This paper investigates the post-buckling behavior of functionally graded porous (FGP) perfect/imperfect cylindrical shells under external pressure in a thermal environment. The properties of these porous cylindrical shells are assumed to be temperature-dependent, determined using the modified rule of mixture and Touloukian formulation. The governing equations are derived from classical shell theory

The stability of composite structures are fundamental problems in continuum mechanics. In present study, considering piezoelectric and electrostrictive effects simultaneously, electro-induced nonlinear buckling and post-buckling characteristics of graphene platelets (GPL) reinforced functionally graded dielectric circular plates are examined. Firstly, equivalent dielectric constant and Young’s modulus

An important part for material modeling is the consideration of electromagnetic fields. In this paper, we add them to Hamilton’s principle for mechanical and thermal fields. We begin with a brief introduction to the electric and magnetic limit cases, which allows a non-relativistic formulation. After introducing the thermodynamic fundamentals, we present the Hamilton functionals for the limit cases

Understanding and accurately quantifying thermoelastic damping (TED) in micro/nanoresonators is a major step in designing them to work well. Empirical and theoretical evidence suggests that classical elasticity theory (CET) and the Fourier heat equation break down when applied to structures with minuscule dimensions. This research presents an innovative framework to approximate TED value in miniature

The paper considers a time-iterative approach, to solve a classical 2D problem of hydromechanics for a viscous fluid flow around a circle. Using the boundary integral equation method and special Green’s function outside the cylinder, a closed system of integral representations is obtained, to determine the perturbed values of the stream and vorticity function in the flow region. The solution is constructed

The problem of the influence of distributed dislocations on the equilibrium stability of a rectangular bar loaded with a longitudinal force is investigated. In the subcritical (unperturbed) state, the body experiences a finite plane inhomogeneous deformation. The dislocation density tensor depends on the coordinate measured along the bar thickness and has only one nonzero component corresponding to

We give an explicit description of the spectral closure for the three-dimensional linear Boltzmann-BGK equation in terms of the macroscopic fields, density, flow velocity and temperature. This results in a new linear fluid dynamics model which is valid for any relaxation time, thus providing an optimal hydrodynamic model for rarefied gas flow over a large range of Knudsen numbers. The non-local exact

The compaction process is often carried out in relation to transportation infrastructure. The process is complex since the soil is a heterogeneous environment. Adequate compaction is necessary to ensure the homogeneity and durability of the pavement. This paper presents a novel visual method for assessing soil compaction. A slow-motion camera (optical sensor) and tracking markers placed on the compaction

A kinematic model of 4D continuum with different types of symmetry is introduced and a unified kinematic model of long-range electromagnetic and gravitational fields is proposed. We define the 4D vector potential, introduce 4D distortion tensor, and show that its antisymmetric part gives the classical definition of the electric field intensity vector and the pseudovector of magnetic induction. On the

Liquid crystal elastomers are a class of materials which shows unusual characteristics due to its dual nature, i.e. the orientational behavior of liquid crystals combined with the intrinsic features of elastomers. Apart from inhomogeneities, the mesogens, which are linked to the polymer chains in LCEs and are modeled as a unit nematic director, are oriented along a unique direction in case of a monodomain

The corresponding mathematical model of cyclic viscoplastic deformation of damaged material, a structural element counteracting multiaxial disproportionate modes of hybrid thermomechanical loading, is considered. The model is determined by the relations between viscoplastic deformation and failure, as well as the evolution equations of damage accumulation kinetics and the material strength criterion

Polyamide 12 (PA12) is a semi-crystalline thermoplastic used in the automotive and aerospace industries due to its high resistance to chemicals and abrasion and its good thermal stability. The material can be processed with various manufacturing technologies, including selective laser sintering (SLS), which offers great potential for industrial production due to its excellent and reproducible mechanical

A plane strain problem for forced time-harmonic vibrations of an elastic layer lying on an acoustic half-space is considered. The validity of the approximate formulation involving the classical Kirchhoff theory for plate bending as well as its shortened forms is investigated. The developed asymptotic framework demonstrates that the aforementioned theory is not able to predict the effect of the plate

