An active composite material is assumed to be composed of a passive isotropic elastic matrix with spherical voids containing active rod-like elements, each of which being in diametrical contact with the void’s surface. A ball-bearing fixation between the rod and the contact pads is assumed, and thereby the normal contact becomes a primary mode through which the rod-like elements transfer active loading

The recent advances of solid mechanics of polymer networks are that they can be well-modelled by a physically-based size-dependent constitutive relation via a simplified strain gradient elasticity theory. However, boundary value problems of plate models composed of polymer networks have not been reported, which limit wide applications of the models in the engineering science. In this paper, we systematically

Eshelby's inhomogeneity problem is solved within the second form of Mindlin's first strain gradient elasticity theory for the prediction of the effective elastic properties of composites. Considering Green's function technique, an integral equation is established for an ellipsoidal inhomogeneity embedded in a homogeneous elastic medium and subjected to non-uniform boundary conditions. Within isotropic

The present study provides closed-form expressions of propagation (kinking) angles by generalizing maximum energy release rate criterion in linear elastic fracture mechanics (LEFM) within micropolar theory of elasticity to address the in-plane, brittle crack propagation phenomenon in size-dependent materials with the presence of particle rotations.

In this paper, we propose a self-consistent scheme for the calculation of the components of the effective electrical conductivity tensor. The calculations were fulfilled for a microinhomogeneous material, the components of which have the Hall effect. The presence of the Hall effect leads to appearance of asymmetry of the components of the conductivity tensor and to dependence of these components on

For the first time, strict analytical solutions for the elastic fields and the strain energies of an infinitely thin dilatational disk (DD) and a dilatational cylindrical inclusion (CyI) of finite length coaxially embedded in an infinite elastically isotropic cylinder with free surface are given and analyzed in detail. The solutions are represented in an integral form that is suitable for further analytical

The main objective of this study is to implement extended finite element method (XFEM) to two-dimensional (2D) micropolar structures in order to extract basic fracture parameters required in linear elastic fracture mechanics (LEFM) in a computationally efficient manner, and thus to provide basis to explore the crack propagation phenomenon within this framework. The stress and couple-stress intensity

Estimating model parameters from experimental data is a common practice across various research fields. For nonlinear models, the parameters are estimated using an optimization algorithm that minimizes an objective function. Assessing the certainty of these parameter estimates is crucial to address questions such as “what is the probability the estimation error is smaller than 5%?”, “is our experiment

Engineering interleaves of composite laminates with carbon nanotubes (CNTs) improves interlaminar fracture toughness, creating also conductivity, which can be employed for damage identification. The paper explores machine learning (ML) solution of the inverse problem of the defect identification for interleaves with anisotropic conductivity (aligned CNTs). The electrical and geometrical properties

Unlike ordinary solid materials, underground nano-materials such as kerogen, have relatively small dimensions and suffer from unavoidable in-situ stresses. The coexistence of size effects and initial stresses poses a great challenge to the constitutive modeling of deeply buried nano-inclusions. Despite the theories of strain gradient elasticity (SGE) and initially stressed elasticity (ISE) have been

Indentation of the coated piezoelectric transversely isotropic half-space by a conical conductive punch is modeled. The coating is assumed to be functionally-graded (continuously inhomogeneous in depth) with all group of electromechanical properties varying independently in depth according to arbitrary continuous functions or piecewise homogeneous. The problem is described mathematically in terms of

The effective elastic and conductive properties of matrix composites depend on two geometric factors – inhomogeneity shapes and orientation distribution – and on the property contrast between the matrix and inhomogeneities. The roles of the two geometric factors are strongly coupled; both are also coupled with the role of the property contrast. These issues are examined, with particular attention paid

The effects of oven temperature during printing on nonlinear vibration for fractional-order PET films are considered in this paper. The effect of temperature, fractional order modelling and some other parameters are analysed with respect to the response of the resonance. Fractional order kelvin-Voigt ontological relationship is used to describe the characteristics of viscoelastic materials. The differential

A mechanical heart valve, an essential prosthetic for managing valvular heart disease, consists of a metal frame housing two or three leaflets (depending on the design) that control blood flow within the heart. However, leaflet dysfunction can impede their movement, leading to valve defects. This study extensively investigates the hemodynamics of such a bileaflet mechanical heart valve with dysfunctions

Coupling of piezoelectric and semiconducting properties can stimulate a field-particle coupling wave (FPCW) between electric field and charge carriers on an elastic wave-front (EWF) propagating in a piezoelectric semiconductor. The wave velocity of a FPCW is usually greater than the EWF as vibration frequency rises such that carrier behavior on and in front of the EWF will be disturbed in advance.

