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

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

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

In this paper, the analytical solution of two dissimilar orthotropic functionally graded half-layers with interface Volterra-type screw dislocation under anti-plane transient loading is studied using linear elasticity theory. The energy loss is displayed by viscous damping, and the rate of gradual alteration of elastic stiffness, damping constant and mass density of two dissimilar non-homogeneous half-layers

This study involves thermal, metallurgical and mechanical analysis during tungsten inert gas welding of Ti–6Al–4V alloy aiming at optimizing the welding current to enhance the mechanical properties. Firstly, a 3D transient FEM simulation of TIG Ti–6Al–4V weld using ABAQUS software, based on a Gaussian distribution of power density in space, has been built to predict the effect of welding current on

Friction stir welding (FSW) of 6-mm-thick AA 6061-T6 plates for taper threaded tool were studied in this investigation in terms of torque and different forces. A plain taper tool in addition to threaded tool is also incorporated in the study to analyze the effectiveness of threads. Welding was conducted at a constant rotational speed of 1100 RPM and varying traverse speeds between 45 and 135 mm/min

In this study, the flow of fluid in the fuel injector nozzle of a Diesel engine was simulated under steady-state and transient conditions using ANSYS Fluent. At first, a nozzle for which experimental results were available was simulated. Then, validating the results, the \( k - \varepsilon \) turbulence model and the Schnerr–Sauer cavitation model were selected for the numerical simulation of a real

In the present work, computational fluid dynamics approach is adopted to study the possibility of using porous media in combustion and emission in a single-cylinder four-stroke spark ignition engine. The combustion behavior inside the engine without and with application of porous media is studied. The analysis with application of PM signifies enhanced combustion behavior. The compression ratio is kept

Silicon carbide particulates-reinforced polymer matrix composites have gained a reputation among composite materials due to their excellent mechanical properties. But these materials are categorized as hard to machine materials due to hardness and the abrasive nature of reinforcing particulates. For that purpose, it becomes necessary to develop a machining method which can be extensively used for machining

Numerical methods are normally employed for elastoplastic analysis of structures due to complicated nature of the analyses alongside the absence of a closed analytical solution to these problems. Evidently, the chief part of the analyses comprises the computation of stress which is typically a function of strain history and the related elastoplastic parameters. Accordingly, the choice of the stress-updating

This paper presents the development of a small and lightweight differential hexapedal microrobot, inspired by cockroach locomotion mechanism. Detailed design, prototyping and performance evaluation are reported in this paper. The manufacturing process of the microrobot uses Smart Composite Microstructure method by employing origami-inspired techniques. Each leg of the robot has 2-DoF in Cartesian space