Head of Division: Professor Andrew McBride
Vision: Grounded in the fundamentals, we provide innovative solutions to understand the built and natural environment, and develop the next generation of leaders.
The University of Glasgow has a long history of research in Civil Engineering. The UK's first Chair of Civil Engineering was established at the University in 1840. Early occupants, such as William J. M. Rankine, set a research ethos that has endured. Rankine worked at the boundaries of engineering; translating and refining new ideas so that they might ultimately be used in engineering design.
Research in the Division of Infrastructure & Environment can broadly be categorised into four main themes outlined below.
Events this week
There are currently no events scheduled this week
GCEC Seminar: Robust and efficient approximation of the compressible Euler and Navier-Stokes equations
Title: Robust and efficient approximation of the compressible Euler and Navier-Stokes equations
Abstract: Structure preserving numerical methods provide theoretical guarantees of
reliability for situations where ad-hoc stabilization techniques can fail.
In this talk we present fully discrete approximation techniques for the
compressible Euler and Navier-Stokes equations that is second-order
accurate in time and space and guaranteed to be invariant domain
preserving. This means the method maintains important physical invariants
and is guaranteed to be stable without the use of ad-hoc tuning parameters.
We discuss the underlying algebraic discretization technique based on
collocation and convex limiting, and briefly comment on a high-performance
implementation utilizing SIMD (single instruction multiple data)
vectorization and OpenMPI parallelization. We conclude with a short
overview of concrete applications to related hyperbolic equations such as
the shallow water equations and the Euler-Poisson system.
GCEC Seminar: Statistical finite element method for physics-informed digital twin of infrastructures (20 May, 2022)
Speaker: Eky Febrianto
Title: Statistical finite element method for physics-informed digital twin of infrastructures
Abstract: The monitoring of infrastructure assets using sensor networks is becoming increasingly prevalent. A digital twin in the form of a finite element (FE) model can help make sense of the copious amount of collected sensor data. This talk will introduce a statistical finite element method (statFEM) that provides the means of synthesising measurement data and FE models. In statFEM, the data and FE model are random variables with uncertainties associated with measurement error, random inputs, and modelling assumptions. A physics-informed prior density distribution of the system response, e.g., strain or displacement, is given by a conventional stochastic forward problem. The posterior density of the system response is obtained through the Bayes rule from the postulated prior density and a data-dependent likelihood function. This talk will also present the application of statFEM to predict the structural response of an instrumented steel railway bridge and nonlinear continuous welded rail system.
Biosketch: Eky is a lecturer in computational mechanics and a member of the Glasgow Computational Engineering Centre (GCEC) at the University of Glasgow. He obtained his PhD in computational mechanics from the University of Cambridge. He did his postdoctoral research on a strategic theme of data-centric engineering at The Alan Turing Institute and was a visiting research fellow at the University of Cambridge. His research combines aspects of advanced computational methods, geometry, and statistics for developing physics-informed digital twins of engineering structures across scales.
Location: James Watt South Building, Room 603, Creaitivity Lab
GCEC Seminar (31 March, 2022)
Speaker: David Kamensky
GCEC Seminar: Of Microbes, Mechanics and Materials (09 June, 2021)
Speaker: Anupam Sengupta
Title: Of Microbes, Mechanics and Materials
Abstract: Understanding how microbes interface, exchange and communicate with their local surroundings is central to the grand quest for a theory of microbial ecology. From simple to complex fluids, from compliant to rigid surfaces, microbes inhabit plethora of micro-environments spanning vastly different structures, dynamics, and internal energies. Currently we lack a biophysical framework that could explain, generalize, and crucially, predict the if-s, the how-s, and the why-s of the microbe-environment interactions. Research in my lab aims to fill this gap by interfacing soft matter physics and fluid mechanics with microbiology and genetic engineering. In this talk I will discuss that microbes – across individual, species and community scales – are inherently coupled to their micro-environments, and that their behavioural and physiological traits emerge as a consequence of active biophysical feedbacks between the material, information and energy transport processes. Using vignettes from our recent experiments in model gut and aquatic microbial systems, I will demonstrate how microbes and their micro-environments crosstalk via biomechanical coupling, leading to emergence of traits that ultimately translate into ecological and eco-physiological functions. I will discuss the generality of our results across microbial worlds, specifically touching upon the role and ramification of fluctuations in microbial environments. I will conclude by discussing why our efforts to unpack the microbe-mechanics-materials nexus are central to deciphering microbial fitness, succession, and selection, not least for their emerging prospects in medical diagnostics, biotechnology, and bioremediation during current climatic trends.
Bio: Anupam Sengupta is an ATTRACT Fellow and tenure track Professor of Biological Physics at the University of Luxembourg. Anupam directs the Physics of Living Matter Group, a cross-disciplinary team of scientists working on emergent functionalities in biological systems. Research in the Sengupta Lab spans soft and living matter physics, microfluidics, optics and microbiology. Anupam holds a B.S. and M.S degree (Dual Degree) in Mechanical Engineering from IIT Bombay, India, and a Ph.D. in Soft Matter Physics for his thesis on Liquid Crystal Microfluidics, carried out at the Max Planck Institute for Dynamics and Self Organization, Göttingen, Germany (2013). As a postdoc at MIT (Cambridge, USA) and ETH Zurich (Switzerland), Anupam switched fields to work on the physical ecology of aquatic microbes, and the mechanics of microbial growth and adaptation. Anupam is a recipient of the Human Frontiers Cross-Disciplinary Fellowship (2014-2017) by the International Human Frontier Science Program Organization, and was selected as one of the six “promising young scientists for future” by Nature during the 65th Lindau Meeting for Nobel Laureates in Lindau, Germany. Anupam is the Director for Undergraduate Physics Studies at the University of Luxembourg.
Zoom link: https://uofglasgow.zoom.us/j/97254708828?pwd=bk9KR094WkZEQWZJT09xdHFSak0yUT09
GCEC Seminar: Multiscale modeling of lung biomechanics (12 May, 2021)
Speaker: Prof Daniel Hurtado
Title: Multiscale modeling of lung biomechanics
Abstract: Covid-19 pneumonia has quickly become a leading cause of death worldwide, boosting the interest of the scientific computing community in creating accurate models of the respiratory system for in silico experimentation and medical discovery. In this talk, I will present our current efforts towards creating a multiscale framework to achieve whole-lung predictive simulations. Drawing concepts from finite-deformation homogenization theory, I will introduce a microstructural model for the poroelastic behavior of the lung tissue. I will further discuss our validation efforts and comment on the predictiveness of the tissue model. Finally, I will present how the proposed micromechanical model can be integrated into whole-lung simulations of healthy and diseased conditions and discuss future directions in lung modeling.
Short Bio: Daniel Hurtado is an associate professor with the School of Engineering and the Institute for Biological and Medical Engineering at Pontificia Universidad Catolica de Chile. He leads the Computational Medicine Group, an interdisciplinary team that focuses on creating physiology-based digital replicas of the human lungs, with applications in the study of mechanical ventilation therapies and early diagnosis of pulmonary diseases. Prof. Hurtado received his M.S. and Ph.D. degrees from the California Institute of Technology as a Fulbright fellow. He is an elected member of the World Council of Biomechanics since 2018.
