John Paul MorrisseyThe University of Edinburgh | UoE · School of Engineering
John Paul Morrissey
Ph.D.
Research Fellow at the University of Edinburgh working on all things granular.
About
28
Publications
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331
Citations
Introduction
DEM simulations, data analysis and experiments. Cohesive and bonded materials. Multiscale systems.
Additional affiliations
Education
October 2009 - May 2013
September 2006 - May 2009
September 2002 - May 2005
Publications
Publications (28)
An adhesive elasto-plastic contact model for the discrete element method with three dimensional non-spherical particles is proposed and investigated to achieve quantitative prediction of cohesive powder flowability. Simulations have been performed for uniaxial consolidation followed by unconfined compression to failure using this model. The model h...
The overall aim of this project was to relate ground penetrating radar (GPR) to a ballast fouling index (FI).
Laboratory research aimed at characterising the electromagnetic properties has enabled researchers worldwide to determine ballast thickness using impulse ground penetrating radar (GPR) – based upon derived values of the relative electrical...
Across industry the majority of raw materials handled are particulate in nature, ranging
in size and properties from aggregates to powders. The stress regimes experienced
by the granular solids vary and the exhibited bulk behaviours can be complex and
unexpected. The prevalence of granular solids makes them an area of interest for
industry and rese...
Regardless of its origin, in the near future the challenge will not be how to generate data, but rather how to manage big and highly distributed data to make it more easily handled and more accessible by users on their personal devices. VELaSSCo (Visualization for Extremely Large-Scale Scientific Computing) is a platform developed to provide new vi...
This paper presents a generic framework of Model Driven Design (MDD) with its application for a twin screw granulation process using a mechanistic-based population balance model (PBM). The process kernels including nucleation, breakage, layering and consolidation are defined in the PBM. A recently developed breakage kernel is used with key physics...
Attrition and breakage of agglomerates are prevalent during production and handling processes in many industries. Therefore, it is highly desirable to be able to model and analyse the agglomerate breakage process under various loading conditions. The ensemble strength and breakage patterns of agglomerates are still not well understood despite a sig...
Bonded contact models have been increasingly used in the discrete element method (DEM) to study cemented and sintered particulate materials in recent years. Several popular DEM bond models have been proposed in the literature; thus it is beneficial to assess the similarities and differences between the different bond models before they are used in...
With increasing train speed and wheel axle load, severe vibrations can occur in a ballasted trackbed, thereby accelerating the degradation of the ballast particles and ultimately causing excessive settlement. To gain insights into the long-term trackbed behavior and the ballast degradation evolution, a full-scale ballasted track experiment with eig...
Discrete Element Method (DEM) simulations have the potential to provide particle-scale understanding of twin-screw granulators. This is difficult to obtain experimentally because of the closed, tightly confined geometry. An essential prerequisite for successful DEM modelling of a twin-screw granulator is making the simulations tractable, i.e., redu...
Wet granulation is a process used to create larger stable agglomerates (granules) from fine powders. However, despite wide adoption, it is often inefficiently operated, with high recycle ratios in continuous processes and high rejection rates in batch processes. This numerical study simulates a GEA ConsiGma™ 1 Twin Screw Granulator (TSG), following...
With the rapid development of high-speed railway over the world in recent years, more and more researchers are focused on the strength, stiffness and stability of the embankment. It’s more and more popular to use the discrete element method (DEM) to study cemented granular materials (e.g. rocks and concrete). This paper verified the Timoshenko beam...
Wet granulation is a process used to create larger stable agglomerates (granules) from fine powders. However, despite wide adoption, it is often inefficiently operated, with high recycle ratios in continuous processes and high rejection rates in batch processes. This numerical study simulates a GEA ConsiGma™ 1 Twin Screw Granulator (TSG), following...
