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This open access book provides a cross-sectoral, integrative and multi-scale design and planning approach for adaptive urban transformation of fast urbanising deltas, taking the Pearl River Delta (China) as a case study. Deltaic areas are among the most promising regions in the world. Their strategic location and superior quality of their soils...book 2023
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Chen, L. (author), Maher, G.D. (author), Hulshoff, S.J. (author)Parameters for SGS models within the variational multiscale method for the Stokes equations are determined using two different methods. Both linear and nonlinear models are considered. Firstly, optimal parameters are found using a goal-oriented model-constrained technique minimising L2 error. Secondly, parameters are obtained using the...conference paper 2014
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Esposito, R. (author), Hendriks, M.A.N. (author)One of the most harmful degradation process for concrete structures is the alkali-silica reaction. This process starts at aggregate level with a gel swelling and can produce damage up to macro level, by compromising the integrity and capacity of the structure. In order to better understand the complex nature of this phenomenon, a multiscale...conference paper 2013
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Lloberas Valls, O. (author), Everdij, F.P.X. (author), Rixen, D.J. (author), Simone, A. (author), Sluys, L.J. (author)The multiscale framework presented in [1, 2] is assessed in this contribution for a study of random heterogeneous materials. Results are compared to direct numerical simulations (DNS) and the sensitivity to user-defined parameters such as the domain decomposition type and initial coarse scale resolution is reported. The parallel performance of...conference paper 2013
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Trebotich, D. (author), Miller, G.H. (author), Bybee, M.D. (author)We present a new method for particle interactions in polymer models of DNA. The DNA is represented by a bead-rod polymer model. The main objective in this work is to implement short range forces to properly model polymer-polymer and polymer-surface interactions. We will discuss two methods for these interactions: (1) a new rigid constraint...conference paper 2006
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Lube, G. (author)The numerical solution of the nonstationary, incompressible Navier-Stokes model can be split into linearized auxiliary problems of Oseen type. We present in a unique way different stabilization techniques of finite element schemes on isotropic and hybrid meshes. First we describe the state-of-the-art for the classical residual-based SUPG/PSPG...conference paper 2006
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Lloberas Valls, O. (author), Rixen, D.J. (author), Simone, A. (author), Sluys, L.J. (author)In this contribution we describe a methodology for the multiscale analysis of heterogeneous quasi-brittle materials. The algorithm is based on the finite element tearing and interconnecting FETI [1] method cast in a non-linear setting. Adaptive multiscale analysis is accounted for with the use of selective refinement at domains that undergo...conference paper 2011
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Lloberas Valls, O. (author), Everdij, F.P.X. (author), Rixen, D.J. (author), Simone, A. (author), Sluys, L.J. (author)Concurrent multiscale analysis of quasi-brittle heterogeneous materials such as concrete and rock is conducted employing non-overlapping domain decomposition techniques. Initially a coarse discretization with effective properties is considered at each domain. A zoom-in technique is performed at those domains in which non-linearities take place....conference paper 2012
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Nguyen, V.P. (author), Stroeven, M. (author), Sluys, L.J. (author)In this contribution, we present the mechanical behaviour of the hardening cement paste explicitly taking into account its complex microstructure. The microstructure of the cement paste is obtained via numerical cement hydration simulation. A simple nonlocal isotropic damage model is adopted for different constituents of the cement paste. The...conference paper 2009
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John, V. (author), Tambulea, A. (author)Two realizations of finite element variational multiscale (VMS) methods for the simulation of incompressible turbulent flows are studied. The difference between the two approaches consists in the way the spaces for the large scales and the resolved small scales are chosen. The paper addresses issues of the implementation of these methods, the...conference paper 2006
