Numerical modelling of effective thermal conductivity for modified geomaterial using lattice element method

Rizvi, Zarghaam Haider; Shrestha, Dinesh; Sattari, Amir; Wuttke, Frank

doi:10.1007/s00231-017-2140-2

Cited by 26 publications

(12 citation statements)

References 30 publications

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“…Generally, discrete lattice models have been extensively used to successfully represent complex failure mechanisms occurring in heterogeneous materials, such as concrete or rocks [23][24][25][26]. They have also been applied in multiphysics failure applications [27,28], thermal conductivity [29], vibration analysis [30,31], dynamic crack propagation [32,33] and impact applications [34,35]. However, none of these models is comparable to the present model, which provides the failure mechanisms in mode I and mode II in terms of embedded discontinuities in Timoshenko lattice beam elements.…”

Section: Discrete Lattice Model With Embedded Strong Discontinuitiesmentioning

confidence: 99%

Crack propagation in dynamics by embedded strong discontinuity approach: Enhanced solid versus discrete lattice model

Nikolić

Nam

Ibrahimbegović

et al. 2018

Computer Methods in Applied Mechanics and Engineering

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In this work we propose and compare the two models for crack propagation in dynamics. Both models are based on embedded strong discontinuities for localized cohesive type crack description and both provide the advantage to not to require tracking algorithms. The first one is based on discrete lattice approach, where the domain is discretized with Voronoi cells held together prior to crack occurrence by cohesive links represented in terms of Timoshenko beams. The second one is based on constant strain triangular solid element. In both models, propagation of cracks activates enhancements in the displacement field leading to embedded strong discontinuities. The latter remain localized inside the element, regulated by the localized traction separation behavior defined through exponential softening law. Thus, the both models provide the result that remain mesh-independent, with fracture energy as the model parameter. We show that implementation in dynamics framework can be obtained by adding inertial effects without modifying the existing quasi-statics models. In order to provide reliable results, classical implicit Newmark algorithm can be used for time integration. The two presented models are subjected to dynamic crack propagation benchmarks, where detailed analysis on strain, kinetic, plastic free and dissipated energy during simulation is verified by comparison to the amount of total work which is introduced into the system. The main strength of the proposed approach is that cracks initiation, propagation, their coalescence, merging and branching are automatically obtained without any tracking algorithms. In addition, since the discontinuities remain localized inside elements, accurate results can be obtained even with coarser grids, leading to efficient methodology capable of capturing complex crack patterns in dynamics.

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Section: Discrete Lattice Model With Embedded Strong Discontinuitiesmentioning

confidence: 99%

Crack propagation in dynamics by embedded strong discontinuity approach: Enhanced solid versus discrete lattice model

Nikolić

Nam

Ibrahimbegović

et al. 2018

Computer Methods in Applied Mechanics and Engineering

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“…The Thermal Lattice Element Method (TLEM), which is derived from condensed matter physics, offers a solution to the complex problem of heat propagation in granular assembly [2,4,5]. In principle, the lattice-based models are working on atomic lattice models [36].…”

Section: Hard Computational With Thermal Lattice Element Methodsmentioning

confidence: 99%

“…The twobody interactions are used to model many-body interactions. The critical factor in many-body interactions is that the chosen time step is such that any temperature disturbance is felt only to the neighbouring particle in one step [4,5]. For this work, the constant contact among the elements is considered.…”

Section: Generation Of the Granular Mediamentioning

confidence: 99%

“…and the miscellaneous factors: properties of soil components, ions, salts, additives, and hysteresis effect, etc. [4][5][6]. The dominant factors controlling the changes are the environmental factors, such as the water content and porosity of the sand [7].…”

Section: Introductionmentioning

confidence: 99%

“…All these studies suggest the importance of inclusion of the microstructure and the distribution of pore spaces in the granular system. An alternative hybrid approach to model the heat transfer in a fast and realistic manner is the Lattice Element Method (LEM) [4,36]. The domain is discretised with randomly generated seed points which are then partitioned into Voronoi cell to find the neighbouring seed points.…”

Section: Introductionmentioning

confidence: 99%

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Soft and hard computation methods for estimation of the effective thermal conductivity of sands

et al. 2020

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Thermal properties of sand are of importance in numerous engineering and scientific applications ranging from energy storage and transportation infrastructures to underground construction. All these applications require knowledge of the effective thermal parameters for proper operation. The traditional approaches for determination of the effective thermal property, such as the thermal conductivity are based on very costly, tedious and time-consuming experiments. The recent developments in computer science have allowed the use of soft and hard computational methods to compute the effective thermal conductivity (ETC). Here, two computation methods are presented based on soft and hard computing approaches, namely, the deep neural network (DNN) and the thermal lattice element method (TLEM), respectively, to compute the ETC of sands with varying porosity and moisture content values. The developed models are verified and validated with a small data set reported in the literature. The computation results are compared with the experiments, and the numerical results are found to be within reasonable error bounds. The deep learning method offers fast and robust implementation and computation, even with a small data set due to its superior backpropagation algorithm. However, the TLEM based on micro and meso physical laws outperforms it at accuracy.

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Yoshioka

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Pötschke

et al. 2021

GeomInt–Mechanical Integrity of Host Rocks

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An essential scientific goal of the GeomInt project is the analysis of potentials and limitations of different numerical approaches for the modelling of discontinuities in the rocks under consideration in order to improve the understanding of methods and their synergies with regard to theoretical and numerical fundamentals. As numerical methods, the “Lattice Element Method” (LEM), the non-continuous discontinuum methods “Discrete Element Method” (DEM), the “Smoothed Particle Hydrodynamics” (SPH), the “Forces on Fracture Surfaces” (FFS) as well as the continuum approaches “Phase-Field Method” (PFM), “Lower-Interface-Method” (LIE), “Non-Local Deformation” (NLD) and the “Hybrid-Dimensional Finite-Element-Method” (HDF) will be systematically investigated and appropriately extended based on experimental results (Fig. 3.1).

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Numerical modelling of effective thermal conductivity for modified geomaterial using lattice element method

Cited by 26 publications

References 30 publications

Crack propagation in dynamics by embedded strong discontinuity approach: Enhanced solid versus discrete lattice model

Crack propagation in dynamics by embedded strong discontinuity approach: Enhanced solid versus discrete lattice model

Soft and hard computation methods for estimation of the effective thermal conductivity of sands

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