To solve the deformations and stiffnesses changes of linear rolling guideway under different loads, and to provide reference for the structural design of the carriage, this paper presents an analytical model of three-degrees-of-freedom static stiffness for linear rolling guideway considering the structural deformations of the carriage. In this study, first, the contact loads and elastic deformations

Drillstring vibration is known to cause failures of drilling equipment, including the drill bit. In particular, stick-slip vibration has been known for causing premature failure of the drill bit, hence resulting in reducing the rate of penetration. With dual reaming while drilling, cutting forces are acting on the drillstring due to the simultaneous contact of the reamer and the drill bit. Field studies

A novel trapezoidal corrugated perforated fin core is proposed in this study. The porosity of the fin surface, or perforations, is indicated to promote the unusual behavior of increasing the heat transfer coefficient, while reducing the friction factor with respect to its non-perforated counterpart, primarily due to surface transpiration, which leads to better flow mixing and successive boundary layer

Material flow has a significant impact on the joint properties and is one of the most challenging aspects to be understood in dissimilar friction stir welding. The present study emphasizes the role of process parameters on material flow, mechanical properties and corrosion behavior of dissimilar friction stir welds of AA5083-AA6061. Microstructural analysis revealed that the onion ring sub-layer width

To achieve the purpose of Ginkgo biloba leaves continuous harvesting, a ginkgo leaf picking device is designed. The device is consisted of a picking executive composed from a round rod picking hand and a rotating drum, a frame, a motor, a motor base, a coupling, a bearing seat, a motor support frame, a deciduous box, and a connecting screw. And the picking theoretical analysis and calculation are carried

In the current investigation a mathematical model is simplified to explore the numerical treatment for the thermal and flow behavior in a magneto hydrodynamics Casson fluid through a micro channel by taking TiO2−CuO/Eg nanoparticles. The combined effects of temperature jump, porous medium and velocity slip are incorporated. Using the dimensionless variables one can obtain the governing differential

Nowadays, laser drilling has found extensive medical applications such as drilling of titanium implants. However, laser drilling of such implants has encountered several restrictions such as low penetration depth, high thickness of recast layer and heat affected zone (HAZ). Therefore, various approaches such as magnetic field and/or ultrasonic vibration aided laser drilling have been proposed to overcome

On the road to real applications, although there are lots of efforts focusing on mechanical and physical features in the literature, their machining abilities were examined in a very limited manner. In this study, machining properties of pumice reinforced AA7075 syntactic foams manufactured via the newly offered sandwich infiltration technique were investigated by performing face turning. Physical

This article presents the effect of volute chamfering on the performance of a forward swept centrifugal fan. The numerical analysis is performed to obtain the performance parameters such as static pressure rise coefficient and total pressure coefficient for various flow coefficients. The chamfer ratio for the volute is optimized parametrically by providing a chamfer on either side of the volute. The

This research features one parameter family of solutions representing rotationally symmetric flow of non-Newtonian fluid obeying Reiner-Rivlin model. Such flows take place over a revolving plane permeable surface through origin such that fluid at infinity also undergoes uniform rotation about the vertical axis. Heat transfer accompanied with viscous heating effect is also analyzed. A similarity solution

Thick-walled cylindrical and spherical pressure vessels are often subjected to autofrettage, a process in which the vessel is loaded at the inner wall to cause a partial or complete plastic deformation emanating from the inner wall, followed by unloading. This introduces the beneficial compressive residual stresses in the vicinity of the inner wall. Depending on the type of the loading, there are five

An experimental investigation has been observed on hardness, sintered density and corrosion behaviour of two-layered structured Al-xCu/Al sample through powder metallurgical route under hot compaction condition. The samples were prepared with different percentages of Cu content (x: 5 wt. %, 10 wt. % and 15 wt. %) in the aluminium matrix with a constant pressure of 400 MPa with different hot-pressed

