In this work, a mathematical system of wave propagation in generalized thermo-piezoelectric anisotropic smart material under primary magnetic field and rotation influence is considered. The system of equations for this phenomenon are given in the case of generalized thermoelasticity for three models, namely, Lord–Shulman (LS), Green–Lindsay (GL), and dual-phase-lag (DPL). Furthermore, it is assumed

An analytical model is developed in this article to study the effects of liquid sloshing on dynamics of articulated vehicle carrying liquid in turning maneuver. To investigate the interaction between the fluid and the vehicle, a four-axle tractor-semitrailer tanker with 32 degrees of freedom has been used. The method of separation of variables is used to solve Laplace equation together with the wall

Based on the Tresca yield criterion, an analytical method is proposed to determine the elastoplastic interface around a circular hole in an infinite plate subjected to biaxial tension-compression loads at infinity. Comparing with the plastic region formed under the action of biaxial tension-tension or biaxial compression- compression loads, the characteristic of the plastic regions is that they cannot

Weld of mining dump truck (MDT) frame is prone to fatigue damage due to the unreasonable local structure of cavity with stiffeners. However, there are considerable limitations in the engineering implementation of both size and topology optimization of the frame. Therefore, a discrete optimization method for the structure composed of cavity with stiffeners like MDT frame joint is proposed. Considering

Conventional noise control solutions used in the transportation industry have proven to be effective in minimizing structure-borne sound at mid to high frequencies; however, a lightweight means to control low-frequency structure-borne sound remains elusive. Recent advancements in additive manufacturing technologies have enabled researchers to develop novel acoustic metamaterial concepts capable of

Viscoelastic (VE) dampers are powerful tools for mitigating structural response when exposed to an earthquake. The fractional models for these dampers are adequately capable of taking the effects of ambient temperature and excitation frequencies into account. In this paper, the effect of these dampers on reducing the life-cycle cost of steel structures and the exceedance probability of different damage

Marine structures, such as ships and oil platforms, are often subject to green water propagating over their decks and causing overloading. Understanding the spatial and temporal evolution of these events allows estimation of water loads and thus an analysis of the structural dynamics. From this information the design of marine structures can be improved. This article investigates the evolution of green

In this paper, the author tested the influence of the addition of 1200 g of steel fibers per every beam improve the mechanical characteristics of concrete. The idea to make a better concrete mix by adding steel fibers was realized through this paper’s project task. The author's aim is to prove the fact that steel fibers increase the compressive strength and tensile strength of concrete's by adding

Secondary power system based on gas turbine engine is usually used for starting the aircraft main engine at ground and finds similar application in air during the emergency. The secondary power system comprises of an auxiliary power unit (APU) and an air starter. APU provides stand-alone power to the main engine subsystems and air to the air starter for starting main engine. The main rotor system of

This article is carried out with the Green-Naghdi theory of thermoelasticity with memory-dependent derivative to study the effects of a magnetic field and laser pulse in a generalized thermoelastic orthotropic elastic medium. Utilizing Laplace and Fourier integral transform to solve the problem analytically, the fundamental equations of the two-dimensional problem are expressed as a vector-matrix differential

A systematic research on the fracture failure of the tenon of X20Cr13 blade has been carried out. This research consists of two parts: comprehensive analysis and simulation analysis. The fretting wear produces the failure source which leads to the occurrence and development of cracks. M23C6 carbides damage the continuity of matrix structure and create conditions for the initiation and propagation of

Here, nonlinear buckling and postbuckling properties of cylindrical silicon nanopanels of finite length resting on elastic foundation exposed to axial compression have been studied by taking into account surface free energy (SFE) effect. Size-dependent governing equations were constructed by integrating classical shell theory and Gurtin-Murdoch elasticity theory. Surrounding elastic media were considered

Structural members exhibit hysteretic behavior under cyclic loading. Among the hysteresis models available in the literature, the differential model proposed by Bouc-Wen is most widely used, owing to its robustness. This model involves many parameters that define the shape of the hysteresis loops. Estimating these unknown parameters is an identification problem that can be tackled by optimization algorithms

One of the essentials for designing composite structures exposed to heat is the correct choice of reinforcing materials. In the present research work, a comparison is made between the performances of two well-known advanced materials, Shape Memory Alloys (SMAs) and Carbon Nanotubes (CNTs), in thermal bucking behavior of thin composite beams with simply supported boundary conditions. First, the effect

Flanged joints’ looseness is among the common causes for the failure of industrial structures with flanged joints the timely detection of which can prevent the imposition of heavy financial losses and in some cases injuries. There are conventional methods for detecting this fault and each of them has its own drawbacks. For instance, torque control methods have high error of measurement, impedance-based