Zoom link: https://uofglasgow.zoom.us/j/92841584390?pwd=aHZFYUtBS2kyU0duK3ZmanVEeXl4Zz09
GCEC Seminar: Adaptive tensor methods for scientific computing (30 April, 2021)
Speaker: Damiano Lombardi
Title: Adaptive tensor methods for scientific computing
Abstract: High-dimensional problems arise in many areas of science and engineering. The so called "curse of dimensionality" makes the solution approximation a challenging task, preventing us from using standard discretisations. Several classes of methods have been proposed (and are currently investigated) in the literature in order to approximate the solution of high-dimensional problems: tensor methods are one of them. They consist in using in a systematic way the principle of separation of variables in order to provide an approximation of the solution. In the methods which are proposed in the literature, the "size" of the tensor (called rank) is often fixed a priori, which could lead to severe limitations on realistic problems. The main goal of the work is to propose adaptive tensor methods: the memory used and the tensor format (to some extent) are computed along with the solution approximation in order to fulfil a prescribed accuracy and optimise the computational resources.
In this talk, we are going to discuss first a possible discretisation of a 3d-3d Vlasov-Poisson system. The results obtained are encouraging and provide a motivation for two methodological investigations: the first one consists in defining an adaptive piece-wise tensor decomposition; the second one is an investigation of a multi-linear system solver which is particularly well suited for systems of parametric Partial Differential Equations. Some theoretical results and some numerical experiments are shown.
Brief bio: Damiano Lombardi is a researcher in scientific computing at Inria Paris since 2013, working in the COMMEDIA team (mathematical modeling of the cardiovascular system).
Zoom link: https://uofglasgow.zoom.us/j/96209524406?pwd=Snd3V0VFKy9aR3BzWm5rM0Z5bERVQT09
From discrete particles to continuum fields (04 March, 2021)
Speaker: Thomas Weinhart
Micro–macro transition methods are used to calibrate and validate continuum models from discrete data, obtained from either experiments or simulations. Such methods generate continuum fields such as density, momentum, stress, etc, from discrete data, i.e. the particles' positions, velocity, and forces. Performing this micro–macro transition step is especially challenging for heterogeneous and dynamic situations.
Here, we present a mapping technique, called coarse-graining, to perform this transition. This method has several advantages: (1) By construction, the obtained macroscopic fields are consistent with the continuum equations of mass, momentum and energy balance. (2) boundary interactions are accounted for in a self-consistent way and thus allow for the construction of locally accurate stress fields, even near boundaries. (3) Partial stresses and drag forces can be determined for individual constituents, which is critical for developing mixture models, e.g. for segregation. (4) The method does not require ensemble-averaging and thus can be efficiently exploited to investigate static, steady and time-dependent flows.
The method is valid for any discrete data, e.g. particle simulations, molecular dynamics, experimental data, etc. However, for the purpose of illustration we consider data generated from discrete particle simulations. We show how to practically use coarse-graining for both steady and unsteady flows using our open-source tool MercuryCG, which is available as part of the discrete particle solver MercuryDPM (http://www.mercurydpm.org/).
GCEC Seminar: High-Fidelity Simulation of Brittle Fracture Problems (09 February, 2021)
Speaker: Prof Adrian Lew
A 4D multiscale experimental approach to capture micro-processes within geomaterials (soils and rocks): the focus on deformation and fluid flow interactions (21 January, 2021)
Speaker: Dr Elma Charalampidou
Rock and soil deformation processes are of crucial importance for most surface or subsurface engineering applications, in particular when these applications are related to energy field application or interactions with engineering structures. There is a strong need for field studies to be complemented with lab-scale testing. The latter provides functional information on the mechanical behaviour of the tested material (e.g. E, G, ν). Furthermore, this sort of data are useful input parameters for modelling (e.g. FEM). However, these global measurements (average within the sample’s boundaries) cannot always reveal in detail the micro-processes occurring during frictional sliding and/or brittle faulting of a rock mass or deformation in soils, particularly when the tested material (or representative volume) contains textural heterogeneities (diagenetic or due to deformation) – which is a quite common case in any field application.
Non-destructive full-field testing becomes of great importance to lab-testing since a variety of parameters can be investigated on the very same core. This is very practical especially for limited samples coming e.g. from a well. Furthermore, a combined use of non-destructive techniques – with different sensitivity and resolution – can provide 2D, 3D and 4D information and further explain the occurring micro-processes in a range of scales (from cm to ?m). Extrapolating this knowledge to the field scale leads to potentially fewer layers of uncertainty.
This talk will demonstrate how a combined use of non-destructive methods describe processes that take place during frictional sliding and brittle deformation in weakly cemented sands and sedimentary rocks. Methods will include a) Acoustic Emissions, their related source mechanisms and ultrasonic tomography – all linked to damage sensitivity; b) x-ray CT – related to density variations within the material; c) neutron tomography – sensitive to the presence of hydrogen and, thus, fluids containing it. Examples will focus on lab-deformed cores and cores with natural textural heterogeneities. The observed micro-processes on weakly cemented sands (natural and artificially cemented), sandstones and carbonates will be discussed. The correlation of these results can shed further light onto the deformation and fluid flow interactions within the tested materials (as compared to the conventional stress-strain measurements at the boundaries of the sample) and also offer more detailed information to mitigate potential risks at field-scale applications.
Elli-Maria (Elma) Charalampidou is an Assistant Professor at the Institute of Geoenergy Engineering, School of Energy, Geoscience, Infrastructure and Society at Heriot Watt University (Edinburgh). Elma is the Head of the Soil and Rock Mechanics Technical Committee of the European Society for Experimental Mechanics (EuraSEM) and is also an Editorial Board Member for Scientific Data (Nature).
Elma’s research relates to understanding and quantifying the physical and hydro-chemo-thermo-mechanical processes controlling the occurrence of strain localisation and instability modes in geomaterials, which has implications for H2 and/or CO2 storage, geothermal energy extraction and fluid induced seismicity.
Elma works primarily in the field of experimental mechanics examining: a) the conditions for fault creation/re-activation and the frictional behaviour of materials; b) the brittle-ductile transition and the localised deformation in rocks and sediments; c) single- and two-phase flow within naturally and lab-induced deformed rocks and sediments as well as fluid-rock interactions.
Elma applies a multi-scale experimental approach using a range of non-destructive methods with different sensitivities and resolutions, such as acoustic emissions and moment tensor analysis, ultrasonic tomography, x-ray computed tomography, neutron tomography and digital image correlation together with destructive methods, such as optical and scanning electron microscopy.
Hydro-mechanical behaviour of hydrophobic granular soils (03 December, 2020)
Speaker: Christopher Beckett
In this seminar, Chris will present work from his team examining the hydro-mechanical behaviour of hydrophobic granular soils; materials that are new to geotechnical engineering and offer opportunities to revolutionise water sequestration infrastructure. The seminar will start with a brief introduction to these unusual materials as well as the unsaturated soil mechanics of traditional hydrophilic soils, before exploring the consequences of these mechanisms for hydrophobic soils and what new perspectives these observations offer on traditional unsaturated soil mechanics.