Understanding the chip formation mechanisms during machining is an important factor to facilitate the choice of cutting tools and machining parameters. Despite the appearance of new sophisticated methods and advanced equipment, the technique so called quick-Stop Test (QST) remains efficient, less costly, and easier to apply in the investigation of chip formation in cutting process. In present paper

The axial hydraulic force of centrifugal pump is an important parameter affecting pump performance. The force mainly includes the force inside impeller and in clearance. Due to the special structural characteristics of the clearance, the influence of grid discretization method on the calculation of axial force in the clearance is not fully understood. Therefore, based on the Reynolds-averaged method

To explore the spool orifice’s particle motion and erosion morphology in an electro-hydraulic servo valve under a small opening, a modeled particle motion visualization test and CFD calculation were conducted to study typical particle trajectory. The influence of pressure differential, particle shape, and particle diameter on the erosion rate along the working edges was discussed. The erosion characteristic

The present analysis deals with the ground taxiing of aircrafts and considers, in particular, their turning at rather low speed with very small path radii among obstacles that may be very close to each other, for example inside the hangars or on the flight decks of the aircraft carriers where other planes stand stationary. To succeed in this operation, it is crucial to optimize the path and avoid dangerous

For low impact docking systems (LIDS) developing for rendezvous and docking of spacecraft, the main interface docking seal (MID seal) is one of the key components, and its seal and adhesion performances are crucial for mating LIDS-adapted spacecrafts. An elastomeric seal-on-seal structure is one of the mainstream designs of the MID seal and is generally made of silicone rubbers that can adapt to complex

Work-related musculoskeletal disorders (MSDs) are among the most commonly reported issue in Europe. Using robotic exoskeletons to support users in performing heavy industrial tasks can effectively mitigate the work-related MSDs. In this paper, a dynamic model of a hybrid exoskeleton is presented to analyze the assistive effect. The exoskeleton in this study is able to passively support the human shoulder

The valves of an internal combustion engine play an essential role in the automobiles and their surroundings significantly affect their thermo-mechanical behavior. The work aims to assess numerically the effect of the real thermo-mechanical boundary conditions on the valves by considering the actual complex surrounding. For this purpose, we have subdivided the valve into seven adequate zones. We have

An Autonomous Underwater Vehicle (AUV) is an underactuated mobile robotic system. This paper is focused on the control of an AUV, which is an interesting problem in robotics. In engineering applications, achieving a precise mathematical model for a given system is not realistic due to the existence of many unknown and unpredictable phenomena in real systems. Therefore, less reliant algorithms on the

Nickel-based thick hardface coatings are employed in nuclear power plants because of their superior wear and high-temperature resistance properties. Unfortunately, fabrication of a crack-free coating with less dilution is difficult using the conventional hardfacing techniques like Plasma Transferred Arc (PTA), Metal Inert Gas (MIG) etc. A sound coating having optimum hardness and better wear resistance

Limited driving range and availability of charging infrastructures are still among the main barriers of adoption of electric vehicles (EVs) in the market. Combination of those limiting factors causes ‘range anxiety’ in EV users. While different EV battery technologies and charging infrastructures are under development, one short-term solution to reduce EV users’ range anxiety is to provide the EV user

Surface texturing is an effective technology in improving the tribological performance of artificial joints. However, the mechanism behind it is still a controversial topic, especially when talking about the functionality of hydrodynamic pressure. In this paper, Finite Difference Method was used to solve the steady-state Reynolds equation. It was found that, under the given conditions, hydrodynamic

Dynamic model of balance rope under multiple constraints with friction is established via using non-equal-length element division method (NEL-EDM) based on absolute nodal coordinate formulation. Then, the natural frequency of balance rope under multiple constraints is derived by the proposed method. The KDP generalized-alpha scheme is expanded to differential algebraic equations (DAEs) with friction

