54 results on '"Eremeyev, Victor A."'
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2. On strength analysis of highly porous materials within the framework of the micropolar elasticity
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Eremeyev, Victor A., Skrzat, Andrzej, Stachowicz, Feliks, and Vinakurava, Anastasia
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- 2017
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3. On the Elastic Plates and Shells with Residual Surface Stresses
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Altenbach, Holm and Eremeyev, Victor A.
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- 2017
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4. On effective surface elastic moduli for microstructured strongly anisotropic coatings.
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Eremeyev, Victor A., Rosi, Giuseppe, and Naili, Salah
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THEORY of wave motion , *ELASTIC modulus , *DISPERSION relations , *ENERGY function , *STRAIN energy - Abstract
The determination of surface elastic moduli is discussed in the context of a recently proposed strongly anisotropic surface elasticity model. The aim of the model was to describe deformations of solids with thin elastic coatings associated with so-called hyperbolic metasurfaces. These metasurfaces can exhibit a quite unusual behaviour and concurrently a very promising wave propagation behaviour. In the model of strongly anisotropic surface elasticity, strain energy as a function of the first and second deformation gradients has been introduced in addition to the constitutive relations in the bulk. In order to obtain values of surface elastic moduli, we compare dispersion relations for anti-plane surface waves obtained using the two-dimensional (2D) model and three-dimensional (3D) straightforward calculations for microstructured coatings of finite thickness. We show that with derived effective surface moduli, the 2D model can correctly describe the wave propagation. [ABSTRACT FROM AUTHOR]
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- 2024
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5. On nonlinear rheology of masonries and granular media.
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Reccia, Emanuele and Eremeyev, Victor A.
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MASONRY , *BRICKS , *DEFORMATIONS (Mechanics) - Abstract
We introduce a new rheological nonlinear model for some granular media such as masonries. The latter may demonstrate a rather complex behaviour. In fact, considering a masonry one can see that relative rotations of bricks are most important in comparison with deformation of bricks themselves. As a result, one gets stresses and couple stresses as static characteristics of such a medium. Using the Cosserat point approach for modelling of orientational interactions between masonry elements we provide a deformation energy for such a medium which takes into account both material and geometrical nonlinearity. [ABSTRACT FROM AUTHOR]
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- 2024
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6. Surface finite viscoelasticity and surface anti-plane waves.
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Eremeyev, Victor A.
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ACOUSTIC surface waves , *DISPERSION relations , *RELAXATION phenomena , *VISCOELASTICITY , *STRESS relaxation (Mechanics) - Abstract
We introduce the surface viscoelasticity under finite deformations. The theory is straightforward generalization of the Gurtin–Murdoch model to materials with fading memory. Surface viscoelasticity may reflect some surface related creep/stress relaxation phenomena observed at small scales. Discussed model could also describe thin inelastic coatings or thin interfacial layers. The constitutive equations for surface stresses are proposed. As an example we discuss propagation shear (anti-plane) waves in media with surface stresses taking into account viscoelastic effects. Here we analysed surface waves in an elastic half-space with viscoelastic coatings. Dispersion relations were derived. [ABSTRACT FROM AUTHOR]
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- 2024
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7. M-integral for finite anti-plane shear of a nonlinear elastic matrix with rigid inclusions.
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Eremeyev, Victor A. and Naumenko, Konstantin
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SHEAR (Mechanics) , *SHEARING force - Abstract
The path-independent M-integral plays an important role in analysis of solids with inhomogeneities. However, the available applications are almost limited to linear-elastic or physically non-linear power law type materials under the assumption of infinitesimal strains. In this paper we formulate the M-integral for a class of hyperelastic solids undergoing finite anti-plane shear deformation. As an application we consider the problem of rigid inclusions embedded in a Mooney–Rivlin matrix material. With the derived M-integral we compute weighted averages of the shear stress acting on the inclusion surface. Furthermore, we prove that a system of rigid inclusions can be replaced by one effective inclusion. [ABSTRACT FROM AUTHOR]
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- 2024
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8. On rotary inertia of microstuctured beams and variations thereof.
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Eremeyev, Victor A. and Elishakoff, Isaac
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METAMATERIALS , *MICROSTRUCTURE , *KINEMATICS , *DEFORMATIONS (Mechanics) , *ROTATIONAL motion - Abstract
We discuss the classic rotary inertia notion and extend it for microstructured beams introducing new microinertia parameters as an additional dynamic response to microstructure changes. Slender structures made of beam- or platelet-lattice metamaterials may exhibit not only large translations and rotations but also general deformations of inner structure. Here we considered a few examples of beam-like structures and derive their inertia properties which include effective mass density, rotary inertia and microinertia. Extended dynamic characteristics related to enhanced kinematics may be crucial for description of origami-like structures or other beam-lattice metamaterials. • Rotary inertia and its extensions for a few microstructured beams was discussed. • Rotary inertia and microinertia maybe dominant for some microstructures. • Rotary and microinertia may essentially depend on deformations. • Correspondence to other generalized models of slender structures and media is given. [ABSTRACT FROM AUTHOR]
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- 2024
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9. On the material symmetry group for micromorphic media with applications to granular materials.
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Eremeyev, Victor A.
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GRANULAR materials , *CONTINUUM mechanics , *FLUID dynamics , *NONLINEAR systems , *ELASTICITY - Abstract
Highlights • New definition of the local material symmetry group within the nonlinear micromorphic continuum. • Definitions of micromorphic solids, fluids and subfluids. • Granular material as a micromorphic subfluid. Abstract Within the framework of the theory of nonlinear elastic micromorphic continua we introduce the new definition of the local material symmetry group. The group consists of ordered triples of second- and third-order tensors describing such changes of a reference placement that cannot be recognized with any experiment. Using the definition we characterize the micromorphic isotropic media, micromorphic fluids, solids and special intermediate cases called micromorphic subfluids or micromorphic liquid crystals. We demonstrate that some typical behaviour of such complex media as granular materials can be described within the micromorphic subfluids mechanics. [ABSTRACT FROM AUTHOR]
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- 2018
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10. Can we really solve an arch stability problem?
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Chróścielewski, Jacek and Eremeyev, Victor A.
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ARCHES , *NONLINEAR equations , *BOUNDARY value problems , *PROBLEM solving - Abstract
We bring attention to the problem of solving nonlinear boundary-value problems for elastic structures such as arches and shells. Here we discuss a classical problem of a shear-deformable arch postbuckling. Considering a postbuckling behaviour of a circular arch we discuss the possibility to find numerically a solution for highly nonlinear regimes. The main attention is paid to the problem of determination of all solutions. The main conclusion that there is no guarantee to find all solutions, in general. [ABSTRACT FROM AUTHOR]
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- 2024
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11. On dynamics of origami-inspired rod.
