With the prospective of developing an integrated monitoring system aimed at assessing whether a landing gear has experienced hard impact during the approach, a dedicated method is developed aimed at determining vertical speed by means of strain measurement via FBG strain sensors. Representative impacts on simple structural elements have been reproduced in laboratory, as aluminum slender beams of different

To solve the problem of shift shock during the inertia phase caused by generalized disturbances in wheel loaders and other construction instruments, a robust double closed-loop tracking control method based on an improved disturbance observer (DOB) has been proposed. In this method, the inner loop robustly suppresses disturbance and the outer loop realizes trajectory tracking. The improved DOB based

The magnetization and demagnetization process of electrohydraulic servo valve with permanent magnet torque motor is the last manufacturing process of electrohydraulic servo valve before its service, which has a significant effect on the output characteristics and magnetic stability of both torque motor and electrohydraulic servo valve. However, the previous studies mainly focus on the static state

Isomorphism identification is an essential step in mechanism configuration synthesis. Although various detection methods have been proposed, some of them can only effectively identify kinematic chains (KCs) within 10 links or complex programs that are needed to identify multilink KCs. In this study, a new isomorphism identification method is proposed based on the distance concept of graphs and the

In this study, the thermal histories of the welded copper plates have been numerically determined under different welding conditions. In order to determine the amount of heat produced by the welding tool, Frigaard formula was used and in the next step, the welding process was modelled using the obtained heat values. The numerical results have been compared with empirical results and it was cleared

High performance thermoplastic is often used in automotive and aerospace sectors. Friction stir welding (FSW) has been a suitable method for joining these thermoplastic materials. However, the process characteristics vary dynamically, even at same parametric conditions due to process disturbances. While quite a few studies have been reported in experimental investigation, the usage of sensors for the

This research manuscript compares the metallurgical changes and mechanical behavior of AISI 316 and Monel 400 dissimilar weldments developed by Interpulse TIG welding process with ERNiCrMo-3 and ER316 filler wires. Metallurgical aspects are envisioned by using optical and scanning electron microscopes. Mechanical behavior of welded joints were studied by conducting tensile and microhardness tests.

In this study, a layering method of carburized ring is presented. A finite element (FE) model for analyzing bearing stiffness characteristics is established considering the residual stress in the carburized layer. The residual stress in the carburized layer of a double-row conical roller bearing is tested and the influence of the distribution of residual stress in carburized layer on the bearing stiffness

The key to sustainable development in the footwear industry through the principles of circular economy lies in taking care of the design, as well as the introduction of innovative and more resource efficient materials and processes to reduce or avoid the use of water, energy, hazardous chemicals and to minimise emissions and waste. In fact, the environmental footprint is already being considered as

Magnetic field assisted powder mixed electrical discharge machining (MFAPM-EDM) is a variant of EDM process where magnetic field coupled with electric field is used with addition of fine powder in dielectric to improve the surface quality, machining rate and stability of the process. Aluminium 6061 alloy as workpiece was selected due to growing use in aviation, automotive, naval industries. In this

Nominal strength prediction remains the main challenge in the field of design and manufacturing of composite laminates. An approximate model to study the stress distribution around a circular hole in composite laminates is derived in this study. This model is constructed using well-known cohesive zone models and mainly depends on the un-notch strength and in-plane fracture toughness. The model attempts

A structure of a cylindrical shell with a circular plate end cap is usually used in connect different shaft system and it is necessary to estimate the axial stiffness in order to analyze the vibration of the rotor system. This paper builds the model of this structure. The theoretical solution of the bending deflection of the circular plate and the cylindrical shell are deduced by using the classic

Large optical mirrors require an ultra-precise machining equipment, and a high level of surface-forming precision must be achieved. However, optical mirror processing systems (OMPSs) are susceptible to human behaviors, mechanical structural errors, and processing environments. The factors that affect quality include artificially formulated processes, slurry choice, joint friction, force-induced deformation

An unsteady natural convective boundary layer fluid flow of thick incompressible Al2O3−SiO2/water hybrid nanofluid is discussed over an oscillating permeable stretching surface. The radiative and chemically reactive hybrid nanofluid flow is induced in rotating coordinates. Essential thermophysical properties of hybrid nanofluid are utilized. The boundary layer equations governing the present phenomena

In the present study, development of a novel oriented polymeric composite comprising of Polycaprolactone (PCL) polymer and carbonyl iron filler particles (CIP) is presented. Incorporation of permanent magnets into solvent based extrusion 3 D printing set up produced the oriented polymeric composites. The microwave absorption properties of the oriented composite were investigated and compared with non-oriented

Additive manufacturing has gained increasing attention in recent years in numerous industrial sectors due to its inherent characteristics, e.g. tool-free production and unprecedented freedom of design. However, in some applications such as heat exchangers the design has to follow certain restrictions, e.g. to allow for the removal of unfused powder, which can be enclosed in cavities. Moreover, in case