This article aims to investigate the post-buckling behavior of plates and cylindrical panels made of functionally graded materials (FGM) and carbon-nanotubes reinforced composites (FG-CNTRC) under mechanical loads. Unlike the other high order shear deformation theories, the proposed formulation is elaborated within a double directors finite shell element which allows a parabolic distribution of the

Today, tunable soft elastomeric actuators due to their remotely-controllability, fast-response and stiffening have gained great attention. This article aims to develop analytical and numerical tools for thermo-mechanical analysis of an incompressible isotropic thermally-soft actuator subjected to finite bending deformation. To model the finite bending of soft actuator, amongst all existing energy density

The present study is focused on the numerical investigation in time domain of the deformation in thermoelastic material with one relaxation time (Lord and Shulman theory) with voids under dependence of modulus of elasticity and thermal conductivity on reference temperature. For dependency on reference temperature, we have taken two cases: (i) linear case and (ii) quadratic case. For numerical investigation

In the present article, a theoretical investigation has been carried out to analyze the propagation of shear horizontal surface waves (SH-waves) in a structure consisting of a functionally graded piezoelectric material (FGPM) layer lying over an FGPM half-space. The material properties of FGPM layer are assumed to have exponential function distribution along the thickness direction whereas those of

This paper presents a screw theory approach for the computation of the instantaneous rotation axes of indeterminate spherical linkages. Since the last part of the XIX century, the determination of the instantaneous rotation, or velocity, centers of planar mechanisms has been studied using the Aronhold-Kennedy theorem, extended to the spatial case until the second part of last century. In the beginning

In Minimally Invasive Surgery (MIS) surgeons operate through small incisions in the body of the patient and due to the lack of the degrees of freedom their capability to manipulate the organs is limited. Thus, surgeons are forced to adopt awkward postures and this may lead to musculoskeletal injuries. This paper presents a new articulated mechanism designed for application in MIS providing an additional

The braking phenomenon is an aspect of vehicle stopping performance where with kinetic energy due to the speed of the vehicle is transformed into thermal energy via the friction between the brake disk and its pads. The heat must then be dissipated into the surrounding structure and the airflow around the brake system. The frictional thermal field during the braking phase between the disk and the brake

In this article, frequency analysis of multi-sized hybrid nano-composites (MHC) disk (MHCD) resting on elastic media and located in an environment with gradually changed temperature feature is presented. Carbon fibers (CF) or carbon nanotubes (CNTs) in the macro or nano sizes respectively are responsible for reinforcing the matrix. For prediction of the efficiency of the properties MHCD’s modified

This study deals with the nonlinear bending analysis of elastic tubes made of functionally graded (FG) porous material based on modified couple stress theory. Immovable simply supported and clamped boundary conditions are assumed for the FG porous microtubes resting on nonlinear elastic foundation. Transverse pressure load is applied uniformly on the upper surface of the microtube which is exposed

An analytical model was developed for rectangular overlapped platelet reinforced composites subjected to unidirectional axial load. Two sets of the matrix/platelet displacement solutions (far-field and transient), were exactly derived based on the theory of elasticity. These displacement solutions were then superposed for achieving analytical expressions for the matrix/platelet 3D stress field components

In spite of considerable importance in engineering practice, especially in aerospace structures, thermal postbuckling behavior of nanocomposite curved panels has received little attention. This article aims to analyze different situations of postbuckling response of carbon nanotube (CNT) reinforced composite flat and cylindrical panels exposed to uniform temperature rise. CNTs are embedded into isotropic

One of the most important engineers’ considerations is their concern about structural stability. This article copes with buckling and post-buckling examinations of rotating clamped-clamped functionally graded beams due to interaction between thermal environment and rotation. The considered beam is subjected to a uniform temperature rising at the same time with its rotation at constant speed. The temperature

Because of extensive industrial applications of polymers, several continuum and material science studies have focused on the polymers' viscohyperelasticity characterization. Although finite element methods have powerful ability in simulating complex materials' mechanical behavior, involve high computational costs. Therefore in this article mechanical responses of polymeric viscohyperelastic materials

In this study, the principle of minimum potential energy has been used to deduce the mapping relationship between beam deformation and rail deformation with consideration of the constraint effects of a subgrade system. Based on the above mapping relationship, a dynamic simulation analysis on the train-track-bridge coupled system has been carried out. Taking the index of riding comfort as the investigation

This article presents a new design of a 2-DOF active lockable joint, which can be applied in parallel reconfigurable manipulators as well as in other applications such as haptic devices. The direct and inverse kinematic problems of the proposed joint were considered in detail, and the kinematic features of the input cranks are presented. Velocity equations, Jacobians, and singular positions of the

Due to the high strength to weight ratio of composites, their applications are extending rapidly in many industries. Composites can be fabricated by using different constituent (including fiber and matrix) materials. Different curing cycles and thermal expansion coefficients of matrix and fibers in hybrid composites may lead to residual stresses and distortion. Residual stresses can decrease the durability