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Berinskii, Igor and Eremeyev, Victor A.
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DISPERSION relations , *NONDESTRUCTIVE testing , *EQUATIONS of motion , *THEORY of wave motion , *ORIGAMI , *MOTION - Abstract
We discuss the dynamics of a relatively simple origami-inspired structure considering discrete and continuum models. The latter was derived as a certain limit of the discrete model. Here we analyze small in-plane deformations and related equations of infinitesimal motions. For both models, dispersion relations were derived and compared. The comparison of the dispersion relations showed that the continuum model can capture the behavior of origami structures, which can be helpful in the materials properties determination and nondestructive evaluation. [ABSTRACT FROM AUTHOR]
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- 2023
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12. Acceleration waves in the nonlinear micromorphic continuum.
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Eremeyev, Victor A., Lebedev, Leonid P., and Cloud, Michael J.
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ACCELERATION waves , *ELASTICITY , *NONLINEAR mechanics , *TENSOR products , *ENGINEERING - Abstract
Highlights • Acceleration waves in the nonlinear micromorphic medium are studied. • The formulas for the acoustic tensors are derived. • For the relaxed micromorphic continuum, the strong ellipticity condition is violated. Abstract Within the framework of the nonlinear elastic theory of micromorphic continua we derive the conditions for propagation of acceleration waves. An acceleration wave, also called a wave of weak discontinuity of order two, can be treated as a propagating nonmaterial surface across which the second derivatives of the placement vector and micro-distortion tensor may undergo jump discontinuities. Here we obtain the acoustic tensor for the micromorphic medium and formulate the conditions for existence of acceleration waves. As examples we consider these conditions for the linear micromorphic medium and for the relaxed micromorphic model. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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13. Anti-plane surface waves in media with surface structure: Discrete vs. continuum model.
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Eremeyev, Victor A. and Sharma, Basant Lal
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SURFACE structure - Abstract
We present a comparison of the dispersion relations derived for anti-plane surface waves using the two distinct approaches of the surface elasticity vis-a-vis the lattice dynamics. We consider an elastic half-space with surface stresses described within the Gurtin–Murdoch model, and present a formulation of its discrete counterpart that is a square lattice half-plane with surface row of particles having mass and elastic bonds different from the ones in the bulk. As both models possess anti-plane surface waves we discuss similarities between the continuum and discrete viewpoint. In particular, in the context of the behaviour of phase velocity, we discuss the possible characterization of the surface shear modulus through the parameters involved in lattice formulation. [ABSTRACT FROM AUTHOR]
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- 2019
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14. Ellipticity of gradient poroelasticity.
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Eremeyev, Victor A.
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STRAINS & stresses (Mechanics) , *ELLIPTIC equations , *ELASTICITY , *ENERGY density , *EQUILIBRIUM , *POROELASTICITY - Abstract
We discuss the ellipticity properties of an enhanced model of poroelastic continua called dilatational strain gradient elasticity. Within the theory there exists a deformation energy density given as a function of strains and gradient of dilatation. We show that the equilibrium equations are elliptic in the sense of Douglis–Nirenberg. These conditions are more general than the ordinary and strong ellipticity but keep almost all necessary properties of equilibrium equations. In particular, the loss of the ellipticity could be considered as a criterion of a strain localization or material instability. [ABSTRACT FROM AUTHOR]
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- 2023
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15. A layer-wise theory of shallow shells with thin soft core for laminated glass and photovoltaic applications.
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Naumenko, Konstantin and Eremeyev, Victor A.
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PHOTOVOLTAIC cells , *LAMINATED glass , *THIN films , *DIFFERENTIAL equations , *GLASS construction - Abstract
The aim of this paper is to develop a robust layer-wise theory for structural analysis of curved glass and photovoltaic panels. By the analogy to the existing theories of plates, governing equations for doubly curved layers including kinematic relations, equilibrium conditions and constitutive equations are introduced. Applying assumptions of shear rigidity of skin layers and moments-free core layer as well as approximations of thin shallow shell, a reduced form of governing differential equations is proposed. Compared to the classical theories of shells the derived system includes an additional second order differential equation. As a result, additional boundary conditions should be satisfied for any edge of the shell. The importance of these extensions is demonstrated for long cylindrical panel with for two examples of simple supports: one with free edges, where relative in-plane displacements of skins are allowed, and one with framed edges, where cross-section rotations of all layers are assumed the same. For both cases closed-form analytical solutions related to a shell strip approximation are presented. Displacement bounds in monolithic and layered cases are derived, and the dependence of deformation and stress characteristics on the radius of curvature and types of supports are illustrated. [ABSTRACT FROM AUTHOR]
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- 2017
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16. Surface/interfacial anti-plane waves in solids with surface energy.
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Eremeyev, Victor A., Rosi, Giuseppe, and Naili, Salah
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SURFACE energy , *PLANE wavefronts , *SOLIDS , *ELASTICITY , *STRAINS & stresses (Mechanics) , *KINETIC energy - Abstract
In this paper we discuss new type of surface anti-plane waves localized near the surface an elastic half-space and in the vicinity of plane interface between two half-spaces, when considering surface strain and kinetic energies. We also consider the case of non-perfect interface, i.e. when a jump of displacement or of its gradient, with the aim of modelling lacking of adhesion between solids. The phase velocity profiles and dispersion relations of surface waves are presented and several different material parameters are considered. Among the results, we observe an anomalous dispersion when the surface/interface is stiffer than the bulk material. These results can be exploited for the nondestructive characterization and the analysis of thin inter-phases between two solids, and can find several engineering applications. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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17. The effect of shear deformations' rotary inertia on the vibrating response of multi-physic composite beam-like actuators.
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Malikan, Mohammad and Eremeyev, Victor A.
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SHEAR (Mechanics) , *COMPOSITE construction , *ACTUATORS , *LAXATIVES , *ELASTICITY - Abstract
In the present work, the flexomagnetic (FM) behaviour of a vibrating squared multi-physic beam in finite dimensions. It is assumed that the bending and shear deformations cause rotary inertia. In the standard type of the Timoshenko beam the rotary inertia originated from shear deformations has been typically omitted. It means the rotary inertia resulting from shear deformation is a new concept considered here. Thus, the novelty in this work is that the effect of shear deformation's rotary inertia (SDRI) on the FM response will be considered in detail. When it comes to nanosize, the well-posed nonlocal elasticity assumption of Eringen can be worth choosing. In this study, the weak form (differential) of strain-driven nonlocal theory is taken into hand for easiness. The procedure of solution will be in regard to the advantage of the Galerkin weighted residual technique based on an analytical flow for the meta beam located at simply-simply supported ends. Several separate studies will show how SDRI and FM can influence each other. The observations give some new achievements in the series of studies on FM. It has been earned that the SDRI can directly impress the flexomagnetic feature of small-scale actuators. [ABSTRACT FROM AUTHOR]
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- 2022
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18. Nonlinear strain gradient and micromorphic one-dimensional elastic continua: Comparison through strong ellipticity conditions.
