Page 14 - The Combined Finite-Discrete Element Method

Preface

Computational mechanics of discontinua is a relatively new discipline of computational
mechanics. It deals with numerical solutions to engineering problems and processes where
constitutive laws are not available. Particle- based modelling of micro-structural elements
of material is used instead. Thus, the interaction and individual behaviour of millions,
even billions, of particles is considered to arrive at emergent physical properties of prac-
tical importance.
Methods of computational mechanics of discontinua include DEM (Discrete Element
Methods), DDA (Discontinua Deformation Analysis Methods), Methods of Molecular
Dynamics, etc.
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In the last decade of the 20 century, the Discrete Element Method has been coupled
with the Finite Element Method. The new method is termed the ‘Combined Finite-Discrete
Element Method’. Thanks to the relatively inexpensive high performance hardware rapidly
becoming available, it is possible to consider combined finite-discrete element systems
comprising millions of particles, and most recently even billions of particles. These, cou-
pled with recent algorithmic developments, have resulted in the combined finite-discrete
element method being applied to a diversity of engineering and scientific problems,
ranging from powder technology, ceramics, composite materials, rock blasting, mining,
demolition, blasts and impacts in a defence context, through to geological and environ-
mental applications.
Broadly speaking, the combined finite-discrete element method is applicable to any
problem of solid mechanics where failure, fracture, fragmentation, collapse or other type
of extensive material damage is expected.
In the early 1990s, the combined finite-discrete element method was mostly an academic
subject. In the last ten years, the first commercial codes have been developed, and many
commercial finite element packages are increasingly adopting the combined finite-discrete
element method. The same is valid for the commercial discrete element packages. The
combined finite-discrete element method has become available to research students, but
also to engineers and researchers in industry. It is also becoming an integral part of many
undergraduate and postgraduate programs.
A book on the combined finite-discrete element method is long overdue. This book
aims to help all those who need to learn more about the combined finite-discrete ele-
ment method.