This paper aims to develop a closed-form semi-empirical formula for predicting the buckling load of simply supported and clamped supported composite panels with a circular cutout subjected to uniaxial and biaxial load conditions. The finite element method (FEM) was used to develop and validate the semi-empirical equation. The effective moduli approach for lumping layers was used to transform the laminated

This is the first research on the vibrational analysis of functionally graded graphene platelets reinforced composite (FG-GPLRC) viscoelastic annular plate within the framework of higher order shear deformation theory (HSDT). Hamilton’s principle is employed to establish governing equations of motion within the framework of HSDT. In this article, viscoelastic properties are modeled according to Kelvin-Voigt

In this paper, the k-median of a graph is used to decompose the domain (mesh) of the continuous two- and three-dimensional finite element models. The problem of k-median is stated as an optimization problem and is solved by utilizing eight robust meta-heuristic algorithms. The Artificial Bee Colony algorithm (ABC), Cyclical Parthenogenesis algorithm (CPA), Cuckoo Search algorithm (CS), Teaching-Learning

The objective of this study is to apply Gram-Schmidt orthogonalization procedure for generating displacement functions. This procedure allows us to obtain numerically stable functions to be used in vibration analysis of novel composite beams via the Ritz method. Within this study, the theoretical modeling based on third-order shear deformation beam theory is derived to deal with free and forced vibration

The main objective of this research is to make a mathematical modeling of photothermal wave propagation in a semiconducting medium due to Lord-Shulman (L-S) theory with diffusion and rotation effects. Firstly, the governing equations are given based on generalized thermoelasticity with one relaxation time, diffusion effect, and the entire medium is rotated with a steady angular velocity. Then, applying

We discuss the reflection waves phenomenon in a generalized thermoelastic micropolar half-space under initial stress, electromagnetic field, and diffusion based on two models: Lord-Shulman (LS) and Dual-Phase-Lag (DPL). The governing equations are formulated by considering new parameters as a constitutive equation, equation of motion, diffusion equation, and micropolar equation in the context of two

In this article the photothermal and void parameters of a semiconductor rotational medium are investigated when there is a fixed thermal relaxation time. We obtain the displacement, temperature, stress components, and carrier density concentration in a thermoelastic solid. Considering the normal mode technique under the effectiveness of the rotation, photothermal, and voids on the obtained components

Ordinary differential equations of motion for a broad spectrum of parallel manipulators are derived and implemented in manipulator input coordinates for system simulation and controller design. Equations of motion are systematically embedded in singularity free domains of manipulator configuration space, assuring controllability and existence of a unique solution of the equations of motion. The kinematic

This article presents the dynamic modeling and nonlinear analysis of two-link flexible manipulator with generic payload whose center of gravity is different than the point of attachment with the link. The manipulator is driven by harmonic joint motions and subjected to a constraint force at the terminal end due to its interaction with working environment. Hamilton’s approach is adopted to dynamically

In this study, the free vibration analysis of carbon nanotubes reinforced magnetorheological elastomer (CNT-MRE) sandwich beam has been presented. The sandwich specimens are made of thin elastic strips integrated with CNT-MRE core. The viscoelastic properties of MRE and CNT-MRE are identified using ASTM E756-05 standard test. The natural frequencies and damping factors of with and without CNT reinforced

Rotational autofrettage is one of the new and potential methods for strengthening thick-walled hollow circular disks/cylinders against internal pressure, thermal gradient, and rotational speed in service. The method makes use of the centrifugal force resulting from the high speed rotation of the disk/cylinder to induce plastic deformation at its inner side. On subsequent unloading of the centrifugal

This research aims to develop a finite element model of nonpneumatic tires (NPTs) with different spoke shapes to study the geometric effects on the NPT for the maximum stiffness and minimum local stress. Four types of spoke structure were classified from reviewed articles and intellectual property. These were based on a few criteria including (1) manufacturability using polyurethane or engineering

In this study, in-plane natural frequencies and the dynamic stability of a curved beam subjected to a uniformly distributed periodic axial load with suspended spring–mass systems are investigated by using the FEM. The natural frequency results obtained from the developed FE code are compared with the ANSYS model results to verify the accuracy of the present model. The effect of the stiffness coefficients

In this paper, the nonlinear vibration control of sandwich shallow doubly-curved nanoshells with functionally graded piezoelectric (FGP) nanocomposite sensors and actuators is investigated based on surface/interface piezoelectric theory and nonlocal piezoelectric theory. The FGP sandwich shallow doubly-curved nanoshell is supposed to rest on the visco-Pasternak foundation. To get a desired vibration

