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1 – 10 of over 1000The purpose of this paper is to propose a novel quasi-nonlocal coupling of the bond-based peridynamic model with the classical continuum mechanics model to fully take advantage of…
Abstract
Purpose
The purpose of this paper is to propose a novel quasi-nonlocal coupling of the bond-based peridynamic model with the classical continuum mechanics model to fully take advantage of their merits and be free of ghost forces.
Design/methodology/approach
This study reconstructs a total energy functional by introducing a coupling parameter that alters only the nonlocal interactions in the coupling region rather than the whole region and a modified elasticity tensor that affects the local interactions. Then, the consistency of force patch test is enforced in the coupling region to completely eliminate the ghost force in a general energy-based coupling scheme. For a one-dimensional problem, these coupling parameters are further determined through an energy patch test to preserve the energy equivalence or through an l1-regularization. And, for a two- or three-dimensional problem, depending on the existence of a solution to the discretized force patch test, they are determined through an l1-minimization or l1-regularization.
Findings
One- and two-dimensional numerical examples under affine deformation have been conducted to verify the accuracy of the quasi-nonlocal coupling method, which exhibits no ghost force. Moreover, the coupling model can reproduce almost the same deformation behaviors of points near the crack for a cracked plate under tension as that from a pure peridynamic model, the former with a rather low computational cost and an easier application of boundary conditions.
Originality/value
This work is aiming at getting over long-standing ghost force issues in the energy-based coupling scheme. The numerical results from the cracked plate problem are exhibited promising extension to dynamic problems.
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Beichuan Yan, Richard A. Regueiro and Stein Sture
The purpose of this paper is to develop a discrete element (DE) and multiscale modeling methodology to represent granular media at their particle scale as they interface solid…
Abstract
Purpose
The purpose of this paper is to develop a discrete element (DE) and multiscale modeling methodology to represent granular media at their particle scale as they interface solid deformable bodies, such as soil‐tool, tire, penetrometer, pile, etc., interfaces.
Design/methodology/approach
A three‐dimensional ellipsoidal discrete element method (DEM) is developed to more physically represent particle shape in granular media while retaining the efficiency of smooth contact interface conditions for computation. DE coupling to finite element (FE) facets is presented to demonstrate initially the development of overlapping bridging scale methods for concurrent multiscale modeling of granular media.
Findings
A closed‐form solution of ellipsoidal particle contact resolution and stiffness is presented and demonstrated for two particle, and many particle contact simulations, during gravity deposition, and quasi‐static oedometer, triaxial compression, and pile penetration. The DE‐FE facet coupling demonstrates the potential to alleviate artificial boundary effects in the shear deformation region between DEM granular media and deformable solid bodies.
Research limitations/implications
The research is being extended to couple more robustly the ellipsoidal DEM code and a higher order continuum FE code via overlapping bridging scale methods, in order to remove dependence of penetration/shear resistance on the boundary placement for DE simulation.
Practical implications
When concurrent multiscale computational modeling of interface conditions between deformable solid bodies and granular materials reaches maturity, modelers will be able to simulate the mechanical behavior accounting for physical particle sizes and flow in the interface region, and thus design their tool, tire, penetrometer, or pile accordingly.
Originality/value
A closed‐form solution for ellipsoidal particle contact is demonstrated in this paper, and the ability to couple DE to FE facets.
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Arman Shojaei, Mirco Zaccariotto and Ugo Galvanetto
The paper aims to use a switching technique which allows to couple a nonlocal bond-based Peridynamic approach to the Meshless Local Exponential Basis Functions (MLEBF) method…
Abstract
Purpose
The paper aims to use a switching technique which allows to couple a nonlocal bond-based Peridynamic approach to the Meshless Local Exponential Basis Functions (MLEBF) method, based on classical continuum mechanics, to solve planar problems.
Design/methodology/approach
The coupling has been achieved in a completely meshless scheme. The domain is divided in three zones: one in which only Peridynamics is applied, one in which only the meshless method is applied and a transition zone where a gradual transition between the two approaches takes place.
Findings
The new coupling technique generates overall grids that are not affected by ghost forces. Moreover, the use of the meshless approach can be limited to a narrow boundary region of the domain, and in this way, it can be used to remove the “surface effect” from the Peridynamic solution applied to all internal points.