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Eremeyev, Victor A. and Reccia, Emanuele
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STRAINS & stresses (Mechanics) , *ELASTICITY - Abstract
We discuss the strong ellipticity (SE) conditions for strain gradient and micromorphic continua considering them as an enhancement of a simple nonlinearly elastic material called in the following primary material. Recently both models are widely used for description of material behavior of beam-lattice metamaterials which may possess various types of material instabilities. We analyze how a possible loss of SE results in the behavior of enhanced models. We shown that SE conditions for a micromorphic medium is more restrictive than for its gradient counterpart. On the other hand we see that a violation of SE for a primary material affects solutions within enhanced models even if the SE conditions are fulfilled for them. • Strong ellipticity (SE) conditions are compared for nonlinear strain gradient (SG) and micromorphic (MM) elasticity. • Relations between SE of enhanced models and of simple nonlinear elastic (primary) material are clarified. • SE within SG approach is independent on SE of primary material, whereas SE of MM model elasticity inherits it partially. • Both models regularize primary material behavior, so non-existence of solutions is avoided. • SE conditions bring information on material instabilities within enhanced models of continua. [ABSTRACT FROM AUTHOR]
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- 2022
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19. Strong ellipticity within the Toupin–Mindlin first strain gradient elasticity theory.
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Eremeyev, Victor A. and Lazar, Markus
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STRAINS & stresses (Mechanics) , *ELASTICITY , *BOUNDARY value problems - Abstract
We discuss the strong ellipticity (SE) condition within the Toupin–Mindlin first strain gradient elasticity theory. SE condition is closely related to certain material instabilities and describes mathematical properties of corresponding boundary-value problems. For isotropic solids, SE condition transforms into two inequalities in terms of five gradient-elastic moduli. • Strong ellipticity (SE) conditions within Toupin–Mindlin first strain gradient elasticity are formulated. • For an isotropic material, SE conditions transform into two inequalities in terms gradient-elastic moduli. • SE conditions and uniqueness of solutions were discussed. • SE conditions and characteristic lengths for a few materials are provided. [ABSTRACT FROM AUTHOR]
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- 2022
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20. On time-dependent nonlinear dynamic response of micro-elastic solids.
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Malikan, Mohammad and Eremeyev, Victor A.
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STRAINS & stresses (Mechanics) , *NONLINEAR equations , *NONLINEAR analysis - Abstract
• A microbeam based on the thin beam model has been assumed. • A dynamic extension of modified couple stress theory has been presented including micro-mass inertia. • A two-step solution technique is performed to solve nonlinear equations; Galerkin decomposition, and Homotopy perturbation methods. • Time-dependent large amplitude frequency has been investigated. A new approach to the mechanical response of micro-mechanic problems is presented using the modified couple stress theory. This model captured micro-turns due to micro-particles' rotations which could be essential for microstructural materials and/or at small scales. In a micro media based on the small rotations, sub-particles can also turn except the whole domain rotation. However, this framework is competent for a static medium. In terms of dynamic investigations of micro materials, it is required to involve micro-rotations' mass inertias. This fact persuades us to pay particular attention to the micro mechanics' samples and directed us to re-derive the modified couple stress model to propose and represent a new micro-mechanic approach which is well-deserved, especially for dynamic studies of microstructures. In carrying out this job, the classical beam has provided the basic form of formulation procedure. The continuum medium has been limited to a square flat non-porous beam deducing a homogeneous isotropic micromaterial. As long as the time-dependent results are concerned due to studying micro-mass inertia in time history, there would be two solution steps. The Galerkin decomposition technique is imposed in accord with an analytical postulate to issue the algebraic problem distributing time-dependent equations. The latter, the Homotopy perturbation method delivers time-dependent outcomes. The solution methods have been validated by building numerical models in Abaqus software. On the new achievements of this study, one can declare that both static and dynamic length scale parameters are very effective in order to study vibrations of microstructures. If the values of these characteristic lengths are considerable, the nonlinear frequency analysis will be essential. Furthermore, the stiffness of the structure will be higher if the values of both length scale parameters increase. [ABSTRACT FROM AUTHOR]
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- 2023
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21. A layer-wise theory for laminated glass and photovoltaic panels.
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Naumenko, Konstantin and Eremeyev, Victor A.
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LAMINATED glass , *CIVIL engineering , *SOLAR cells , *CONSTRAINTS (Physics) , *SYMMETRY (Physics) , *SHEAR (Mechanics) - Abstract
Abstract: Laminated plates with glass skin layers and a core layer from soft polymers are widely used in the civil engineering. Photovoltaic panels currently available on the market are composed from stiff front and back layers and a solar cell layer embedded in a soft polymeric encapsulant. In this paper a layer-wise theory for the structural analysis of glass and photovoltaic laminates is developed. Starting from governing equations for individual layers, kinematical constraints and appropriate interaction forces, a twelfth order system of partial differential equations is derived. The primary variables in the theory include the Airy stress function, the deflection function and the vector of relative in-plane displacements of skin layers. For symmetric laminates a system of uncoupled differential equations with respect to scalar potentials is presented. Three of them correspond to the first order shear deformation plate. The new additional second order differential equation provides a correction function according to the layer-wise theory. Closed form analytical solutions for a plate strip are derived to illustrate the essential influence of this correction for laminates with soft core layer. The importance of additional boundary conditions is shown for examples of free and framed plate edges. [Copyright &y& Elsevier]
- Published
- 2014
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22. Material symmetry group of the non-linear polar-elastic continuum
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Eremeyev, Victor A. and Pietraszkiewicz, Wojciech
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SYMMETRY groups , *NONLINEAR mechanics , *ELASTICITY , *CONTINUUM mechanics , *MICROSTRUCTURE , *MATHEMATICAL transformations , *STRAINS & stresses (Mechanics) - Abstract
Abstract: We extend the material symmetry group of the non-linear polar-elastic continuum by taking into account microstructure curvature tensors as well as different transformation properties of polar and axial tensors. The group consists of an ordered triple of tensors which makes the strain energy density of polar-elastic continuum invariant under change of reference placement. An analog of the Noll rule is established. Four simple specific cases of the group with corresponding reduced forms of the strain energy density are discussed. Definitions of polar-elastic fluids, solids, liquid crystals and subfluids are given in terms of members of the symmetry group. Within polar-elastic solids we discuss in more detail isotropic, hemitropic, cubic-symmetric, transversely isotropic, and orthotropic materials and give explicitly corresponding reduced representations of the strain energy density. For physically linear polar-elastic solids, when the density becomes a quadratic function of strain measures, reduced representations of the density are established for monoclinic, orthotropic, cubic-symmetric, hemitropic and isotropic materials in terms of appropriate joint scalar invariants of stretch, wryness and undeformed structure curvature tensors. [Copyright &y& Elsevier]
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- 2012
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23. A non-linear direct peridynamics plate theory.