GCEC Seminar: Micromorphic Tissue Mechanics Accounting For Non-Affine Myocardial Deformation Characteristics (12 November, 2020)
Speaker: Dr Sebastian Skatulla
Zoom link: https://uofglasgow.zoom.us/j/93968561981?pwd=aHliYjd4bHNhN2pib1pLU1VNT24yZz09
Title: Micromorphic Tissue Mechanics Accounting For Non-Affine Myocardial Deformation Characteristics
Abstract: Cardiovascular diseases are among the most common causes of death in the world. Computational modelling in combination with medical imaging techniques, mechanical tissue testing, as well as cell and molecular biological analysis has the potential to help better understanding the underlying physiological mechanisms of heart failure and guide decision making in finding patient-specific treatment options in the future.
Computational models, however, need to be realistic enough to accurately describe the highly heterogeneous and non-uniform myocardial material composition , its anisotropic mechanical properties, the electro-mechanical interaction during muscle contraction and other biological effects, such as residual stresses and remodelling processes.
In this contribution we want to focus on the passive response of the myocardium which is very compliant exhibiting large strains, in particular, while the heart is contracting and twisting to eject oxygenated blood into the circulatory system during the systolic phase of the heart cycle. In the past it has been discovered that the initially crimped and coiled collagen fibres straighten during passive filling  and that cardiac myocytes exhibit a certain degree of motion flexibility within the constraining cytoskeleton [3, 4]. In contrast to classical models of phenomenological nature, this work proposes a micromorphic continuum-based formulation  which features extra degrees of freedom and corresponding strain and stress measures. The approach can therefore account for the hierarchical fibrous characteristics of the myocardium which are associated with micro-structural deformation of muscle-fibre bundles as well as their motion relative to the bulk material. As such, the assumed hyperelastic material behaviour of myocardial tissue is represented by a non-linear strain energy function which includes contributions linked to the bulk material representing the cytoskeleton and the micromorphic-fibre continuum emulating the micro-kinematics of the interwoven muscle-fibre bundles.
Short Bio: Sebastian Skatulla is an Associate Professor of Structural Engineering and Mechanics at the University of Cape Town. He graduated as Diplom Bau-Ingenieur (TH) from the Karlsruhe Institute of Technology (KIT) in 2003. He was awarded his PhD degree in Mechanical Engineering from the University of Adelaide in 2007.
He is the Director of the Computational Continuum Mechanics Research Group (CCM) which has its research activities centred in multiscale and multiphase continuum methods. Current activities comprise the poroelasticity of Antarctic sea-ice and biological tissue.
He is the President of the South African Association for Theoretical and Applied Mechanics (SAAM) and member of the Scientific Council of the International Centre for Mechanical Sciences (CISM).
 LeGrice, I.J., Smaill, B.H., Chai, L.Z., Edgar, S.G., Gavin, J.B. and Hunter, P.J., Laminar structure of the heart: ventricular myocyte arrangement and connective tissue architecture in the dog. Am. J. Physiol. Heart Circ. Physiol., 269:H571–H582, 1995.
 Robinson, T.F., Geraci, M.A., Sonnenblick, E.H. and Factor, S.M., Coiled perimysial fibers of papillary muscle in rat heart: Morphology, distribution, and changes in configuration. Circulation Research, 63:577–592, 1988.
 LeGrice, I.J., Takayama, Y. and Covell, J.W., Transverse shear along myocardial cleavage planes provides a mechanism for normal systolic wall thickening. Circulation research, 77(1):182–193, 1995.
 Spotnitz, H.M., Spotnitz, W.D., Cottrell, T.S., Spiro, D. and Sonnenblick, E.H., Cellular basis for volume related wall thickness changes in the rat left ventricle. Journal of molecular and cellular cardiology, 6(4):317–331, 1974.
 von Hoegen, M., Skatulla, S. and Schrder, J., , ”A generalized micromorphic approach accounting for variation and dispersion of preferred material directions”, Computers and Structures, 232: 105888, 2020
GCEC seminar: Characterising and modelling fracture in soft solids (21 October, 2020)
Speaker: Prof Maria Charalambides
This talk will summarise studies towards developing predictive numerical models of deformation and fracture within soft solid materials. Computational modelling of the in-vivo mechanical response of various biological materials within the human organism, such as brain tissue, bone, arteries and ingested food, is an increasingly cost-effective design tool for bio-medical, bio-engineering and surgical applications. Hydrated food is one such system produced naturally after swallowing and its mechanical response is a crucial factor during digestion which impacts on the rate of release of nutrients to the human body. We show that a viscoplastic-damage constitutive law calibrated through compression tests on hydrated biscuit particles, can be utilised in Eulerian Finite Element (FE) analysis to predict complex localised deformation-fracture material behaviour during wire cutting at two length scales with high fidelity. We demonstrate that in such materials a fracture term is not always necessary to predict ultimate separation and that the Eulerian FE analysis is a versatile approach based on which largely different material cutting behaviours can be modelled. The use of these methods to develop in silico models of the critical initial digestion stages will be presented.
GCEC Seminar: Finite element and virtual element approximations for problems of isotropic and anisotropic elasticity (15 October, 2020)
Speaker: Prof Daya Reddy
Zoom Link: https://uofglasgow.zoom.us/j/96885164003?pwd=SkRpeExBUVQ2b2JETHlLdStNVFR6UT09
Title: "Finite element and virtual element approximations for problems of isotropic and anisotropic elasticity”
Abstract: This presentation is concerned with the behaviour of elastic bodies under limiting conditions of near-incompressibility and, for transversely isotropic materials, near-inextensibility. The concept of volumetric locking – that is, a lack of convergence - in the context of low-order finite element approximations is well understood, and a variety of effective remedies exist. Corresponding studies in relation to near-inextensibility have on the other hand been somewhat limited. Both theoretical and computational approaches to these classes of problems are explored. The virtual element method (VEM) is a relatively recent extension of the finite element method (FEM) that allows for the use of polygonal or polyhedral elements having any number of sides or surfaces. Near-incompressibility and near-inextensibility are explored using both the FEM and VEM. In particular, the excellent convergence properties of low-order Virtual Element approximations is demonstrated, for small and large deformations.
Biography: Daya Reddy completed a bachelor’s degree in civil engineering at the University of Cape Town and a Ph.D. degree at Cambridge University in the UK. He currently holds the South African Research Chair in Computational Mechanics, in the department of mathematics and applied mathematics at the University of Cape Town.
His teaching and research activities reflect his multidisciplinary perspectives, which he pursues largely through the Centre for Research in Computational and Applied Mechanics, a centre comprising academic staff and postgraduate students in five different departments. Much of his work is concerned with mathematical and numerical analysis of problems arising in solid and fluid mechanics. His many publications include two graduate-level texts and a research monograph, now in its second edition, on plasticity theory.