This work deals with finding the analytical displacements and stresses in thermoelasticity problems involving solid isotropic cylinders and spheres with an emphasis on stress-focusing phenomena relevant to the nuclear industry and high-temperature engineering. The study considers solid spheres and infinitely long solid cylinders with three different types of thermal loading: prescribed outer surface

In this paper, we apply mesoscale numerical modeling to predict the effective elastic properties of conductive carbon-black/ultra-high-molecular-weight-polyethylene nanocomposites. The models are based on X-ray microcomputed tomography images. The images show that for the considered range of carbon additive weight fractions, the conductive carbon black (CB) particles are distributed around the ult

We study the anti-plane shear waves in a domain consisting of an elastic layer (plate) with a coating attached to an elastic half-space (substrate). We assume an imperfect contact between the layer and the half-space, allowing some sliding. We also assume some elastic bonds between the layer and the substrate. On the free top surface we apply the compatibility conditions within the Gurtin–Murdoch surface

The derivation of the boundary conditions is the most challenging part of the asymptotic techniques underlying low-dimensional models for thin elastic structures. At the moment, these techniques do not take into consideration the effect of the environment, e.g., a Winkler foundation, when tackling boundary conditions, and have to be amended. In this paper as an example we consider an antiplane problem

Understanding many micro-vascular diseases is aided by examining the dynamical behavior of blood cells. For instance, micro-vascular stenosis significantly influences the dynamics of red blood cells and hence causes several micro-vascular disorders. Thus, the objective of the current study is to numerically simulate cellular blood flow in stenosed micro-vessels with different stenosis severities and

We detail the energy balance of a propagating hydraulic fracture. Using the linear hydraulic fracture model which combines lubrication flow and linear elastic fracture mechanics, we demonstrate how different propagation regimes are related to the dominance of a given term of the power balance of a growing hydraulic fracture. Taking an energy point of view allows us to offer a physical explanation of

The classic phenomenological models fail to describe the physical landscape of creep deformation for amorphous solids. In this paper, creep behavior of typical metallic glasses with chemical compositions La62Al14Ag2.34Ni10.83Co10.83, Pd20Pt20Cu20Ni20P20 and Cu46Zr39Hf8Al7 were studied. Instead, we attempt to use a modified hierarchically correlated model informed by physics to realize the creep behaviors

This work is related to modeling of metal surface modification process by combined particles beam. On the basis of thermodynamics of irreversible processes, including equations of state in differential form, a nonlinear model is formulated. The model takes into account the interaction of thermal, diffusion and mechanical waves and finiteness of relaxation times of thermal and diffusion processes. For

The manuscript investigates the buckling behaviour of Bernoulli-Euler nanobeams composed of Functionally-Graded (FG) materials with different cross-sectional shapes. This analysis is conducted using the surface stress-driven model of elasticity. The nonlocal governing equations for the elastostatic buckling problem are derived employing the principle of virtual work. The study also includes a parametric

A new method for assimilating a frequency-dependent drag coefficient into time-domain acoustic simulations is presented. The method combines structural (wave propagation) simulations together with acoustic attenuation of the individual frequencies through a model for the frequency-dependent drag coefficient. An incident pressure pulse is obtained experimentally or from a preliminary finite element

The paper develops a new integral micromorphic elastic continuum model, which can describe dispersion properties of band-gap metamaterials, i.e., metamaterials that inhibit propagation of waves in a certain frequency range. The enrichment consists in nonlocal treatment of three terms in the expression for the potential energy density of the standard micromorphic continuum. After proper calibration

The incorporation of ceramics into polymers, forming solid composite electrolytes (SCEs) leads to enhanced electrical performance of all-solid-state lithium metal batteries. This is because the dispersed ceramics particles increase the ionic conductivity, while the polymer matrix leads to better contact performance between the electrolyte and the electrode. In this study, we present a model, based

