Discrete phase method (DPM) model was used to analyse rotary drum systems for segregation behavior. DPM simulations were performed for comparison with a dynamic segregation experimental measurement from the literature. This included dynamic segregation and time-averaged particle velocity field, which were validated with experimental data. In addition, a direct DPM and parcel scaled DPM simulation study

In this paper, an efficient and robust methodology to simulate saturated soils subjected to low-medium frequency dynamic loadings under large deformation regime is presented. The coupling between solid and fluid phases is solved through the dynamic reduced formulation \(u-p_\mathrm{w}\) (solid displacement – pore water pressure) of the Biot’s equations. The additional novelty lies in the employment

Several numerical meshless methods have been proposed to try to solve some of the limitations of traditional mesh-based methods. Among those, the finite pointset method, which has been applied in several physical problems, shows a great potential. This work presents an extension of the available numerical approaches based on the finite pointset method to allow dealing with generalized Newtonian fluids

By utilizing numerical models and simulation, insights about the fracture process of brittle heterogeneous materials can be gained without the need for expensive, difficult, or even impossible, experiments. Brittle and heterogeneous materials like rocks usually exhibit a large spread of experimental data and there is a need for a stochastic model that can mimic this behaviour. In this work, a new numerical

In this work, a robust corrected weakly compressible smoothed particle hydrodynamics scheme combined with several improved interface treatments (CWCSPH-IT) is proposed to investigate viscous or viscoelastic two-phase flows of high density ratios. The proposed viscoelastic two-phase CWCSPH-IT model is mainly derived from three aspects: (a) a combined elastic stress approximation in the momentum equation

In this study, a novel method for improving the simulation of wave propagation in Peridynamic (PD) media is investigated. Initially, the dispersion properties of the nonlocal Bond-Based Peridynamic model are computed for 1-D and 2-D uniform grids. The optimization problem, developed through inverse analysis, is set up by comparing exact and numerical dispersion and minimizing the error. Various weighted

The paper describes the so-called Waterfall Algorithm, which may be used to calculate a set of parameters characterising the spatial structure of granular porous media, such as shift ratio, collision density ratio, consolidation ratio, path length and minimum tortuosity. The study is performed for 1800 different two-dimensional random pore structures. In each geometry, 100 individual paths are calculated

In Japan, the concept of coastal structure design was drastically changed after the Great East Japan Earthquake. In the design of breakwaters, a "resilient" structure is required to prevent a breakwater from fall over damage due to scouring of rubble mound and seabed by tsunami overflows, by installing an additional rubble mound behind the breakwater. The particle method is useful for numerical simulation

Numerical models are widely used for the prediction of stress and strains that the materials undergo in extrusion processes. These factors affect the quality of the extruded product as well as the speed of production process. Due to its meshless nature, the smooth particle hydrodynamics (SPH) method is capable of simulating processes where severe deformations occur. Therefore, it is highly suitable

The superquadric function is employed to represent spherical and non-spherical particles. Although particles with different aspect ratios and surface blockiness can be described using the superquadric equation, the shapes of these particles are geometrically symmetric and further engineering applications are limited. In this work, a poly-superquadric element based on the superquadric function is developed

We present a version of the Discrete Element Method considering the particles as rigid polyhedra. The Principle of Virtual Work is employed as basis for a multibody dynamics model. Each particle surface is split into sub-regions, which are tracked for contact with other sub-regions of neighboring particles. Contact interactions are modeled pointwise, considering vertex-face, edge-edge, vertex-edge

A Correction to this paper has been published: https://doi.org/10.1007/s40571-021-00412-2.

The material point method (MPM) represents an alternative discretization method for numerical simulations. It aims to combine the benefits of a Lagrangian representation of bodies and an Eulerian numerical solution approach. Therefore, especially at high material deformations the method is not prone to mesh distortions such as the finite element method (FEM). For this reason, the MPM is used to a great

Particle methods for high-viscous free-surface flows are of great use to capture flow behaviors which are intermediate between solid and liquid. In general, it is important for numerical methods to satisfy the fundamental laws of physics such as the conservation laws of mass and momentum and the thermodynamic laws. Especially, the angular momentum conservation is necessary to calculate rotational motion

This study presents a modified smoothed particle hydrodynamics (SPH) for modelling liquid-fracture interaction at mesoscale. In this approach, an interparticle force that can provide repulsive force in the short-range and attractive force in the long-range is introduced to model the liquid–liquid and liquid–solid interactions. This interparticle force prevents the SPH particles from clustering and

