scholarly journals Fracture dynamics of solid materials: from particles to the globe

2021 ◽  
Vol 379 (2196) ◽  
pp. 20200122
Author(s):  
Koji Uenishi
Keyword(s):  
Dynamic Fracture ◽  
Global Scale ◽  
Theme Issue ◽  
Solid Materials ◽  
Experimental Conditions ◽  
Gold Mines ◽  
Multi Scale ◽  
Fracture Dynamics ◽  
Fracture Development ◽  
Structural Failures

Solid materials have been used extensively for various kinds of structural components in our surroundings. Stability of such solid structures, including not only machinery, architectural and civil structures but also our solid earth, is largely governed by fracture development in the solids. Especially, dynamic fracture, once occurring—quite often unexpectedly—evolves very rapidly and can lead to catastrophic structural failures and disasters like earthquakes. However, contrary to slowly enlarging fractures that can be recognized spatio-temporally in detail, it is extremely difficult to trace dynamically growing fractures even in controlled laboratory experimental conditions, and its physics still remains unexplored. This theme issue introduces and summarizes recent advancements in our understanding of the widespread topics of dynamic fracture of solids from well-assorted perspectives, involving laboratory experiments, simulations and analytical methods as well as field observations, with the common background of mechanics of fracture. Multi-scale subjects range from fracture of metals at atom or particle levels to disastrous rock bursts in deep gold mines and detection of unique signals before devastating fracture such as large, global-scale earthquakes.This article is part of the theme issue ‘Fracture dynamics of solid materials: from particles to the globe'.

Unexpected, mystifying but simple three-dimensional dynamic fracture phenomena

2021 ◽  
Vol 379 (2196) ◽  
pp. 20200123 ◽  
Author(s):  
Koji Uenishi
Keyword(s):  
Dynamic Fracture ◽  
Three Dimensional ◽  
Concrete Columns ◽  
Analytical Treatment ◽  
Solid Materials ◽  
Fracture Dynamics ◽  
Brittle Solids ◽  
Fracture Development ◽  
Catastrophic Failures ◽  
The One

This contribution addresses what can be learnt from our recent experimental observations of dynamic fracture development in brittle solid materials with real three-dimensional configurations. It is pointed out that the three-dimensional dynamic behaviour of (quasi-)brittle solids is essentially different not only from the one-dimensional dynamic one but also from the three-dimensional static one. The experimental observations include those of cylindrical concrete columns pressurized by deflagration at the centre and ice spheres subjected to dynamic impact at the bottom. Surprisingly, plain fracture patterns can be found through these experiments, but it does not seem simple to describe or predict the involved physical process by conventional analytical treatment or numerical simulations. Indeed, our understanding of mechanical details of actual three-dimensional fracture is still limited, especially in dynamic cases where the length scale of fracture and relevant waves is of the order of the size of solids under consideration. Although a more sophisticated physical interpretation including the dynamic interaction of waves in a relatively high-frequency range is required, the discussed dynamics of three-dimensional fracture development will assist in generating precisely controlled dynamic fracture networks that can be used for practical purposes of dismantling solid structural components and mitigating risks of catastrophic failures. This article is part of the theme issue ‘Fracture dynamics of solid materials: from particles to the globe’.

Multi-Scale Virtual Reality of Sintering

2007 ◽  
Vol 534-536 ◽  
pp. 573-576
Author(s):  
Eugene Olevsky
Keyword(s):  
Global Scale ◽  
Initial State ◽  
Model Framework ◽  
Time Step ◽  
Computational Framework ◽  
Multi Scale ◽  
Scale Modeling ◽  
History Of ◽  
On Line ◽  
Damage Criteria

The directions of further developments in the modeling of sintering are pointed out, including multi-scale modeling of sintering, on-line sintering damage criteria, particle agglomeration, sintering with phase transformations. A true multi-scale approach is applied for the development of a new meso-macro methodology for modeling of sintering. The developed macroscopic level computational framework envelopes the mesoscopic simulators. No closed forms of constitutive relationships are assumed for the parameters of the material. When a time-step of the calculations is finished for one macroscopic element, the mesostructures of the next element are restored from the initial state according to the history of loading. The model framework is able to predict the final dimensions of the sintered specimen on a global scale and identify the granular structure in any localized area for prediction of the material properties.

scholarly journals Extending the Shared Socioeconomic Pathways at the City Scale to Inform Future Vulnerability Assessments — The Case of Boston, Massachusetts