Originality/value
The current study paves the road for future studies on dynamic and static crack propagation problems.
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Andrea Prothero and Pierre McDonagh
This paper adopts a photo-essay approach in examining the Austerity Project within the Republic of Ireland, and considers the intersection between consumer culture and the…
Abstract
Purpose
This paper adopts a photo-essay approach in examining the Austerity Project within the Republic of Ireland, and considers the intersection between consumer culture and the austerity visuals we experience daily.
Methodology/approach
A visual, photo-essay method is adopted. Visual images taken in urban and rural parts of Ireland – under the key themes of ghost housing estates, failed commercial property developments, failed business, and art representations are explored.
Findings
The visual representations and subsequent consumption activities of the authors illustrate how austerity has become a complex act of production and consumption, and the authors consider how these various representations play a role in creating austerity as a state of mind amongst consumers, and the subsequent impact this has on consumption practices, consumer experiences, ideals and identities.
Originality/value
This paper adopts an under-represented research methodology (a photo-essay) to explore the Austerity Project and its intersections with consumer culture.
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Amirmahdi Ghasemi, R. Nikbakhti, Amirreza Ghasemi, Faraz Hedayati and Amir Malvandi
A numerical method is developed to capture the interaction of solid object with two-phase flow with high density ratios. The current computational tool would be the first step of…
Abstract
Purpose
A numerical method is developed to capture the interaction of solid object with two-phase flow with high density ratios. The current computational tool would be the first step of accurate modeling of wave energy converters in which the immense energy of the ocean can be extracted at low cost.
Design/methodology/approach
The full two-dimensional Navier–Stokes equations are discretized on a regular structured grid, and the two-step projection method along with multi-processing (OpenMP) is used to efficiently solve the flow equations. The level set and the immersed boundary methods are used to capture the free surface of a fluid and a solid object, respectively. The full two-dimensional Navier–Stokes equations are solved on a regular structured grid to resolve the flow field. Level set and immersed boundary methods are used to capture the free surface of liquid and solid object, respectively. A proper contact angle between the solid object and the fluid is used to enhance the accuracy of the advection of the mass and momentum of the fluids in three-phase cells.
Findings
The computational tool is verified based on numerical and experimental data with two scenarios: a cylinder falling into a rectangular domain due to gravity and a dam breaking in the presence of a fixed obstacle. In the former validation simulation, the accuracy of the immersed boundary method is verified. However, the accuracy of the level set method while the computational tool can model the high-density ratio is confirmed in the dam-breaking simulation. The results obtained from the current method are in good agreement with experimental data and other numerical studies.
Practical/implications
The computational tool is capable of being parallelized to reduce the computational cost; therefore, an OpenMP is used to solve the flow equations. Its application is seen in the following: wind energy conversion, interaction of solid object such as wind turbine with water waves, etc.
Originality/value
A high efficient CFD approach method is introduced to capture the interaction of solid object with a two-phase flow where they have high-density ratio. The current method has the ability to efficiently be parallelized.
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Employing the Star Wars brand as a case study, this paper seeks to critically discuss the importance of comparative mythology for inter-generational branding and consumption…
Abstract
Purpose
Employing the Star Wars brand as a case study, this paper seeks to critically discuss the importance of comparative mythology for inter-generational branding and consumption practices within arts related markets.
Design/methodology/approach
Secondary data have been gathered focusing on the analysis of material in the form of books, academic journals, films, videos, television programs, websites and media reports related to the interface between comparative mythology, the Star Wars brand.
Findings
First, this paper indicates how the long-standing success of the Star Wars brand mirrors and reflects the power of monomythic storytelling in creating a platform for arts and place building branding associations and extensions for numerous products and services. Second, this study shows and highlights the potential of monomythic structures/storytelling and comparative mythology in acting an underlying cultural platform whereupon several arts brand associations, narratives, extensions and overall strategies can emerge. Finally, this project suggests how arts marketing scholars could further explore the infusion of mythological narratives within branding practices in the areas of performing/visual arts, museums, entertainment and arts related tourism campaigns.
Originality/value
Focusing on the most successful film franchise of all times, this study argues that comparative mythology constitutes an endless source for common templates of artistic, cross-cultural and inter-generational marketing practices focusing on universal moral codes and archetypes.
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