Dynamic boundary conditions (DBC) for solid surfaces are standard in the weakly compressible smoothed particle hydrodynamics (SPH) code DualSPHysics. A stationary solid is simply represented by fixed particles with pressure from the equation of state. Boundaries are easy to set up and computations are relatively stable and efficient, providing robust numerical simulation for complex geometries. However

The particle dynamics in a flighted rotary drum operated with different numbers of flights and under different operating conditions was simulated by using both the Eulerian (computational fluid dynamics, CFD) and the Lagrangian (discrete element method, DEM) approaches. The simulated solid holdups in the flights as a function of the flights’ tip angular position were compared with experimental data

In this work, a promising fully coupled meshfree numerical approach is extended and implemented for the first time in the field of linear static thermoelasticity. A real meshfree method, the so-called finite pointset method (FPM), is applied and implemented in order to solve the strong/classical form of the governing partial differential equations for static linear thermoelasticity. Several benchmark

This paper covers a numerical analysis of a novel approach to increasing the crashworthiness of double hull ships. As proposed in Schöttelndreyer (Füllstoffe in der Konstruktion: ein Konzept zur Verstärkung vonSchiffsseitenhüllen, Technische Uni-versitt Hamburg, Hamburg, 2015), it involves the usage of granular materials in the cavity of the double hull ship. For the modeling of this problem, the discrete

Granular materials are complex systems whose macroscopic mechanics are governed by particles at the grain-scale. The need to understand their grain-scale behavior has motivated significant experimental and modeling efforts. Bridging the grain-scale with the continuum scale is important in order to develop constitutive theories based on grain-scale behavior, as well as for interpreting the results of

DualSPHysics is a weakly compressible smoothed particle hydrodynamics (SPH) Navier–Stokes solver initially conceived to deal with coastal engineering problems, especially those related to wave impact with coastal structures. Since the first release back in 2011, DualSPHysics has shown to be robust and accurate for simulating extreme wave events along with a continuous improvement in efficiency thanks

In recent years, the use of the smoothed particle hydrodynamics (SPH) method has increased. However, most researches have restricted the application of this method to the fluids field. Few publications have reported the use of SPH to study solid problems. Moreover, only a small amount of investigations have considered the interface when two solids are in contact. The standard SPH method is able to

A new hybrid discrete–continuum numerical approach that explores the key advantages of both discrete and continuum approaches is proposed to model unsaturated seepage flows through porous media. In contrast to existing approaches where a porous medium is often represented by a continuum medium or required a background mesh, the proposed approach explicitly exploits the discrete contact network formed

In this paper, we investigate the application of smoothed particle hydrodynamics (SPH) to the computation of 3-D flows in channels with sudden expansion or contraction. In the same context, we also discuss 2-D SPH computations applicable to channels characterized by cross-sections of large aspect ratios. The particle nature of SPH allows us to treat macro-systems similarly to atomic systems, transferring

This paper presents a novel approach to numerical modelling of selective laser melting (SLM) processes characterized by melting and solidification of the deposited particulate material. The approach is based entirely on two homogeneous methods, such as cellular automata and Lattice Boltzmann. The model components operate in the common domain allowing for linking them into a more complex holistic numerical

Each damage of cement mixture is closely related to the heterogeneity and discontinuity of its internal materials. It is very important to analyze the mechanical evolution behavior of cement mixture with the theory of meso-mechanics to reveal the failure mechanism of cement mixture structure. In this paper, the microscopic parameters of the discrete element model are obtained in the compressive tests

ParticLS (Particle Level Sets) is a software library that implements the discrete element method (DEM) and meshfree methods. ParticLS tracks the interaction between individual particles whose geometries are defined by level sets capable of capturing complex shapes. These particles either represent rigid bodies or material points within a continuum. Particle-particle interactions using various contact

We discuss the relevance of the lattice Boltzmann method (LBM) for soft matter alongside other simulation methods. We set up a popular problem of self-assembly of Janus spheres by combining native fluid and particle models in LBM with a simple amphiphilic pair potential. Thermal fluctuations and close contact corrections are also incorporated along with a novel periodic boundary condition for finite-sized

Soft particle materials such as some pharmaceutical and food products are composed of particles that can undergo large deformations under low confining pressures without rupture. The rheological and textural properties of these materials are thus governed by both particle rearrangements and particle shape changes. For the simulation of soft particle materials, we present a numerical technique based

To investigate the rock particle breakage behavior subject to impact load, a series of split Hopkinson pressure bar (SHPB) tests were conducted on selected Nishan rock and Shoushan rock particles within gravel size range at different strain rates. Both rock particles exhibit a typical strain softening macrobehavior and their dynamic peak strengths increase with strain rate. A dynamic increasing factor

