The screw flight, spiral blade welded on the axial cylinder, is the core component of the screw ship unloader and can be seriously worn by the materials during long-term conveying. The damaged screw flight will make the screw ship unloader unable to unload materials or even lead to an accident. However, the existing wear model cannot be directly applied to predict the wear of the screw flight under

The high speed and high power density electromechanical system for the electric vehicle is urgently required to meet stricter emission regulation and achieve higher performance. Therefore, the electromechanical coupling effect is becoming more strengthened and may significantly degrade the performance of the motor and gear system. When gear or motor failures like gear tooth crack or rotor bar breakage

Although analysis/design of multilayer assemblies has been always an active field of research, works on the optimal design of rotating multilayer composite tubes are very limited. This paper addresses the design optimization of rotating multilayer composite tubes under internal heating and pressure. For determining the structural responses, analytical solutions are provided based on different boundary

Total knee prostheses have become established arthroplasty applications in the treatment of damaged or weakened cartilage. New implants are being produced using bio-materials which are compatible with human tissue. In the industry, these prostheses are modeled and manufactured in different design geometries. This study investigated using a novel method for an ideal geometry designed to prevent fracture

The problem deals with an investigation about propagation of Love type waves in a geometrical configuration which is composed of a viscoelastic layer sandwiched between fiber-reinforced layer and a substratum. The substratum is modeled using size-dependent consistent couple stress theory which involves a length scale parameter called characteristic length to capture the role of inner microstructures

In this paper, free vibration and transmission response for the torsional vibration of circular annular plate are presented. To the author’s knowledge, few studies can be found for the torsional vibration from wave standpoint. For this purpose, in this study, natural frequencies for the torsional vibration of annular plate with clamped–clamped and free–free boundaries are calculated. The natural frequencies

Based on judging the different stages of cavitation through high-speed photography experiments, this paper presents a strategy for analyzing the variation in noise under different cavitation stages using the BEM method and Proudman theory. A multi-field synchronous test bench for marine pump hydraulic performance, flow noise, cavitation performance and cavity distribution is built. The critical cavitation

Micromixing has a wide range of biomedical and biochemical applications. Therefore, many researchers have studied this type of microfluidic devices and have attempted to propose a design with better efficiency. Micromixers are classified as passive and active based on their mixing method (whether external energy source is used to improve mixing or not). The active micromixers have attracted the attentions

This paper proposes an adaptive attitude stabilization approach for flexible spacecraft subject to uncertainties, external disturbances, actuator saturation and unknown dynamics. The approach is synthesized based on a modified nonsingular fast terminal sliding surface (NFFTSS) and ensures fast and finite-time convergence independently of the initial states. It employs time-varying gains into the sliding

Improving strength of Al-7075 by applying severe plastic deformation (SPD) leads to a drop in material ductility. The challenge of the present study is to achieve both strength and ductility improvement in Al-7075 by a combination of dual equal channel lateral extrusion (DECLE) and aging heat treatment. The design of experiment (DOE) was also used to obtain the first-order polynomial equations in order

The free vibration of rotating functionally graded porous (FGP) circular cylindrical shell with different boundary conditions is presented analytically in this study. The porous material properties are assumed to be graded in the thickness direction of the cylindrical shell according to three types of porosity distributions. By using Love’s shell theory and Hamilton’s principle, the governing equations

Incremental forming process is a manufacturing process with many advantages, so it has received attention by many researchers, while further investigation is required for incremental forming of sandwich panels. In this study, the response surface method is employed to perform a series of experiments, and the effects of parameters, including vertical step down size, tool diameter, tool rotation speed

Under the microgravity space, many theories derived from the earth's surface become untenable, so a modified vibration equation with fractal derivative is presented in this work. With the help of the semi-inverse method, we successfully develop the fractal variational principle, which not only provides conservation laws in an energy form but also provides physical insight into the nature structures

A computational analysis was carried out on the film cooling technique over the surfaces of eroded plates. The air–water mist coolant was injected through the slotted hole. A flat plate was patterned with various erosions. The loading fraction, f = 4–16%, and blowing ratio, M = 1–1.6, were simulated to understand their influence on the mist film cooling effectiveness. The coolant injection angle or

In this paper, a new configuration is proposed for using Savonius rotors by installing two Counter-Rotating Savonius Rotors (CRSR) together. In order to study the aerodynamic performance of the CRSR turbine, 2D unsteady turbulent flow around the CRSR turbine is simulated using commercial CFD software ANSYS-Fluent16.0. Turbulence modeling is done using \(k - \omega\) SST model. Numerical results demonstrate

