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The Stress-Memory Effect of Fracture Stiffness During Cyclic Loading in Low-Permeability Sandstone

Kluge, C. (author), Blöcher, Guido (author), Hofmann, Hannes (author), Barnhoorn, A. (author), Schmittbuhl, Jean (author), Bruhn, D.F. (author)

The hydraulic performance and mechanical stability of open fractures are crucial for several subsurface applications including fractured geothermal reservoirs or nuclear waste repositories. Their hydraulic and mechanical properties (fluid flow and fracture stiffness) are both strongly dependent on the fracture geometry. Any change in...

journal article 2021

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Toward nanomechanical models of liquid-phase exfoliation of layered 2D nanomaterials: Analysis of a π − peel model

Botto, L. (author)

In liquid-phase exfoliation for the production of 2D nanomaterials fluid forces are used to gently overcome adhesive interlayer forces, leading to single- or few-layer 2D nanomaterials. Predicting accurately the critical fluid shear rate for exfoliation is a crucial challenge. By combining notions of fluid mechanics and fracture mechanics, we...

journal article 2019

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Numerical Investigation into the Effect of Splats and Pores on the Thermal Fracture of Air Plasma-Sprayed Thermal Barrier Coatings

Krishnasamy, J. (author), Ponnusami, Sathiskumar A. (author), Turteltaub, S.R. (author), van der Zwaag, S. (author)

The effect of splat interfaces on the fracture behavior of air plasma-sprayed thermal barrier coatings (APS-TBC) is analyzed using finite element modeling involving cohesive elements. A multiscale approach is adopted in which the explicitly resolved top coat microstructural features are embedded in a larger domain. Within the computational...

journal article 2019

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Accelerating crack growth simulations through adaptive model order reduction

Rocha, I.B.C.M. (author), van der Meer, F.P. (author), Taumaturgo Mororo, L.A. (author), Sluys, Lambertus J. (author)

Accurate numerical modeling of fracture in solids is a challenging undertaking that often involves the use of computationally demanding modeling frameworks. Model order reduction techniques can be used to alleviate the computational effort associated with these models. However, the traditional offline-online reduction approach is unsuitable...

journal article 2019

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Upscaling Cement Paste Microstructure to Obtain the Fracture, Shear, and Elastic Concrete Mechanical LDPM Parameters

Sherzer, G. (author), Gao, P. (author), Schlangen, E. (author), Ye, G. (author), Gal, E. (author)

Modeling the complex behavior of concrete for a specific mixture is a challenging task, as it requires bridging the cement scale and the concrete scale. We describe a multiscale analysis procedure for the modeling of concrete structures, in which material properties at the macro scale are evaluated based on lower scales. Concrete may be viewed...

journal article 2017

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Microscale Testing and Modelling of Cement Paste as Basis for Multi-Scale Modelling

Zhang, H. (author), Šavija, B. (author), Chaves Figueiredo, S. (author), Lukovic, M. (author), Schlangen, E. (author)

This work aims to provide a method for numerically and experimentally investigating the fracture mechanism of cement paste at the microscale. For this purpose, a new procedure was proposed to prepare micro cement paste cubes (100 × 100 × 100 µm3) and beams with a square cross section of 400 × 400 µm2. By loading the cubes to failure with a...

journal article 2016

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Bridging Scales with a Generalized Finite Element Method

Garzon, J. (author), Gupta, V. (author), Simone, A. (author), Duarte, C.A. (author)

The generalized FEM (GFEM) has been successfully applied to the simulation of dynamic propagating fractures, polycrystalline and fiber-reinforced microstructures, porous materials, etc. A-priori knowledge about the solution of these problems are used in the definition of their GFEM approximation spaces. This leads to more accurate and robust...

journal article 2012

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Cold cracking in DC-cast high strength aluminum alloy ingots: An intrinsic problem intensified by casting process parameters

Lalpoor, M. (author), Eskin, D.G. (author), Ruvalcaba, D. (author), Fjaer, H.G. (author), Ten Cate, A. (author), Ontijt, N. (author), Katgerman, L. (author)

For almost half a century the catastrophic failure of direct chill (DC) cast high strength aluminum alloys has been challenging the production of sound ingots. To overcome this problem, a criterion is required that can assist the researchers in predicting the critical conditions which facilitate the catastrophic failure of the ingots. This could...

journal article 2011

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Automated Modelling of Evolving Discontinuities

Nikbakht, M. (author), Wells, G.N. (author)

The automated approximation of solutions to differential equations which involve discontinuities across evolving surfaces is addressed. Finite element technology has developed to the point where it is now possible to model evolving discontinuities independently of the underlying mesh, which is particularly useful in simulating failure of solids....

journal article 2009

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A cohesive segments method for the simulation of crack growth

Remmers, J.J.C. (author), De Borst, R. (author), Needleman, A. (author)

A numerical method for crack growth is described in which the crack is not regarded as a single discontinuity that propagates continuously. Instead, the crack is represented by a set of overlapping cohesive segments. These cohesive segments are inserted into finite elements as discontinuities in the displacement field by exploiting the partition...

journal article 2003

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Time-dependent fracture of cementitious materials

Van Zijl, G.P.A.G. (author), De Borst, R. (author), Rots, J.G. (author)

The response of cementitious materials is highly time dependent. On the one hand, it can lead to delayed collapse of structures fabricated of such materials. On the other hand, the time dependence is associated with the relaxation of peak stresses, which avoids, or postpones damage. A finite element formulation is presented for the analysis of...

journal article 2000

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A plane stress softening plasticity model for orthotropic materials

Lourenco, P.B. (author), De Borst, R. (author), Rots, J.G. (author)

journal article 1997

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An interface element for modelling the onset and growth of mixed-mode cracking in aluminium and fibre metal laminates

Hashagen, F. (author), De Borst, R. (author)

journal article 1997

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Some recent developments in computational modelling of concrete fracture

De Borst, R. (author)

journal article 1997

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Uncoupled numerical method for fracture analysis

Van Vroonhoven, J.C.W. (author), De Borst, R. (author)

journal article 1997

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A gradient-enhanced damage approach to fracture

De Borst, R. (author), Benallal, A. (author), Heeres, O.M. (author)

journal article 1996

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Failure in plain and reinforced concrete - An analysis of crack width and crack spacing

Sluys, L.J. (author), De Borst, R. (author)

journal article 1996

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Gradient plasticity in numerical simulation of concrete cracking

De Borst, R. (author), Pamin, J. (author)

journal article 1996

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The crack growth mechanism in asphaltic mixes

Jacobs, M.M.J. (author), Hopman, P.C. (author), Molenaar, A.A.A. (author)

The crack growth mechanism in asphalt concrete (Ac) mixes is studied. In cyclic tests on several asphaltic mixes crack growth is measured, both with crack foils and with cOD-gauges. It is found that crack growth in asphaltic mixes is described by three processes which are parallel in time: cohesive crack growth in the mortar, adhesive crack...

journal article 1995

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Constitutive Model for Reinforced Concrete

Feenstra, P.H. (author), De Borst, R. (author)

journal article 1995