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Naumenko, Konstantin and Eremeyev, Victor A.
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LINEAR momentum , *DEGREES of freedom , *TORQUE , *ANGULAR momentum (Mechanics) , *RIGID bodies , *ROTATIONAL motion - Abstract
In this paper a direct non-local peridynamics theory for thin plates is developed. Peridynamic points are assumed to behave like rigid bodies with independent translation and finite rotation degrees of freedom. The non-local mechanical interaction between points is characterized by force and moment vectors. The balance equations including the linear momentum, the angular momentum and the energy are presented. Peridynamic deformation states of the plate are introduced including the actual bond vector (relative translation of two points within the bond) and the relative finite rotation tensor (actual relative orientation of two points in the bond). The corresponding power-conjugate bond force and bond moment states are derived. The framework to develop constitutive equations for the plate peridynamic states is addressed. Special cases of the theory including plates with zero drilling moments, membranes, soft interlayers as well as stiff plate layers with small relative rotations are considered. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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24. On a flexomagnetic behavior of composite structures.
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Malikan, Mohammad and Eremeyev, Victor A.
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COMPOSITE structures , *SHEAR (Mechanics) , *MAGNETIC fields , *ENERGY density - Abstract
The popularity of the studies is getting further on the flexomagnetic (FM) response of nano-electro-magneto machines. In spite of this, there are a few incompatibilities with the available FM model. This study indicates that the accessible FM model is inappropriate when considering the converse magnetization effect that demonstrates the necessity and importance of deriving a new FM relation. Additionally, the literature has neglected the converse FM coefficient in the Lifshitz invariant inside the free energy constitutive relation. This fact inspires us to endeavor and conduct a new characteristic formulation for static analysis of axially compressed piezomagnetic nanobeams comprising the FM effect. This novel FM model is competent and suitable for various boundary conditions, encompassing analytical, semi-analytical, and numerical solving strategies. However, based on the previous FM equation established with respect to Euler-Bernoulli and Timoshenko beams, the governing equations are ill-posed due to the corresponding energy density. Despite that, this error will not remain in the finalized equations in the present model by conjecturing a gradient of the magnetic field and a different formulation. Moreover, the inverse FM parameter will appear in the magnetic field relation. As the literature reported, non-uniform deformed piezomagnetic structures are capable of presenting more outstanding flexomagneticity. In actuality, a non-uniform elastic strain appears as a response to the magnetic field gradient (converse effect) that causes this study to deduce the nanobeam with higher-order shear deformations. Furthermore, the local governing equations will be transferred into the nonlocal phase according to the nonlocal differential, particularly nonlocal integral elasticity which itself is a strong nonlocality. Through this theory, and in regard to the converse FM impact, an analytical expression is applied for computing critical buckling loads within several ends conditions of the nanobeam. Our present results and achievements will hopefully be an effective contribution to theoretical studies on the mechanics of intelligent nanostructures. [ABSTRACT FROM AUTHOR]
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- 2022
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25. Strong ellipticity conditions and infinitesimal stability within nonlinear strain gradient elasticity.
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Eremeyev, Victor A.
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STRAINS & stresses (Mechanics) , *STATICS , *ELASTICITY - Abstract
We discuss connections between the strong ellipticity condition and the infinitesimal instability within the nonlinear strain gradient elasticity. The strong ellipticity (SE) condition describes the property of equations of statics whereas the infinitesimal stability is introduced as the positive definiteness of the second variation of an energy functional. Here we establish few implications which simplify the further analysis of stability using formulated SE conditions. The results could be useful for the analysis of solutions of homogenized models of beam-lattice materials at different scales. • Nonlinear strain gradient elasticity is studied. • First- and second-order strong ellipticity conditions (1st and 2nd SE) are formulated. • Relations between SE and infinitesimal stability is clarified. • Infinitesimal stability implies the weak form of 2nd SE. • 1st and 2nd SE imply infinitesimal stability of affine deformations. • Infinitesimal stability could be proven even without SE. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
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26. Effect of surface on the flexomagnetic response of ferroic composite nanostructures; nonlinear bending analysis.
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Malikan, Mohammad and Eremeyev, Victor A.
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DIFFERENTIAL quadrature method , *STRAINS & stresses (Mechanics) , *NONLINEAR analysis , *NEWTON-Raphson method , *LATERAL loads - Abstract
Our analysis incorporates the geometrically nonlinear bending of the Euler-Bernoulli ferromagnetic nanobeam accounting for a size-dependent model through assuming surface effects. In the framework of the flexomagnetic phenomenon, the large deflections are investigated referring to von-Kármán nonlinearity. Employing the nonlocal effects of stress coupled to the gradient of strain generates a scale-dependent Hookean stress–strain scheme related to the small scale. Taking into account the supports of the nanobeam in two cases, that is, totally fixed and hinged, the deformations are predicted. A constant static lateral load is postulated uniformly along the length of the beam, which forces the deformation. As the analysis is based on the one-dimensional media, the electrodes are embedded so that they give off a transverse magnetic field creating a longitudinal force. The newly developed mathematical model is computed by means of the differential quadrature method together with the Newton-Raphson technique. The computational section discusses and reveals the numerical results in detail for the characteristics and parameters involved in the design of beam-like magnetic nanosensors. As shown later, the conducted research presents that there is a strong linkage between the surface effect and the flexomagneticity behavior of the bulk. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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27. A relationship between effective work of adhesion and peel force for thin hyperelastic films undergoing large deformation.