Daya Reddy is actively involved in bodies that work towards strengthening the scientific enterprise and providing science advice to policymakers. He served a term as president of the Academy of Science of South Africa, and is currently president of the International Science Council, the largest representative non-governmental global scientific organization.
He is a recipient of the Award for Distinguished Service from the South African Association for Computational and Applied Mechanics,the SAMS Award for Research Distinction, and the Order of Mapungubwe from the President of South Africa. He has held numerous visiting positions, including those of Visiting Faculty Fellow at the University of Texas at Austin and the Timoshenko Lecturer at Stanford University. He is a recipient of the Georg Forster Research Award from the Alexander von Humboldt Foundation of Germany.
GCEC Seminar: Computational Fluid-Structure Interaction Modeling for Aerospace and Biomedical Applications (03 September, 2020)
Speaker: Prof Ming-Chen Hsu
Title: Computational Fluid-Structure Interaction Modeling for Aerospace and Biomedical Applications
Speaker: Prof. Ming-Chen Hsu, Department of Mechanical Engineering, Iowa State University
Abstract: Fluid-Structure Interaction (FSI) is a multiphysics phenomenon that occurs when moving or deformable structures interact with internal or surrounding fluid flows. The coupling between the dynamics of the fluid and mechanics of the structure often gives rise to unexpected behaviors vital to many science and engineering problems. In this presentation, I will discuss a new computational FSI framework developed based on isogeometric and immersogeometric analysis with application to the modeling and simulation of aerospace and biomedical problems. The fully-coupled FSI formulation is derived using the augmented Lagrangian approach to enforce kinematic and traction constraints and naturally accommodates nonmatching and non-boundary-fitted fluid-structure interfaces. This novel method can make direct use of the CAD boundary representation of a complex design structure and effectively deal with FSI problems involving large deformations of the fluid domain, including changes of topology. The key ingredients to achieving high simulation accuracy will be reviewed. The proposed FSI framework is applied to engineering and science applications at different scales, ranging from studying complex military aircraft tail buffeting due to different angles of attack to understanding prosthetic heart valve leaflet flutter under physiological conditions. The findings and challenges will be shown and discussed in detail.
Biography: Ming-Chen Hsu is an Associate Professor in the Department of Mechanical Engineering at Iowa State University. He received his MS degree in Engineering Mechanics from UT Austin in 2008 and PhD degree in Structural Engineering from UC San Diego in 2012. From 2012 to 2013, he was a postdoctoral fellow at the Institute for Computational Engineering and Sciences at UT Austin before joining Iowa State University. He is the recipient of the 2019 USACM Gallagher Young Investigator Award and is listed as a Web of Science Highly Cited Researcher from 2016 to 2019. He has published over 70 peer-reviewed journal papers and serves on several national and international professional society committees on computational methods and applications. His research focuses on computational mechanics, engineering, and sciences with an emphasis on fluid-structure interaction problems.
Compressive Failure of Carbon Fibre Composites in Flexural and Hybrid Tests (21 August, 2020)
Speaker: Professor Michael Wisnom
High-performance fibre-reinforced polymer composites are the current state-of-the-art for lightweight structures and their use is rising exponentially in a wide range of applications from aerospace to sporting goods. They offer outstanding mechanical properties: high strength and stiffness, low weight, and low susceptibility to fatigue and corrosion. The use of high strength, high stiffness materials in fibre form mitigates the tendency for premature brittle failure, enables components to be formed at low or moderate temperatures, and enables anisotropic designs to target the primary load-carrying demands. Fibres are particularly efficient in uniaxial tension but, under compression, composites suffer a range of failures typically associated with fibre micro-buckling or kinking, linked to matrix or interfacial issues; these mechanisms couple in a complicated way at a variety of physical lengthscales. Often, these types of failure determine the practical usage of composites and set design limits well below the expected intrinsic performance of the constituent fibres.
This presentation focuses on the challenge of improving the absolute performance of composites in compression, both to address practical limitations of current materials, and as a demonstration of the value of quantitative hierarchical materials design.
Michael Wisnom is Professor of Aerospace Structures at the University of Bristol, Director of Bristol Composites Institute (ACCIS) and Editor in Chief of Composites Part A. His research is on the mechanics and failure of composites: developing novel test configurations, analysis approaches, and material architectures.
GCEC Seminar: Phase-field modeling of brittle fracture: an overview and a new paradigm to address multiple solutions (18 June, 2020)
Speaker: Laura De Lorenzis
Abstract: The phase-field modeling approach to fracture has recently attracted a lot of attention due to its remarkable capability to naturally handle fracture phenomena with arbitrarily complex crack topologies in three dimensions. On one side, the approach can be obtained through the regularization of the variational approach to fracture introduced by Francfort and Marigo in 1998, which is conceptually related to Griffith's view of fracture; on the other side, it can be constructed as a gradient damage model with some specific properties. The functional to be minimized is not convex, so that the necessary stationarity conditions of the functional may admit multiple solutions. The solution obtained in an actual computation is typically one out of several local minimizers. Evidence of multiple solutions induced by small perturbations of numerical or physical parameters was occasionally recorded but not explicitly investigated in the literature.
In the first part of this talk, the speaker gives a brief overview of the phase-field approach to fracture and of recent related research carried out in her group. In the second part of the talk, the focus is placed on the issue of multiple solutions. Here a paradigm shift is advocated, away from the search for one particular solution towards the simultaneous description of all possible solutions (local minimizers), along with the probabilities of their occurrence. We propose the stochastic relaxation of the variational brittle fracture problem through random perturbations of the functional and introduce the concept of stochastic solution represented by random fields. In the numerical experiments, we use a simple Monte Carlo approach to compute approximations to such stochastic solutions. The final result of the computation is not a single crack pattern, but rather several possible crack patterns and their probabilities. The stochastic solution framework using evolving random fields allows additionally the interesting possibility of conditioning the probabilities of further crack paths on intermediate crack patterns.
Bio-sketch: Laura De Lorenzis received her Engineering Degree and her PhD from the University of her hometown Lecce, in southern Italy, where she then became Assistant and later Associate Professor of Mechanics. In 2013 she moved to the TU Braunschweig, Germany, as Professor and Director of the Institute of Applied Mechanics. Since February 2020 she is Professor of Computational Mechanics at the ETH Zürich. She was visiting scholar in several renowned institutions, including Chalmers University of Technology, the Hong Kong Polytechnic University, the Massachusetts Institute of Technology (Fulbright Fellowship), the Leibniz University of Hannover (Alexander von Humboldt Fellowship), the University of Texas at Austin and the University of Cape Town. She is the recipient of several prizes, including the RILEM L’Hermite Medal 2011, the AIMETA Junior Prize 2011, the IIFC Young Investigator Award 2012, two best paper awards and two student teaching prizes. In 2011 she was awarded a European Research Council Starting Researcher Grant. She authored or co- authored more than 120 papers on international journals on different topics of computational and applied mechanics.
