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This paper investigates the influence of aggregate shape on the diffusivity of mortar in three dimensions by random packing models of ellipsoidal and convex polyhedral particles. From a digital mesostructure and by a lattice approach, the diffusivity of mortar can be predicted. Simulations are compared with experimental results from literature and are discussed for mono-sized and multi-sized particle packing with and without interfacial transition zones (ITZ). It was found that the shape of aggregate has a significant effect on the diffusivity of mortar, and for oblate ellipsoids, the shape effect is most pronounced comparing to prolate ellipsoids and polyhedrons. [ABSTRACT FROM AUTHOR]

Abstract: In this paper we present thermo-plasticity model for dealing with localized failure with softening, which is capable of accounting for mechanical loading and heat transfer simultaneously. The main point concerns the localized failure of the structure which results with heterogeneity of stress and strain field for temperature dependent properties. We discuss how to employ structured mesh for such case, and construct the appropriate enhancements of the displacement and temperature fields by using the finite element method with embedded discontinuities (ED-FEM). For clarity, we first consider 1D case, and provide several illustrative numerical simulations. We then provide the corresponding generalization of the proposed model to 2D case and its numerical implementation based upon structured ED-FEM mesh. [Copyright &y& Elsevier]

Abstract: Coupled electro-mechanical problems are frequently encountered when dealing with micro electro-mechanical systems (MEMS) with capacitive actuation and/or readout systems; their numerical solution can be extremely time consuming, due to the nonlinearity of the coupling terms. Coupled electrostatic – structural dynamic simulations are carried out in this paper through an innovative numerical procedure, based on the combined use of a domain decomposition technique and of a proper orthogonal decomposition methodology. The approach is assessed through the analysis of the dynamic response of a doubly clamped beam and of a plane resonator subjected to an electrostatic actuation, showing computational gains up to 98%. [Copyright &y& Elsevier]

Abstract: This paper introduces an original model to simulate the bond failure between concrete and reinforcing steel bars. The model was developed to be used in threedimensional analyses within the framework of the Finite Element Method and for general loading cases. It was designed using a hierarchical approach by combining what is called the base model, which acts as the skeleton of the model and introduces the basic response under monotonic and reversed loading, and four independent and optional sub-models used to enhance the simulation when needed, by considering the cyclic resistance degradation, the peak stress slip evolution, the reload slip evolution and the radial stress effect. The model implementation within the framework of the Finite Element Method is described and its accuracy is assessed using a series of validation tests. At the end, the main conclusions extracted from this work are presented. [Copyright &y& Elsevier]

Abstract: This paper describes features of a fully coupled thermo-mechanical model for Friction Stir Welding (FSW) simulation. An apropos kinematic setting for different zones of the computational domain is introduced and an efficient coupling strategy is proposed. Heat generation via viscous dissipation as well as frictional heating is considered. The results of the simulation using the proposed model are compared with the experimental evidence. The effect of slip and stick condition on non-circular pin shapes is analyzed. Simulation of material stirring is also carried out via particle tracing, providing insight of the material flow pattern in the vicinity of the pin. [Copyright &y& Elsevier]

Abstract: The main objective of the paper is to present the computational model of a bi-cable aerial ropeway, which provides a scope for investigating the nonlinear interaction between the carrying cable motion and the swaying motion of traveling passenger carriers, depending on cable track inclination. To solve nonlinear equations of motion of two coupled sub-systems: multi-span cable and carriers idealized as physical pendulums, the special numerical method is developed, where initial vibrations of carriers (before entering a cable track) are used as a base for predicting further history of motion. Numerical analysis performed for different inclinations of a cable track led to the conclusion that nonlinear interaction effects are not significant and can be neglected to simplify the computational procedure in further research. [Copyright &y& Elsevier]

Abstract: Mid-frequency response analysis often faces computational difficulties when a conventional modal approach is used for a finite element linear system. In this paper, the computational burden is relieved by frequency sweep algorithm or mode acceleration method for a reduced-order system constructed by algebraic substructuring, a variant of model order reduction. The two methods are compared with the help of numerical experiments and their computational complexity. As demonstrated by the finite element simulations, in which proportional damping is assumed, of a turbo-prop aircraft and a ring resonator, the frequency sweep algorithm for reduced-order systems shows the best performance among all considered numerical solutions, including the conventional approach. [Copyright &y& Elsevier]

Abstract: In this paper, sloshing waves have been analyzed for baffled and un-baffled tanks. Numerical simulations were carried out based on volume of fluid (VOF) techniques with arbitrary-Lagrangian–Eulerian (ALE) formulation which adopts the displacement of solid, the pressure and displacement in the fluid as variables to model the coupled system. The response of the coupled system is obtained by using the well-known software ADINA, which offers efficient fully coupled fluid–structure interaction capabilities by finite element method. The results obtained are compared with the available experimental data to demonstrate the reduction of sloshing effects in fluid model. [Copyright &y& Elsevier]

This paper presents a Petrov–Galerkin natural element method for the nonlinear analysis of 2-D dynamic contact problems without friction. The frictionless dynamic contact problem is formulated according to the linearized total Lagrangian method incorporated with the linearized penalty method. The displacement increment is approximated with Laplace interpolation functions defined with the help of Voronoi polygons, while the admissible virtual displacement is expanded with constant strain functions which are supported on Delaunay triangles. The spatial numerical integration is carried out by applying the conventional Gauss quadrature rule to Delaunay triangles and the temporal time integration is performed by the implicit Newmark method. The validity of the proposed method is examined through the illustrating numerical experiments. [Copyright &y& Elsevier]

A moving rail vehicle may cause propagating waves to the surroundings potentially leading to detrimental effects for the track construction, nuisances for the surroundings and interference with delicate electronic equipment. A full computational model should be able to couple a correct simulation of the rigid body motion of the different train parts with accurate prediction of the solid wave propagation in the ground. This paper integrates the dynamics of the vehicle and the elastic soil into one monolithic system. Equations of motion for the train have been merged the system representing the FEM problem for the rest of the structure. Three models of modern high-speed locomotives were run over a solid finite element model of a rail structure. [Copyright &y& Elsevier]