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Eremeyev, Victor A. and Naumenko, Konstantin
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ADHESION , *ELASTICITY , *DEFORMATIONS (Mechanics) , *THIN films , *STRAINS & stresses (Mechanics) - Abstract
A method to determine the effective work of adhesion for hyperelastic thin films undergoing large deformations is presented. Starting from energy balance equation a relationship between work of adhesion, the peel force, the peel angle, and the stretch is derived. Based on this relation a procedure to compute the energy of adhesion from peel tests is proposed. To this end the peel force as well as the engineering stress vs. engineering strain diagram for thin film is required. The derived relationship shows that the non-linearity of the stress-stain relation must be taken into account in computing the effective work of adhesion from the peel force. The processing of experimental data within the standard linear elasticity approach would lead to an overestimation of effective work of adhesion. The error would increase with a decrease of the peel angle. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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28. Flexomagnetic response of buckled piezomagnetic composite nanoplates.
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Malikan, Mohammad and Eremeyev, Victor A.
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STRAINS & stresses (Mechanics) , *MAGNETIC field effects , *MAGNETISM , *MAGNETIC fields , *DIFFERENTIAL equations , *FLEXURAL vibrations (Mechanics) - Abstract
In this paper, the equation governing the buckling of a magnetic composite nanoplate under the influence of an in-plane one-dimensional magnetic field, assuming the concept of flexomagnetic and considering the resulting flexural force and moment, is investigated for the first time by different analytical boundary conditions. To determine the equation governing the stability of the nanoplate, the nonlocal strain gradient theory has been used by taking into account the classical plate theory. The axial magnetic force, which is originated from the magnetic field, is investigated. After extracting the governing differential equation, the critical buckling load is obtained for different support conditions. The effect of nonlocal parameter, sheet aspect ratio and the effect of one-dimensional magnetic field on critical load are discussed. It was earned that if the nanoplate is rectangular so that the value of aspect ratio is less than one, the flexomagnetic response will be more noticeable. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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29. Interaction of a helical shell with a nonlinear viscous fluid
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Girchenko, Anna A., Eremeyev, Victor A., and Altenbach, Holm
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FLUID dynamics , *STRUCTURAL shells , *NONLINEAR systems , *METAMATERIALS , *MICROSTRUCTURE , *PIEZOELECTRICITY , *ENGINEERING design - Abstract
Abstract: In recent years a significant progress in synthesis of metamaterials with perspective and unusual functional properties is observed. The properties of these metamaterials highly depend on their microstructure. In particular, helical shell structures have found various applications, for example in MEMS/NEMS, optics and medicine, see e.g. (Delclos, Aim, & Pouget, 2008; Ghosh & Fischer, 2009; Pendry, 2004). In Girchenko, Eremeyev, and Morozov (2011) we are taken into account the piezoelectric properties of helical shells. Here we analyze the interaction of the elastic helical shell with a non-Newtonian fluid. The interaction of the shell with the environment is highly important for engineering design, e.g. in medical applications when the shell operates in a fluid. The non-Newtonian fluid is assumed to be of pseudoplastic type. [Copyright &y& Elsevier]
- Published
- 2012
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30. Surface viscoelasticity and effective properties of thin-walled structures at the nanoscale
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Altenbach, Holm, Eremeyev, Victor A., and Morozov, Nikita F.
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SURFACES (Technology) , *VISCOELASTICITY , *STRUCTURAL analysis (Engineering) , *BENDING (Metalwork) , *STIFFNESS (Mechanics) , *STRUCTURAL plates , *NANOSTRUCTURED materials - Abstract
Abstract: We discuss the influence of surface viscoelasticity effects on the effective properties of materials such as effective bending stiffness of plates or shells. Viscoelastic properties in the vicinity of the surface can differ from the properties of the bulk material. This difference influences the behavior of nanostructural elements. In particular, the surface viscoelastic stresses are responsible for the size-depended dissipation of nanosized structures. Using the extension of the Gurtin–Murdoch model and the correspondence principle of linear viscoelasticity we derive the expressions of the stress and couple stress resultant tensors for shear deformable plates and shells. [Copyright &y& Elsevier]
- Published
- 2012
- Full Text
- View/download PDF
31. On the shell theory on the nanoscale with surface stresses
- Author
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Altenbach, Holm and Eremeyev, Victor A.
- Subjects
- *
SURFACES (Technology) , *STRAINS & stresses (Mechanics) , *NONLINEAR differential equations , *THIN films , *POROUS materials , *NANOSTRUCTURED materials , *ELASTICITY , *THICKNESS measurement - Abstract
Abstract: Below we discuss the derivation of the governing nonlinear shell equations taking into account the surface stresses. The surface effects are significant for the modeling of some structures as nanofilms, nanoporous materials and other nano-size structures. In particular, the surface stresses are responsible for the size effect, i.e. dependence of the material properties on the specimen size. The theory of elasticity with surface stresses is applied to the modeling of shells with nano-scaled thickness. It will be shown that the resultant stress and couple stress tensors can be represented as a sum of two terms. The first term in the sum depends on the stress distribution in the bulk material while the second one relates to the surface stresses. Hence, the resultant stress and couple stress tensors are linear functions with respect to the surface stresses. As an example the effective stiffness properties of a linear elastic Cosserat shells taking into account the surface stresses are presented. [Copyright &y& Elsevier]
- Published
- 2011
- Full Text
- View/download PDF
32. A new hyperbolic-polynomial higher-order elasticity theory for mechanics of thick FGM beams with imperfection in the material composition.
- Author
-
Malikan, Mohammad and Eremeyev, Victor A.
- Subjects
- *
FUNCTIONALLY gradient materials , *ELASTICITY , *DEGREES of freedom , *BESSEL beams , *GALERKIN methods , *SHEARING force - Abstract
A drawback to the material composition of thick functionally graded materials (FGM) beams is checked out in this research in conjunction with a novel hyperbolic-polynomial higher-order elasticity beam theory (HPET). The proposed beam model consists of a novel shape function for the distribution of shear stress deformation in the transverse coordinate. The beam theory also incorporates the stretching effect to present an indirect effect of thickness variations. As a result of compounding the proposed beam model in linear Lagrangian strains and variational of energy, the system of equations is obtained. The Galerkin method is here expanded for several edge conditions to obtain elastic critical buckling values. First, the importance of the higher-order beam theory, as well as stretching effect, is assessed in assorted tabulated comparisons. Next, with validations based on the existing and open literature, the proposed shape function is evaluated to consider the desired accuracy. Some comparative graphs by means of well-known shape functions are plotted. These comparisons reveal a very good compliance. In the final section of the paper, based on an inappropriate mixture of the SUS304 and Si 3 C 4 as the first type of FGM beam (Beam-I) and, Al and Al 2 O 3 as the second type (Beam-II), the results are pictured while the beam is kept in four states, clamped–clamped (C–C), pinned–pinned (S–S), clamped-pinned (C–S) and in particular cantilever (C–F). We found that the defect impresses markedly an FGM beam with boundary conditions with lower degrees of freedom. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
