Rolling element bearing (REB) is a critical component in any rotating machinery. It is subjected to surface damage during operation due to localised fatigue. Any prediction about damage severity helps in effective maintenance planning. Defect size estimation is one of the methods of assessing damage severity in REB and is the subject of this study. Several researchers have formulated analytical as

We show that conventional finite element technology can be applied to topology optimization of 2D and 3D continua. Nodal design variables, classical Newton-Raphson solution for the first-order KKT equations and the screened-Poisson equation are sufficient to produce smooth results without the use of level-sets or phase-field technologies. Side-constraints are addressed with variable transformation

The submerged air-inflated membrane cylinder is studied through perturbation and numerical integration. The problem depends on the distance between the anchors and a parameter which quantifies the pressure difference. Partial similarity and full similarity solutions are found. The results show nonlinear phenomena such as instability, snap through and hysteresis, especially during the deflation process

In this paper, we study the adhesion behavior of a circular and extensible plate adhered to a rigid substrate based on the finite deformation theory. The energy method is used to derive the governing equations associated with boundary conditions. Due to the highly nonlinear nature of the problem and undetermined parameters on the boundary conditions, we solve the system of equations by an optimization-based

Buckling of a biaxially compressed anisogrid stiffened composite cylindrical panel with clamped edges is considered in this paper. The panel is subjected to compressive load applied to its curved sides. This loading results in the biaxial compression of the panel due to Poisson's effect. The anisogrid lattice reinforcement of the panel is modelled as a layer with average effective stiffness characteristics

Recently, a unified fractional heat conduction model is newly proposed, which is a further improvement of the fractional thermoelasticity theory. It would be interesting to know how the newly developed fractional derivative definitions affects the thermal fracture behavior when some defects such as cracks exist in the medium. This work is aimed at analyzing the thermal fracture problem of an elastic

An accurate constitutive model is one of the basic aspects to ensure a precise simulation. This study presents an improved unified viscoplastic model to simulate the various behavior of P92 steel under low cycle fatigue (LCF) and creep fatigue interaction (CFI) loadings. In the proposed model, an accumulated inelastic strain dependent parameter is introduced into the nonlinear kinematic hardening rule

A finite volume based approach is employed in the solution of unit cell problems at different orders of the asymptotic field expansion to construct a homogenization theory for anti-plane shear loading of unidirectional fiber-reinforced periodic structures. This new construction complements and further extends our recent contribution to asymptotic homogenization based on locally-exact elasticity unit

Nickel-based alloys are often selected for manufacturing components operating in extreme conditions such as high-temperature thermo-mechanical cyclic loadings because of their good corrosion and high temperature resistance. This is, for instance, the case for solar receivers where the material undergoes daily cycles going from ambient temperature to approximately 700 °C. To predict the material behavior

In the paper, free vibration analysis of tapered Functionally Graded Material (FGM) plate with the inclusion of porosity has been performed. The tapered porous FGM plate is considered resting on a two-parameter (Winkler and Pasternak) elastic foundation. The displacement model of the kinematic equation for the plates in the present formulation is based on the First-order shear deformation theory (FSDT)

In this work, we propose a non-classical Kirchhoff plate model to investigate surface energy and gradient elasticity effects on the static bending and free vibration behavior of micro-plates. Gurtin-Murdoch surface elasticity theory and a single-parameter gradient elasticity theory are combined to capture three types of size effects. The equations of motion and related boundary conditions of the model

This paper investigates the thermal vibration and buckling of the functionally graded carbon nanotube reinforced composite (FG-CNTRC) quadrilateral plate using the meshless method. Four distributions of the reinforcements along the thickness direction are considered, which are the uniform distributions (UD), FG-V, FG-O and FG-X. The corresponding effective material properties including Young's modulus

The analytical solutions for the mode-I and mode-II stress intensity factor (SIF) of arbitrary distributed offset parallel cracks in brittle solids were generated based on the Kachanov method and superposition principle. By analyzing the SIF ratio, effects of the horizontal interval, vertical interval, crack inclination angle and crack length on the interaction of offset parallel cracks were estimated

This paper aims at studying the influence of the different support types on the free nonlinear vibration frequency of a beam, both by analytical and numerical approaches and its dependence on the vibration amplitude. First, an analytical study of two cases of simply supported beams is carried out by using the nonlinear normal modes (NNM) and the multiple scale methods to obtain the analytical expressions

The description of a problem involving the existence of an interface or of a strong discontinuity requires to solve partial differential equations on a moving domain, whose evolution is also unknown, leading to severe difficulties, especially when the interface undergoes topological changes. The solution becomes even more complex when the whole problem domain changes, such as in mechanical problems