GCEC Seminar: Numerical Modeling of Rock Mass in Finite Element Simulations of Deep Tunneling (12 March, 2020)
Speaker: Magdalena Schreter
Title: Numerical Modeling of Rock Mass in Finite Element Simulations of Deep Tunneling
Abstract: Analyzing the mechanical behavior of the rock-support system during the construction of a deep tunnel poses a complex three-dimensional time-dependent problem. To cope with these complexities, finite element simulations are a powerful tool for predicting the deformations occurring during the excavation process, for dimensioning the required tunnel support and for determining critical situations close to collapse. However, in terms of their predictive capacity, they strongly rely on the employed constitutive model for the surrounding rock mass, being the major lead-bearing part of the tunnel structure. In this lecture, challenges and methods for modelling the mechanical behavior of rock mass are discussed, and the application of an advanced constitutive model for rock mass in finite element simulations of the construction of a section of the Brenner Base Tunnel is presented.
Biosketch: Magdalena Schreter was born in Austria in 1991. From 2009 to 2015 she studied Civil Engineering at the University of Innsbruck, completing her Master’s thesis in the field of concrete structures. In 2015, Magdalena was employed as a university assistant at the Unit for Strength of Materials and Structural Analysis at the University of Innsbruck. In December 2018, she received her PhD for her thesis “A Gradient-Enhanced Rock Damage-Plasticity Model for Numerical Analyses of Deep Tunneling”, supervised by Prof. Günter Hofstetter. Since March 2019, she has been working as a postdoctoral researcher at the Unit of Strength of Materials and Structural Analysis at the University of Innsbruck.
GCEC Seminar: Computational Inverse Mechanics to Facilitate Smart Structural Systems (31 January, 2020)
Speaker: John Brigham
Title: Computational Inverse Mechanics to Facilitate Smart Structural Systems
Abstract: Opportunities for leveraging computational mechanics are highly prevalent for the optimisation, control, and/or characterisation of increasingly complex systems through the development and utilization of sophisticated computational inverse solution strategies. Moreover, the application of computational inverse techniques cuts across several disciplines, and is particularly relevant for a wide range of smart structure/structural system applications. In terms of smart systems, capabilities range from developing a self-aware system (e.g., characterization of the current state, including potential damage and degradation) to facilitating adaptability (e.g., control or design optimisation to adapt based on the current state and environment).
This talk will present an overview of the activities of the Computational Diagnostics and Inverse Mechanics Research Group led by John Brigham, and then focus on two specific efforts to utilize computational mechanics and inverse solution strategies: (1) for the efficient solution of problems in characterisation of material properties in solids and structures and (2) optimal design of a smart material morphing building surface tile. These examples will show how many of the same tools, or at least the same overall framework, can be used to address a wide range of inverse problem applications. Yet, the particular challenges of each application will often require unique attention, especially if given additional practical objectives, such as a need for computational efficiency.
Biosketch: John Brigham received a BE from Vanderbilt University and a MS and PhD from Cornell University. Following his PhD in 2008 he joined the University of Pittsburgh as an Assistant Professor, and was later promoted to Associate Professor in the Department of Civil and Environmental Engineering, with a secondary appointment in the Department of Bioengineering. John joined the Department of Engineering at Durham University as an Associate Professor in Applied Mechanics in 2016 and was promoted to a Chair in Engineering in 2019. Focusing on computational mechanics and inverse problems, John’s research group is actively involved in a number of diverse projects, including kinematic analysis of the heart for improved diagnosis of cardiovascular disease, novel design concepts and optimal design strategies for smart material morphing structures, and efficient and accurate quantitative nondestructive evaluation algorithms.
Seminar talk by Dr Dimartino (10 December, 2019)
Speaker: Dr Simone Dimartino
Institute for Bioengineering, The School of Engineering, The University of Edinburgh, Edinburgh EH9 3DW, UK
3D printing of ordered structures: applications in chemistry and engineering
Perfectly ordered structures have been reported to drastically outperform traditional packing in a variety of applications in chemistry and engineering. While this used to be a rather theoretical concept, 3D printing now enables the fabrication of such ordered structures, with complex geometry, and with resolution at the micron scale.
In this lecture I will present a holistic toolbox to design, manufacture and characterize such structures. In my research group we blend a range of modelling and experimental methods, from fluid dynamics to machine learning, from materials science to engineering practice. I will demonstrate how our approach to 3D printing delivers optimized structures and materials with improved performance, with specific focus on applications in the separation sciences (e.g. chromatography) and biotechnology sectors (e.g. bioreactors).
Hopefully this talk will spark your interest on this topic, and make you realize how 3D printed structures could complement and boost your research, regardless of its background and scope!
Dr. Dimartino is a Senior Lecturer at the Institute for Bioengineering at the University of Edinburgh. He did his PhD at the University of Bologna on membrane-based separations in the biopharmaceutical industry (2009), followed by an academic position at the University of Christchurch, New Zealand, where he explored new separation methods for the production of biologics. He now employs 3D printing methods for the fabrication of devices with perfectly ordered internal morphology, with applications ranging bioseparations, biocatalysis and heat transfer. To know more about his research please watch:
- Fun science communication video here.
- Interview on the future of 3D printing and chromatography here.
Finding the Needle in the Haystack: A Simple Path to Matrix Removal and Robust Solid Phase Extraction Methods (24 September, 2019)
Speaker: Daniel Trenzinger
Complex sample matrices create difficult challenges for scientists performing chromatography and mass spectrometry. Matrix interferences often cause matrix effects, inconsistencies in quantification and an overall lack of method robustness and reproducibility. These matrix components can also shorten column lifetime and lead to an increase in instrument downtime. Solid phase extraction (SPE) is a very powerful tool that leads to more robust, reproducible analytical results by reducing matrix effects and chromatographic complexity while also providing the ability to increase analyte concentration. However, it can sometimes be challenging to know how and where to begin creating SPE methods. In this seminar, we will outline several different approaches to sample cleanup using a variety of SPE tools. These approaches provide simple sample preparation solutions for a wide range of analytical needs, from routine analysis to highly selective analyte targeting and concentration.
Nanoscale simulations and digital design of construction materials (17 May, 2019)
Speaker: Enrico Masoero
Concrete and other composite construction materials owe their properties to the collective behaviour of multiple interacting phases. Optimising the chemical composition of these complex materials is a challenge that often requires long and costly experimental campaigns. There is hope that the increasing predictive abilities of models and simulations will soon provide an in-silico route to complement the design of new composite materials, enabling a preliminary shortlisting of promising solutions that can later be tested using fewer but more focussed experiments. Within this picture, a crucial role is played by modelling and simulation at the nanoscale, where the linkage between molecular chemistry, structure, and properties starts to emerge. This talk will discuss the pathway to exploit the predictive abilities of molecular simulations to obtain constitutive laws for larger scale models, e.g. homogenisation theory and Finite Element simulations. Special attention is paid to the mesoscale between the nanometre and the micrometre, where unique structural features (e.g. mesopores) and properties emerge, which can significantly affect the macroscopic behaviour of the material. Two examples are discussed in some details: one is about molecular modelling of geopolymer cements, and the other one is about mesoscale simulations of calcium silicate hydrate precipitation and calcium silicates dissolution. The results are analysed in terms of ability to predict relationships between structure, chemistry, and properties of individual phases, which is the starting point to then combine different phases, e.g. using appropriate homogenisation schemes.