This paper describes the development of a mathematical model for a beta-type Stirling engine with rhombic drive mechanism. This model is based on thermodynamics, heat transfer, mass transfer, and machine dynamics considerations, and it estimates the power output and efficiency of a beta-type Stirling engine depending on different geometric and operational variables. The model is used to conduct a parametric

In this paper, a new beam element based on third-order Reddy beam theory and modified couple stress theory is introduced for static and dynamic analyses of microbeams. The beam is resting on Kelvin–Voigt-type viscoelastic foundation. Equilibrium equations are derived by using Hamilton’s principle. Galerkin finite element method is applied to the governing equations, and shape functions of the new beam

What lies at the core of an elastoplastic finite element analysis is updating the stress and its related plastic variables. The process is carried out through integrating an array of elastoplastic fundamental relationships, which are typically called constitutive equations. The complex essence of such relations as well as the usual lack of analytical closed-form solutions to these problems compels

The main objective of this study is to investigate the post-buckling thermal load–deflection path of rotating pre-twisted microblades/beams made of temperature-dependent functionally graded materials (FGMs) via nonlinear non-classical first-order shear deformation theory (FSDT). To this end, modified strain gradient theory (MSGT) as well as the von Karman geometric nonlinearity is used to develop the

The cavitation strengthening test of Aluminum lithium Alloy (8090Al–Li) was carried out with different pressure process parameters. The roughness, residual stress, and morphology of the treated samples were studied. A high dislocation density was formed in the cavitation area of the workpiece, which resulted in surfacing hardening. The cavitation effect occurred in the collapse area. It was beneficial

In this study, experimental and numerical investigations were carried out in order to determine the mechanical properties and impact response of hybrid composite laminate. The hybrid composite laminate was formed from plain woven carbon fiber reinforced epoxy (CFRE) and plain woven glass fiber reinforced epoxy (GFRE) fiber using VARTM (vacuum-assisted resin transfer molding) process. The mechanical

Fatigue failure cracking under fluctuating stressing has been a major concern of engineering for many years. Fatigue failures have become more common and thereby significantly influencing engineering design as sources of vibration and dynamic loading of components have increased. The repairs of damaged metallic structures using bonded composite patch have been proved as an economical method to increase

The turbine housing is subjected to thermal load which is essential to be taken into account in the design process. In this paper, a three-dimensional conjugate heat transfer simulation of a wastegated turbine housing has been performed. The model has been validated with data from thermocouple measurements and thermography pictures. Moreover, the effect of ventilation speed on temperature distribution

Nonlinear thermal stress analysis in a functionally graded hollow thick cylinders and spheres under the effect of high temperatures and temperature differences is considered by taking into account the material properties of the body both temperature dependent and radially graded, except Poisson’s ratio which is taken to be constant for simplicity. These conditions result in nonlinear governing differential

In order to weaken the strict geometric constraint relationship between the axes of joints so as to reduce manufacturing/assembling errors of overconstrained mechanism, a configuration design methodology for single-loop non-overconstrained mechanism with inactive joints is proposed in this paper based on the screw theory. After completing analysis of degrees of freedom, the design principle and corresponding

The composite materials exposed to dynamic loads may suffer damage at strength value, which is under own yield strengths. Also, improper environmental conditions accelerate the damage process. In this study, the effect of heavy chemical environments such as acid and alkaline and retaining time for these environments on flexural strength and fatigue behavior of E-glass/epoxy laminated composites was

Generalized thermoelasticity based on Lord–Shulman theory that admits the second sound effect is developed for continuum-based modeling of the thermoelastic wave propagation in functionally graded material (FGM) rods with a variable cross-sectional area under quadratic thermal shock loading. The geometry of the problem, as well as the distribution of material properties, is defined continuously with

In this work, the behaviors of flow field and pressure fluctuations in both time and frequency domains in an axial flow pump through changing various impeller blade angles are studied and investigated by using a CFD technique. The blade angles are changed between 30°, 45º, 60º and 75º. Numerical results are validated with the experimental values, as a good agreement was found between them. The developed

The present research deals with the small and large amplitude free vibrations of thick functionally graded material (FGM) beams. Beams are resting on an elastic foundation which consists of the Winkler layer, shear layer and nonlinear springs. The effect of uniform temperature elevation is also included into the formulation. A third-order shear deformation beam theory is adopted as the basic assumption

This article investigates a specific type of cardiac assist device, its functional performance, and its effects on the hemodynamic patterns of blood flow through the aortic network. The aforementioned assist device can be implanted in a given patient suffering from left ventricular failure. Our previous study focused on multi-balloons device. The current cardiac assist device is composed of two semi-cylindrical

In this study, Inconel 625 superalloy matrix composite materials were produced via powder metallurgy by using high-purity elemental powders and wolfram carbide (WC) reinforcement. The powder mixtures were shaped by applying 500 MPa pressure. The sintering process was carried out at 1275 °C under argon atmosphere with 90 min holding time. The densities of the produced samples were determined according