Structural mechanics and mechanical reliability issues are becoming more and more challenging in the semiconductor industry due to the continuous trend of the device dimensional shrinkage and simultaneous increased operative temperature and power density. As main consequence of the downsizing and more aggressive operative conditions, the mechanical robustness assessment is now having a central role

Volumetric efficiency (VE) is an extremely important index to evaluate the performance of pump and motor. Efforts have been concentrated on the causes and character of leakage loss, but few quantitative analyses of pump kinematic clearances (KCs) identification and nonlinear compression loss caused by air content are discussed. This paper clarifies the nonlinear compression loss resulted from the air

Mass unbalance, shaft misalignment, rotor asymmetry, and force due to rotor weight are the main causes of vibrations in rotary machines especially when the shaft is not symmetric. Although extensive researches have been carried out to determine the effect of each on the increase of vibration levels far, there has been no clear study on the simultaneous existence of all these parameters and their interactions

From the designer’s point of view, the static precise finite element model of the single ball-raceway, the overall and the unit slice of the rolling linear guide (RLG) are established based on the limited data obtained. According to the contact characteristics of a single ball-raceway, Hertz theory and finite element method (FEM) are used to determine the maximum contact stress and deformation of RLG

Submerged friction stir welding (FSW) is used to improve the weld zones mechanical properties in the present study. This research aims to obtain the optimized process parameters used to fabricate the AA6063 Submerged FSW joint. In the Submerged FSW process, the most important influential factors are tool rotational speed, traverse speed, and pin profile in a seawater environment. The different workpieces

Fiber reinforced polymer composites are quickly gaining market share in structural applications, but further growth is limited by their lack of toughness. Fiber hybridization is a promising strategy to toughen composite materials. By combining two or more fiber types, these hybrid composites offer a better balance in mechanical properties than non-hybrid composites. This study presents the effect of

The paper presents a numerical investigation on the junction flow occurring at the intersection between a wall and a protruding circular cylinder. Simulations of flow for Reynolds number (Re) in the range [125 - 20000] have been carried out using OpenFOAM, an open source CFD tool. Plots of stream tracers have been used to qualitatively characterize the flow topology as either attachment or separation

The knowledge of polymer matrix composites machinability has increased with its rise in multi-field structural applications. Drilling of polymer matrix composites is required to achieve structural integration with greater accuracies. Delamination due to drilling affects the material strength and it occurs at both the entry and hole exit planes. The delamination on the exit plane is critical. The effect

Performance parameters such as power loss, minimum film thickness, and maximum oil temperature of the sector-shaped tilting pad thrust bearings employing the new micro-structural geometries on pad surfaces have been investigated. The lubrication equation incorporating the mass-conservation issue is discretized using the finite element method and the solution of resulting algebraic equations is obtained

As unmanned coal mining technology gradually replaces the traditional mechanized coal mining technology, shearer operation mode is changed from local control to remote control in intelligent fully mechanized mining face. In remote control mode, it is difficult to protect the personnel who straying into the shearer operator space without observation and reminder from the shearer operator. Hence, it

Fiber reinforced plastic materials are able to be customized according to the application and behavior of materials. In this work, the effect of meticulous nanoclay, Cloisite 20B, inclusion (with various concentrations) on the interlaminar fracture toughness glass fiber reinforced plastic (GFRP) composite was experimentally investigated. The mode-I tests were conducted based on a double cantilever

It is important to suppress cavitation phenomenon for lower vibration and noise, which can be realized by structure optimization to reduce cavitation bubbles of flow field. Nonetheless, performance factors in hydrodynamic retarder are usually conflicted when conducting a structure design, it is hard to simultaneously restrain cavitation and improve the retarding performance. In our study, a combination

In smart structures, achieving a reliable set of measurement signals to monitor the system’s performance is critical. Also, the essence of using the optimum batch of sensors and an efficient algorithm to process these signals is significant for active vibration control of these structures. This paper primarily introduces a method of sensor fusion using the Kalman filter as an observer to gain the proper