In this study, we introduce a three-phase-lag (TPL) bioheat transfer model for living biological tissue by considering the heat conduction law that includes heat flux, temperature gradient and thermal displacement gradient, among the constitutive relation. The formulated TPL bioheat model is an extension of bioheat transfer models proposed by Pennes, Cattaneo-Vernotte and Tzou. The semi-analytical

Variation of cyclic loading effect on fatigue crack growth is investigated under plane strain and small scale yielding (SSY) conditions. The material is characterized by a finite strain elastic viscoplastic constitutive model with hardening and hardening-softening-hardening hardness functions. Displacements corresponding to the isotropic linear elastic mode I crack field are prescribed on a remote

Surface roughness obtained from different preparation processes such as sanding, shot blasting, and sand blasting were considered in this study. The effects of surface roughness on shear strength of single-lap adhesive joint were examined. 2024-T3 aluminum sheets were cut into standard pieces and then sanded with seven sandpapers with different mesh, shot blasted for four different duration times and

Due to wide-ranging applications of piezoelectric nanostructures as the next generation of smart devices, this article analyzes size-dependent buckling and free vibration performance of fluid-conveying functionally graded-graphene nanoplatelets reinforced composite (FG-GPLRC) porous cylindrical nanoshell embedded in piezoelectric layer and subjected to the temperature gradient and a uniform electrical

Two-variable sinusoidal shear and normal deformation theory is used in this paper for elastic analysis of doubly curved nanoshells resting on elastic foundation. Thickness stretching effect is accounted based on higher-order shear and normal deformation theory. The transverse displacement is decomposed into bending and stretching components based on two-variable sinusoidal shear deformation theory

In this work, for the first time, bending and free vibration of porous and functionally graded cylindrical micro/nano shells are studied based on the modified couple stress and three dimensional elasticity theories. The well-known power law and even type function are respectively used to consider the variation of functionally graded material properties and porosity distribution. The governing equations

This research, which is a continuation of the previously published paper, develops the idea for estimating the behavior of axially crushed multicell thin walled structures. This approach employs new crushing mechanisms or simply crushing modes for different configurations of multiweb corner elements based on simulation, geometric, and kinematic observations. Furthermore, a new model is introduced named

The dynamic behavior of the thin plates resting on a fractionally damped viscoelastic foundation subjected to a moving point load is investigated. This work explores the application of fractional calculus in the modeling of a viscoelastic foundation. A parametric study is executed to determine the impacts of the fractional-order derivative, foundation parameters, velocity and acceleration of the moving

This article deals with nonlinear vibration study of variable thickness cylindrical panels made of multi-scale composite materials containing epoxy matrix, glass fibers, and carbon nanotubes (CNTs). The elastic properties of multi-scale material have been defined in the context of 3D Mori-Tanaka scheme considering unidirectional aligned macro-fibers and randomly oriented CNTs. It is considered that

This study investigates thermal effect on free vibration of cracked single-walled carbon nanotubes (SWCNTs) embedded in an elastic medium under different boundary conditions. The nonlocal Euler–Bernoulli beam equations are derived using the Hamiltonian principle. The interaction of the elastic medium and the SWCNT is modeled using Winkler-type foundation. The effect of low and high temperatures, crack

Layerwise theory (LT) along with third-order, hyperbolic, and combination of sinusoidal and exponential shear deformation theories (TSDT, HSDT, and SESD) is applied to calculate thermal stresses in a five-layer simply supported circular sandwich plate subjected to a temperature gradient. The sandwich plate is made of five layers consisting of two functional graded (FG) face sheets, two adhesive layers

In this study, by applying three-dimensional FEM, the nut screwing process is analyzed to obtain the prevailing torque Tp confirming anti-loosening. Since the nut unscrewing properties after the nut tightening is more important to prevent the nut self-loosening, the nut unscrewing is also analyzed to obtain the residual prevailing torque Tpu newly defined in this process. Both results of Tp and Tpu

Based on the first-order shear deformation (FSD) model and nonlocal elasticity theory, the simultaneous effects of shear and small scale on the nonlinear vibration behavior of functionally graded carbon nanotube-reinforced composite (FG-CNTRC) beams are investigated for the first time. To this end, the governing equations of bending and stretching with von Kármán geometric nonlinearity are decoupled

Enlightened by the Caputo fractional derivative, the present study deals with a novel mathematical model of elasto-thermodiffusion to investigate the transient phenomena for an isotropic three-dimensional thermoelastic medium subjected to permeating gas induced by a rectangular thermal pulse, where the heat conduction equation is defined in an integral form of a common derivative on a slipping interval

Welded structures are commonly used in the industry, especially, in the transport sector. Indeed, when these structures are subjected to the cyclic loadings, the analysis of the fatigue strength of welded joints became very important and quite complicated. There are many factors underlying this problem. The most critical of these factors that affect the resistance of fatigue is the nature of the material