zone ◽

Concrete Beams ◽

Process Zone ◽

Damage Zone ◽

Damage Model ◽

Lattice Models ◽

Gradient Enhancement

The size effect of a quasi-brittle fracture is associated with the size of fracture process zone relative to the structural characteristic length. In numerical simulations using damage models, the nonlocal enhancement is commonly adopted to regularize the softening response. However, the conventional nonlocal enhancement, both integral and gradient approaches, induces a spurious spreading of damage zone. Since the evolution of fracture process zone cannot be captured well, the conventional nonlocal enhancement cannot predict the size effect phenomenon accurately. In this paper, the localizing gradient enhancement is adopted to avoid the spurious spreading of damage. Considering the three-point bend test of concrete beams, it is demonstrated that the dissipation profiles obtained with the localizing gradient enhancement compare well with those of reference meso-scale lattice models. With the correct damage evolution process, the localizing gradient enhancement is shown to capture the size effect phenomenon accurately for a series of geometrically similar concrete beams, using only a single set of material parameters.

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A continuum damage-based three-dimensional fracture simulation method for brittle-like materials

International Journal of Damage Mechanics ◽

10.1177/10567895211045116 ◽

2021 ◽

pp. 105678952110451

Author(s):

Bin Sun ◽

Zhao-Dong Xu

Keyword(s):

Crack Growth ◽

Fracture Process ◽

Damage Model ◽

Three Dimensional ◽

Fracture Mechanisms ◽

Continuum Damage ◽

Growth Path ◽

Fracture Simulation ◽

3D Crack Growth ◽

Crack Growth Path

Current numerical methods cannot simulate well three-dimensional (3D) fracture process of solids. In order to study 3D fracture process of brittle-like materials and improve crack growth path prediction accuracy, a method is developed based on continuum damage mechanics and finite element method. In the developed method, damage is computed by homogenizing stress or strain in the preset characteristic field for reducing the spurious mesh sensitivity. Meanwhile, an additional procedure is used to consider the unstable and competing fracture process, which can be used to consider stress redistribution due to local damage evolution during the fracture process simulation. In addition, a damage model of concrete is also developed and used to describe material damage. Finally, 3D fracture process of two numerical examples, were simulated and compared with the experimental results by using the developed method. The 3D crack growth path and macroscopic mechanical behaviors can be predicted by the developed method coupled with a damage model. From the comparison, the effectiveness and modeling capability of the developed method are verified, which can be used to study 3D fracture mechanisms of concrete-like materials.

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Comparison of two homogenization methods using a damage model for a fibrous membrane, based on the fibers' fracture process at the microscale

European Journal of Mechanics - A/Solids ◽

10.1016/j.euromechsol.2012.10.006 ◽

2013 ◽

Vol 39 ◽

pp. 1-10 ◽

Cited By ~ 1

Author(s):

A. Bel-Brunon ◽

M. Coret ◽

K. Bruyère-Garnier ◽

A. Combescure

Keyword(s):

Fracture Process ◽

Damage Model ◽

Fibrous Membrane ◽

Homogenization Methods

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An updated continuum damage model to investigate fracture process of structures in DBTT region

International Journal of Fracture ◽

10.1007/s10704-008-9250-2 ◽

2008 ◽

Vol 151 (2) ◽

pp. 199-215 ◽

Cited By ~ 2

Author(s):

Zhao-Xi Wang ◽

Jian Lu ◽

Hui-Ji Shi ◽

Dong-Feng Li ◽

Xianfeng Ma

Keyword(s):

Fracture Process ◽

Damage Model ◽

Continuum Damage ◽

Continuum Damage Model

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Detecting the fracture process zone in concrete using scanning electron microscopy and numerical modelling using the nonlocal isotropic damage model

Canadian Journal of Civil Engineering ◽

10.1139/l06-132 ◽

2007 ◽

Vol 34 (4) ◽

pp. 496-504 ◽

Cited By ~ 5

Author(s):

H Hadjab-Souag ◽

J.-F. Thimus ◽

M Chabaat

Keyword(s):

Finite Element Method ◽

Finite Element ◽

Electron Microscope ◽

Fracture Process ◽

Fracture Process Zone ◽

Process Zone ◽

Damage Model ◽

Object Oriented ◽

Isotropic Damage ◽

Scanning Electron

This paper deals with two aspects of the characterization of the fracture process zone (FPZ) in quasi-brittle materials such as concrete. An overview is given of the possibility of using a destructive technique, such as the scanning electron microscope, and a numerical model, such as the nonlocal isotropic damage model (NLIDM), to detect FPZ characteristics, e.g., length and width of the FPZ. The fracture of concrete requires the consideration of progressive damage, which is usually modelled by a constitutive law and can be studied by a numerical method. The object-oriented finite element method (OOFEM) has recently been used in damage studies, and thus the FPZ is calculated on the basis of one of the damage models (the NLIDM). The results obtained from the experimental investigation are similar to those obtained using the NLIDM, which has proven to be a useful tool for analysis of the cracking process.Key words: object-oriented finite element method, nonlocal isotropic damage model, fracture process zone, scanning electron microscope.

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