Enrico obtained his PhD in structural engineering at Politecnico di Torino, Italy, in 2010, with a dissertation on structural collapse. From 2010 until 2013 he was postdoc at the Concrete Sustainability Hub at MIT, USA, working on nanoparticle simulation of cement hydration. Since 2013, Enrico is Lecturer in Structural Engineering at Newcastle University, in the UK. His core research is in the hygro-chemo-mechanics of cement and concrete, from the nanoscale up to the macroscale of engineering application. Enrico has authored 23 articles in international journals. He has been a member of the TU1404 COST Action on concrete durability, and is member of the ASCE EMI Materials Properties committee. At Newcastle University, Enrico teaches Structural Mechanics, Engineering Materials, Structural Collapse, and Multiscale Modelling.
GCEC Seminar: On analysis and applications of discrete scattering theory involving edges (02 May, 2019)
Speaker: Dr. Basant Lal Sharma
In the presence of length scales, the elastic wave propagation problem, as well as those involving other kinds of dynamical phenomena (lattice waves or phonons, electronic transport, etc), involve an interplay between wave dispersion and structural features.
The present talk concerns an exposure to the analysis of discrete scattering effects in certain simple structures. As a prototype example of diffraction phenomenon, a discrete analogue of Sommerfeld diffraction by a half plane has been recently analysed for three different lattice structures: square, triangular, and hexagonal. The two simple cases that have been recently studied correspond to semi-infinite row with discrete Neumann condition and discrete Dirichlet condition. Both kinds of half-row `defects’ have been analyzed in infinite lattices as well as in waveguides using Fourier analysis.
The talk will give a flavour of the mathematical formulation and some techniques which are useful to derive physically relevant entities; for the infinite lattice, an example of the latter is far-field wavefunction and for the waveguides, the reflectance and transmittance. The talk will also include some open problems associated with these newly emerging developments as well as some glimpses of the ongoing work. An application of the developed framework to electronic transport in nanotubes will be also briefly discussed.
Multiscale Modelling of Reinforced Concrete (Structures) (05 April, 2019)
Speaker: Adam Sciegaj
Since concrete cracks at relatively low tensile stresses, the durability of reinforced concrete structures is highly influenced by its brittle nature. Cracks allow for ingress of harmful substances, e.g. chlorides, which in turn cause corrosion of the reinforcement. Therefore, crack widths are limited in the design codes. For larger structures, precise crack width prediction requires detailed models, which can become computationally expensive. Hence, multiscale modelling methods are of interest.
In this presentation, a multiscale model for reinforced concrete based on Variationally Consistent Homogenisation (VCH) is outlined. An effective reinforce concrete solid is considered at the macroscale, while the subscale modelling comprises plain concrete, reinforcement bars and the bond-slip interaction between the materials. The effective macroscopic response is obtained upon computational homogenisation of the response of individual Representative Volume Elements (RVEs), in a nested FE^2 (Finite Element squared) algorithm. Furthermore, enrichment of the multiscale model by a macroscopic reinforcement slip variable is addressed. Several application examples of modelling uniformly and non-uniformly reinforced concrete deep beams with this multiscale method are given, and results in terms of force-deflection relations, crack width and crack patterns are presented.
About the speaker:
Adam Sciegaj is a visiting PhD student from Chalmers University of Technology in Gothenburg, Sweden. His research is focused on developing a multiscale modelling framework for reinforced concrete structures, with the aim to make it possible to study the crack growth in detail for large-scale structures, like e.g. bridges.
From dry quicksand to unsinkable suspensions - exploring the underlying links between dry granular flow and wet suspensions (19 February, 2019)
Speaker: Dr Jin Sun
The flow behaviour of dry granular materials, e.g. free flowing sand, is commonly observed to be very different from wet suspensions, e.g. sticky cornstarch-water mixtures. We show, through particle simulations and rheology experiments, that the different behaviour can be put in a unifying rheological framework, where the interplay between particle-size scaling and the observation window gives rise to the perception. More interestingly, the underlying microstructure and force networks bear surprising similarities, which can be used to understand many sometimes puzzling non-linear flow phenomena.
A particular example is shear thickening, where suspension viscosity increases with shear stress or shear rate. It is a ubiquitous feature of many different particle systems and flow processes in nature and industry, particularly for particles of intermediate sizes (diameter 1 μm ≤ d ≤ 50 μm) at high concentrations. This phenomenon has been traditionally explained as being driven purely by hydrodynamic interactions. However, recent theoretical, modelling and experimental work has shown the inadequacy of this mechanism, by elucidating the important role of frictional particle contact.
In this talk, I will present experimental and simulation evidence for shear thickening as a transition from a typical colloidal to a granular behaviour, in which the formation of frictional non-hydrodynamic contacts is key. We have directly quantified the contact contribution to the suspension viscosity during shear thickening by means of shear-reversal rheological measurements, providing new and unambiguous evidence. I will finally describe the ‘tuning’ of shear thickening and other rheological properties based on the understanding of particle contacts, by means of active control or suspension formulation.
Collecting and Storing Data from Internet-based Sources (11 June, 2018)
Speaker: Peter Smyth
The Urban Big Data Centre at the University of Glasgow's next data skills training course will be held on Monday 11th June 2018.
Collecting and Storing Data from Internet-based Sources will be an afternoon session providing researchers with the essential skills required to effectively use Application Programming Interfaces (APIs) for downloading data from a variety of online data sources. It will then cover the use of databases for storing and retrieving data and demonstrate how to automate the collection processes. Full course details below.
Collecting and Storing Data from Internet-based Sources
Course instructor: Peter Smyth, Reasearch Associate, University of Manchester
Course duration: half day (Monday 11th June, 2018, 1:15pm – 4:45pm)
Course location: Jura teaching lab, Level 4 Annexe, Glasgow University Library
Audience: Researchers who need to collect Internet based data, e.g. social media and store it over a period of time
£25 - For UK registered students
£35 - For staff at UK academic institutions, Research Council UK funded researchers, UK public sector staff and staff at UK registered charity organisations
£50 - For all other participants
Pre-requisite knowledge: Some knowledge of Python would be useful but not essential as all code used will be provided.
Many websites allow researchers and developers to download data using their Application Programming Interface (API). This data is often in formats that social scientists are unfamiliar with (e.g. JSON). Downloaded data can be processed immediately or stored in a database for later processing in a package like R or Stata. Data can be collected at regular intervals over a period of time, using the built-in functionality of the Windows or Linux operating systems.
Course participants will be introduced to the following:
- Understand the JSON data format
- Understand how to use APIs to collect data
- Data storage and retrieval using a database (SQLite)
- Ability to set up automated procedures to collect data
Short Presenter Bio:
Peter Smyth is a Research Associate at the University of Manchester, based in the Cathie Marsh Institute. He has spent 35 years working in IT at various large and small commercial organisations before taking an MSc in Big Data Analytics at Sheffield Hallam University and moving into academia. In his previous roles he used any convenient programming environment to hand to solve problems. Now he teaches a variety of programming languages to help others to do the same.
