Abstract In this study, an experimental and numerical analysis of the bond-slip model is made on timber-to-timber bonding connections. The variables examined in this study are the types of adhesives used for bonding, the length of adhesion, and the types of reinforcement used to increase the adherence to the adhesion surface. Two different types of adhesives were used namely polyurethane and epoxy

Abstract This article presents a study of multiobjective shape optimization of nonuniform microbeams made of functionally graded materials (FGMs). The goal is to discover the optimal shape functions and volume fraction distribution to maximize the critical buckling load and fundamental frequency while minimizing the mass and material cost of the microbeam. Based on Timoshenko beam theory with the modified

Abstract The procedure in which a spatial heat source is subjected to tumor position to destroy the tumor cells without affecting the neighboring healthy tissues is known as hyperthermia treatment. During this process, accurate prediction and control of temperature is very important for the successful hyperthermia treatment. In this paper, we considered a mathematical heat transfer model in multi-layer

Abstract The present article studies free vibration analysis of sandwich doubly curved shell composed of a honeycomb core and carbon nanotubes (CNTs) reinforced piezoelectric face-sheets. First-order shear deformation theory as well as Hamilton’s principle is employed to derive the governing equations of motion. The effective material properties of core and face-sheets are estimated using the Gibson's

Abstract This study analyzes a vibration transmission system model composed of excitation component, interface paths and receiver component from the perspective of interface path transfer. Since the rough surface topography has a certain influence on the vibration transmission of the interface, the surface spectrum analysis of the contact surface is firstly given by using the areal power spectral density

Abstract Longitudinal wave propagation in carbon nanotubes has been investigated by using Rayleigh-Bishop rod model and nonlocal strain gradient elasticity theory in the present study. Size dependent governing equation of motion has been obtained with variational formulation. Validation of the proposed model has been achieved with developed lattice dynamics model which considers neighborhood interaction

Abstract The isomorphism identification among planar kinematic chains is an essential step in the structural synthesis. This article presents some new concepts, such as the regression loop and the regression loop set. The regression loop is a combination of independent loops. According to the mathematical operation “⊗,” the regression loop set is considered to be the unique representation from kinematic

Abstract In this paper, the propagation of Rayleigh waves in homogeneous isotropic thermoelastic medium in the presence of voids with Green-Lindsay model is considered. A vector matrix differential equation is formed by employing normal mode analysis to the considered equations which is then solved by eigenfunction expansion method. The frequency equations for different cases are derived and the path

Abstract As the automated fiber placement (AFP) manufacturing technology is developed, curvilinear fiber path composite structures received extensive attention. Therefore, developing a design framework capable of optimizing such structures is a significant challenge for researchers and engineers in this domain. In this article, an open-source ABAQUS/MATLAB-based framework is developed for the bending-induced

Abstract This study investigates the folding pattern design and deployment behavior of origami-based foldable conical structures. The geometric analysis is performed to design the six fold line pattern to obtain foldable conical structures. A single-story origami cone, modeled with pin-jointed framework, is selected for the analytical investigation. The axial strains, nodal forces, relative rotation

Abstract The buckling and vibration of laminated plates with various types of non-uniform compressive edge loads is analyzed. This problem requires that first the elasticity problem be considered to obtain the distribution of in-plane stresses, and after that, the buckling problem is solved. The method of solution is based on the R-functions theory and the variational Rayleigh-Ritz method. The results

Abstract In this article, a large deformation analysis of a flexible manipulator is examined by using the discrete time transfer matrix method. Since this robotic analysis is very demanding in terms of both computation time and memory usage, the main goal is to reduce the computational complexity compared to the conventional algorithm. In this study, the proposed model is validated with Euler–Bernoulli

Abstract In this work, we design an experimental campaign to assess the attenuation performance of a medium-scale resonant wave barrier operating within the frequency range of 50–100 Hz. In particular, the dispersive properties of (i) bare soil, (ii) a configuration of “dead masses” placed over the soil surface, and (iii) a locally resonant barrier, also known as metabarrier, are compared numerically

Abstract The present article deals with the thermal shock response in homogeneous orthotropic medium under the purview of Green-Lindsay model in the presence of voids. The normal mode analysis is used to obtain vector matrix differential equation which is then solved by eigenvalue approach. In order to illustrate the analytical developments, the numerical solution is carried out and the effect of voids

Abstract In this article, the chaos areas in the response of a Kelvin-Voigt viscoelastic plate under a combination of harmonically parametric and external random excitations were obtained, throughout a fully analytic approach. It was observed that how the structural damping, the linear and nonlinear elasticity, the amplitude, and frequency of parametric force and the intensity of the white noise excitation