2019 ◽  
Vol 06 (03n04) ◽  
pp. 2050009
Author(s):  
Jayne Lino ◽  
Guillaume Rohat ◽  
Paul Kirshen ◽  
Hy Dao
Keyword(s):  
Climate Change ◽  
Global Scale ◽  
Research Field ◽  
Climate Change Research ◽  
Multi Scale ◽  
Vulnerability Assessments ◽  
Neighborhood Scale ◽  
The City ◽  
Neighborhood Level

Climate change will impact cities’ infrastructure and urban dwellers, who often show differentiated capacity to cope with climate-related hazards. The Shared Socioeconomic Pathways (SSPs) are part of an emerging research field which uses global socioeconomic and climate scenarios, developed by the climate change research community, to explore how different socioeconomic pathways will influence future society’s ability to cope with climate change. While the SSPs have been extensively used at the global scale, their use at the local and urban scale has remained rare, as they first need to be contextualized and extended for the particular place of interest. In this study, we present and apply a method to develop multi-scale extended SSPs at the city and neighborhood scale. Using Boston, Massachusetts, as a case study, we combined scenario matching, experts’ elicitation, and participatory processes to contextualize and make the global SSPs relevant at the urban scale. We subsequently employed the extended SSPs to explore future neighborhood-level vulnerability to extreme heat under multiple plausible socioeconomic trajectories, highlighting the usefulness of extended SSPs in informing future vulnerability assessments. The large differences in outcomes hint at the enormous potential of risk reduction that social and urban planning policies could trigger in the next decades.

scholarly journals Rules of collective migration: from the wildebeest to the neural crest

2020 ◽  
Vol 375 (1807) ◽  
pp. 20190387 ◽  
Author(s):  
Adam Shellard ◽  
Roberto Mayor
Keyword(s):  
Neural Crest ◽  
Individual Cell ◽  
Embryonic Stem ◽  
Stem Cell Population ◽  
Scale Analysis ◽  
Collective Migration ◽  
Theme Issue ◽  
Cell Behaviour ◽  
Multi Scale ◽  
Universal Principles

Collective migration, the movement of groups in which individuals affect the behaviour of one another, occurs at practically every scale, from bacteria up to whole species' populations. Universal principles of collective movement can be applied at all levels. In this review, we will describe the rules governing collective motility, with a specific focus on the neural crest, an embryonic stem cell population that undergoes extensive collective migration during development. We will discuss how the underlying principles of individual cell behaviour, and those that emerge from a supracellular scale, can explain collective migration. This article is part of the theme issue ‘Multi-scale analysis and modelling of collective migration in biological systems’.

scholarly journals Multi-scale analysis and modelling of collective migration in biological systems

2020 ◽  
Vol 375 (1807) ◽  
pp. 20190377
Author(s):  
Andreas Deutsch ◽  
Peter Friedl ◽  
Luigi Preziosi ◽  
Guy Theraulaz
Keyword(s):  
Biological Systems ◽  
Collective Behaviour ◽  
Coherent Motion ◽  
Collective Cell Migration ◽  
Scale Analysis ◽  
Collective Migration ◽  
Theme Issue ◽  
Multi Scale ◽  
Recent Developments ◽  
Multi Scale Analysis

Collective migration has become a paradigm for emergent behaviour in systems of moving and interacting individual units resulting in coherent motion. In biology, these units are cells or organisms. Collective cell migration is important in embryonic development, where it underlies tissue and organ formation, as well as pathological processes, such as cancer invasion and metastasis. In animal groups, collective movements may enhance individuals' decisions and facilitate navigation through complex environments and access to food resources. Mathematical models can extract unifying principles behind the diverse manifestations of collective migration. In biology, with a few exceptions, collective migration typically occurs at a ‘mesoscopic scale’ where the number of units ranges from only a few dozen to a few thousands, in contrast to the large systems treated by statistical mechanics. Recent developments in multi-scale analysis have allowed linkage of mesoscopic to micro- and macroscopic scales, and for different biological systems. The articles in this theme issue on ‘Multi-scale analysis and modelling of collective migration’ compile a range of mathematical modelling ideas and multi-scale methods for the analysis of collective migration. These approaches (i) uncover new unifying organization principles of collective behaviour, (ii) shed light on the transition from single to collective migration, and (iii) allow us to define similarities and differences of collective behaviour in groups of cells and organisms. As a common theme, self-organized collective migration is the result of ecological and evolutionary constraints both at the cell and organismic levels. Thereby, the rules governing physiological collective behaviours also underlie pathological processes, albeit with different upstream inputs and consequences for the group. This article is part of the theme issue ‘Multi-scale analysis and modelling of collective migration in biological systems’.