A theoretical study on defect and notch sensitivity in orthotropic materials is carried out, with the aim to make explicit the bridging between notch effect and defect sensitivity. Analogies and differences with the isotropic case are highlighted, and the relevant parameters necessary to quantify the transition from a fracture-mechanics-controlled to a notch-mechanics-controlled behaviour are discussed

This paper investigates the nonlinear free vibration and nonlinear dynamic hygrothermal buckling behavior of imperfect functionally graded carbon nanotube-reinforced composite (FG-CNTRC) cylindrical panels under hygrothermal environment. The nonlinear temperature distribution is assumed along the thickness direction. The structure is resting on a generalized nonlinear viscoelastic foundation which

The classical theory of elasticity is an idealized model of a continuum, which works well for many engineering applications. However, with careful experiments one finds that it may fail in describing behavior in fatigue, at small scales and in structures having high stress concentration factors. Many size-dependent theories have been developed to capture these effects, one of which is the consistent

In this paper, the nonlinear dynamic analysis of the circular truss equivalent to the cylindrical shell under the influence of the thermal excitation and the damping coefficient are studied. The annular truss structure is equivalent to the cylindrical shell structure based on the previous equivalent process, and the nonlinear dynamic equations of the equivalent cylindrical shell considering the effect

In this paper, a new system of damage detection equations for damage identification of cylindrical shells is developed based on classic finite element method, incomplete noisy modal data and model updating. Classic finite element technique in conjunction with Sander's thin shell theory is deployed in order to construct the finite element model of cylindrical shells and compute vibration data. To overcome

This work investigates two aspects linked to the nature of the feasible domain of anisotropic laminates. In the first part of the paper, proofs are given on the non-convexity of the feasible domain for full anisotropic and for membrane-orthotropic laminates, either in the lamination parameters space or in the polar parameters one. Then, adopting the polar formalism, some particular cases are studied

In this paper, the dynamic stability of axially transporting viscoelastic beams with two-frequency parametric excitation and 1:3 internal resonance is investigated for the first time. The governing equation and corresponding inhomogeneous boundary conditions are developed by the Newton’s second law. The viscoelastic characteristic of the transporting Euler-Bernoulli beam obeys the Kelvin-Voigt model

This paper focuses on the primary development of novel analytical and numerical studies for the smart plate structure due to the effects of point mass locations, dynamic motions, and network segmentations. Instead of the alternative capabilities in active and passive control systems, the technical application of the present work can also be found in the energy harvesting system. The simplified theoretical

A new formulation to calculate shakedown limit load of structures under stochastic conditions of strength and loading is developed. Direct structural reliability design is based on the required failure probabilities by chance constrained programming, which is an effective approach of stochastic programming if it can be formulated as an equivalent deterministic optimization problem.

Buckling behavior may occur during the lithiation process of wire-like electrodes, and it can cause the mechanical degradation of lithium-ion batteries (LIBs). In this study, we focused on the stress evolution and buckling behavior of wire-like electrodes with a concentration-dependent elastic modulus, and we considered the two-phase reaction. The elastic finite deformation theory was adopted to establish

The incremental normal compliance of a contact of “irregular” (non-elliptical) shape between two elastic half spaces is considered. The contact is modeled as external crack. An approximate expression for the stress intensity factor (SIFs) around its boundary, in conjunction with Rice (1975) theorem that interrelates SIFs and crack compliances, are used to evaluate the crack compliance. The results

Nanoscopic elastic behavior of the field quantities in the vicinities of nanosize defects and nano-inhomogeneities cannot be properly described within the size independent classical theory. As a remedy to this type of dilemmas and enhancement of the accuracy of the solution, polar or gradient continuum theories may be utilized. The current work is concerned with composites consisting of micropolar

Composite adhesive bonded joints are widely used in various industrial and technological applications, including aerospace, electronics, biomedical, automotive, ship building and construction. In this paper, the attention is focused on layered structures consisting of two adherent beams bonded together by an adhesive layer. For such structures, a modeling approach based on the classical Timoshenko

Carbon nanostructures as one of the efficient candidates have been employed to reinforce various types of nanocomposites. Accordingly, the current study employs the recently proposed three-dimensional graphene network, i.e. Hexagonal Graphene Network (HGN), Triangular Graphene Network (TGN) and Quadrilateral Graphene Network (QGN), as the reinforcements for highly applicable metallic glass (MG) nanocomposites