This paper develops a theoretical model for energy and exergy analyses of a solar-powered Lithium-water absorption refrigeration system using a recto-trapezoidal flat plate solar collector. The effect of collector fluid inlet temperature is to examine the overall performance of the solar collector and the vapour absorption system for a wide range of design variables. The parameters computed are energy

In this paper, the statistical analyses of the ammonia-water absorption refrigerant system (ARS) are presented. For this purpose, different surface response methods, including the Central composite design (CCD) and Box- Behnken design (BBD), have been studied and compared first to obtain the best response. An attempt is made to study the effect of some factors (mass flow rate, isentropic efficiency

The aim of this article is design, fabricate, and control a conceptual prototype of a flexible wearable robot to increase fingers’ force using a novel cable mechanism. In this robot, force and position are controlled in separate phases by a fuzzy system equipped with emotional learning. A Flexible structure has been chosen for this robot, because flexible gloves are lighter and much more suitable for

The machining of titanium based hybrid composite by conventional method is very complicated because of its enhanced strength-to-weight ratio, resistance to corrosion, abrasion and fatigue and this hybrid composite is extensively necessary for automobile, aerospace, sports, spacecrafts, marine and bio-medical industries. In this paper, an investigation is presented based on a novel optimization algorithm

In the present paper, nonlinear forced vibrations of an axial moving nanobeam which is vertically influenced by an external harmonic excitation and gravity is analyzed by considering the effects of linear damping. Considering certain assumptions, a nonlinear Euler-Bernoulli beam theory is developed. With the implementation of the nonlocal elasticity theory, the governing integro-partial-differential

Hybrid Laser-Arc Welding (HLAW) is a relatively new joining technique that combines advantages from both laser beam welding and arc welding. The interaction between laser beam and arc welding provides advantageous synergic effects, especially for thick joints. On the other hand, this interaction brings extra complexity to HLAW, limiting its acceptance in industry. Therefore, it is still necessary to

A good heat dissipating condition will help give full play to the performance and reliability of electronic components and devices. To strengthen the heat dissipating performance, a novel bionic heat sink of pin fins has been designed. The configuration of cooling pin fins in this heat sink is based on phyllotaxis theory in biology. The bionic configuration of the cooling pin fins has better homogeneity

AZ91 and AZ31 Mg alloys are used for lightweight structures with excellent specific strength. Fusion welding of Mg alloys is not suitable due to its high affinity towards oxygen. The present research investigates joining performance of AZ91 and AZ31 using indigenously developed friction stir welding set-up at different welding and rotational speed. The results show that highest value of microhardness

To improve the efficiency and accuracy of reliability assessment for structures with small failure probability and time-consuming simulation, a new structural reliability analysis method (RCA-PCK) is proposed, which combines PC-Kriging model and radial centralized adaptive sampling strategy. Firstly, the PC-Kriging model is constructed by improving the basis function of Kriging model with sparse polynomials

The main purpose of this research is to investigate the thermoporoelastic behavior of non-homogeneous circular plate made up of auxetic metamaterial rested on an auxetic material plate. The plate is non-uniform, restrained with flexible support at outer edge and subjected to structure-structure interaction and thermo-mechanical load. The plate material is graded in transverse direction and the Poisson's

A theoretical model of a four-pad bearing profile with unique adjustable or controllable features is simulated in the present study by considering load directed between the pads. Radial and tilt adjustable mechanism of the four bearing pads can effectively control and modify the rotor operating behaviour. Inward and outward motions of the bearing pads result in the generation of narrow and broader

The present study aims to investigate the influence of food waste (citrus limetta peel) filler size on the thermal and mechanical behaviour of epoxy resin based composites. The present research work was undertaken with three different categories of fillers i.e. (i) (100–250) µm and ii) (350–500) µm and iii) (650–800) µm in 15 wt.%. The epoxy resin modified with citrus limetta peel (CLP) fillers was

The paper presents a design of a small-scale centrifugal compressor to match the performance of up to 20% larger diameter compressor in order to meet the demands for a higher mass flow rate and wide operating range for turbocharging applications. This development considers the 44 mm diameter impeller design involving transonic blading and state-of-the-art blade features. In the course of design, the

Conventional oil lubricated journal bearings experience a degradation in the lubrication properties of oil at high temperatures thereby making the use of oil lubricants impractical in a hot working environment. Under these conditions, powder lubricants can be used for the successful operation of the rotor-bearing system. Whirl instability is a serious problem for rotors supported on journal bearings

In this paper, the oxygen transport in a capillary network and the surrounding tissue was simulated by considering the influence of red blood cells (RBCs). To simplify this problem, the erythrocytes as the oxygen carriers were modelled as one-dimensional (1 D) spheres, and oxygen and haemoglobin diffusion took place only in the radial direction. The direction of movement of the RBCs at the network

