EPSRC Reference: |
EP/H030123/1 |
Title: |
GGS - Modelling forces and stresses in gigantic granular systems for coastal engineers |
Principal Investigator: |
Latham, Dr J |
Other Investigators: |
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Researcher Co-Investigators: |
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Project Partners: |
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Department: |
Earth Science and Engineering |
Organisation: |
Imperial College London |
Scheme: |
Standard Research |
Starts: |
01 October 2010 |
Ends: |
30 November 2014 |
Value (£): |
475,827
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EPSRC Research Topic Classifications: |
Coastal & Waterway Engineering |
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EPSRC Industrial Sector Classifications: |
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Related Grants: |
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Panel History: |
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Summary on Grant Application Form |
The Research Team is based within the Applied Modelling and Computation Group (AMCG) at Imperial in the Department of Earth Science and Engineering. The industrial partners, Sogreah Consultants, and Baird & Associates, are world leaders in Coastal Engineering and have committed considerable financial support. This project exploits the VGW EPSRC project in which numerical models were developed.To meet this century's challenge of extensive and accelerating future coastal change, society will expect coastal engineers to design resilient structures to hold the line against flood and erosion where it is deemed necessary. The first choice construction material and design approach for such structures will often be to use armour layers of massive rocks or concrete units. Currently, designers do not understand the details of how they work, relying heavily on empirical methods. This project will reveal fundamental mechanisms that cause disintegration of these rubble mound coastal structures and breakwaters. With our further enhanced simulation tools we will re-create the construction process, examine inherent heterogeneity, explore unit shapes and their interaction with under-layer rock geometry, examine scale effects, and use vibration and other proxies for wave disturbance, all to study block motion, contact force and stress heterogeneity and risk of concrete unit breakages.The aims are to:(1) Promote a shift in design approach from empirical to scientifically-determined damage and breakage probabilities. This requires modelling the solid geometry together with both the static and transient dynamic stress states within gigantic granular systems of complex-shaped concrete units and rock armour used in coastal structures and breakwaters, during construction, when at rest and as perturbed by external forces. (2) Extend the stress and deformation analysis tools of our world-leading 3D FEMDEM modelling technology that combines the multi-body interaction and motion modelling (i.e. Discrete Element Model, DEM) with the ability to model internal deformation of arbitrary shape (Finite Element Model, FEM) to the point where they can be readily harnessed to deliver a more fundamental understanding of a wide range of environmental and industrial problems.The layers of concrete units and rocks targeted in this coastal research are an extreme case of particulate or granular media intensively studied by physicists, with solid-like behaviour dominating but potentially fluid-like behaviour possible, should they become unravelled in a storm. Scientists have long been able to see stresses in photo-elastically deformed grain pack experiments using any 2D grain shapes, but have had no such property or tool to interrogate our real-world 3D granular systems. This is all about to change following research by the PI and co-workers - the development of a generic 3D computer model based on FEMDEM developed under our VGW EPSRC grant. No other model (presented in the literature) handles multi-body dynamics of complex-shaped deformable particles with greater accuracy, capturing the stress components everywhere in time and space. This project will bring fresh modelling capability to both fundamental science and engineering applications of granular materials. Information about temporal and spatial heterogeneity of stress will become available to underpin the workings at the heart of our currently limited understanding of granular material behaviour that is so vexing the physicists.Applications of numerical models to loading and collapse of silos, mineral and powder processing/handling, avalanching, and geotechnics have all been attempted using DEM. Upgrading DEM to FEMDEM, taking account of deformability, dynamics and the angularity/complexity of particle shape in these multi-body systems will significantly improve simulations, extending applications to unprecedented fields such as biomechanics and nuclear systems, too numerous to list here.
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Key Findings |
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Potential use in non-academic contexts |
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Impacts |
Description |
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Summary |
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Date Materialised |
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Sectors submitted by the Researcher |
This information can now be found on Gateway to Research (GtR) http://gtr.rcuk.ac.uk
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Project URL: |
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Further Information: |
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Organisation Website: |
http://www.imperial.ac.uk |