As efficiency of PV modules decreases with temperature rise, cooling methods can increase the power output and efficiency. One of the strategies for this purpose is passive cooling by implementing fins to the backside of a module. In the present study, annual energy output of a 50 W panel is analytically calculated in two unfinned and pin-finned cases based on hourly meteorological data for Shiraz

The Gantry-Tau is a family of parallel manipulators with three linear actuators. This mechanism is of interest for various applications because of the large workspace and its performance in terms of high acceleration, precision, and stiffness characteristics. This paper presents workspace analysis and calibration for a Gantry-Tau mechanism using its forward kinematics. The mathematical model of the

In this paper, an isogeometric analysis (IGA) approach for free vibration analysis of functionally graded skew folded (FGSF) plates is presented for the first time. This method uses non-uniform rational B-splines (NURBS) as basis functions to provide a flexibility in refinement process. Furthermore, the IGA is able to exactly regenerate the geometry in comparison with the finite-element method (FEM)

In the present work, vibration, acoustic and thermal signals were correlated to the semi-autogenous grinding mill working parameters such as total power and inlet water flow rate, and then these parameters were monitored using vibration, acoustic and thermal analyses. Next, the influential controlling parameters were obtained to monitor the mill conditions via SPSS software and afterward by exploiting

A tactile feedback device of a piezoelectric ciliary body beam is presented. In order to investigate the relationship between the sizes of the ciliary body beam, the position of the piezoelectric ceramics plates and the frequency of the excitation signal, the electromechanical coupling dynamic model of the piezoelectric ciliary body beam is established. According to the boundary conditions and the

Decreasing stress in a part or piece of equipment especially in a stress concentration point without increasing thickness or using stronger material is always an interesting issue for design engineers. In this paper, piezoelectric patches were used for stress concentration reduction around various hole sizes in thin-walled cylindrical shells subjected to internal pressure. Applied voltage to piezoelectric

In the present study, the flow and aerodynamic features of a sharp trailing edged flat plate airfoil are systematically compared with NACA0012 airfoil. The studies are conducted for three different Reynolds numbers 1.89 × 105, 2.83 × 105 and 3.78 × 105 and angles of attack 20°, 25° and 30°. The present study shows that the occurrence of vortex shedding phenomena for the flat plate is substantially

Restraint system, especially the seatbelt, is the critical load source of the chest injury. The consequence has become the crucial part of the traffic accident, which is a great burden to the society in terms of money loss. Thus, when protecting the occupant’s safety, chest injuries from the restraint loading on the occupants should also be reduced or avoided with proper methodology during the impact

In the current study, plastic buckling and postbuckling behavior of aluminum alloy plates under uniaxial, biaxial and combined compressive/shear loadings using 3D standard and incompatible elements are investigated. In this study, the finite element code considering geometrically and material nonlinearities is developed based on the incremental theory of plasticity. Obtained results show that the bifurcation

Hyperthermia is one of the methods for cancer therapies by creating artificial fever. Protection of healthy tissues around the tumor tissue, which has a high temperature, is one of the major issues in this treatment. In present study, the two-dimensional transient model of biological tissue with a tumor is taken into account. The area of the tumor is embedded with micro/nano superparamagnetic materials

Magneto-thermoelastic interactions in an isotropic homogeneous elastic half-space with two temperatures are studied using mathematical methods under the purview of the Lord–Şhulman (LS) and Green–Lindsay (GL) theories, as well as the classical dynamical coupled theory (CD). The medium is considered to be permeated by a uniform magnetic field. The general solution obtained is applied to a specific problem

Piezoelectric materials have wide applications due to their special electromechanical coupling characteristics but are vulnerable to sudden failure because of their brittle nature. Researchers have been profoundly interested in investigating the fracture of piezoelectric materials under different applied conditions. In the present work, tri-layer plates with interface cracks in piezoelectric materials

In this paper, the relationship between the cutting conditions and the wear mechanisms in turning Inconel718 from both modeling and experiment points of view has been studied. The tool chosen consists of a hard fine-grained WC with 6% Co with TiAlN layer. As a result, the recommended machining conditions with minimal wear would be the selection of a tool with a radius of 1.6 mm and the cutting velocity

In this study, the nonlinear vibration and stability of a simply supported axially moving Rayleigh viscoelastic beam equipped with an intermediate nonlinear support are investigated. The type of considered nonlinearity is geometric and is due to the axial stretching. The Kelvin–Voigt model is used to regard the beam internal damping. The Hamilton’s principle is employed to derive the governing equations