A Multi-Scale Scheme for Modelling Fracture under Dynamic Loading Conditions

2014 ◽  
Vol 627 ◽  
pp. 37-40
Author(s):  
A. Karamnejad ◽  
L.J. Sluys
Keyword(s):  
Dynamic Loading ◽  
Static Problem ◽  
Global Scale ◽  
Local Scale ◽  
Material Point ◽  
Computational Homogenization ◽  
Scale Model ◽  
Multi Scale ◽  
Damaged Zone ◽  
Scale Scheme

Fracture in heterogeneous materials under dynamic loading is modelled using a multi-scale method. Computational homogenization is considered, in which the overall properties at the global-scale are obtained by solving a boundary value problem for a representative volume element (RVE) assigned to each material point of the global-scale model. In order to overcome the problems with upscaling of localized deformations, a non-standard failure zone averaging scheme is used. Discontinuous cohesive macro-cracking is modelled using the XFEM and a gradient-enhanced damage model is used to model diffuse damage at the local-scale. A continuous-discontinuous computational homogenization method is employed to obtain the traction-separation law for macro-cracks using averaged properties calculated over the damaged zone in the RVE. In the multi-scale model, a dynamic analysis is performed for the global-scale model and the local-scale model is solved as a quasi-static problem. Dispersion effects are then captured by accounting for the inertia forces at the local-scale model via a so-called dispersion tensor which depends on the heterogeneity of the RVE. Numerical examples are presented and the multi-scale model results are compared to direct numerical simulation results. Objectivity of the multi-scale scheme with respect to the RVE size is examined.

scholarly journals Uncertainty quantification patterns for multiscale models

2021 ◽  
Vol 379 (2197) ◽  
Author(s):  
D. Ye ◽  
L. Veen ◽  
A. Nikishova ◽  
J. Lakhlili ◽  
W. Edeling ◽  
...  
Keyword(s):  
Decision Making ◽  
Uncertainty Quantification ◽  
Computational Models ◽  
Building Blocks ◽  
Computational Science ◽  
Proof Of Concept ◽  
Multiscale Models ◽  
Theme Issue ◽  
Multi Scale ◽  
Speed Up

Uncertainty quantification (UQ) is a key component when using computational models that involve uncertainties, e.g. in decision-making scenarios. In this work, we present uncertainty quantification patterns (UQPs) that are designed to support the analysis of uncertainty in coupled multi-scale and multi-domain applications. UQPs provide the basic building blocks to create tailored UQ for multiscale models. The UQPs are implemented as generic templates, which can then be customized and aggregated to create a dedicated UQ procedure for multiscale applications. We present the implementation of the UQPs with multiscale coupling toolkit Multiscale Coupling Library and Environment 3. Potential speed-up for UQPs has been derived as well. As a proof of concept, two examples of multiscale applications using UQPs are presented. This article is part of the theme issue ‘Reliability and reproducibility in computational science: implementing verification, validation and uncertainty quantification in silico ’.

Drivers of parasite β-diversity among anuran hosts depend on scale, realm and parasite group

2021 ◽  
Vol 376 (1837) ◽  
pp. 20200367 ◽  
Author(s):  
Paulo Mateus Martins ◽  
Robert Poulin ◽  
Thiago Gonçalves-Souza
Keyword(s):  
Infectious Disease ◽  
Spatial Scale ◽  
Regional Scale ◽  
Global Scale ◽  
Spatial Distance ◽  
Parasite Diversity ◽  
Theme Issue ◽  
Diversity Patterns ◽  
Essential Step ◽  
Β Diversity

A robust understanding of what drives parasite β-diversity is an essential step towards explaining what limits pathogens' geographical spread. We used a novel global dataset (latitude −39.8 to 61.05 and longitude −117.84 to 151.49) on helminths of anurans to investigate how the relative roles of climate, host composition and spatial distance to parasite β-diversity vary with spatial scale (global, Nearctic and Neotropical), parasite group (nematodes and trematodes) and host taxonomic subset (family). We found that spatial distance is the most important driver of parasite β-diversity at the global scale. Additionally, we showed that the relative effects of climate concerning distance increase at the regional scale when compared with the global scale and that trematodes are generally more responsive to climate than nematodes. Unlike previous studies done at the regional scale, we did not find an effect of host composition on parasite β-diversity. Our study presents a new contribution to parasite macroecological theory, evidencing spatial and taxonomic contingencies of parasite β-diversity patterns, which are related to the zoogeographical realm and host taxonomic subset, respectively. This article is part of the theme issue ‘Infectious disease macroecology: parasite diversity and dynamics across the globe’.

