### Fracture modelling saves money, increases productivity and makes mining safer

**Submitting Institution**

Queen Mary, University of London**Unit of Assessment**

General Engineering**Summary Impact Type**

Technological**Research Subject Area(s)**

Mathematical Sciences: Numerical and Computational Mathematics

Information and Computing Sciences: Computation Theory and Mathematics

Engineering: Resources Engineering and Extractive Metallurgy

**Download original**

PDF**Summary of the impact**

From 1995 Professor Munjiza's research at QMUL has led to the development of a series of algorithms which can predict the movement and relationship between objects. These algorithms have been commercialised by a range of international engineering and software companies including Orica, the world's leading blasting systems provider (via their MBM software package), and the software modelling company, Dassault Systems (via their Abaqus software). Through these commercialisation routes Munjiza's work has generated significant economic impact which is global in nature. For example, his predictive algorithms have enabled safer, more productive blast mining for Orica's clients — in one mine alone, software based on Munjiza's modelling approach has meant a 10% increase in productivity, a 7% reduction in costs and an annual saving of $2.8 million. It has also been used in Dassault Systems' Abaqus modelling software, which is the world's leading generic simulation software used to solve a wide variety of industrial problems across the defence, automobile, construction, aerospace and chemicals sectors with associated economic impact.

**Underpinning research**

Between 1995 and 2004 Professor Antonio Munjiza (QMUL 1995-present), a computational engineer, conducted research that led to the development of the combined finite discrete element method [he has written three monographs on the subject, see s.3]. As part of a project with ICI (now Orica), this method was used to produce a software package for rock blasting (MBM). Following further research he developed the next generation of related algorithms, which included No Binary Search (NBS) and a number of open-source software packages called `Y'. In 2010, NBS became a part of Dassault Systems' Abaqus Explicit modelling software package, incorporated within their Smoothed Particle Hydrodynamics (SPH) method suited for solving fluid and large strain Lagrangian simulations.

Although finite element methods were well established in many branches of engineering and routinely used in the solution of large-scale industrial problems, the finite element description is not the most appropriate model. Munjiza's contribution was to marry discrete and finite elements into predictive models for progressive fractures. The combined finite/discrete element (FDEM) approach, in which the problem is analysed by a combination of the two methods, is particularly suited to problems in which progressive fracturing takes place as is the case in rock blasting situations and missile impact situations [1, 2]. Munjiza's research has focused on the numerical modelling of particulate processes in environmental science. While most discontinuum modelling uses spheres to represent particles, his work has led to developments that tackle the complexity of realistically shaped bodies such as those exhibited by rock fragments [3].

Munjiza's work has also led to efficient computational simulation of these fracture mechanics [4], which has resulted in advances in modelling software, both in industry and in the research sector. He has invented a number of original algorithmic solvers such as NBS linear search, MR linear search (widely employed in molecular dynamics), a combined single-smeared approach to fracture, and several others. These methods require less computational resource (in terms of time and memory) than their predecessors, while still resulting in faithful models of the interaction between molecules, for example, or the propagation of fractures from an explosion.

A number of research institutions around the world have developed research software using FDEM in the form of Y-code, which is open source enabling technology developed by Munjiza. For instance Munjiza, in collaboration with the University of Toronto has developed Y-geo, Y-gui and Y-blast based on Y [5]. Imperial College London, in collaboration with Munjiza, have developed VGEST based on Y. Through these software developments the technology is now being used across a variety of industrial sectors, such as mining, petroleum, mineral processing and aerospace. Further, several government labs in the USA are pursuing research based on Munjiza's FDEM.

**References to the research**

1. Munjiza, A., Andrews, K.R.F. (1998). NBS contact detection algorithm
for bodies of similar size. *Int. J. Num. Methods Eng.*, 43,
131-149.

2. Munjiza, A., Andrews, K.R.F (2000). Penalty Function Method for
Combined Finite-Discrete Element Systems Comprising Large Number of
Separate Bodies. *International Journal for Numerical Methods in
Engineering*, 49 (11), pp. 1377-1396

3. Latham, J.-P., Munjiza, A. (2004). The Modelling of Particle Systems
with Real Shapes. *Philosophical Transactions of the Royal Society A:
Mathematical, Physical and Engineering Sciences*, 362 (1822), pp.
1953-1972.

4. Rougier, E., Munjiza, A., John, N.W.M. (2004). Numerical Comparison of
Some Explicit Time Integration Schemes Used in DEM, FEM/DEM and Molecular
Dynamics. *International Journal for Numerical Methods in Engineering*,
61 (6), pp. 856-879.

5. Mahabadi, O. K.; Grasselli, G.; Munjiza, A. (2010). Y-GUI: A graphical
user interface and pre- processor for the combined finite-discrete element
code, Y2D, incorporating material heterogeneity. *Computers &
Geosciences*, 36, pp. 241-252.