Modeling Environmental Discharge of Sediment: Challenges and Development (21 May, 2018)
Speaker: Dr. Tree S.N. Chan
Sediment or particle-laden turbulent jets and plumes are commonly found in natural and engineered environments. Examples include volcanic eruptions, deep sea hydrothermal vents, discharge of partially-treated wastewater and dredge disposal operations. Predicting the transport and fate of particles in turbulent jet flows is of great interest to the geophysical, engineering and environmental communities, but with considerable challenges. In this talk, recent development on the mathematical modeling of sediment jets will be presented. For jets with dilute sediment concentration, particles have negligible effect on flow and turbulence modulation. A stochastic Lagrangian particle tracking approach is used to predict the motion of a large number of particles using the mean jet flow and turbulent fluctuations. Particle velocity fluctuations are modelled by an autocorrelation function which mimics the trapping and loitering of sediment particles in turbulent eddies. For vertical dense jets and plumes with high particle concentration, fluid flow and turbulence are modulated by the negative buoyancy of falling particles. An integral jet model approach is proposed, using a jet spreading hypothesis related to particle properties and local mean jet velocity. Predictions of these simple yet trackable models are in excellent agreement with experimental data and multiphase computational fluid dynamics modeling over a wide range of jet-plume regime, particle properties and concentrations.
Multi-physics couplings appearing in micro-to-macro porous media encompassing damage, transport and adsorption-induced strain (11 April, 2018)
Speaker: David Grégoire
Starting from failure analysis and crack propagation driven by mechanical or hydraulic loading conditions in quasi-brittle porous media, we will discuss some multi-physics couplings appearing in micro-to-macro porous media encompassing damage, transport and adsorption-induced strain under saturated and unsaturated conditions. Applications range from oil and gas recovery enhancement, CO2 or energy storage and nuclear containment vessel tightness assessment.
Surface Enhanced Raman Scattering (SERS) sensors for the detection of pollutant in water (28 November, 2017)
Speaker: Dr Nathalie Lidgi-Guigui
Abstract: The Raman scattering is a well known analytical chemistry technique where the light is scattered by the vibrating bounds of a molecule. As so it gives a molecular fingerprint of a specific compound. However, Raman scattering is not a very sensitive technique. To circumvent this drawback, it is possible to take advantage of the optical properties of metallic nanoparticles (NP). When exposed to light, coherent oscillations of the free electron gas are taking place on the NP. These so called Localized Surface Plasmon (LSP) create an electromagnetic field which is the basis of the near field enhancement of Raman scattering. This electromagnetic effect is responsible for an enhancement factor that can be as high as 10^8. Another effect, the chemical effect, has a weaker contribution to the Raman scattering enhancement. Its origin is discussed among the community but is probably based on the shifting of the molecules energy levels when it is bound to the NP surface.
In this talk we will focus on the use of SERS substrate for the detection of pollutant in water. We will present results concerning hydrophobic and hydrophilic compounds. The first are organic molecules, consisting of two or more fused aromatic rings known as polycyclic aromatic hydrocarbons (PAHs). This group of compounds have received considerable attention due their toxicity and carcinogenicity. The hydrophilic compound that we have worked on is paracetamol. This is the most used drug around the world and as so it is highly found in waste water. However, in order to study its impact on the marine environment it is first needed to be able to quantify its presence.
Obviously, these two class of pollutants do not present the same issues in terms of sensing. In the first case it is important to reach a very low limit of detection when the quantification and the specificity are the key for the hydrophilic pollutants. We will present the strategy of surface functionalization we have adopted in both case that include the use of Molecular Imprinted Polymers (MIP) for the detection of paracetamol and the exploitation of pi-pi stacking for the detection of naphthalene, fluoranthene and benzo[A]pyrene.
In the last part of the talk, I will show how the nanostructured surface can play an active role in the functionalization. We have recently demonstrated that the LSP can support chemical reactions such as the well known click chemistry thiol-ene reaction. It is even possible to go further and to performed a different functionalization on different direction of a nanostructure by taking advantage of the light polarization.
Biography: After completing my undergraduate studies in material sciences at the University Pierre and Marie Curie in Paris, I followed my interest in nanotechnologies by enrolling in a doctoral program at the Unité Mixte de Physique CNRS Thales where I developed my field of expertise the nanoparticles growth and their electronic properties. After obtaining my Ph.D. in 2005, I joined the team of Prof. R. E. Palmer at the University of Birmingham where I studied the growth and deposition of size selected clusters and their interactions with proteins. The skills I developed in liquid phase AFM were valued through my second post-doc at the University of Evry. Since 2010 I am a reader at the University Paris 13. My main research interests focus on the development of highly sensitive sensors for biomolecules and pollutants. In my group, we use and develop original lithography techniques to fabricate large assembly of organized nanostructures for SERS (Surface Enhanced Raman Spectroscopy). Through the years we have developed several functionalization paths that have enable us to pre-concentrate analytes, to detect their presence in low concentration and to follow their structural evolution. Recent results are focusing on the possibility of making these sensors active by exploiting the tremendous ideas of plasmon based chemistry.
UBDC Seminar: Using Cycling Flow Data to Analyse Injury Risk (27 November, 2017)
Speaker: Dr. Rachel Aldred
The Urban Big Data Centre's next free seminar will take place on Monday 27th November (10:30-12pm) as we welcome Dr Rachel Aldred, a reader in Transport at the University of Westminster, to talk about her research insights into cycling injury risk.
Using the Case-Control Method to Study Effects of the Built Environment on Cycling Injury Risk
Rachel will introduce the use of the case-control method to study cycling injury risk, comparing this to case-crossover approaches. After outlining some examples, she will describe her pilot case-control study of cycling injury risk in London in 2013-4, including dataset issues and results. There will be time for discussion covering the strengths and weaknesses of the method, the range of datasets that could be used (and their limitations), and how the insights can be used to improve injury risk research.
- An understanding of limitations in road injury research, and the strengths and weaknesses of case-control and case-crossover approaches
- An understanding of how geographical datasets, from OSM data to Strava Metro and modelled flow data, can be used to generate new insights about injury risk
UBDC Seminar: Governance and Empowerment in the Smart City (30 October, 2017)
Speaker: Liesbet van Zoonen
Liesbet van Zoonen, academic director of the Center for BOLD Cities will be visiting the Urban Big Data Centre on Monday 30th October to give a lecture entitled 'Governance and Empowerment in the Smart City'. The talk will take place in UBDC's Conference Room and will be followed by a discussion and refreshments.
Governance and Empowerment in the Smart City
While ‘smart city’ is already a stale term in IT and urban discourse, the average citizen is unlikely to know what it means, and city civil servants are still catching up on the implications of ‘smart’ for their particular policy and planning arena. Hence, the current cry among smart city companies and professionals is that it is time to ‘involve the people’. However, it is never discussed which people are expected and desired to become involved what desirable outcomes of this involvement are, and what forms of involvement one should strive for.