The aim of this study was to bring forth a model-based control method for trajectory tracking of a normal human-like biped on descending and ascending stairs using the straight knee state and to verify the controller performance in the straight knee state periods. Contemplating a straight state in knee joints does not consent to each leg’s shank link to undertake angular rotations greater than thigh

A combined heating and power (CHP) system with a Stirling engine for building applications has been proposed in the present work. The use of these systems in building applications will be more common if they have significant advantages from the viewpoints of the pollution emission and operational cost in comparison with the other similar systems. The Stirling engine was modeled with consideration of

In this study, the commercially pure aluminum powder was compacted by single-action and floating dies at room temperature. The effect of compaction method on densification was studied using density distribution, microhardness measurements and scanning electron microscope (SEM) along the compaction axis of processed samples. The density measurements of compacted samples through the floating die process

Upper limb disability is one of the major adversities faced by post-stroke patients. Eating is one of the fundamental activities of survival for all living beings. The robotic rehabilitation systems for people with upper limb disabilities must have the capability of assisting the patients, providing appropriate forces/torques, during various eating activities. In this study, a 3-D, four-DOF dynamic

The aim of the study is to evaluate the parametric effect of a power take-off (PTO) system on an integration system of an oscillating buoy wave energy device with a pile-restrained floating breakwater. To consider the viscous effect, the study is carried out with three conditions using OpenFOAM, i.e., the linear optimal PTO system, the fixed PTO damping coefficient, and the Coulomb PTO system. The

By introducing the \(C^{2}\) continuous hexahedral element, the free vibration finite element analysis of the nanobeam and nanoplate structures is reported based on the second strain gradient (SSG) theory and three-dimensional elasticity model. The SSG elasticity presents the powerful higher-order continuum theory which can be efficiently used to capture the size-effect on the nano-objects. The finite

The synchronous belt drive with noncircular pulleys can be used to obtain accurate transmission with a specific motion law, but the shortage of big belt slack caused by noncircular pulleys limits its application. In order to reduce the belt slack, a novel synchronous belt drive with noncircular pulleys, which is formed by a driving circular pulley, a driven eccentric pulley and a noncircular tension

The geometrically nonlinear forced vibration response of magneto-electro-thermo-elastic (METE) rectangular plates is analyzed herein using a numerical approach. The shear deformation effect is taken into account based on the first-order shear deformation plate theory. The geometrical nonlinearity is also considered using the von Kármán hypothesis. Based upon a variational approach, the energy functional

In this paper, an adaptive unscented Kalman filter (AUKF) algorithm is applied to simultaneous localization and mapping (SLAM), based on adaptation of a scaling parameter. The scaling parameter is a design parameter in the unscented Kalman filter (UKF) which can improve the quality of the approximation. An adaptive method is designed to find the suitable value for the scaling parameter to improve the

The aim of the study was to investigate the effect of ignition timing and hydrogen fraction on the performance and exhaust emissions of an engine. The engine was converted from port injection system to direct injection with enrichment hydrogen to natural gas at WOT condition and engine operation at 4000 rpm. The results showed that when hydrogen volume fraction was raised from 0 up to 50% at 20 bar

This paper studies the flattening process of empty and polyurethane foam-filled composite-metal tubes, experimentally. To prepare these specimens, metal tubes were wrapped with a fiber-reinforced composite using hand layup method. For the metal tubes, two kinds of materials, aluminum and brass, were used, and the composite tubes were made of woven E-glass fiber and vinyl ester resin. A composite tube

This paper presents an analytical solution based on four-variable refined plate theory for dynamic analysis of cross-ply composite laminates integrated with piezoelectric fiber-reinforced composite actuator attached to the upper surface. This theory considers parabolic transverse shear strains through the plate thickness. Equations of motion for simply supported rectangular plates are derived using

Unmanned helicopters have gained great importance during recent years due to their special abilities such as hover flight, vertical take-off and landing, maneuverability and superior agility. The advances in electronic devices technologies lead to more powerful and lighter processors to be used in avionic systems which have attracted more attention to these UAVs. The first steps of utilizing an unmanned

In this paper, the use of the inverse solution method for estimating the mass of moving load on an inclined functionally graded material (FGM) Timoshenko beam is discussed based on the measured displacements. Fletcher–Reeves (FR) method is used to solve the inverse problem. Also, in the process of solving the inverse problem and in order to solve the direct problem, Newmark method is applied for discretization

A rigid-flexible coupled dynamic model of the planetary gear transmission system was developed considering the flexibility of the internal ring gear (flexible internal ring gear) and the sun shaft based on the shell theory and Timoshenko beam theory, respectively. For the dynamic modeling, the time-varying meshing stiffness and static transmission error excitations were considered and the Runge–Kutta