Abstract This article deals with a new model of photothermoelastic and semiconducting two-dimensional solid cylinder in the context of Lord–Shulman's theory of thermoelasticity. The surface of the cylinder has been loaded by ramp-type heat. The double Laplace transform has been applied, and its inversions have been calculated by using the Tzou method. The numerical results for the carrier density increment

Abstract This article studies free vibration of a functionally graded porous cylindrical small-scale shell made from porous metal and ceramic based on power law distribution. It is bonded with an adjustable array of strip-like piezoelectric elements. The behavior of integrated structure is modified by change of quantity and location of the elements. Motion equations are achieved through first-order

Abstract This article presents the axial buckling analysis of polymer-CNT-fiber nanocomposite annular system (PCFCAS) resting on Winkler-Pasternak substrates under various temperature gradients. With the aid of Hamilton’s principle and the higher-order shear deformation theory (HSDT), the governing equations are derived. For developing an accurate solution approach, a generalized differential quadrature

Abstract In this study, the vibrational characteristics of a rotating multi-hybrid nanocomposite reinforced (MHCR) cantilevered disk (MHCRCD) are presented. The centrifugal and Coriolis effects due to the rotation are considered. The strains and stresses can be determined via the high-order shear deformable theory (HSDT). For access to various mass densities, as well as the Poisson ratio, the rule

Abstract Based on mixed thermal-elastohydrodynamic lubrication, the dynamic contact of ball bearings with worn band is investigated, and the film thickness, pressure, profile and interfacial temperature are analyzed. The temperature-pressure-viscoelastic equation of lubricant is constructed. The surface roughness, the elastic deformation and the worn band are included in the film thickness. The discretization

Abstract Mechanical systems especially annular disks have many applications in different fields such as engineering, agriculture, and medicine. In this regard, the large amplitude vibrations of multi-scale hybrid nanocomposite annular system (MHCAS) under hygrothermal environment and subjected to mechanical loading. Also, the structure is covered with elastic foundation. The matrix material is reinforced

Abstract This work aims to study the of a functional gradation (FG) composite rotor shaft under the influence of temperature variation and the power law index, to find out how to choose the type of FG composition, depending on vibratory behavior. The modeling of the structure is done by the hierarchical polynomial (h-p) version of the finite element method. A theoretical study based on Timoshenko’s

Abstract The mechanical behavior of a thick-walled pressure vessel composed of an incompressible isotropic nonlinearly elastic material subjected to the combined pressure and extension-torsion loading is investigated. An analytical solution is proposed for the general form of the free strain energy density, and different models including well-known Neo-Hookean, Mooney-Rivlin, and recently presented

Abstract In this article, the forward and backward wave frequencies of rotating truncated conical thick shells are investigated. The shell is composed of epoxy as the matrix and functionally graded (FG) graphene nanoplatelets (GPLs) as the reinforcement, which are dispersed with four different patterns through the thickness direction. The effective material properties are estimated using the Halpin-Tsai

Abstract The aim of the present study is concerned with an electromagnetic field, gravity field, rotation and initial stress on generalized thermoelastic medium with voids in the dual-phase-lag model (DPL) and Lord-Shulman (L-S). The problem deals with more applications in geophysics, engineering, acoustics, astronomy, industry, and petroleum extraction. A normal mode method is proposed to analyze

Abstract This article presents flutter prediction of composite wind turbine blades through time domain aeroelastic analysis using unsteady blade element momentum (BEM) theory based aerodynamic model. Comparison of the flutter speeds obtained in the present study with those previously obtained through Eigen solution based approach using Theodorsen’s theory based aerodynamic model for several different

Abstract The governing equations of magneto-thermoelastic semiconductor solid half-space with diffusion in plasma theory during the photothermal process are formulated in the context of a two-temperature generalized theory of thermoelasticity with triple-phase-lags in a specialized plane. Two velocity equations are obtained. The plane wave solutions of these equations bespeak the existence of four

The analysis of free vibrations of a thermoelastic hollow sphere with voids is investigated under dual-phase-lag generalized thermoelasticity and Erigen’s nonlocal elasticity. By implementing the stress-free thermal boundary conditions, the frequency relation is obtained for possible modes in a compact form. Numerical iteration technique with the help of MATLAB is used for generating numerical data

In this study, a three-dimensional trabecular structure is constructed with the help of micro-computed tomography scan data of a rat distal femur, and the finite element analysis (FEA) is carried out to analyze the stress distribution. Compressive loads 1000 N, 2000 N, and 4000 N were applied in longitudinal and transverse directions. The FEA showed that the percentage increase of stress in the transverse

The linear and nonlinear frequencies of the diaphragm are analyzed in this paper. Firstly, the nonlinear vibration equation is set up based on the d’Alembert principle considering the geometric nonlinearity. Then, the Galerkin method and improved L-P method are employed to obtain the linear and nonlinear solutions of the governing equation. And the results from the finite element method (FEM) are introduced