In this paper, we use a 2D bond-based peridynamic model to investigate the strength of disk-shaped particles including pre-cracks. We use a diametral (or Brazilian) test to break the particles. For the flawless particles, we find that the stress distribution compares well with an analytical model accounting for the size of the contact zone, and the particle stiffness tends linearly to a well-defined

The peridynamic theory of solid mechanics is applied to modeling the deformation and fracture of micrometer-sized particles made of organic crystalline material. A new peridynamic material model is proposed to reproduce the elastic–plastic response, creep, and fracture that are observed in experiments. The model is implemented in a three-dimensional, meshless Lagrangian simulation code. In the small

A numerical analysis is validated against a Swiss Federal Commission for Technology and Innovation (CTI)—frame impact experiment conducted by the Swiss Company Geobrugg. The discrete element method is used to simulate the impacting object, while the highly nonlinear structural response is analysed with the finite element method. Both methods are coupled within an open-source multi-physics research

The impingement of a droplet on a rigid square obstacle in a microchannel is simulated numerically using a high-density-ratio pseudo-potential multi-relaxation time LBM. The effects of Reynolds (Re) number, Weber (We) number, contact angle, obstacle size and kinematic viscosity ratio on the droplet dynamics after impact are investigated. It was found that the formation of the liquid film around the

We investigate the use of reduced-order modelling to run discrete element simulations at higher speeds. Taking a data-driven approach, we run many offline simulations in advance and train a model to predict the velocity field from the mass distribution and system control signals. Rapid model inference of particle velocities replaces the intense process of computing contact forces and velocity updates

In this work, we explore the underlying structure of most common bond models used in particle dynamics and discrete element methods, to derive simple equilibrium conditions and stability requirements that must be fulfilled for a model to stand effective and reliable. We then propose a simple model taking into account such considerations, with which we are able to capture inter-particle bonding very

This paper presents a new Smooth Particle Hydrodynamics computational framework for the solution of inviscid free surface flow problems. The formulation is based on the Total Lagrangian description of a system of first-order conservation laws written in terms of the linear momentum and the Jacobian of the deformation. One of the aims of this paper is to explore the use of Total Lagrangian description

The multi-phase flow of air and bio-particulate matter exists in many biological and environmental systems such as aerodynamic separating devices, fluidized bed combustion, and feed processing machinery. Integration of the computational fluid dynamics (CFD) and discrete element method (DEM) codes was performed to study bio-particle loading ratios' effect on the cyclone device performance. Every individual

VisualSPHysics, an open-source tool for creating realistic visualizations of smoothed particle hydrodynamics (SPH) simulations, is presented here. The proposed approach is used to import SPH simulations (from DualSPHysics code) into 3D graphics software (Blender) and supports a wide range of visual effects (realistic lighting and materials, texturing, motion blur and foam simulation). The tool features

Current discrete/lattice methods can simulate a continuous mechanical behavior thanks to a network of bonds. The main drawback of these approaches is the need of a calibration process to link the emerging behavior of the structure and the parameters of the local mechanical bond. It is proposed in this work to use a fast and recent reduction model technique to build once and for all an exhaustive data

The aim of this work is to understand the granular behavior of metal powder during the spreading phase of the LBM process in order to study the effect of powder properties and process parameters on the quality of the layer deposited before laser fusion. This is a numerical work performed with simulations based on the discrete element method where each powder grain is simulated. The numerical model

Granular materials have been widely used in the field of geotechnical engineering. Being one of the intrinsic properties of granular materials, the internal grain porosity greatly affects their mechanical properties, grain crushing in particular. In this article, the single porous grains with different degrees of disordered pore distribution were generated and fully investigated with discrete element

In high geostress areas, rocks tend to experience plastic deformation processes and show ductility. Therefore, the study of the mechanical properties of rocks, especially the post-peak behavior, is crucial for underground geotechnical engineering. For this reason, the macroscopic mechanical property of marble is studied by using the PFC/PBM numerical method. An improved numerical marble sample with

We outline a phenomenological model to assess friction at the interface between two bodies in mutual contact. Although the approach is general, the application inspiring the approach is the discrete element method. The kinematics of the friction process is expressed in terms of the relative 3D motion of the contact point on the two surfaces in mutual contact. The model produces expressions for three

This work presents a discrete element model (DEM) of the impeller–tumbler wear test in order to investigate high-stress impact–abrasion mechanisms on steel plates with the use of abrasive granite particles. A DEM calibration procedure of the granite particles is first performed to set particle-scale DEM parameters such as particle shape, density and frictions. The simulations of the impeller–tumbler