When the ball bearing serving under the combined loading conditions, the ball will roll in and out of the loaded zone periodically. Therefore the bearing stiffness will vary with the position of the ball, which will cause vibration. In order to reveal the vibration mechanism, the quasi static model without raceway control hypothesis is modeled. A two-layer nested iterative algorithm based on Newton–Raphson

In this study, nano-sized SiC particles are added to AZ91 magnesium alloy using friction stir processing (FSP) and friction stir vibration processing (FSVP) to produce surface nano-composite layers. FSVP is a modified method of FSP in which the specimen is vibrated during FSP. The influence of FSP and FSVP pass numbers on mechanical and microstructural behaviors of the developed surfaces is investigated

Incremental Sheet Forming (ISF) is a sheet metal forming process, which relies on minimum part-specific tooling. Extra Deep Drawn (EDD) steel has been used for making door inners, dash panels, bodyside inners, etc. due to its good weldability and relatively low yield strength. However, to date very limited work is reported on ISF of EDD steel. Besides, no work, which exhaustively discusses the practicability

Labyrinth seal systems are used in aeroengines to seal the clearance, the understanding of the wear mechanism of labyrinth seal system is necessary to achieve better sealing performance. In this work a series of tests are conducted on a high-speed test rig capable of fin tip speeds of 100 m/s. With force and temperature measurements recorded in each case, the influence of specimen geometry is investigated

In this paper, a novel 6-degrees-of-freedom (DOF) hybrid mechanism is proposed to realize position and posture adjusting for large-volume equipment. The designed hybrid manipulator is composed of the lower and upper modules, namely, a 3-DOF redundant spatial parallel mechanism (SPM) and a 3-DOF planar parallel mechanism (PPM), which has three rotational and three translational DOFs. According to the

Biodiesel such as linseed oil can be derived from the feedstock of vegetables without disturbing supplies of food and the ecosystem. An experimental and comparative analysis was carried out to explore the effect of exhaust gas recirculation (EGR) and fuel injection pressure (FIP) on the emissions and efficiency of a CRDI diesel engine fuelled with linseed biodiesel/diesel blend. The engine characteristics

This study intends to investigate a dynamic modeling and design of controller for a planar serial chain, performing 2-DoF, in interaction with a cable-driven robot. The under study system can be used as a rehabilitation setup which is helpful for those with arm disability. The latter goal can be achieved by applying the positive tensions of the cable-driven robot which are designed based on feedback

In present work, cryorolling is performed to obtain the higher mechanical strength of the received material. Close to 50% and 30% increments in tensile and yield strengths of the material are observed for 40% thickness reduction. However, limited ductility has been obtained for cryorolled samples. Post annealing heat treatment is performed on cryorolled samples to obtain combined enhancement in strength

This study presents the results of an investigation on the tensile behaviour of hybrid polymer composites under different strain rates. Glass/carbon, aramid/carbon, glass/aramid, and glass/aramid/carbon hybrid laminates were produced using vacuum assisted resin transfer molding method with epoxy resin system. Uniaxial tensile testing was performed to determine the tensile strength, modulus and failure

Filler-free (FF) welding processes namely, Activated Tungsten Inert Gas welding (ATIG), Laser Beam Welding (LBW), and Friction Stir Welding (FSW) were utilized for joining the nuclear grade 9Cr-1Mo-V-Nb ferritic-martensitic steel and 316 L(N) austenitic stainless steel. A comparative investigation was made by assessing the weld geometries, metallurgical features, material mixing proportions, carbon

In this study, a novel approach based on synergy of cooperative game theory, reliability-based design optimization (RBDO) and Monte Carlo simulation (MCS) is proposed to address the reliability-based multi-objective optimal synthesis of path generating four-bar mechanisms, taking into account the influence of dimensional uncertainty on the reliability of mechanism. Tracking error (TE), deviation of