33. Enriched buckling for beam-lattice metamaterials.
- Author
-
Eremeyev, Victor A. and Turco, Emilio
- Subjects
- *
MECHANICAL buckling , *METAMATERIALS , *MICROSTRUCTURE - Abstract
• For beam-lattice metamaterials a complex buckling behaviour is demonstrated. • Buckling of pantographic beam is analyzed. • Instability under tension for a beam with cross potent microstructure with sliders is presented. We discuss two examples of beam-lattice metamaterials which show attractive mechanical properties concerning their enriched buckling. The first one considers pantographic beams and the nonlinear solution is traced out numerically on the base of a Hencky's model and an algorithm based on Riks' arc-length scheme. The second one concerns a beam-lattice with sliders and the nonlinear solution is discussed in analytic way and, finally, extended to the case of uniform in-plane tension. Some concluding remarks draw possible future developments and challenges. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
34. Leonid M. Zubov: A life devoted to nonlinear mechanics.
- Author
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Eremeyev, Victor A., Lebedev, Leonid P., and Ogden, Raymond W.
- Published
- 2014
- Full Text
- View/download PDF
35. Flexoelectricity and apparent piezoelectricity of a pantographic micro-bar.
- Author
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Eremeyev, Victor A., Ganghoffer, Jean-François, Konopińska-Zmysłowska, Violetta, and Uglov, Nikolay S.
- Subjects
- *
FLEXOELECTRICITY , *TORSION , *PIEZOELECTRICITY , *STIFFNESS (Engineering) , *GEOMETRY - Abstract
We discuss a homogenized model of a pantographic bar considering flexoelectricity. A pantographic bar consists of relatively stiff small bars connected by small soft flexoelectric pivots. As a result, an elongation of the bar relates almost to the torsion of pivots. Taking into account their flexoelectric properties we find the corresponding electric polarization. As a results, the homogenized pantographic bar demonstrates piezoelectric properties inherited from the flexoelectric properties of pivots. The effective stiffness properties of the homogenized bars are determined by the geometry of the structural elements and shear stiffness whereas the piezoelectric properties follow from the flexoelectric moduli of the pivots. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
36. Transverse surface waves on a cylindrical surface with coating.
- Author
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Eremeyev, Victor A., Rosi, Giuseppe, and Naili, Salah
- Subjects
- *
SHEAR waves , *ACOUSTIC surface waves , *MODULUS of rigidity , *DISPERSION relations - Abstract
We discuss the propagation of transverse surface waves that are so-called whispering-gallery waves along a surface of an elastic cylinder with coating. The coating is modelled in the framework of linearized Gurtin–Murdoch surface elasticity. Other interpretations of the surface shear modulus are given and relations to so-called stiff interface and stiff skin model are discussed. The dispersion relations are obtained and analyzed. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
37. On stress singularity near the tip of a crack with surface stresses.
- Author
-
Gorbushin, Nikolai, Eremeyev, Victor A., and Mishuris, Gennady
- Subjects
- *
SURFACE cracks , *SURFACE properties , *SQUARE root , *SYMMETRY - Abstract
In the framework of the simplified linear Gurtin–Murdoch surface elasticity we discuss a singularity of stresses and displacements in the vicinity of a mode III crack. We show that inhomogeneity in surface elastic properties may significantly affect the solution and to change the order of singularity. We also demonstrate that implicitly or explicitly assumed symmetry of the problem may also lead to changes in solutions. Considering various loading and symmetry conditions we show that the stresses may have logarithmic or square root singularity or be bounded in the vicinity of a crack tip. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
38. Wave transmission across surface interfaces in lattice structures.
- Author
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Sharma, Basant Lal and Eremeyev, Victor A.
- Subjects
- *
INTERFACE structures , *LATTICE dynamics , *ELASTICITY , *SQUARE waves , *SURFACE area - Abstract
Within the lattice dynamics formulation, we present an exact solution for anti-plane surface waves in a square lattice strip with a surface row of material particles of two types separated by a linear interface. The considered problem is a discrete analog of an elastic half-space with surface stresses modelled through the simplified Gurtin–Murdoch model, where we have an interfacial line separating areas with different surface elastic properties. The main attention is paid to the transmittance and the reflectance of a wave across the interface. The presented results shed a light on the influence on surface waves of surface inhomogeneity in surface elastic properties such as grain and subgrain boundaries. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
39. Mechanical simulation of artificial gravity in torus-shaped and cylindrical spacecraft.
- Author
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Dastjerdi, Shahriar, Malikan, Mohammad, Eremeyev, Victor A., Akgöz, Bekir, and Civalek, Ömer
- Subjects
- *
SHEAR (Mechanics) , *SPACE stations , *GRAVITY , *STRAINS & stresses (Mechanics) , *SURFACE of the earth , *SPACE vehicles - Abstract
Large deformations and stress analyses in two types of space structures that are intended for people to live in space have been studied in this research. The structure under analysis is assumed to rotate around the central axis to create artificial gravitational acceleration equal to the gravity on the Earth's surface. The analysis is fully dynamic, which is formulated based on the energy method by using the first-order shear deformation shell theory in two systems, cylindrical and torus. Also, the nonlinear von Kármán strain field has been assumed. The obtained set of partial differential equations has been solved using the semi-analytical polynomial solution method (SAPM). The main purpose of this paper is to study the effects of unusual conditions in the space outside the Earth's atmosphere (which is a complete vacuum environment without pressure) on the strength of the analyzed structure. The numerical results of the governing equations have been evaluated using those of other studies and the simulation efficiency performed in this research has been proven. Finally, the effect of important parameters on the numerical results, including the angular velocity of the structure (which causes artificial gravity), the amount of imposed mechanical and hygro-thermal loads, the structure size and material specifications have been investigated in more detail. • Large dynamic deformations of torus-shaped and cylindrical space structures are studied. • Artificial gravity due to rotations is taken into account. • Hygro-thermal effects are also considered. • Functionally graded structures are analyzed. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
40. On rotational instability within the nonlinear six-parameter shell theory.
- Author
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Chróścielewski, Jacek, dell'Isola, Francesco, Eremeyev, Victor A., and Sabik, Agnieszka
- Subjects
- *
MODULUS of rigidity , *NUMERICAL analysis , *NONLINEAR theories , *ROTATIONAL motion , *MICROPOLAR elasticity - Abstract
Within the six-parameter nonlinear shell theory we analyzed the in-plane rotational instability which occurs under in-plane tensile loading. For plane deformations the considered shell model coincides up to notations with the geometrically nonlinear Cosserat continuum under plane stress conditions. So we considered here both large translations and rotations. The constitutive relations contain some additional micropolar parameters with so-called coupling factor that relates Cosserat shear modulus with the Cauchy shear modulus. The discussed instability relates to the bifurcation from the static solution without rotations to solution with non-zero rotations. So we call it rotational instability. We present an elementary discrete model which captures the rotational instability phenomenon and the results of numerical analysis within the shell model. The dependence of the bifurcation condition on the micropolar material parameters is discussed. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
41. On a 3D material modelling of smart nanocomposite structures.
- Author
-
Malikan, Mohammad, Dastjerdi, Shahriar, Eremeyev, Victor A., and Sedighi, Hamid M.