This study employs the Discrete Element Method (DEM) to study a 25 mm diameter, GEA ConsiGma™ 1 Twin Screw Granulator (TSG), with a typical 60°configuration for kneading elements. The DEM simulations were conducted using the commercial code. Wet granulation is a process used to create larger stable agglomerates (granules) from fine powders. It is c...
VELaSSCo (Visual Analysis for Extremely Large-Scale Scientific Computing) is an
EC FP7 project involving a consortium of seven European partners (Fig. 1).
VELaSSCo aims to provide new visual analysis methods for large-scale
simulations serving the petabyte era.
The main output of the project is the VELaSSCo platform which has been
designed a...
This guide provides a reference for how to successfully use the Timoshenko Beam Bond Model (TBBM) in EDEM® to model the three dimensional response of a cemented granular material under loading. A reference manual, which includes the theory of the TBBM and a description of the input parameters required to run the model, is available separately.
A step-by-step example problem for the Edinburgh Elasto-Plastic Adhesion (EEPA) model.
A confined/unconfined uniaxial compression problem is described.
This reference manual provides the key information regarding an bonded beam contact model for EDEM that has been developed over many years at the University of Edinburgh. The contact model has been implemented as a User Defined Library (UDL) through the API capabilities of EDEM.
Reference manual for the Edinburgh Elasto-Plastic Adhesion (EEPA) Model, available in EDEM.
This guide provides the key information regarding an adhesive elasto-plastic contact model for EDEM that has been in development over many years at the University of Edinburgh. The contact model has been implemented as a User Defined Library (UDL) through t...
Bulk handling of powders and granular solids is common in many industries and often gives rise to handling difficulties especially when the material exhibits complex cohesive behavior. In this study the effect of moisture on the level of cohesion, and thus handleability, of iron ore fines is investigated. The compression and flow function of the ir...
Powders and bulk solids are stored and handled in large quantities in many industries. The materials can differ greatly in size, shape and type but are commonly affected by handling and storage difficulties, such as the blockage of silo outlets or transfer points, which occur as a result of the development of cohesion.
Adhesive forces between part...
Bulk handling of powders and granular solids is common in many industries and often gives rise to handling difficulties especially when the material exhibits complex cohesive behaviour. For example, high storage stresses in a silo can lead to high cohesive strength of the stored solid, which may in turn cause blockages such as ratholing or arching...
In this study, the behaviour of iron ore fines with varying levels of adhesion was investigated using a confined compression test and a uniaxial test. The uniaxial test was conducted using the semi-automated uniaxial EPT tester in which the cohesive strength of a bulk solid is evaluated from an unconfined compression test following a period of cons...
In this paper, the loading behaviour of iron ore fines was investigated using both a confined compression test and a uniaxial test. This provides a comprehensive description of the material behaviour in terms of bulk compressibility, loading-unloading stiffness, unconfined strength and lateral pressure ratio. The effect of moisture content on the i...
Many powders and particulate solids are cohesive in nature and the strength often exhibits dependence on the consolidation stress. As a result, the stress history in the material leading up to a handling scenario needs to be considered when evaluating its handleability. This paper outlines the development of a DEM contact model accounting for plast...
The overall aim of this project was to relate Ground Penetrating Radar (GPR) to ballast fouling. The 10-year old University of Edinburgh full-scale trackbed was revisited and the fouling of the ballast was recalibrated following environmental changes, using the Ionescu fouling index. A series of GPR experiments were undertaken on the trackbed using...
Many powders and particulate solids are stored and handled in large quantities in various industries. Many common handling and storage difficulties are caused by the material cohesion. The cohesive strength of a bulk material is a function of its past consolidation stress. For example, high material cohesive strength in a silo can result from high...
Industrial processes in many sectors including pharmaceutical, food, and chemical sectors involve bulk materials with varying degree of cohesivity. Cohesive solids can experience a number of flow problems including arching, ratholing, segregation, channelling and flooding. A better understanding of these problems can help to improve the handling of...