This research investigates the scattering behavior of Love waves, also known as Q waves in seismology, induced by an interface crack between an orthotropic elastic layer and an isotropic elastic half-space where the orthotropic layer serves as a wave guide medium. The Dispersion relation and phase velocity have been obtained by using convenient boundary conditions for the Love wave propagation. Using

The dimensions of seismic metamaterials pose limitations that make attenuating ultra-low frequency seismic surface waves (with a starting frequency near 0 Hz) in confined spaces through structural design a significant challenge. This paper introduces a locally resonant seismic metamaterial (SM) characterized by an ultra-low frequency wide bandgap, created by placing a nylon barrier embedded with steel

We develop a theory for thermal convection in a double porosity material of Brinkman–Forchheimer type when there is a single temperature. The saturating fluid is one of Kelvin–Voigt type, and the equation for the temperature is one due to C.I. Christov. It is shown that the global nonlinear stability threshold coincides with the linear stability one. A thoroughly analytical discussion of both linear

This paper concerns the general axisymmetric problem in plasticity in conjunction with the hypothesis of Haar and von Karman for calculating stress fields. No other restriction is imposed on the yield criterion. The stress equations comprising the yield criterion and the equilibrium equations without body forces are statically determined in the sense that there are four equations involving only the

The paper deals with the derivation of asymptotically correct equations governing the long-wave bending response of a rectangular ultrathin elastic isotropic plate taking into account surface effects within the framework of the Gurtin-Murdoch theory of surface elasticity. The upper and lower faces are assumed to be pre-stressed by residual surface stresses which can be either tensile or compressive

This paper offers an informal instructive introduction to some of the main notions of geometric continuum mechanics for the case of smooth fields. We use a metric invariant stress theory of continuum mechanics to formulate a simple generalization of the fields of electrodynamics and Maxwell’s equations to general differentiable manifolds of any dimension, thus viewing generalized electrodynamics as

A novel variational model is proposed to address design control for composite multilayered metamaterials self-assembled via vapor deposition. The model is formulated within the framework of continuum mechanics, with the reference configuration corresponding to the equilibrium lattice of the substrate material. To account for the potential mismatch with the free-standing equilibrium lattices of each

This article examined the thermoelastic behavior of functionally graded (FG) materials using a partially modified thermoelastic heat transfer model. The model utilized the three-phase lag thermoelasticity theory and incorporated higher-order fractional derivatives of Caputo and Fabrizio to address advanced thermodynamic and mechanical properties. These improvements showed great potential for applications

The article analyzes the impact of contact conduction on the intensity of heat flow in a bundle of steel round bars. This issue is related to the optimization of the heat treatment of the bars, as contact conduction is a key mechanism in the heating process of the considered charge. A proprietary computational model, based on the analysis of thermal resistances, was used for the analysis. To quantify

Viscous fingering instability has been analyzed through empirical studies using miscible flow displacement in fractured porous media. While significant research has been conducted on viscous fingering, limited information is available regarding its behavior in fractured porous structures. The experiments were conducted in rectangular porous models with fractures oriented at \({0}^\circ \), \({45}^\circ

This paper is devoted to the static bifurcation of a nonlinear elastic chain with softening and both direct and indirect interactions. This system is also known as a generalized softening FPU system (Fermi–Pasta–lam nonlinear lattice) with \(p = 2\) nonlinear interactions (nonlinear direct and second-neighbouring interactions). The static response of this n-degree-of-freedom nonlinear system under

This study investigated the thermoelastic vibration behavior of microbeams supported by a Pasternak foundation, characterized by two elastic parameters: the shear layer modulus and the Winkler modulus. The thermoelastic behavior of the beam was modeled using the Moore–Gibson–Thompson (MGT) heat conduction theory, which accounted for finite thermal wave speeds and included a higher-order time derivative

We consider a model of two layers for two cases. In the first case, a viscoelastic upper layer over an elastic half-space. In the second case, an elastic upper layer over a viscoelastic half-space. The upper layer’s surface is taken to be traction-free and is subjected to a constant thermal shock. This model is solved in the context of the generalized thermoelasticity theory with one relaxation time

