This study presents an effective procedure for extracting the first few bridge frequencies using the data collected by a moving test vehicle. Previously, the effectiveness of the vehicle scanning method for bridge frequencies was hampered by factors such as vehicle frequency and road surface roughness. To this end, the contact-point response of the vehicle with the bridge that is free of the vehicle

Stress-induced phase transformations in linear elastic solids are considered for the case of plane strain on the basis of a previously developed procedure that includes finding the optimal composite microstructures which provide the exact lower bound of the energy and the equilibrium new phase volume fraction that satisfies the thermodynamic equilibrium condition. Stress–strain diagrams are constructed

We investigate antiplane Stoneley waves, localized at the discontinuity surface between two perfectly bonded half-spaces. Both half-spaces are elastic linear isotropic and possess a microstructure that is described within the theory of couple stress materials with micro-inertia. We show that the microstructure deeply affects wave propagation, which is permitted under broad conditions. This outcome

The kinematic-wave theory of particle settling in tube centrifuges has become a subject of scientific discussion. Specifically, the common assumption was made that the flow in a rotating tube of large length/diameter ratio can be treated in one-dimensional approximation. The respective results have been found in agreement with measurements. However, an analysis of the two-dimensional settling process

This paper deals with the nonlinear buckling and post-buckling of sandwich cylindrical panels with non-uniform porous core and functionally graded face sheets. The sandwich cylindrical panels are subjected to axial compression load. Two cases of boundary conditions are considered. Based on the Donnell shell theory with von Kármán geometrical nonlinearity in conjunction, the governing equations are

We report on the unified approach to the classification of defects in continuum-based analysis of the defect self-distortions. Defects of various dimensionality including point, linear, surface, and volume defects are considered depending on the domain of self-distortion definition. The results of analytical calculations of elastic fields and the energies of dislocations, disclinations, and inclusions

Research results of damage and failure of unidirectional laminate packages under tension are presented. A study of the kinetics of damage and failure of the laminate structure is carried out by means of acoustic emission (AE) and synchronous video recording. The conformity between failure proceses occurring on the microscopic, mesoscopic and macroscopic scale levels and the recorded AE events including

Precision-guided projectiles (PGPs) experience severe shock loads during launch emanating from the propellant gases and the surrounding air. The complex flow environment that exists within the confined space of the barrel and at muzzle exit is significantly influenced by the speed of the projectile, the compressibility of the air, and the rapid state transition of the projectile from the confined volume

The present work unveils the features of heat dissipation and acoustic emission accompanying the fatigue crack growth in a titanium alloy (Ti-0.8Al-0.8Mn and Ti Grade 2) using the compact tension and Charpy V-notch specimens. The quantitative measurements of the heat dissipation rate were carried out by an original heat flux sensor. The obtained results reveal that there exist two appreciably different

A model for calculating the sliding friction force between a surface with regular relief and a viscoelastic foundation in dry conditions is suggested. The Winkler type viscoelastic foundation with both normal and tangential compliances is considered. The local Coulomb friction law is assumed between the surfaces. The total friction is calculated including the contribution of both local adhesive friction

We study unsteady elastic-diffusion vibrations of a rectangular isotropic Kirchhoff plate. The coupled elastic-diffusion multicomponent continuum model is used to formulate the problem. We are using the d’Alembert variational principle to obtain from the model the equations of longitudinal and transverse vibrations of a rectangular isotropic elastodiffusive Kirchhoff plate. The problem solution is

Multilayered bulk Al–Cu–Al metal-matrix composite was fabricated by means of high-pressure torsion and subsequent annealing. The resulting composite had a heterogeneous structure consisting of ductile aluminum matrix and hard intermetallic inclusions with a gradient decrease in grain size and layer thickness when moving from the center to the periphery of the sample. Precipitation of \(\hbox {Al}_{2}\hbox

The paper is concerned with the classical Flamant problem of the theory of elasticity. The classical solution of this problem obtained by A. Flamant in the nineteenth century specifies the stresses and the displacements induced in a half-plane by a concentrated force applied to the half-plane boundary in the normal direction. Being presented in numerous textbooks in the theory of elasticity, this solution

The present problem aims to study the scattering behavior of SH-waves by a circular cavity near two symmetrically permeable interface cracks in the piezoelectric bi-material half-space. The steady-state response of the problem is obtained, with the aid of the Green’s function method and the complex function method. Above all, the essential expression of Green’s function is constructed by the mirror

A variational principle of Herglotz type with a Lagrangian that depends on fractional derivatives of both real and complex orders is formulated, and the invariance of this principle under the action of a local group of symmetries is determined. By the Noether theorem the conservation law for the corresponding fractional Euler–Lagrange equation is obtained. A sequence of approximations of a fractional