Directed laser deposition (DLD) has become a popular forming method however it is a process with drastic temperature changes, during which the temperature accumulation effect easily causes deposition defects. Wherein the selection of the process parameters could affect the shape quality and mechanical property of the formed parts. This work investigates the distribution characteristics of the temperature

In this paper we present a structural optimization approach that is based on explicit B-spline representation of the design, conforming with CAD standards. The methodology and implementation are general and can accommodate arbitrary B-spline degrees. The spline-based parametrization enables to incorporate explicit constraints on minimum and maximum areas of holes and on curvatures of boundaries. Therefore

In this article, static, dynamic and natural frequency analyses of functionally graded porous annular sector plate reinforced by graphene nanoplatelets are investigated for the first time. The plate is a composition of a layered model with uniform or nonuniform dispersion of graphene platelets in a metallic matrix including open-cell interior pores. The extended rule of mixture and the modified Halpin–Tsai

Innovative thin-walled structures, bio-inspired by the microstructure of Morpho wings, were proposed as energy absorbing devices in this study. A finite element model, experimentally validated, was used to investigate the crush responses and deformation modes of 18 multi-layered tubes with different geometrical configurations. The crashworthiness parameters were determined for the bio-inspired structures

This study is in investigation of free vibration behavior of functionally graded hyperboloidal and barrel helices with variable cross section. Material and geometric variations of noncylindrical helices are assumed to be along the rod axis. Governing differential equations of motion, including rotatory inertia, axial and shear deformations are derived by the Timoshenko beam theory. Then, transfer matrix

A three-dimensional (3D) fiber stress formula was developed to reduce the deviation of the two-dimensional (2D) fiber stress formula in calculating the 3D stress. The on-axis and off-axis stress–strain relationship was first presented. The 3D fiber stress formula was then derived analytically. Finite element method (FEM) of filament-wound (FW) thick-walled cylinders with symmetrical/balanced-layers

This article presents an analytical approach to investigate the geometrically nonlinear response of doubly curved imperfect shallow shells made of functionally graded carbon nanotube reinforced composite (FG_CNTRC) under in-plane and lateral loads. For all of the case studies, the edges of shells are assumed to be diaphragm supports, which are subjected to in-plane edge-loads. The governing equations

Investigating the effect of the uncertainty in the parameters on time-varying chatter stability is critical to refrain from the time-varying regenerative chatter in turning. In this study, the influence of tool wear on the cutting force coefficient (CFC) in turning processing is taken into consideration, and CFC variation during cutting time is described by the Gamma process. The model of the time-varying

In conventional finite element–Lagrangian methods, the dynamics model of a flexible robot is usually formulated based on a critical assumption that the kinetic energy of an element is approximately calculated with an integral of mass point energy. Since the energy integral is implicit, the formulation of the dynamics model is also very complex and implicit. Hence, this article develops a new mathematical

This article contains theoretical analysis and experimental study of the original mechatronics system with flexible characteristics which we can adapt to changing needs and external interference. The main purpose of our research is to find a solution that allows tailoring the desired characteristics of systems regardless of changing conditions without their mechanical interference. The system consists

Application of composite lattice structures in aerospace application can bring about considerable weight savings, thus allowing for increased payload weight. This study is devoted to reliability analysis of composite anisogrid lattice interstage structure (CALIS) used in typical launch vehicle (LV). CALIS is usually formed in to thin-walled cylindrical or conical shell via helical and circumferential

Submarines are one of the most advanced marine vehicles navigating from the surface of the water to the depths of the seas and able to perform various operations. Submarines have no benefit in terms of speed relative to surface floats, but also the advantage of a (moving underwater) dive deep into the deep seas. Diving and hovering of a submarine are carried out with the help of water ballast tanks

This article is a comprehensive investigation into the equations of the size-dependent free vibration of a special type of fluid-conveying nanotubes, i.e., double-walled boron nitride nanotubes, in a thermal environment. The motion equations are obtained through the use of nonlocal strain gradient theory for piezoelectric materials combined with the first-order shear deformation theory and Hamilton’s

Large extrusion container (EC) is the key part of an extrusion machine, and generally it depends on shrink fitting of multi-layers to boost its strength. Because of the harsh condition of high temperature and pressure, the shrinkage between every 2 layers of EC would be consumed due to creep deformation. However, shrinkage loss would generate insufficient support to each outer layer and result in axial

For the first time, the nonlinear forced vibration analysis of graphene nanoplatelets reinforced composite (GPLRC) annular plate under hygro-thermal environment and subjected to mechanical loading is presented. The GPLRC imperfect annular plate’s displacement fields are determined using third-order shear deformation theory (third-order SDT) and nonlinearity of vibration behavior of this structure is