The purpose of this paper is to present a methodology for obtaining granular models from a GPU parallel implementation of the geometric separation particle packing strategy. This methodology is suitable for the generation of large-scale granular models used in discontinuous media simulations. The proposed approach uses disk-shaped particles (two-dimensional approach) and parallelization mechanisms

Coronavirus causes some illnesses to include cold, COVID-19, MERS, and SARS. This virus can be transmitted through contact with different atomic matrix between humans. So, this atomic is essential in medical cases. In this work, we describe the atomic manner of this virus in contact with various metallic matrix such as Fe, Al, and steel with equilibrium molecular dynamic method. For this purpose, we

A new constructive method, called optimized advance front method (OAFM), for ellipse packing is proposed. The OAFM allows particle rotation at several angles and movement along a local advance front. Combined with the ellipse approximated by four connected arcs and a series of sequential coordinate transformations, the OAFM generates dense ellipse packing with any imposed size, aspect ratio, and orientation

In this study, a new methodology for coupling smoothed particle hydrodynamics (SPH) and the Voronoi-cell lattice model (VCLM) is proposed for simulating fluid–structure interaction (FSI). Free-surface flow of the fluid is modeled using SPH; the structural components are modeled by the VCLM, which accounts for both geometric and material nonlinear behaviors. The FSI algorithm is effective regardless

In this study, moving least square (MLS) shape functions are employed to reduce the cell-crossing error occurred in conventional material point method (MPM) when material particles pass through grid cell boundaries. The level of smoothness of MLS shape functions for mapping information from material particles to a background grid can be controlled by the support size of MLS weight functions. A simple

Among other numerical issues, it is well known that the finite element method (FEM) lacks objectivity in reproducing high deformation rates due to extreme external actions. In geotechnical applications, the coupling of large solid deformations with the pore fluid flow is a critical subject, being one of the multiple scenarios where FEM could have restricted applications. In order to overcome the aforementioned

Rope shovels and other heavy mining equipment used for loading fragmented rocks to extract minerals from the earth are used in almost every open pit mine. The optimization of the loading process is of enormous value due to the extremely large amount of material turn over. In this work, a full-scale numerical model of the loading process is developed. Granular material of copper ore is modeled in a

The material point method (MPM) has been increasingly used to simulate coupled hydro-mechanical problems involving large deformations. However, when addressing saturated porous media with an almost incompressible liquid phase, the classic explicit MPM with low-order interpolation functions is not stable if no further stabilization approach is used. In this study, a solid-velocity–liquid-velocity-based

A simple and robust C++ code for the material point method (MPM) called Karamelo is presented here. It was designed to provide an open source, fast, light and easy-to-modify framework for both conducting research on the MPM and research using the MPM, instead of a finite element package. This paper presents the overall philosophy, the main design choices and some of the original algorithms implemented

The FOSS CFD-SPH code SPHERA v.9.0.0 (RSE SpA) is improved to deal with “fluid–solid body” interactions under no-slip conditions and laminar regimes for the simulation of hydrodynamic lubrication. The code is herein validated in relation to a uniform slider bearing (i.e. for a constant lubricant film depth) and a linear slider bearing (i.e. for a film depth with a linear profile variation along the

Masonry arches are usually composed of individual blocks or voussoirs, which are highly discontinuous and nonlinear, and it is extremely difficult or even impossible to simulate their collapse behavior using finite element methods. Therefore, a combined finite–discrete element method (FDEM) is employed to simulate the collapse behavior of dry-joint masonry arches induced by spreading supports. With

Discrete element modeling (DEM) of polydisperse granular materials is significantly more computationally expensive than modeling of monodisperse materials as a larger number of particles are required to obtain a representative elementary volume, and standard contact detection algorithms become progressively less efficient with polydispersity. This paper presents modified contact detection and inter-processor

This paper presents a brief review of grand challenges of Smoothed Particle Hydrodynamics (SPH) method. As a meshless method, SPH can simulate a large range of applications from astrophysics to free-surface flows, to complex mixing problems in industry and has had notable successes. As a young computational method, the SPH method still requires development to address important elements which prevent

The discrete element method (DEM) is a general discrete modeling technique traditionally used to model granular material and discontinuous phenomena such as fracture and fragmentation of solids. We investigate the efficacy of DEM to model deformable elastic continua, cantilever beams in particular, and describe their mechanical behavior under loading. Of distinct interest is the ability of DEM to capture