This paper investigates the forward and inverse kinematics in screw coordinates for a planar slider-crank linkage. According to the definition of a screw, both the angular velocity of a rigid body and the linear velocity of a point on it are expressed in screw components. Through numerical integration on the velocity solution, we get the displacement. Through numerical differential interpolation of

Fused Deposition Modeling (FDM), is one of the most popular and widely used Additive Manufacturing filament based technology employing materials such as Acrylonitrile Butadiene Styrene (ABS), Polycarbonate (PC), Thermoplastic Polyurethane (TPU) and Polylactic Acid (PLA). In this technique, the part is built up layer-by-layer, affecting, both the resolution along the z-axis, and the mechanical properties

A numerical study is performed to investigate nanofluids' flow field and heat transfer characteristics between the domain bounded by a square and a wavy cylinder. The left and right walls of the cavity are at constant low temperature while its other adjacent walls are insulated. The convective phenomena take place due to the higher temperature of the inner corrugated surface. Super elliptic functions

In the wind tunnel facility, a test structure is often used for measuring its vibrational response to the aerodynamic excitation. A support is needed to sustaining the structure and it is mandatory that this support does not influence the vibrational energy to be measured. To this aim, the maximum amount of energy decoupling between the structure and the support is desired. This work is focused around

A double-end lower limb rehabilitation robot is introduced in the paper, which can realize the rehabilitation training of the abduction and abduction, internal rotation and external rotation of human lower limb. The kinematics and dynamics of the robot are analyzed. Based on the motion trajectory planning of the lower limb rehabilitation robot, the motion state and dynamic state of the cable are analyzed

In this study, the effect of crack on free vibration of a large deflected cantilever plate, which forms the case of a pre-stressed curved plate, is investigated. A distributed load is applied at the free edge of a thin cantilever plate. Then, the loading edge of the deflected plate is fixed to obtain a pre-stressed curved plate. The large deflection equation provides the non - linear deflection curve

Modeling an accurate and effective heat source is a challenge when describing the thermal behavior of wheel/rail contact, conventionally modeled using Goldak’s heat source. This Gaussian distributed model transplanted directly from the welding field is quite different from the ellipsoidal heat source on the contact patch. An innovative heat source model which reflects the shape and size of contact

This paper aims to present the integrated design, development, and testing procedures for a state-of-the-art torsion-based series elastic actuator that could be reliably employed for long-term use in force-controlled robot applications. The main objective in designing the actuator was to meet weight and dimensional requirements whilst improving the long-term durability, ensuring high torque output

Split sleeve cold expansion (SSCE) is a crucial cost-effective process to improve the fatigue life of metallic structures with holes in the aerospace industry. In this study, the effects of the workpiece material’s yield strength (290.9 MPa to 377.8 MPa) and the applied SSCE expansion percentage (3.330% to 4.377%) on mandrel pulling force and residual stresses were investigated numerically for aluminum

The motion of a part on a curved surface mounted upon a linear vibratory feeder is of great importance in mass production. In this article, the conveying surface or track is modelled by a bilinear surface inclined to all axes with the curvature varying throughout the surface. An experimental test rig is fabricated to study the part motion on the feeder surface. Dynamics of the part on the surface is

This study presents a novel cylindrical vane pump based on the traditional working principle. The efficiency of the cylindrical vane pump was verified by experimental validation and numerical analysis. Numerical analysis, such as kinematics analysis, was performed in Pro/Mechanism and unsteady flow-field analysis was performed using ANSYS FLUENT. The stator surface equations were derived using the

The sealing characteristics of an annular power cylinder based on the Twin-rotor piston engine are studied, which provides a theoretical foundation for the sealing design of a new high-power density piston engine. In this paper, the basis thermodynamic realization process of an annular power cylinder is presented. The Runge Kutta equation is used to establish the coupled leakage model of adjacent working