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De Borst, R. (author), Hulshoff, S.J. (author), Lenz, S. (author), Munts, E.A. (author), Van Brummelen, E.H. (author), Wall, W.A. (author)The basic idea of multiscale methods, namely the decomposition of a problem into a coarse scale and a fine scale, has in an intuitive manner been used in engineering for many decades, if not for centuries. Also in computational science, large-scale problems have been solved, and local data, for instance displacements, forces or velocities, have...conference paper 2006
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Lloberas Valls, O. (author), Rixen, D.J. (author), Simone, A. (author), Sluys, L.J. (author)In this contribution we describe a methodology for the study of softening brittle materials at different scales of observation. The goal is to account for a higher resolution at those areas that undergo the non-linear processes. We apply the FETI (Finite Element Tearing and Interconnecting) technique to glue different domain resolutions during...conference paper 2009
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Ferjaoui, Khalil (author), Georget, Fabien (author), Scrivener, Karen (author)To reduce the CO2 footprint of construction materials, concrete producers blend their cement with Supplementary Cementitious Materials (SCMs). And even though such blended systems are eco-friendlier than the Ordinary Portland Cement (OPC), they are required to respect standards. In this context, understanding and predicting the durability of...conference paper 2021
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Qian, Z. (author), Schlangen, E. (author), Ye, G. (author), Van Breugel, K. (author)Cracking in cement-based materials is usually not easy to predict, because of the complexity of their microstructures. Concrete is a composite material of mortar and coarse aggregates, and mortar consists of cement paste and sands. The fracture processes in these materials are related, and this paper aims to reveal the relationship by developing...conference paper 2012
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De Borst, R. (author), Hulshoff, S.J. (author), Lenz, S. (author), Munts, E.A. (author), Van Brummelen, E.H. (author), Wall, W.A. (author)The basic idea of multiscale methods, namely the decomposition of a problem into a coarse scale and a fine scale, has in an intuitive manner been used in engineering for many decades, if not for centuries. Also in computational science, large-scale problems have been solved, and local data, for instance displacements, forces or velocities, have...conference paper 2006
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Maher, G.D. (author), Hulshoff, S.J. (author)The Variational Germano Identity [1, 2] is used to optimize the coefficients of residual-based subgrid-scale models that arise from the application of a Variational Multiscale Method [3, 4]. It is demonstrated that numerical iterative methods can be used to solve the Germano relations to obtain values for the parameters of subgrid-scale models...conference paper 2014
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Lloberas-Valls, O. (author), Everdij, F.P.X. (author), Rixen, D.J. (author), Simone, A. (author), Sluys, L.J. (author)In this contribution, dual and primal domain decomposition techniques are studied for the multiscale analysis of failure in quasi-brittle materials. The multiscale strategy essentially consists in decomposing the structure into a number of nonoverlapping domains and considering a refined spatial resolution where needed. In multiscale analysis of...conference paper 2014
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Winckelmans, G. (author), Cocle, R. (author), Dufresne, L. (author), Capart, R. (author), Bricteux, L. (author), Daeninck, G. (author), Lonfils, T. (author), Duponcheel, M. (author), Desenfans, O. (author), Georges, L. (author)This paper aims at presenting DNS and LES as applied to the simulation of vortex wakes: in laboratory conditions (moderate to medium Reynolds numbers) and up to real aircraft conditions (high to very high Reynolds numbers). Only incompressible flows are considered. DNS and LES are able to capture complex 3-D physics provided one uses high...conference paper 2006
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Krishnya, S. (author), Yoda, Y. (author), Elakneswaran, Y. (author)Mechanical properties of cement paste are indispensable and frequent requirement in structural analysis of concrete and other cement-based materials, and therefore the theoretical predictions have obtained considerable attention in the field of material engineering. Despite of being an active research area, available models for accurately...conference paper 2021
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Alves Maia, M. (author), Rocha, I.B.C.M. (author), van der Meer, F.P. (author)In a concurrent (FE2) multiscale modeling is an increasingly popular approach for modeling complex materials. As such, it is especially suited for modeling composites, as their complex microstructure can be explicitly modeled and nested to each integration point of the macroscale. However, this generality is often associated with exceedingly...conference paper 2022