- Subjects
- *
SMART structures , *STRAINS & stresses (Mechanics) , *HAMILTON'S principle function , *SMART materials , *COMPOSITE construction , *COMPOSITE structures , *STRAIN tensors - Abstract
Smart composites (SCs) are utilized in electro-mechanical systems such as actuators and energy harvesters. Typically, thin-walled components such as beams, plates, and shells are employed as structural elements to achieve the mechanical behavior desired in these composites. SCs exhibit various advanced properties, ranging from lower order phenomena like piezoelectricity and piezomagneticity, to higher order effects including flexoelectricity and flexomagneticity. The recently discovered flexomagneticity in smart composites has been investigated under limited conditions. A review of the existing literature indicates a lack of evaluation in three-dimensional (3D) elasticity analysis of SCs when the flexomagnetic effect (FM) exists. To address this issue, the governing equations will incorporate the term ∂ / ∂z , where z represents the thickness coordinate. The variational technique will guide us in further developing these governing equations. By using hypotheses and theories such as a 3D beam model, von Kármán's strain nonlinearity, Hamilton's principle, and well-established direct and converse FM models, we will derive the constitutive equations for a thick composite beam. Conducting a 3D analysis implies that the strain and strain gradient tensors must be expressed in 3D forms. The inclusion of the term ∂ / ∂z necessitates the construction of a different model. It should be noted that current commercial finite element codes are not equipped to accurately and adequately handle micro- and nano-sized solids, thus making it impractical to model a flexomagnetic composite structure using these programs. Therefore, we will transform the derived characteristic linear three-dimensional bending equations into a 3D semi-analytical Polynomial domain to obtain numerical results. This study demonstrates the importance of conducting 3D mechanical analyses to explore the coupling effects of multiple physical phenomena in smart structures. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
42. Design of metamaterials: Preface.
- Author
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Misra, Anil, Hild, François, and Eremeyev, Victor A.
- Subjects
- *
DESIGN , *METAMATERIALS - Published
- 2023
- Full Text
- View/download PDF
43. Anti-plane shear waves in an elastic strip rigidly attached to an elastic half-space.
- Author
-
Mikhasev, Gennadi, Erbaş, Barış, and Eremeyev, Victor A.
- Subjects
- *
ELASTIC waves , *SHEAR waves , *MODULUS of rigidity , *PARTICLE size determination , *FREE surfaces - Abstract
We consider the anti-plane shear waves in a domain consisting of an infinite layer with a thin coating lying on an elastic half-space. The elastic properties of the coating, layer, and half-space are assumed to be different. On the free upper surface we assume the compatibility condition within the Gurtin–Murdoch surface elasticity, whereas at the plane interface we consider perfect contact. For this problem there exist two possible regimes related to waves exponentially decaying in the half-space. The first one, called transversely exponential–transversely exponential (TE–TE) regime, is related to waves described by exponential in transverse direction functions; the second, transversely harmonic–transversely exponential (TH–TE) regime, corresponds to waves in the upper layer which have the harmonic behaviour in the transverse direction. Detailed analysis of the derived dispersion equations for both regimes is provided. In particular, the effects of surface stresses, the layer thickness as well as of the ratio of shear moduli of the upper layer and half-space on the dispersion curves is analysed. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
44. On the generalized model of shell structures with functional cross-sections.
- Author
-
Dastjerdi, Shahriar, Malikan, Mohammad, Eremeyev, Victor A., Akgöz, Bekir, and Civalek, Ömer
- Subjects
- *
PARTIAL differential equations , *NONLINEAR analysis - Abstract
In the present study, a single general formulation has been presented for the analysis of various shell-shaped structures. The proposed model is comprehensive and a variety of theories can be used based on it. The cross-section of the shell structure can be arbitrarily analyzed with the presented equations. In other words, various types of shell structures, including cylindrical, conical, spherical, elliptical, hyperbolic, parabolic, and any non-geometric structure with functional cross-section, can be modeled mechanically with only one partial differential equation system. The obtained equations have been solved by applying SAPM semi-analytical solution method. In order to present a comprehensive research, dynamic nonlinear analysis is considered. The variation of material properties through the thickness has been assumed as functionally graded and its effect on the strength of the shell structure with the functional cross-section has been investigated. The numerical results have been compared with available papers and also with FEM results for some structures that there is no paper available for validation. Different types of shell structures have been studied in terms of cross-sectional shape and properties. Finally, the effects of some important factors on the results such as boundary conditions, nonlinear analysis, dynamic analysis, and rotation of the structure around its central axis have been conducted thoroughly. This study and its original governing equations can be considered as a comprehensive reference for mechanical analysis of various shell structures with functional cross-sectional shape. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
45. On the influence of a surface roughness on propagation of anti-plane short-length localized waves in a medium with surface coating.
- Author
-
Mikhasev, Gennadi I., Botogova, Marina G., and Eremeyev, Victor A.
- Subjects
- *
SURFACE roughness , *SURFACE coatings , *CURVILINEAR motion , *SURFACE defects , *ELASTICITY , *MICROSTRUCTURE - Abstract
We discuss the propagation of localized surface waves in the framework of the linear Gurtin–Murdoch surface elasticity and taking into account a roughness of a free boundary. We derive a boundary-value problem for anti-plane motions with curvilinear boundary and surface stresses. Using the asymptotic technique developed earlier, we obtain the form of a localized wave and analyze its amplitude evolution. As the main result we present the dependence of the wave amplitude on the roughness magnitude. The presented results could be used for non-destructive evaluation of the surface microstructure using surface waves-based devices. In particular, measuring the decay rate with the depth one can estimate roughness of a surface and appearance of new surface defects. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
46. On instabilities and post-buckling of piezomagnetic and flexomagnetic nanostructures.
- Author
-
Malikan, Mohammad, Uglov, Nikolay S., and Eremeyev, Victor A.