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

Polylactic acid (PLA) nanofibrous networks have gained substantial interest across various engineering and scientific disciplines, such as tissue engineering, drug delivery, and filtration, due to their unique and multifunctional attributes, including biodegradability, tuneable mechanical properties, and surface functionality. However, predicting their mechanical behaviour remains challenging due to

The macroscopic behaviors of materials are determined by interactions that occur at multiple lengths and time scales. Depending on the application, describing, predicting, and understanding these behaviors may require models that rely on insights from atomic and electronic scales. In such cases, classical simplified approximations at those scales are insufficient, and quantum-based modeling is required

Structural schemes of applicative interests in Engineering Science frequently encounter the intricate phenomenon of discontinuity. The present study intends to address the discontinuity in the flexure of elastic nanobeam by adopting an abstract variational scheme. The mixture unified gradient theory of elasticity is invoked to realize the size-effects at the ultra-small scale. The consistent form of

Nanocomposites can show different properties according to the type of reinforcements they have. In this article, a model for the study of nanocomposites is examined, which is able to examine all nanocomposites with elliptical, cylindrical, spherical and rectangular reinforcements. Also, in this model, unlike some other models, the effects of interphase section are included. The results obtained from

There has been tremendous recent interest in Direct Air Capture (DAC) systems. A key part of any DAC system are the multiple air intake units. In particular, the arrangement of such units for optimal capture and sequestration is critical. Accordingly, this work develops an easy to use model for a modular unit system, where an approximate flow field is computed for each unit and the aggregate flow field

The drying phenomenon in soils involves complex interactions between thermal, hydrological, and mechanical effects within a multiphase system. While several researches (both mechanics and mixture theory approach) has been applied to study various thermo-hydro-mechanical (THM) coupled processes in porous media, incorporating both multiphase flow and phase change in soil drying remains limited. This

The paper proposes a transparent and compact form of constitutive and equilibrium relations for the plane thermoelasticity of quasicrystal solids. The symmetry and positive definiteness of the obtained extended tensors of material constants are studied. An extension of the Stroh formalism is proposed for solving plane problems of thermoelasticity for quasicrystals. It is proved that the eigenvalues

Estimation of macroscopic properties of heterogeneous materials has always posed significant problems. Procedures based on numerical homogenization, although very flexible, consume a lot of time and computing power. Thus, many attempts have been made to develop analytical models that could provide robust and computationally efficient tools for this purpose. The goal of this paper is to develop a reliable

A new scaling theory called finite similitude has appeared in the open literature for the scaling of physical systems. The theory is founded on the metaphysical concept of and consequently can in principle be applied to all physics. With regard to the application of the theory to multi-physics however, an obstacle is dissimilar mathematical formulations, that are preferred and applied in practice.

Micromechanical modelling of particulate composites with non-ellipsoidal particle shapes presents significant challenges because analytical approaches based on the fundamental results of Eshelby cannot be used. On the other side, direct numerical evaluations by finite element analysis can involve high computational cost in the case when particle features have small radius of curvature, sharp edges

Although auxetic metamaterials exhibit unique and unusual mechanical properties, such as a negative Poisson's ratio, their mechanics remains poorly understood. In this study, we model a graded beam fabricated from graphene origami-enabled auxetic metamaterials and investigate its dynamics from the perspective of different shear deformation theories. The auxetic metamaterial beam is composed of multiple

A three-dimensional rate-independent framework consistent with thermodynamics is presented to study the dissipative response of metals. The entropy inequality is transformed into equality by introducing a non-negative, continuous rate of dissipation function. The constitutive relation that relates the Hencky strain and Cauchy stress is parametrized by replacement stress, instead of the plastic strain

We propose a weak form of the transient heat equations for solid bodies, as a time-dependent spatial variation of the heat displacement vector field, whose time derivative is the heat flux. This develops the variational principle originally proposed by Biot, inasmuch Fourier’s law is embedded as a holonomic constraint, while energy conservation results from the variation (the vice-versa from Biot)