Psychological and pedagogical support of the social success of adolescents in school

2021 ◽  
pp. 34-42
Author(s):  
Artyom Gennadievich Shabanov ◽  
Keyword(s):  
Self Regulation ◽  
Deep Understanding ◽  
Global Scale ◽  
Social Attitudes ◽  
Expert Assessment ◽  
Ideological Position ◽  
Social Success ◽  
Multi Scale ◽  
The Social

At present, the issue of development, formation and support of the social success of the younger generation is relevant on a global scale and in Russia. In adolescence, new basic needs and leading activities are formed, so it is very important to effectively interact with other people and positively self-actualize. The purpose of the article is to analyze the social success of adolescents and develop recommendations for the psychological and pedagogical development of success. Methodology and methods of research. An activity-based approach that sets the benchmark for the inclusion of a teenager in a variety of directions of emotionally saturated socially recognized and socially approved activities. Adolescence was studied in the works of L. I. Bozhovich, T. V. Dragunov, N. I. Krylov, A.V. Petrovsky, N. N. Tolstykh, D. I. Feldstein, D. B. Elkonin, E. Erikson and others. Studies of the theory of success were conducted on a multi-scale in various branches of social and humanitarian knowledge by domestic scientists (V. I. Bakshtanovsky, N. A. Baturin, O. I. Efremova, E. T. Konyukhova, E. M. Korzh, G. Yu. Ksenzova, V. A. Labunskaya, A. K. Markova, N. I. Nefedova, A. M. Rikel, G. L. Tulchinsky) and foreign scientists (A. Bandura, U. James, D. A. Dilman, K. Mannheim, R. Strenberg, P. Tillich, E. Fromm). Research methods: test of life orientations (D. Krambo, L. Makholik, adaptation of D. A. Leontiev), questionnaire “Determination of success” (D. A. Bukhalenkova), questionnaire “Style of self-regulation of behavior”, expert assessment of social success (N. V. Kalinina). Conclusion. Pedagogical observation allowed us to judge the lack of a deep understanding of social success among adolescents, the veiled value views on social attitudes, principles, norms and requirements. The respondents are influenced by authorities who directly invest certain ideals of the present and future in the ideological position of a teenager.

Alteration and dissolution of Na-montmorillonite in simulated groundwaters

2012 ◽  
Vol 1475 ◽  
Author(s):  
E. Myllykylä ◽  
M. Tanhua-Tyrkkö ◽  
A. Bouchet
Keyword(s):  
Inductively Coupled Plasma ◽  
Batch Experiments ◽  
Solid Materials ◽  
Experimental Conditions ◽  
Secondary Minerals ◽  
Fresh Waters ◽  
Inductively Coupled ◽  
Icp Ms ◽  
Order Of Magnitude ◽  
Plasma Mass Spectrometry

ABSTRACTThis study aims at gaining a better understanding of the behaviour of montmorillonite in contact with different ground waters; alteration of montmorillonite and possible formation of secondary minerals. Batch experiments were conducted with purified Swy-2 montmorillonite in simulated fresh (I=0.05 M, pH 8) and saline (I=0.1 M, pH 11) waters at 25 and 60ºC in anaerobic (Ar(g)) conditions. The concentrations of Al, Fe; Mg and Si were analysed from ultra-filtered solution samples with HR-ICP-MS (High Resolution Inductively Coupled Plasma Mass Spectrometry). The amount of released Si depended strongly on the experimental conditions. The Si concentrations at 60oC in the saline and fresh waters showed a difference greater than an order of magnitude. The initial purified montmorillonite and the solid materials from experiments were analysed with XRD. The analysis indicated that the nature of smectite did not change, but the experimental conditions, more or less, modified the structure of montmorillonite, e.g., in fresh waters the XRD spectra showed peaks typical of mixed layer minerals, which can refer to the presence of either randomly ordered illite/smectite or randomly ordered collapsed smectite/ hydrated smectite layers. The dissolution of montmorillonite was studied also by modelling with TOUGHREACT. The experimental and modelled results were compared revealing a need to develop the model e.g. in respect of the evolution of pH.

Sign in / Sign up

Export Citation Format

Share Document