Wear is one of the main mechanical factors that limits the survival of total knee replacements (TKRs) and it is known to be highly dependent on the local kinematics of the knee joint. In this study, an analytical wear model was coupled to a multibody dynamic model to obtain wear distribution at the lateral and medial contact plateaus of different TKRs. The major aim was to analyze if wear distribution

In the paper, a pragmatic approach to finding the dual formulation for isotropic perfectly plastic materials given a dissipation potential dependent on three cylindrical invariants and involving the Ottosen shape function is proposed and illustrated by examples. The main goal is to provide instructions on how to perform the Legendre transformation used when passing from a dissipation potential to its

Closed-form unified solutions using the distributed transfer functions (DTFs) method are presented for the first time for the static short/open-circuit sensing and voltage/charge actuation of moderately thick beam cantilevers with co-localized surface-bonded piezoelectric patches. For this purpose, the smart beam is divided into three segments, of which the clamp and free sides parts are elastic, while

In this paper, a Duffing-type energy harvester with time delay circuit under narrow-band random excitation is studied by using the method of multiple scales. The analytical expressions of the steady-state responses near the principal resonance and their stable conditions are derived. Results show that the phenomenon of stochastic jump is found, and the operational bandwidth of the nonlinear energy

By employing Mindlin’s Form II gradient elasticity theory (strain gradient elasticity theory), we investigate the SH surface wave propagating in a strain-gradient layered half-space. The dispersion equation of the SH surface wave is derived analytically. For the general case where both the surface layer and the half-space are strain-gradient elastic materials, the dispersion equation involves 10 material

The overall time-dependent and nonlinear responses of two-phase magnetostrictive polymer composites are obtained by coupling micromechanical analysis for magnetoelastic coupled composites with a time-integration algorithm for thermorheologically complex materials. The nonlinear magnetoelastic behavior is due to large magnetic driving fields while the nonlinear viscoelastic response is associated with

A finite-element model is presented based on the four-variable shear deformation refined theory for active vibration control of a functionally graded carbon nanotube-reinforced composite spherical panel with integrated piezoelectric layers, acting as an actuator and a sensor. The linear distribution of the electric potential across the thickness of the piezoelectric layer and different distribution

The unsteady wake of a rotating and translating sphere is experimentally investigated at Reynolds numbers (Re) ranging from 115 to 550 for two rotational speeds. Non-dimensional rotational speed, \(\Omega^{ * }\), is defined as the ratio of the maximum azimuthal speed of the sphere and the speed of translation. Motion of the sphere is generated using a specially designed mechanism in a channel, and

This work proposes a new calculation algorithm of the Wentzel–Kramers–Brillouin (WKB) solution for slow linear time-varying (LTV) systems based on the recursive formulation. For a linear dynamic system with time-varying (TV) mass, damping or stiffness, the recursive relations in real function form among the components of the WKB solution are obtained. The integral terms within the sampling intervals

The main purposes of the present paper are as follows: (1) to analytically derive the general solution (stress functions) for an orthotropic elastic half plane with a crack or a notch; (2) to derive the Riemann–Hilbert equation as the analytical method; (3) to solve the present problem using two methods, one is a Cauchy integral method and other is a Riemann–Hilbert method; and (4) to derive the general

Due to the high computational cost of finite element analyses, particularly in optimization tasks, establishing a high-fidelity surrogate model is of immense importance to engineers. Analyses of fiber steering composite cylinders are costly and often involve high nonlinearity. Among different metamodeling approaches, machine learning techniques provide effective models that can capture high nonlinearity

An anisotropic stress-driven growth model of living tissue is presented for tissue engineering based on Eulerian deformation tensor and growth potential. The evolution of growth is simply defined by the homeostatic pressure and Cauchy stress caused by the left Cauchy–Green deformation tensor that is an Eulerian deformation measure. For more generality, anisotropy is considered by proposing the concept

The present paper is devoted to the development of the method for searching an approximate solution of non-stationary problems on a variable interval. This method was first proposed by L.I. Slepyan. Here, the field of its applicability has been expanded to systems of equations, including equations of both hyperbolic and parabolic type. We describe the procedure of such approach in detail on a number

This paper aims to contribute with a hierarchically enhanced recovery-based error estimator by using the Zienkiewicz–Zhu (ZZ) recovery procedure and a generalized finite element formulation. The proposed stress recovery consists in an approximation procedure that is enriched hierarchically by using partition of unity (PU) and an enrichment function. In other words, the approximation matrix used for

The paper presents the first results of an exploratory research work, aiming the experimental evaluation of the mechanical contact between conforming surfaces of metallic bodies. The proposed procedure—that is based on the measurement of electric potentials—is able to determine the actual contact pattern and estimate the force distribution on the opposing surfaces. In the present paper, the contact

In the version of the article originally published [1], Eqs. (19)–(21) and (31) were shown incorrectly. The corrected equations are the following.