This paper deals with the nonlinear forced vibration of imperfect penta – graphene plates integrated with piezoelectric actuator layers. The plate is subjected to combination of mechanical, thermal, and electrical loadings. Based on the first order shear deformation plate theory, the governing equations are established taken into account the effect of the von Kármán type of geometrical nonlinearity

In this article, a mathematical derivation is made to develop a nonlinear dynamic model for the nonlinear frequency, and chaotic responses of the graphene nanoplatelet (GPL) reinforced composite (GPLRC) doubly-curved panel subject to an external harmonic load. Using Hamilton's principle and the Von-Karman nonlinear theory, the nonlinear governing equations are derived. For developing an accurate solution

Fracture behavior of Shape Memory Polymers (SMPs) and their self-healing property is one of the up-to-date subjects through the literature, where only a few researches have been conducted. Nowadays, because of the exceptional properties of SMPs and their implementation in 4D printing, they are most taken into attention. In this study, thermomechanical coupling effect on 3D fracture analysis of SMPs

A generic methodology to deal with the mechanics of beams and shafts with cracks is presented. The elastic energy of the system under static loading is written in a comprehensive manner to remarkably reduce the 3D computations indispensable to the identification of the crack breathing mechanism. With a new reformulation of the problem, the breathing mechanism identification is distilled down to the

In view of recent developments in advanced manufacturing and nanomaterial technologies, which have enabled realization of novel material architectures at small-scale, a mixed variational temperature-dependent rate-dependent thermo-viscoplastic continuum element is proposed and developed for elastic, plastic, and thermal wave propagation problems. The variational scheme is based on a Hamiltonian approach

The work presented hereafter deals with an important issue arising in frictional contact problems involving flexible bodies: the occurrence of more than one solution, with an emphasis on the quasi-static incremental problem in the presence of rectilinear obstacle and in two dimensions. The conditions for the existence of multiple solutions to the quasi-static incremental problem, with an intrinsic

In this research, with the aim to estimate the onset of fracture in key-hole notched components, made of brittle materials and subjected to combined tension-tear loading, the fracture limit curves are developed in terms of the notch stress intensity factors (NSIFs) based on the maximum tangential stress (MTS) and mean stress (MS) criteria. In order to verify the curves developed, a series of fracture

Hyperelastic fiber-reinforced materials are conventionally modeled based on the contributions of their constituent materials. A unified invariant-base constitutive model, named Matrix-Fiber-Interaction (MFI) model, is proposed to take into account particularly the mechanical interaction contribution of the constituent materials in fiber-reinforced elastomers with two fiber families. Its high predictive

We extend the isotropic non-linear damage rheology model with a scalar damage parameter to a more complex formulation that accounts for anisotropic damage growth under true triaxial loading. The model takes account of both the anisotropy of elastic properties (associated with textural rock structure) and the stress- and damage-induced anisotropy (associated with loading). The scalar, isotropic model

Coulomb friction model with unilateral contact is a basic, but reliable, model to represent the resistance to sliding between solid bodies. It is nowadays well-known that this model can be formulated as a second–order cone complementarity problem, or equivalently, as a variational inequality. In this article, the Coulomb friction model is enriched to take into account the resistance to rolling, also

In the first Part (Part I) of this series, the plane quasi-static incremental problem was formulated as a mixed complementarity-inclusion problem and as a linear complementarity problem. The current paper (Part II of the series) presents a numerical examination for the existence or the occurrence of multiple solutions to the quasi-static incremental problem of a two degree of freedom elastic system

Non-ordinary state-based peridynamics (NOSBPD) and finite element method (FEM) are coupled to study the discontinuous problems, in which the damage criteria can be adopted from the viewpoint of strain and stress tensors. The coupling method takes full use of advantages of NOSBPD in dealing with discontinuous issues and the high efficiency of FEM, which also can eliminate the surface effect in PD. The

Stress-gradient materials are generalized continua with two generalized stress variables: the Cauchy stress field and its gradient. For homogenization purposes, we introduce an extension to stress-gradient materials of the principle of Hashin and Shtrikman. The variational principle is first stated within the framework of periodic homogenization, then extended to random homogenization. Contrary to

In this paper, a new network and then a corresponding constitutive model of rubber-like materials are proposed. The materials are assumed to be composed of equal-length helical subnetworks which can slide along their occupied space. According to equivalence of external force, the network of this kind of materials is simplified to a sample network which only has subnetworks in three principal directions

Critical values of the pressure leading to self-contact in a flexible and inextensible loop subjected to uniform hydrostatic pressure have been predicted using variants and approximations of the harmonic balance method. Moreover, a modified perturbation method has been employed that has shown some advantages over conventional perturbation approach to the problem. A comprehensive comparison is made