- Subjects
- *
STRAINS & stresses (Mechanics) , *ELASTICITY , *MATHEMATICAL models , *DETECTORS , *MECHANICAL buckling - Abstract
We focus on the mechanical strength of piezomagnetic beam-like nanosize sensors during post-buckling. An effective flexomagnetic property is also taken into account. The modelled sensor is selected to be a Euler-Bernoulli type beam. Long-range interactions between atoms result in a mathematical model based on the nonlocal strain gradient elasticity approach (NSGT). Due to possible large deformations within a post-buckling phenomenon, the resultant equations are essentially nonlinear. We establish the results using an analytical approach, including a variety of boundary conditions. We visualize the effective response of the designed sensor for several key components. It was obtained that the flexomagnetic effect is meaningful for less flexible boundary conditions. Besides, it was found that the failure originated from post-buckling occurs sooner if the numerical amounts of nonlocal parameter and the strain gradient one are respectively so small and exceedingly large. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
47. Torsional stability capacity of a nano-composite shell based on a nonlocal strain gradient shell model under a three-dimensional magnetic field.
- Author
-
Malikan, Mohammad, Krasheninnikov, Maxim, and Eremeyev, Victor A.
- Subjects
- *
MAGNETIC fields , *THREE-dimensional modeling , *INDUCTIVE effect , *COORDINATES , *MECHANICAL buckling - Abstract
• Torsional buckling of a nano-composite shell is analyzed by means of first-order shear deformation shell theory. • Both stiffness-softening and stiffness-hardening of the nanoshell are considered based on the nonlocal strain gradient theory. • The magnetic field is investigated concerning three-dimensional magnetic effects. • Three-dimensional analysis of the magnetic field presents that the transverse effect of the field is the most significant influence on the torsional stability of the shell. • It is crucial to study the magnetic field in three dimensions while the higher values of circumferential half-wave numbers are taken into account. This paper considers a single-walled composite nano-shell (SWCNS) exposed in a torsional critical stability situation. As the magnetic field affects remarkably nanostructures in the small size, a three-dimensional magnetic field is assessed which contains magnetic effects along the circumferential, radial and axial coordinates system. Based on the results of the nonlocal model of strain gradient small-scale approach and the first-order shear deformation shell theory (FSDST), the problem is estimated. Afterward, the numerical results are taken analytically and compared with other existing literature. Hereafter, the influences of various factors, such as the magnetic field, are discussed deeply. It is observed that when the magnetic field is studied in three dimensions, the transverse magnetic effect is the most serious factor that affects fundamentally the torsional stability of the shell. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
48. On the structural behaviour of existing RC bridges subjected to corrosion effects: Numerical insight.
- Author
-
Zucca, Marco, Reccia, Emanuele, Longarini, Nicola, Eremeyev, Victor, and Crespi, Pietro
- Subjects
- *
BRIDGE foundations & piers , *REINFORCED concrete corrosion , *FINITE element method , *NONLINEAR analysis , *DYNAMIC loads , *STRUCTURAL engineering , *DEAD loads (Mechanics) - Abstract
• The collapse mechanisms of R.C. existing bridges piers subjected to corrosion effects has been analyzed considering static and dynamic loads. • An analytical approach has been considered to introduce the corrosion effects in the finite element model implementation. • Linear and non-linear numerical analyses have been carried out considering an existing R.C. bridge located in Northern Italy in order to evaluate its safety level under different load cases. • Different interventions have been proposed to prevent the collapse of the bridge. The evaluation of the structural behaviour of existing reinforced concrete (RC) bridges represents one of the most current structural engineering research topics due to their strategic importance, especially if they are subjected to corrosion effects which can lead to a significant reduction of load-bearing capacity of the main structural elements (e.g., the piers). In the last decades, different types of numerical approaches have been proposed for the evaluation of the structural behaviour of these strategic infrastructures, especially after the recent collapses that have affected this type of structures during last years. In this paper, the structural behaviour of an existing RC bridge subjected to corrosion effects due to carbonation is analysed by means of an efficient procedure based on the implementation of a Finite Element Model (FEM) where the main structural elements are implemented using only Timoshenko beam elements. The safety level of the bridge has been evaluated considering different load conditions (e.g. traffic load, seismic action, etc.) calculated according to the Italian Design Code (NTC2018). Finally, a retrofitting intervention is proposed in order to guarantee and adequate safety level of the bridge under the considered different load combinations. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
49. Continuum models for pantographic blocks with second gradient energies which are incomplete.
- Author
-
Stilz, Maximilian, dell'Isola, Francesco, Giorgio, Ivan, Eremeyev, Victor A., Ganzenmüller, Georg, and Hiermaier, Stefan
- Subjects
- *
CONTINUUM mechanics , *MECHANICAL energy , *ENERGY consumption , *DEFORMATIONS (Mechanics) , *TORSION , *RIGID bodies - Abstract
We postulate a deformation energy for describing the mechanical behavior of so called pantographic blocks, that is bodies constituted by stacking of N layers of pantographic sheets. We remark that the pantographic effect is limited in the plane of pantographic sheets and therefore only the second derivatives of transverse displacements along the pantographic fibers appear in the chosen deformation energy. We use this novel energy to predict the behavior of pantographic blocks when subjected to : (i) compression and traction test, (ii) torsion, (iii) shear and (iv) bending. A linearization of the energy shows one floppy mode in addition to the rigid body motions, assuming perfect pivots, similar to pantographic sheets. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
50. Identifying traction–separation behavior of self-adhesive polymeric films from in situ digital images under T-peeling.
- Author
-
Nase, Michael, Rennert, Mirko, Naumenko, Konstantin, and Eremeyev, Victor A.
- Subjects
- *
SELF-adhesive vinyl film , *DEFORMATIONS (Mechanics) , *LEAST squares , *TRACTION (Engineering) , *NONLINEAR theories , *ADHESION , *RITZ method , *MICROSCOPES - Abstract
In this paper procedures are developed to identify traction–separation curves from digital images of the deformed flexible films during peeling. T-peel tests were performed for self-adhesive polymeric films. High quality photographs of the deformed shape within and outside the zone of adhesive interaction were made in situ by the digital light microscope. The deformed line is approximated by a power series with coefficients computed by minimizing a least squares functional. Two approaches to identify the traction–separation curve for the given deformation line are proposed. The first one is based on the energy integral of the non-linear theory of rods and allows the direct evaluation of the adhesion force potential. The second one utilizes the complementary energy type variational equation and the Ritz method to compute the adhesion force. The accuracy of both approaches is analyzed with respect to different approximations for the deformed line and the force of interaction. The obtained traction vs. axial coordinate and the traction–separation curves provide several properties of the adhesive system including the maximum adhesion force, the length of the adhesive zone and the equilibrium position, where the adhesive force is zero while the separation is positive. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
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