In this talk, Liesbet van Zoonen discusses the need for the empowerment of citizens and civil servants against the big IT and platform companies, and presents the action research that her research centre for Big Open and Linked Data (BOLD) Cities conducts. Combining data science with participatory methods proves a promising way, she will argue, to help both citizens and civil servants to keep the city as a public space enabling public life.
Simple Rheology Unifying Dense and Dilute Granular Flows/Unified Theory of the Cessation of Sediment Transport Mediated by a Newtonian Fluid (09 October, 2017)
Speaker: Professor Thomas Pahtz
In my presentation, I will talk about two topics. First, I will present a simple granular flow rheology that unifies the classical m(I) rheology of dense granular flows with the granular kinetic theory of dilute granular flows. This unification is considered as one of the major open problems in the field. I will show that the unified rheology is consistent with discrete element method simulations of a large range of complex geophysical flows: steady sediment transport in viscous and turbulent liquids and air, steady gravity flows down an inclined plane, and homogeneous shear flows. Second, I will present a new perspective on the sediment transport cessation threshold, which is the threshold value of the fluid shear stress at which standard expressions for the sediment transport rate predict vanishing transport (i.e., the threshold that is often displayed in the Shields diagram). I will present evidence that this threshold is not an entrainment threshold, but instead the minimal fluid shear stress required to resupply transported particles with energy that they lose when rebounding at the bed surface. Based on discrete element method simulations, I will present an analytical theory that predicts this threshold for arbitrary environments. I will show that this theory is simultaneously consistent with measurements in viscous and turbulent subaqueous and aeolian environments without being fitted to them. One of the major implications of this theory is that the sediment entrainment threshold and the threshold shown in the Shields diagram are two very different things associated with two very different problems, although they are usually being treated as one and the same.
Discrete Element Method (DEM) Open Forum & ESyS-Particle Workshop (30 August, 2017)
You are cordially invited to attend a casual gathering of Discrete Element Method (DEM) enthusiasts to discuss current and future trends in particle-based numerical modelling. This $free Open Forum welcomes anyone who currently undertakes scientific or engineering research using DEM software; either Open Source or proprietary. The purpose is to stimulate discussion about DEM software, techniques and methods in a relaxed and collegial manner. Generous breaks and discussion periods will facilitate collaboration and comradery. The forum will also serve to launch ESyS-Particle v3.0; including the recent additions of Darcy flow and self-gravity.
Modelling the Stress and Strain Behaviour of a DC Smelting Furnace Lining (16 June, 2017)
Speaker: Herman Kotze
The refractory linings used in smelting furnaces undergo cooling and heat-up cycles when the furnaces are shut down and restarted. Severe deformation, cracks and metal penetration have been observed during furnace excavation. An improved understanding of furnace refractory linings under thermal and mechanical loads need to be developed. To model these linings prove to be quite a challenge and as a first step a 3D finite element model of a DC smelting furnace was developed. The use of adjusted material properties for approximating the lining as a solid are also evaluated and discussed. This presentation will focus on the background of the problem and different modeling techniques investigated. I will present the results of the steady state model and discuss current transient implementations and progress.
Herman Kotze obtained his B.Eng degree in Mechanical Engineering from the University of Pretoria in 2014. He completed his Honours in Metallurgical Engineering in 2015 focusing on Numerical Methods, Finite Element Modeling, Refractories and Pyrometallurgy. He is currently doing his masters as part of the Pyrometallurgical Modeling group at the University of Pretoria under the supervision of Dr Johan Zietsman and Prof Schalk Kok.
On the modelling of reinforced composites using a damage-plasticity approach in LS-DYNA (19 April, 2017)
Speaker: Peter Grassl
The structural performance of reinforced composites relies heavily on the mechanical interaction between reinforcement and concrete. In nonlinear finite element analyses, the interaction of reinforcement and matrix is either modelled by merged or coincident with slip approaches. Here, the performance of these two approaches in the modelling of failure of reinforced concrete is investigated using the finite program LS-DYNA. Firstly, the influence of element size on the response of tension-stiffening analyses with the two modelling approaches is investigated. Then, the results with two approach are compared for plain and fibre reinforced tension stiffening and a drop test experiment. The talk should be of interest for those working on fibre reinforced composites. Furthermore, those interested in commercial software for nonlinear failure analysis in general might find this talk useful, as it will show capabilities of LS-DYNA for modelling fracture.
Free colloquium on Innovation, High-tech sectors and Knowledge Space, 31st March in Glasgow (31 March, 2017)
Speaker: external speakers
Invitation to a free Knowledge Exchange colloquium on 31st March
'Innovation, High-tech sectors and Knowledge Space: UK’s current stand and future uncertainty'
you are warmly welcomed to attend a free Knowledge Exchange colloquium, funded by the UK Economic and Social Research Council (ESRC).
To be held in Glasgow on Friday, 31st March, this colloquium will be an important opportunity for private and public sectors to discuss and debate on, the stand and competitiveness of UK’s high-tech sectors and innovation activities; the potential impacts of the Brexit on UK’s high-tech sectors, and how these sectors and specially designated knowledge spaces could react to Brexit and future uncertainties through innovative business models.
Confirmed speakers for this colloquium include:
- Sandrine Kergroach (Policy Analyst, Science and Technology Policy Division of OECD)
- Jose Enrique Garcilazo (Head of Unit for the Rural and Regional Development Programme within the Regional Development Policy Division at the OECD)v
- Carol Stewart (Board of Directors for the Association of University Research Park; Business Development Manager of David Johnston Research + Technology Park, Canada)
- Paul Tostevin (Associate Director in Savills World Research)
- Simon Smith (Economic Development Manager of Glasgow City Council)
- Stuart Patrick (Chief Executive of Glasgow Chamber of Commerce)
- John Goddard (Emeritus Professor of Regional Development Studies, Newcastle University)
- Dave Valler (Reader in Spatial Planning, Oxford Brookes University)
- Zhai Lei (Professor of Project Management, Nankai University, China)
Registration and further programme information is available via our Eventbrite page. You could also follow this event on twitter: #BrexitHTS. Please register as space is limited and catering must be ordered in advance.
We hope you can join us and please forward this information to anyone that this might interest.
Topology Optimization for Metal Additive Manufacturing: Recent Developments and Computational Challenges (22 March, 2017)
Speaker: Matthijs Langelaar
Metal Additive Manufacturing (AM) has reached the level of maturity needed for industrial production of end-use parts. The complexity of the part geometry is no longer the main cost factor in AM, which leads to exciting opportunities for design optimization. In particular topology optimization forms an ideal method to benefit from AM design freedom, but existing approaches do not consider AM restrictions. This presentation will highlight recent advances in combining topology optimization with a main geometric AM restriction on angles of overhanging surfaces, and also discuss the necessary next steps and associated challenges for optimization and computational mechanics.
Matthijs Langelaar received his MSc degree in Mechanical Engineering from Twente University, worked on Robotics at DLR Germany and did his PhD research at Delft University of Technology. His research interest is Design Optimization, specifically Topology Optimization and Optimization under Uncertainty.