In a recent paper of the authors, a novel nodal-based floating frame of reference formulation (FFRF) for solid finite elements has been proposed. The nodal-based approach bypasses the unhandy inertia shape integrals ab initio, i.e. they neither arise in the derivation nor in the final equations of motion, leading to a surprisingly simple derivation and computer implementation without a lumped mass

This paper deals with the buckling phenomenon of periodic Vierendeel beams. Closed-form solutions for critical loads and deformed shapes are presented. They are built by exploiting several auxiliary solutions obtained for the discrete periodic girder and for a geometrically nonlinear micro-polar equivalent model. In particular, the girder when subjected to sinusoidal self-equilibrated systems of inner

A passively self-tuning resonator configuration is presented in this study. Under certain operating conditions, a self-resonating system has the capability to passively adjust dynamical characteristics until the whole system becomes resonant. A clamped–clamped beam with an attached mass sliding along the beam and a slight gap that, under a harmonic input excitation and well-defined operating regime

Mechanical metamaterials are systems which derive their mechanical properties from their structure rather than their intrinsic material composition. In this work, we investigate a class of highly anisotropic mechanical metamaterials designed by the introduction of diamond and elliptically shaped perforations which possess the ability to show auxetic behaviour. By the use of finite element simulations

The objective of this contribution is the computation of the Airy stress function for functionally graded beam-type structures subjected to transverse and shear loads. For simplification, the material parameters are kept constant in the axial direction and vary only in the thickness direction. The proposed method can be easily extended to material varying in the axial and thickness direction. In the

In this paper, a numerical solution strategy is proposed for studying the large deformations of rectangular plates made of hyperelastic materials in the compressible and nearly incompressible regimes. The plate is considered to be Mindlin-type, and material nonlinearities are captured based on the Neo-Hookean model. Based on the Euler–Lagrange description, the governing equations are derived using

In the original paper, we erroneously used the total potential energy (Helmholtz free energy of the material plus potential energy of the external forces) in the entropy inequality.

A new efficient multiscale simulation method based on fast Fourier transform (FFT) is developed to analyze the nonlinear behaviors of three-dimensional four-directional braided composites under compressive loading which is the key concern for design in the engineering application. The braid yarns within the composites are represented by the microscale unidirectional representative volume element. Both

A gradient-enhanced ductile damage model at finite strains is presented, and its parameters are identified so as to match the behaviour of DP800. Within the micromorphic framework, a multi-surface model coupling isotropic Lemaitre-type damage to von Mises plasticity with nonlinear isotropic hardening is developed. In analogy to the effective stress entering the yield criterion, an effective damage

The effective properties of the fiber-reinforced composite materials with fibers of circle cross section are investigated. The novel estimation for the effective coefficient of thermal conductivity refining the classical Maxwell formula is derived. The method of asymptotic homogenization is used. For an analytical solution of the periodically repeated cell problem the Schwarz alternating process (SAP)

On the basis of a theoretical study, this research incorporates an eccentricity into a system of compressed double-walled carbon nanotubes (DWCNTs). In order to formulate the stability equations, a kinematic displacement with reference to the classical beam hypothesis is utilized. Furthermore, the influence of nanoscale size is taken into account with regard to the nonlocal approach of strain gradient

In the present research, a new criterion based on maximum shear stress (MSS) theory is developed for fracture investigation of orthotropic materials under mixed mode I/II loading. The crack is assumed to be embedded both along and across the fibers in the isotropic matrix. Self-similar crack propagation is assumed based on experimental observations and the reinforcement isotropic solid (RIS) concept

In the present manuscript, the time-dependent capillary gravity wave motion in the presence of a current and an undulated permeable bottom is analyzed. The spectral method is used to simulate the time-dependent surface elevation. Also, the Laplace–Fourier transform method is used to obtain the integral form of the surface elevation, and the asymptotic form of the associated highly oscillatory integral

Glacier ice flow is shaped and defined by several properties, including the bedrock elevation profile and the basal slip distribution. The effect of these two basal properties can be present in similar ways in the surface. For bedrock recovery, this makes distinguishing between them an interesting and complex problem. The results of this paper show that in some synthetic test cases it is indeed possible