In this study, we focus on the bending analysis of the 2 D FG nanoplate based on a new high-order shear deformation theory (HSDT). This kind of HSDT is one of the most accurate HSDT because the shape functions are selected as an accurate combination of exponential, trigonometric and polynomial functions. The mechanical properties of the nanoplate vary along the length and thickness, based on arbitrary

This paper presents the passive vibration isolation problem for a specific kind of Stewart Platform called flexure jointed hexapod (FJH). For purpose of analyzing the relationship between passive vibration isolation and parameters of the FJH, an existing dynamic model of the hexapod is re-cast appropriately to obtain the transfer function matrix from disturbance to generalized coordinates of the payload

In addition to the textile industry, unwinding of cable or fiber is used in various fields such as electronics, communication, and guided weapons. The cable released from the package exhibit a complicated behavior, entailing a combination of rotational and translational motion. This causes problems such as entangling and fracture. Therefore, it is necessary to study boundary and adhesion conditions

The classical Fourier heat conduction theory as well as the widely used Fick’s diffusion law predicts an infinite wave velocity. This is physically unrealistic. By generalizing the classical Fourier’s and Fick’s laws, this paper presents a hyperbolic diffusion law to apply heat and moisture coupling. The transient response of the hygro-thermo-elastic field in infinitely long hollow cylinders subjected

This work presents a higher order finite element (FE) model to gauge the static behaviour of hygrothermo-magneto-electro-elastic (HTMEE) plates with different electro-magnetic circuits. The FE model is composed of eight-noded isoparametric elements. The displacement equations are presumed to obey the higher order shear deformation theory (HSDT) and the governing equations of motion are obtained with

This paper focuses on the autonomous motion control of 3-D underactuated overhead cranes in the presence of obstacles, and an “offline motion planning + online trajectory tracking” framework is developed. In the motion planner, to meet the balance between transfer time and energy consumption, the transfer mission is formulated as an energy-time hybrid optimal control problem. And a simple and conservative

The commonly used grasp simulators such as GraspIt! and OpenRAVE use wrench space formulations and grasp quality metrics such as ϵ and v to identify stable grasps in dynamic conditions. However, wrench space formulations are derived based on static mechanical equilibrium equations, and the physical attributes of the object such as stiffness and mass are also not considered for grasp analysis. Above

To study the dynamic compression and tensile mechanical behaviors of a bicomponent epoxy resin matrix composites, which were filled with a semi-crystalline thermoplastic Polyether-ether ketone (PAEK-C) resin, at high strain rate, the dynamic compression and tensile experiments were carried out on a modified split Hopkinson pressure bar (SHPB) and high speed material apparatus, respectively. Stress-strain

This work investigates a nonlinear passive control strategy designed to reduce the peak accelerations in ropeway roller batteries systems by deploying an array of nonlinearly visco-elastic vibration absorbers. The control effectiveness is compared with that of an equivalent array made of linearly visco-elastic absorbers. A nonlinear parametric model describing the interactions between the different

In this paper, the effect of ceramic particles (Zirconium, Boron Carbide and Graphene) on the ballistic resistance of Friction Stir Processed (FSPed) thick AA6061 targets had been explored. The Base Metal AA6061 plates of 25 mm thickness were FSPed by reinforcing Zirconium (Zr), Boron Carbide (B4C) and Graphene (G), thus producing FSPed-Zr, FSPed-B4C and FSPed-G surface composite targets. Microhardness

Rotational autofrettage is a recently proposed method to induce beneficial residual stresses in axisymmetric hollow cylindrical bodies. The feasibility of the process has been studied for both disks and cylinders used in many engineering applications. The earlier analyses of rotational autofrettage of disks are based on certain assumptions. One of the crucial assumptions is the free rotation of the

In the present work, large eddy simulation coupled with immersed boundary (LES-IB) method is applied to simulate a backward facing step (BFS) flow, which is a canonical fluid dynamics problem involving flow separation, recirculation and reattachment that are common in many practical applications. The computed reattachment length, a primary parameter to evaluate the overall performance of the numerical

The present literature illustrates the radiative couple stress fluid runs over a permeable stretched cylinder. The problem has been modelled mathematically introducing the mixed convective condition and magnetic effect. Additionally, the analysis of entropy generation provides the fine points of the flow. The leading PDE equations of the system have been framed non-dimensionally using proper transformation

In this study, a semi-empirical model was proposed to calculate the penetration depth and cavity diameters generated by shaped charge jet into high and ultra-high strength concrete (H&UHSC) targets. A recently proposed axial penetration equation and the two-step mechanism of cavity growth were employed to determine the analysis. The predictions were validated with reference to the experiments conducted