Detailed derivations of the Legendre-Hadamard necessary conditions for energy-minimizing states of fiber-reinforced three-dimensional solids and two-dimensional shells are presented. The underlying conceptual framework is Cosserat elasticity theory in which the Cosserat rotation field controls the orientation of the embedded fibers. This is partially coupled to the continuum deformation gradient by

In our study we approach a Cosserat thermoelastic body in which we take into account both the usual temperature and the microtemperature, that is, the temperature of the microparticles of the body. After constructing the mixed problem with initial and boundary values, in this context, we define an appropriate Hilbert space in which we obtain a temporal evolutionary equation which is equivalent to the

Purely compressed shells are often elegant and highly efficient structural forms, but this leanness may create risk if they are subjected to unexpected patterns and magnitudes of loading, such as may arise due to seismic events. In the same way that historic masonry structures were designed to sustain loads by activating purely compressive force paths, a modern metamaterial can be designed for specific

This paper presents and analyzes the cyclic indentation response of a linear viscoelastic material over the entire time range of the relaxation processes using conical or spherical indenters. Finite Element simulations of cyclic indentation on two Generalized Maxwell materials with different relaxation spectra were performed. A variety of cyclic responses to indentation were generated and analyzed

In the field of mechanical engineering, structural systems that can present different types of symmetries are frequently encountered. The choice of such solutions with symmetries is generally the result of considering factors such as reducing design and production costs, logistical considerations, but also for aesthetic reasons. The existence of these symmetries inside some structures brings new properties

In the present work a formulation of evolutive laws and complementarity conditions in non-smooth elastoplasticity is discussed. The treatment addresses the problem of non-smooth elastoplasticity which is represented by functions characterized by singularities and defined by non-smooth yielding limit conditions and non-differentiable functions. The mathematical theory of subdifferential calculus is

Our study falls within the linear theory of thermoelasticity of Cosserat media. Unlike other works that fall into similar contexts and that use the entropy balance low, our approach is based on an entropy production inequality. The entropy flux tensor is introduced and thermoelastic media are considered for which the stress tensors are dependent on the temperature gradients. In this way, a fourth-order

Underground tunnels serve as vital infrastructure for road and rail transportation, oil and gas pipelines, power grids, and military applications; they are inherently subject to harsh environments characterized by extreme temperatures, chemical erosion, and sudden impacts. To address these challenges, the sophisticated coupled thermoelastic diffusion dynamic model has been developed based on Biot’s

This paper proposes a method for determining the mechanical properties of thin films of highly elastic materials. The method is based on an experiment of indenting a circular specimen with a hole in the center by a ball indenter. The value of the maximum indenting force is used as experimental data. This method determines the neo-Hookean model parameter for incompressible materials, factoring in indenter-specimen

At the microscale and nanoscale, materials exhibit size-dependent behaviors that classical models cannot capture. This analysis introduces a size-dependent higher-order thermoelastic heat conduction model, incorporating spatial and temporal nonlocal effects in a micropolar visco-thermoelastic medium subjected to laser pulse heat flux. The two-phase delay model, featuring higher-order temporal derivatives

We consider a transversely isotropic piezoelectric spheroidal inhomogeneity embedded in an infinite transversely isotropic piezoelectric matrix subjected to a uniform remote axisymmetric electromechanical loading. The inhomogeneity-matrix interface is spring-type in elasticity and weakly conducting in dielectricity. The same degree of interface imperfection in elasticity is realized in both the normal

Aluminum alloys are light and corrosion-resistant materials, which is why they are widely used in structures in many industrial fields (construction, automotive, electric cables). The article deals with the aluminum busduct structure. Therefore, the mechanical and especially electrical properties of busduct welds are the basic criteria for assessing the quality of welds. The aim of the work was to

The use of thermal conduction models, particularly the double-phase lag thermal wave model, is vital for improving thermal therapies in biological tissues. However, existing models have limitations that hinder their practical application. This paper introduces a modified Pennes fractional thermal equation for biological heat transfer that integrates the double-phase lag concept and the fractional Atangana-Baleanu