**Details of the impact**

Munjiza's fracture modelling algorithms are used to develop predictive simulation software for a wide range of industries including the defence, automobile, construction, aerospace and chemicals industries. But they have generated greatest impact in the global mining industry, where his research into finite and discrete element modelling (FDEM) results in more accurate and detailed predictions of blast mechanics, which are computationally tractable. Predictive software based on Munjiza's algorithms has generated commercial and economic impact for major mining companies through increased productivity, a reduction in extraction costs resulting in enhanced profitability for the companies and reduced commodity price for customers. Further, the safety of the process is improved, delivering benefit to employees working within the mine.

**Software used in the mining industry to accurately predict blasting**

Munjiza's fracture modelling methods are widely used in the multi-billion
dollar global mining and extraction industries. Many engineering and
extraction activities are "one-shot" opportunities that, if they go wrong,
cannot be repeated. Take, for example, the blasting of a rock face in open
cut mining. The resulting fragments of ore must be within a certain range
of sizes if they are to be suitable for onward processing. Until the
introduction of the FDEM modelling approach, the development of a blast
design (placing and timing charges of explosives so that the resulting
explosion creates the desired pattern of fractures) was impossible to
predict accurately. Munjiza's algorithms, based on his FDEM methods, have
enabled the development of modelling software, which can predict the
result of explosions in both time and space with sufficient accuracy that
it can be used to design highly productive and safer blasts, for example
via Orica's MBM package and Abaqus Explicit modelling software used by
Coffey Mining.

**Orica and the MBM package**

Orica is a leading multinational corporation that has more than 15,000
employees and an annual revenue in 2010 of $6.5 billion. The company
provides commercial blasting systems, mining and tunneling support systems
in more than 50 countries worldwide. Orica's Mining Services Division is
the world's largest single supplier of commercial explosives and blasting
systems to the mining, quarrying and infrastructure sectors.

**Use of the NBS algorithm in Abaqus software**

Munjiza's NBS algorithm solver is used in Dassault Systèmes' Abaqus
Explicit modelling software package, the world's leading generic
simulation software [Section 5, sources 4,5]. The incorporation of the NBS
algorithm into Abaqus has delivered economic/commercial impact both to
Dassault Systèmes and to their customers, who use the software to solve
engineering problems and improve their business competitiveness. The
incorporation of the NBS solver within the Smoothed Particle Hydrodynamics
(SPH) method in Abaqus Explicit 6.11 improves the functionality of the
software and helps ensure competitive advantage of Dassault Systèmes as
market leader with associated direct economic impact.

Dassault Systèmes S.A. provide several case studies relating to the economic impact their customers have obtained through the use of the NBS solver within the Abaqus Explicit package (see section 5). For example, this Abaqus Explicit software is used by Coffey Mining, a specialist consultancy to the international mining sector. The principal engineer for Coffey Mining, says that the modelling approach based on Munjiza's work allows them to "answer a number of questions simultaneously, [allowing Coffey] to work on the complete 3D mine geometry." This cuts down on the time spent creating models and leads to more accurate predictions [Section 5, source 6].

Eni S.p.A. is a multinational oil and gas consultancy that advises its clients on ways to better manage the lifespans of oil and gas fields. They use the modelling techniques developed by Munjiza within the Abaqus Explicit software to ensure that reservoirs of fossil fuels are managed as sustainably as possible [Section 5, source 7]. "It used to take almost two months to complete a single model suitable for running," says Silvia Monaco, geomechanical engineer in the petroleum engineering department of Eni E&P headquarters. "Now we can build a model in only four weeks... Moreover, the new iterative solver implementation provides a strong reduction in computational times and memory usage that further speeds up the execution of the study."

Abaqus Explicit predictive simulation software has a wide range of other applications including predicting ballistic impact in the defence industry, crashworthiness in car manufacturing, and other uses in the construction, aerospace and chemicals industries. It is expected that the latest combined finite discrete element method as described in three monographs will become an integral part of a number of generic and application-specific software packages, thus further improving productivity, reducing cost, increasing safety and leading to a better environment.

**Sources to corroborate the impact **

- Blasting Technician, Orica Mining Services. Aspect corroborated: Software used in the mining industry to accurately predict blasting & Orica and the MBM package
- Also see — improved mining efficiency using MBM package:

www.oricaminingservices.com/uploads/Fragmentation/Open cut/100064_Case Study_ABT Smashing PerformanceNewlands Eastern Creek_English.pdf - Also see — MBM package used to avoid power lines during blasting:

www.oricaminingservices.com/au/en/page/independent_pages/open_cut_vibration_management - Engineering Specialist, Automotive Industry at Dassault Systemes. Aspect corroborated: Use of the NBS algorithm in Abaqus software
- Munjiza algorithm incorporated into Abaqus Explicit modelling software
package:

http://iwcmm22.jhu.edu/MS2-1.html - Coffey Mining uses Abaqus for geomechanical modelling:

www.3ds.com/company/customer-stories/details/customers/coffeymining/single/1105/?cHash=d136b8a20956be0c363f97cbb 7d67e04 - Eni uses Abaqus to model oil and gas reservoir structure:

www.3ds.com/fileadmin/COMPANY/About-3DS/3DS-Magazines/SIMULIA-Community-News/PDF/simulia-scn-0612.pdf (pp 12-14 and Cover)