A tailor welded blank (TWB) includes two or more blanks joined together in order to make a single blank. Different welding methods are used to join blanks with different characteristics and form TWBs. In this study, a comparison is made among the effects of three different welding methods namely CO2 laser welding, friction stir welding (FSW), and friction stir vibration welding (FSVW) on mechanical

This paper investigates a novel model based on the Magic Formula and the Pan’s model to effectively predict the inherent nonlinear hysteresis behavior of magneto–rheological (MR) dampers. In the proposed model, the hysteresis element is employed from the Magic Formula and Pan’s model, and two new independent horizontal shift parameters, which are separated from one original parameter of the Pan’s model

Condition monitoring performance and diagnosis of rotor-bearing systems depend not only on the methods used, but also on the dynamic complexity of the system itself. Thus, it is important to analyze how changes in parameters under various working conditions impact on dynamic complexity. Most of previous research efforts on this topic have been focused on the analysis of nonlinear dynamics of rotor-bearing

This paper aims to solve the problems of the existing limbs rehabilitation robots in terms of configuration limitations, human-machine compatibility, multimodal rehabilitation training. In addition, the control method of the cable tension of cable drive unit (CDU) loading system is studied to improve loading accuracy of cable tension and safety of the rehabilitation training robot. The novelty of this

In this study, an investigation of magnetohydrodynamics flow of Oldroyd-B fluid by a rotating disk with the influence of thermophoresis on the deposition of particles is discussed. Additionally, the Soret–Dufour effects are taken into consideration. The von Karman transformation is used and the numerical results are obtained through BVP Midrich technique in Maple. The results are given through graphical

Linear Jet system which has a stator in addition to a rotor combines the best elements of two existing technologies of conventional screw propellers and water jets. In designing this propulsion system, tip clearance plays an essential role, since it causes the appearance of tip vortex that leads to a further loss in efficiency and a probability of cavitation phenomenon. Due to lack of any study in

Cemented carbide is a common cutting material with a hardness that significantly affects its usability. A Vickers indentation test was performed to analyse changes in the hardness of cemented carbide cutters with temperature and loads to understand its variation law. Moreover, indentation-induced surface damage was observed, and its elements were analysed. Crack distributions on the indentation surface

Flow and heat transfer of water-based nanofluid over a stretchable rotating disk under the influence of an alternating magnetic field is investigated. The external magnetic field creates a hindrance in the flow and depends on the frequency of the alternating magnetic field. The frequency of an alternating magnetic field can increase or decrease the viscosity of the magnetic fluid in the flow. A set

Performance enhancement of typically sluggish pneumatic brake actuators in Heavy Commercial Road Vehicles (HCRVs) is necessary for the efficacious operation of active safety systems. This study develops a robust Proportional Integral Derivative (PID) controller using the Kharitonov theorem for pneumatic brakes. To account for the inherent time delay present in pneumatic brakes, Padé approximation and

In order to reduce costs for a larger warehouse or expand the floor space of a small warehouse, it is impossible to implement this with a traditional warehouse, which is characterized as poorly utilized space. For the efficient storage and retrieval, the smart warehouse system with autonomous mobile-rack vehicles can optimize the space utilization by providing only a few open aisles at a time for accessing

This paper focuses on cross-section optimization of both rectilinear and curvilinear beams. In particular, analytical models were developed, in order to detect how circular section resistance can be modified following a suitable cut. In fact, removing material from the furthest zone from the neutral axis, may even result in an increase of the section resistance modulus, with consequent beneficial reduction

Roots blowers are widely used in various fields, and their performances are extremely important for their application in the chemical industry. In this study, a Roots blower with a flow capacity of 90 m3/min was investigated using a computation fluid dynamics (CFD) approach, with emphasis on its performance. A previous-generation blower comprising two lobes was simulated, and the calculated volumetric

The inevitable oscillations of the payload decrease the positioning accuracy and lessen the safety in dual cranes carrying a large payload. In the presence of the structural flexibility, the dynamics of dual cranes are governed by the payload swing, pitch, and twisting after considering three-dimensional motions. However, little research has been directed at the modeling and control of three-dimensional

The paper aims to study the antiwear (AW) and extreme pressure (EP) properties of avocado oil mixed with zinc dialkyl dithiophosphate (ZDDP) in concentrations of 1% to 3% by weight for lubrication purposes. The AW and EP tests are conducted as per ASTM-4172 and ASTM-2783 standards respectively. Further, the rheological behavior of avocado oil mixed with ZDDP is determined for varying shear rates of

In industrial machinery and automobiles the critical damping plates are used as shock absorbers to dampen system and return rest position, in the shortest period of time. The paper is focused on the effects of various parameters on critical damping of a complicated system including a tapered bidirectional graded circular plate subjected to radially variable in-plane pre-load and rested on visco-Hetenyi