Based on the strain gradient elasticity theory with three independent length scale parameters, a size-dependent spherical microshell model is established. The governing equations, boundary conditions and initial conditions are derived by Hamilton's principle. Both the static bending and free vibration problems are solved. Some numerical results of the static bending and the free vibration are exhibited

Based on the Timoshenko beam theory, von Kármán geometric nonlinearity assumption and the modified couple stress theory, this paper presents linear and nonlinear free vibration analysis of rotating two-dimensional functionally graded micro-beam with even and uneven porous distributions. The material properties vary along the axial and thickness directions. The NURBS function is employed as the basic

The adhesion of a cell on the substrate can play a significant effect on the physiological behavior, and may be affected by the surface stress, the modulus and the gravity effect of the substrate like elastomers and biological tissues. In this paper, by proposing a surface Green function of a prestretched elastomer incorporating the surface stress and the gravitational effect on the basis of the neo-Hookean

The postbuckling and geometrically nonlinear behaviors of imperfect functionally graded carbon nanotube-reinforced composite (FG-CNTRC) shells under axial compression are investigated in this paper. For the first time, a new type of instability named “snap-backward” with the presence of three limit points on the equilibrium path is proposed. A novel formulation based on non-uniform rational B-Spline

Two distinct length scale transition methodologies are developed to establish effective traction-separation relations for fracture in composite materials within a hierarchical multiscale framework. The two methodologies, one kinetics-based and the other kinematics-based, specify effective fracture properties that satisfy a surface-based Hill-Mandel consistency condition. Correspondingly, the total

A problem of reconstruction of multiple cracks in a beam by means of the natural frequencies corresponding to transverse vibration of the beam is considered. The cracks are simulated by massless rotational springs. It is proved that the cracks can be uniquely identified by three spectra corresponding to three different types of the end conditions. The problem is solved by reducing it to the inverse

To overcome the limitations of widely used criteria, maximum principal stress and maximum tension stress, in simulating and evaluating thermal shock resistance of ceramics for 3-dimension (3D) problems, a temperature-dependent critical fracture energy density criterion was proposed based on the force-heat equivalence energy density principle for the 3D thermal shock fracture problems of ceramic materials

Magnetoelectric (ME) effect is a product property arising out of the interactions between the piezoelectric and the magnetostrictive phase. Multi-phase ME composites being multifunctional materials find use in myriad of applications. In this work, epoxy free two phase and three phase embedded ring ME composites have been fabricated by the press-fit technique. For a comparative study, three phase conventional

In this paper, an improvement is made to an efficient direct method for numerical evaluation of high order singular curved boundary integrals. Then this improved singular integral evaluation method is employed to solve the strongly and hypersingular integrals involved in the dual boundary element method (Dual BEM), which combine the use of displacement and traction boundary integral equations to solve

Motivated by the different uniaxial responses of two actual materials filled with either sifted glass beads or sifted glass grits, the influence of the fillers shape on the finite strain behavior of highly filled composites (>50%) is examined through micromechanical finite element simulations accounting for matrix/filler debonding with a cohesive-zone model. Three-dimensional matrix cells filled with

Nowadays, AFM-based robots are widely utilized for transporting different nanoparticles. Using this devise as a tool for nanomanipulation, it is possible to specify the exact location of a nanoparticle in micro/nano-scale. In the fields of dynamics, contact mechanics and control of nanomanipulation for atomic force microscopy, accurate investigation and analysis of the motion of nanoparticles and the

Fracture and fragmentation in three dimensions are of great importance to understand the mechanical behaviour of quasi-brittle materials in failure stress states. In this paper, a generic computational model has been developed in an in-house C/C++ code using the combined finite-discrete element method, which is capable of modelling the entire three-dimensional fracturing process, including pre-peak

A periodically supported beam on a visco-elastic half-space is considered to model the vibration of railway tracks. The viscosity of the half-space is assumed to be of the Kelvin-Voigt type. Making use of the concept of equivalent dynamic stiffness, the reaction of the half-space to the sleepers is replaced by a system of identical spring located under each sleeper. The frequency-dependent equivalent

We critically assess diffuse interface models for fluid transport in fractured porous media. Such models, often called fracture phase field models, are commonly used to simulate hydraulic stimulation or hydraulic fracturing of fluid-saturated porous rock. In this paper, we focus on the less complex case of fluid transport in stationary fracture networks that is triggered by a hydro-mechanical interaction