In the present work, a novel higher-order zigzag theory is proposed for the bending analysis of sandwich functionally graded plates. Zigzag effects are incorporated with the help of a linear Heaviside step function. The present theory satisfies zero transverse shear stress conditions at the bottom and top surface of the plate along with continuity condition at interfaces for both transverse shear and

Smart control and dynamic investigation of a graphene nanoplatelets composite (GPLRC) cylindrical microshell surrounded by a piezoelectric layer as actuator and sensor based on a numerical solution method called generalized differential quadrature method are presented for the first time. The current structure is under an external load. The strains and stresses can be determined through via the first-order

This article is concerned with a study of electro–magneto–thermoelastic interactions under Green–Naghdi theory-III of generalized thermoelasticity in the presence of initial stress. The fundamental equations of the two-dimensional problem in orthotropic medium under the influence of electric and magnetic field are obtained in the form of a vector–matrix of differential equation by employing normal

In this article, a highly efficient quasi-three-dimensional theory has been used to study the nonlinear hygro-thermo-mechanical bending analysis of a very thick functionally graded material (FGM) rotating disk in hygro-thermal environment considering the porosity as a structural defect. Two applied quasi-three-dimensional displacement fields are assumed in which the strain along the thickness ( ε z

One important aspect of the dynamic performance evaluation of a parallel manipulator is the elastodynamic analysis which calls for the calculation of the stiffness and mass matrices. In the elastodynamic analysis, the motors are assumed to be locked, and thus, the system’s mass matrix should be obtained based on the small-amplitude elastic motion caused by the flexible components. As a sequel to the

This paper aims to study the propagation of surface waves in generalized magneto-thermoelastic media under influence of magnetic field and rotation and its applications in Engineering, Geophysics, and Petroleum extracting. The governing equations are considered for generalized thermoelastic problem under magnetic field and rotation and solved to obtain the general solution in x-z plane. The Lame's

Joint components in complex deployable truss structures on spacecraft show strong nonlinear characteristics, which can produce significant influences on overall dynamic characteristics of jointed beam structure. In this study, the dynamic characteristics of revolute-jointed beam, considering cubic nonlinearity are investigated using describing function method. For the revolute joint, additional degree

The problem of heating a non-homogeneous thermoelastic layer induced by absorbing a penetrating laser radiation throughout its volume is solved by employing the dual-phase-lag theory of thermoelasticity. The surfaces of the layer are taken insulated and traction free. Using the Laplace integral transform technique, a solution to the considered problem is obtained. The results presented graphically

This paper investigates the propagation behaviour of shear wave in a piezo-electro-magnetic material (PEMM) layer overlying a functionally graded piezo-electro-magnetic material (FGPEMM) substrate with a point source existing at their interface. Dispersion equation for shear wave is deduced by using Green’s function method. The effect of various material parameters and functional gradient parameters

This article develops a new reconfigurable wheel composed of Six Adaptive Prisms (6AP). Then, an Unmanned Ground Vehicle (UGV) is established with four proposed wheels to investigate some primary tasks. Wheel-soil formulation of the considered UGV is derived by Soil Contact Model (SCM). Considering SCM results, equations of motion of this robotic system are derived using the Lagrange approach. After

The main objective of this study is the phase-field (PF) vibration analysis of cracked functionally graded graphene platelets-reinforced composite (FG GPL-RC) plates considering stationary cracks. Mindlin’s plate model and phase-field approach are used to express the governing equations. The plate is numerically modeled using the variational finite difference (FD) method. Various convergence studies

The optimal shape of the hole for an isotropic elastic plate weakened by an arbitrary system of cracks is determined analytically using the minimax criterion. The plate is under the action of applied volumetric and surface loads. A criterion and a method for solving the problem of prevention of the fracture of a plate with a hole under the action of the given system of external loads are proposed.

In this article, five fundamental unit cells namely BCC, hexagonal packing, rhombicuboctahedron, diamond, and truncated octahedron, for which there was a lack of accurate analytical yield stress relationship in the literature, were studied analytically and numerically using the Timoshenko and Euler–Bernoulli beam theories. Two different approaches based on force or displacement methods were considered

In this work, a 2D axisymmetric problem for an infinite body is considered. An infinite cylinder composed of a different material and containing a variable heat source lies inside the body. The medium is assumed to be initially quiescent. The theory used is that of thermoelasticity due to Green–Lindsay. The solution is obtained by exponential Fourier and Laplace transform techniques. The inversion

The rotation of micropolar thermoelastic solid with temperature-dependent properties on micropolar material affected by the magnetic and gravity was investigated. The Green–Naghdi (G-N) theory of type II was employed to investigate our problem analytically. It is shown that there exist four reflected plane waves due to the nature of the material and the physical effects. The values of the complex modulus