This study presents a comprehensive analysis of corneal biomechanics using shear wave elastography, leveraging finite element modeling to investigate the mechanical properties of corneal tissue. A 3D axis-symmetric corneal model was developed and subjected to various simulated conditions, including changes in intraocular pressure (IOP), boundary conditions, excitation pressure, and corneal curvature

In this study, a coupled transient thermomechanical finite element model is developed to examine the laser powder bed fusion (L-PBF) process of the Inconel 718 (IN718) and Oxide Dispersion Strengthened (ODS) superalloys (ODS-IN718). The linear isotropic elastic perfectly plastic constitutive model is implemented for the mechanical part whereas all the thermophysical properties are defined as fully

We propose a continuum viscoplasticity model for metals where the kinematic aspects and those pertaining to microstructural reorganizations are intrinsically described through Riemannian geometry. Towards this, in addition to a Euclidean deformed manifold, we introduce a time-parametrized Riemannian material manifold where a metric tensor characterizes the irreversible configurational changes due to

Harmonic boundary excitation of localized oscillatory waves in a mass-in-mass metamaterial is studied. It is shown that switch-on/off of the boundary excitation gives rise to a formation of a sequence of such waves, which propagate keeping its form and velocity. The wave formation is achieved only outside the band gap interval of the excitation frequencies. The boundary reflection of the localized

In this study, the effect of varying weight percentages of carbon fiber powder (CFP) (10 wt.%, 20 wt.% and 30 wt.%) on the mechanical properties of polycarbonate (PC) components produced by plastic injection molding was investigated using analytical, numerical and experimental methods. This research is a novel study in terms of comparing experimental data with microscopic features and full-scale analysis

We propose a three-dimensional macroscopic continuum model designed to predict the remodeling phenomenon of bone tissue. In the proposed model, we focus on the evolution of two crucial stiffness parameters: the bulk and shear moduli. These parameters independently adapt to the mechanical demands to which bone tissue is subjected, mainly to withstand hydrostatic and deviatoric deformations. These mechanical

In this article, the nonlinear coupled two-dimensional space-time fractional order reaction-advection–diffusion equations (2D-STFRADEs) with initial and boundary conditions is solved by using Shifted Legendre-Gauss-Lobatto Collocation method (SLGLCM) with fractional derivative defined in Caputo sense. The SLGLC scheme is used to discretize the coupled nonlinear 2D-STFRADEs into the shifted Legendre

The connection of two orthogonal families of parallel equispaced duoskelion beams results in a 2D microstructure characterizing so-called tetraskelion metamaterials. In this paper, based on the homogenization results already obtained for duoskelion beams, we retrieve the internally-constrained two-dimensional nonlinear Cosserat continuum describing the in-plane mechanical behaviour of tetraskelion

The paper presents an analytical model to study the shear driven debonding of a composite cantilever beam subjected to a point load. The composite structure consists of two elastic beams connected by an interface layer, and the model uses cohesive zone models to simulate the degradation process at the joint. These cohesive zone models are characterized by non-continuous and linear softening in the

Orthodontic tooth movement is the fundamental phenomenon underlying the treatment of dental malocclusions. For orthodontic treatment to be efficient and effective, the amount of force applied to the teeth for every kind of movement should be appropriately dosed, because it is associated with the risk of side effects and the treatment time. However, our knowledge of the complex cascade of events that

This paper considers the problem of symmetrical three-point bending of a prismatic beam with an edge crack. The solution is obtained by the mixed finite element method within the simplified Toupin–Mindlin strain gradient elasticity theory. A mixed variational formulation of the boundary value problem for displacements–strains–stresses and their gradients is applied, simplifying the choice of approximating

In this work, we investigate a dynamic internal dissipation mechanism in the context of cement-based materials by introducing a 1D-enhanced micromorphic beam model with a dynamic internal friction term. Here, we consider an inherent feature in concrete-like materials arising from the multi-scale structure, namely, microcracks. Thus, we assume that the internal dissipation of the energy depends on the

This study examines a mixed initial-boundary value problem in thermoelastic materials with a double porosity structure, taking into account the effects of microtemperature. The existence of a solution is established by converting the problem into a Cauchy-type problem. Given the complexity of the equations, unknowns, and conditions, we apply contraction semigroup theory within a specific Hilbert space