Hard-magnetic soft (HMS) beams made of soft polymer matrix embedded with hard-magnetic particles can generate large and fast deformation under magnetic stimulation. Dynamic modeling and simulation of HMS beams interacting with complex environment are challenging in terms of computational accuracy and efficiency. This paper presents a method for high-order modeling and efficient computation of HMS beams

The study aims to investigate how the mechanics of swelling of a polymer gel is affected by the presence of free-chains due to a partial cross-linking process. The analysis is focused on the equilibrium solution of the mechano-diffusion problem under different states, corresponding to different polymer network fractions before diffusion starts. The limit situations of perfectly cross-linked polymer

Flows of an incompressible Navier–Stokes fluid are frequently assumed to take place in domains whose boundaries are rigid and that the fluid adheres to them, i.e. there is the “no-slip” on the interface between the rigid solid and the flowing fluid. However, in many interesting problems the walls respond as (visco)-elastic structures and different slipping conditions on the fluid–structure interface

A perturbation expansion is offered for the micromechanical prediction of the bifurcation buckling of soft viscoelastic composites with imperfections (e.g. wavy fibers). The composites of periodic microstructure are subjected to compressive loading and are undergoing large deformations. The perturbation expansion applied on the imperfect composites results in a zero and first order problems of perfect

Piezoresistive porous elastomers () are gaining attention in the field of flexible electronics due to their unique properties including ultra softness, ultra lightness, and high sensitivity. These properties can be precisely adjusted through advanced material synthesis and micro/nanofabrication technologies that control the size, shape, and composition of the functional nanoparticles. Despite various

A mapping technique for enhancing the visualisation and analysis of the flow structure in regions near the wall is presented. After identifying a near-wall region of interest, the output of the proposed mapping technique is an analytical expression of the flow variables, satisfying the governing PDEs and boundary conditions, on a stencil of standardised morphology.

Implicit elasticity presents the general response of materials without imposing assumptions at the fundamental level. A popular implausible assumption of continuum mechanics is that the reference configuration is stress-free, since residual stress is ubiquitous in Nature. This paper develops large and small deformation implicit elasticity frameworks using residually stressed reference configurations

If an elastic body is defined as one that does not dissipate energy into heat, the classes of elastic bodies not only include the Green elastic solid, but also some types of implicit constitutive relations recently presented in the literature. In this paper one of such new implicit relations is studied in detail, wherein the energy function depend on the second Piola–Kirchhoff stress tensor and the

The force method and displacement method on the basis of the reciprocal theorem play an important role in the field of structural mechanics and have been successfully applied in structural mechanics. However, it is interestingly found that the unexpected paradox exists when the authors attempt to apply it to problems of deformations of strain gradient beams. The reciprocal relation between higher order

Radially transverse isotropic inclusions in homogeneous isotropic elastic host media are considered. Mellin transform method is used for solution of the volume integral equation of the problem for an isolated inclusion subjected to a constant external stress (strain) field. The tensor structure of the solution is revealed with precision to three scalar functions of the radial coordinate, and the system

Investigation of the geometrical nonlinear action of doubly curved shell panels (DCSPs) in micro scale is the main target of this paper. The proposed microshell panels (MSPs) are assumed to be made of an auxetic honeycomb core (AHOC), leading to negative magnitudes of Poisson's ratio, covered by two nanocomposite enriched coating layers (NCECLs). To conduct the size-dependent nonlinear analysis and

A large electric field is typically present in anodic or passive oxide films. Stresses induced by such a large electric field are critical in understanding the breakdown mechanism of thin oxide films and improving their corrosion resistance. In this work, we consider electromechanical coupling through the electrostrictive effect. A continuum model incorporating lattice misfit and electric field-induced

The effect of a nanoplate buckling at a circular nanohole under the remote uniaxial tension is studied incorporating the surface energy in accordance with the Gurtin–Murdoch surface elasticity model. The hole surface within the framework of the plane problem and the faces of the plate within the framework of the Kirchhoff theory of the plate bending are characterized by both the surface elasticity

We investigate the impact of fluid drainage on the stress–strain state of a fluid–saturated reservoir. Our focus is on the transition from an elastic to an elastoplastic state of the rock mass and the appearance of constitutive instability during plastic yield. We determine the onset of inelastic deformations using the Drucker–Prager yield criterion and Eaton’s solution for an elastic medium. Our findings