Particles 2011 special issue
Article Type: Guest editorial From: Engineering Computations: International Journal for Computer-Aided Engineering and Software, Volume 30, Issue 2
The 2nd International Conference on Particle-based Methods (Particles 2011) was held on 26-28 October 2011, in Barcelona, Spain, following the success of the first conference of this series in 2009. The conference attracted over 250 participants from a wide range of research areas, with many from the computational mechanics community.
The last few years have witnessed a rapidly increasing research interest in the development of different particle-based methods for problems exhibiting discrete and/or discontinuous behaviour. Particles 2011 addressed recent advances in both fundamental and application aspects of many particle-based methods including discrete element methods (DEM), particle finite element methods (PFEM), smoothed particle hydrodynamics (SPH), material points, meshless, lattice models, and others.
As a dominant particle-based method, DEM, in its classic form, has become firmly established as one of the most powerful numerical techniques to model particulate systems. By bonding and de-bonding elements, the method has also been employed to simulate continuum media possessing (progressive) brittle material damage and fracturing failure characteristics, such as concrete structures subject to impact loading, where the conventional finite element method faces substantial numerical challenges. The fundamental differences between these two forms of DEM were for the first time explicitly discussed by two plenary lectures in the conference.
The bonded DEM is essentially a lattice-based discretisation method for continuous media. Unlike some other particle methods such as PFEM and SPH which can be viewed as traditional variational based discretisation methods, the bonded DEM utilises Newton’s second law to provide a set of ordinary differential equations to describe the (dynamic) behaviour of the problem concerned. Crucially, the material properties of the problem are not given as input data, but rather become emerging properties of the DEM model, and thus the calibration of the parameters employed in the bonded DEM becomes crucial. Although some inverse analysis procedures can be followed, some fundamental questions, such as the existence and uniqueness of the model parameters, are still outstanding. Additionally, within classical particle mechanics scaling problems are perceived as a most pressing issue, with computational challenges remaining to enable DEM based methods to simulate macro-scale (industrial-scale)problems within realistic computer resources.
The main theme of this Special Issue is to address some basic computational aspects of the bonded DEM for modelling a continuum and possible discontinuous behaviour. This issue contains seven invited papers presented in the conference;the first two being extended versions of plenary lectures. We hope that these papers make a contribution to the advancement of particle-based methods in general and the bonded DEM in particular.
Y.T. FengGuest Editor
D.R.J. OwenEditor