In this article, the propagation of Rayleigh surface waves in a piezothermoelastic transversely isotropic layer lying over a piezothermoelastic transversely isotropic half-space is investigated in the context of the Green–Naghdi model type III of hyperbolic thermoelasticity. The secular equation of Rayleigh surface waves is derived, and different cases are discussed. Phase velocity, attenuation coefficient

By endowing El Fatmi’s theories of bars with first-order warping functions due to torsion and shear, a family of theories of bars, of various applicability ranges, is effectively constructed. The theories thus formed concern bars of arbitrary cross-sections; they are reformulations of the mentioned theories by El Fatmi and theories by Kim and Kim, Librescu and Song, Vlasov and Timoshenko. The Vlasov-like

A technique for detecting the occurrence and development of local damage in a material is presented. It is based on experimental strain values measured by a limited number of sensors and the results of numerical simulation of a stress–strain state. The technique is applicable for external loads on a controlled object that vary over time by a constant factor. The occurrence and location of damage are

Interactive vibrations and buckling of double current-carrying strips (DCCS) are investigated in this study. Considering the rotational and transverse deformation of the strip, four coupled equations of motion are obtained using Hamilton’s principle. Using the Galerkin method, mass and stiffness matrices are extracted and the stability of the system is determined by solving the eigenvalue problem.

This paper addresses the question to which extent the stiffness of an elastic foundation in general, and of a discontinuity occurring in the foundation in particular, affects the stresses to which a beam resting on such a foundation is exposed to. This is particularly relevant for tramway rails, where foundation discontinuities may be generated in the course of maintenance works. In the presented work

In this paper, a novel analytically method for analyzing the dynamic behavior of beams, under different boundary conditions and in presence of cracks, is proposed. Applying the Timoshenko beam theory and introducing the auxiliary functions, the equation of motion is derived using the Hamiltonian approach. The natural frequencies are obtained by applying the Euler–Bernoulli method and are derived by

In this study, the stability of sandwich conical shells covered by functionally graded and uniform distributed carbon nanotube-reinforced composite coatings under external pressures is carried out. The mechanical properties of the carbon nanotube and matrix are assumed to be graded through the thickness of the coatings via three types of grading rule. The basic relationships and stability equations

In the present contribution Castigliano’s theorem is extended to find more accurate results for the deflection curves of beam-type structures. The notion extension in the context of the second Castigliano’s theorem means that all stress components are included for the computation of the complementary strain energy, and not only the dominant axial stress and the shear stress. The derivation shows that

An imperfection sensitivity analysis for the nonlinear post-buckling behavior of functionally graded (FG) porous micro-tubes is performed in this research. The case of geometrically imperfect micro-tubes surrounded by a nonlinear elastic medium under axial compressive load is analyzed. Properties of the micro-tube with uniform distributed porosity are FG across the radius of the cross-section. Two

It is of great significance in the design and evaluation of anti-impact protective structures to investigate the dynamic mechanical properties of lightweight concrete structures. The present work aims to address this challenging task by the development of an improved large-diameter split Hopkinson pressure bar that can accurately predict the dynamic compressive strength and impact failure characteristics

The Payne effect, the nonlinear mechanical behavior of filled elastomers in oscillatory loading conditions, has received considerable attention in the literature. This is because of the extensive use of these materials in different industrial applications. While experimental investigations of the Payne effect have been comprehensive, the models developed to describe the behavior and predict the response

This paper presents two numerical models (Model L and Model N) and its application in the analysis of dynamic stability of beam-type structures. Both numerical models use two-noded rotation-free finite elements and take into account the exact formulation for finite displacement, finite rotations, and finite strains. Model L was previously developed and is intended for linear elastic material behavior

The dynamic response of an elastic thin plate resting on a cross-anisotropic elastic half-space to a rectangular load moving on its surface with constant speed is analytically obtained. The moving load and the plate and soil displacements are expanded in double complex Fourier series involving the two horizontal coordinates x and y as well as the time and the load velocity. Thus, the plate equation

Phenomenological constitutive equations contain material parameters which cannot be measured directly in the experiment. We address the problem of error-resistant parameter identification for models of large strain elasto-plasticity. The identification is based on tests with a heterogeneous stress state. A methodology is presented which allows us to assess the reliability of identification strategies

Solid solution strengthening plays a key role in the strength increasing of alloying metals, due to that a solid solution of alloying element causes lattice distortion to a certain extent. In the paper, the effect of solid solution magnesium additions on the edge dislocation emission from a blunted crack tip in aluminum alloys is investigated. The critical stress intensity factor for the dislocation