A three-dimensional model of an external gear pump and a new application of an algorithm for the measurement of the unsteady flow rate in hydraulic pipes are presented. The experimental delivery flow ripple was compared with the outcomes of a simulation under different operating conditions. A comprehensive computational fluid dynamics model of the pump and of the high-pressure delivery circuit was

This paper presents a numerical study of regular and hierarchical honeycomb structures subjected to out-of-plane impact loading. The specific energy absorption capacity of honeycomb structures via nonlinear explicit finite element analysis is investigated. The constructed finite element models are validated using experimental data available in the literature. The honeycomb structures are optimized

Accurate fault prediction of rolling bearing can predict the operation condition in advance, which is an important means to ensure the safety and reliability of rotating machinery. Aimed at the data processing of rolling bearing vibration signal with multi-fault and long time series, an intelligent fault prediction model based on gate recurrent unit and hybrid autoencoder is proposed in this paper

Pneumatic dual reciprocating bellows pump has been widely used in chemical transportation due to its good sealing and anticorrosion performances. Nevertheless, the large outlet pulsation limits its performances on precise transportation and control of the fluid. Although the design of employing flexible linkage between the bellows has been proposed as an effective solution for this shortcoming, the

In the heat exchangers, twisted tape insert is a technique to enhance heat transfer. In this paper, the experimental and numerical investigations are arranged to analyze thermal performance with entropy generation analysis on single and double strip helical screw tape inserts. The finite volume method is used with shear stress transport K-ω model to analyze fluid flow in tube with inserts. The Nusselt

Relaxation behavior provides specific information that indicates stress development with elapsed time for the determination of material characterization and constituting of material modeling. In addition, anomalous relaxation behavior of polymeric materials enables experimental analysis of some theoretical variables in constitutive equation. Equilibrium stress is one of the most prevailing variables

In this article, the horizontal hinged heavy duty servo cylinder is taken as the research object. In the actual working process, while the servo hydraulic cylinder outputs the curve force, the cylinder body will also rotate with the hinge point to a certain extent. Because the position of the center of gravity is constantly changing, and the weight of the cylinder body is too large, the friction causes

Melamine-formaldehyde is the most common resin used in the production of high-pressure laminates and low-pressure laminates (melamine impregnated paper), due to its properties of durability, good fire, and heat resistance and good moisture resistance. High-pressure laminate is a common choice for horizontal and vertical applications in the construction and furniture industries, thanks to its durability

This special issue is arranged based on the International Conference on Intelligent Manufacturing and Internet of Things in 2018 (IMIOT2018) which brought together the latest scientific and engineering developments in manufacturing for the future. Four extended papers from the conference and one direct submission were selected after rigorous review and thorough revision to showcase the recent advances

When a cavitating jet enters the atmosphere directly, its cavitating effect weakens rapidly, and the erosion energy it produces cannot be fully utilized. Regarding the problem that existing cavitation nozzles are only used in submerged condition, methods to improve the erosion ability of cavitation jets under nonsubmerged condition are studied. The nozzle is visually simulated using Fluent software

This paper proposes an improved particle swarm optimization to study the forward kinematic of a solar tracking device which has two rotational and one translational degree of freedom. The forward kinematics of the parallel manipulator is transformed into an optimization problem by solving the inverse kinematics equations. The proposed method combines inertial weight with the iterations number and the

The paper represents a probabilistic approach to the finite element modelling of dynamic fracture problems. It is proposed to model internal structural defects and inhomogeneities using the spatial distribution of strength characteristics according to the normal distribution law. The probabilistic approach to modelling dynamic fracture is provided by the introduction of one additional parameter – the

The high-end devices, sophisticated gadgets, smart home appliances, superfast vehicles and aero engines of twenty-first century demand better heat removal for efficient functioning. Thus, with an aim to facilitate higher heat transfer from mechanical and electronic equipment, extensive research throughout the world has been going at a steady pace. One such achievement in the field of heat transfer

As the demand for the transmission of electric power and communication signals in automotive and aerospace vehicles increases, so does the number of structures comprising simplified one-dimensional attachments, such as electrical cabling, affixed to a host plate like primary structure. These attachments are typically uncertain in their geometric or material properties, potentially affecting the response

To reduce the thermal deformation of ball screws, a novel approach inspired by silver ants is proposed. The Saharan silver ant maintains low body temperatures in one of the hottest terrestrial environments by radiating heat to the surrounding environment. Inspired by this, bio-inspired graphene-coated ball screws, which can enhance heat dissipation due to radiative heat dissipation of graphene coating

Cycloidal gears constitute the main working unit of the fluid power gerotor machine. The paper presents a way of increasing the load-carrying capacity of cycloidal unit made of plastic. The aim has been reached through design and material modifications. As a result of those modifications, a design concept of the cycloidal gear system, which is different from the structures previously produced, has

A new geometric design method for foldcores based on the generalized Resch patterns that allow face-to-face bonding interfaces between the core and the skins is proposed. Based on the geometric design method, a systematic numerical investigation on the quasi-static mechanical properties of the generalized Resch-based foldcores made of carbon fiber-reinforced plastic (CFRP) woven fabrics subjected to

The purpose of this study was to investigate the influence of muscle fiber type on the slow component of oxygen uptake (VO2) kinetics and electromyographic activity. Twelve sprinters and ten endurance runners participated in the study. They performed two separate treadmill running tests, the first test being conducted to determine the ventilatory threshold and maximal oxygen uptake. The second test

In this study, experimental investigations carried out to analyze the influences of different in-plane temperature variations on buckling and free vibration responses of metal and fiber-reinforced laminated composite cylindrical panels are presented. Initially, critical buckling temperature is calculated then free vibration analysis is performed as a function of the buckling temperature to analyze

This paper introduces a novel three degree-of-freedom spherical parallel manipulator with 3-PRR topology, where P and R denote a curved prismatic joint and a revolute joint, respectively. The first revolute joint of each PRR leg is actuated via a double Rzeppa-type driveshaft, and hence underlined. The manipulator has at most eight working modes and eight assembly modes. However, only one working mode

The capacities of parallel mechanisms are limited by their height for the narrow space applications, such as the shipboard stability platforms, household simulators, aerospace mechanisms, etc. This paper proposes a novel foldable six-DOF parallel manipulator which has three main limbs with each actuated by two actuators. With the ability to fold in the vertical direction, this mechanism can be deployed

It is a well-established fact that corrosion of mild steels occurs in pipelines, storage tanks, oil reservoirs, boilers, and petrochemicals industries. Green inhibitors are economical, non-toxic and eco-friendly, and forming barrier type layer of organic compounds over metallic materials. In this paper, weight loss, electrochemical measurements containing potential measurements, potentiodynamic polarization

Based on the space curve meshing theory, a novel noncircular line gear mechanism was advanced, namely, this paper presented a design method of the variable speed ratio noncircular line gear with coplanar axes. Firstly, the universal contact curve equations of the constant speed ratio and variable speed ratio line teeth were established. After the constraint equations of the rotating angle of the driving

The burrs and delamination induced in milling of carbon fiber reinforced polymer have been studied extensively to suppress them. The cavity defect is still generated frequently on the machined surface of carbon fiber reinforced polymer when the fiber cutting angle is obtuse, resulting in the performance degradation of carbon fiber reinforced polymer parts. Nevertheless, there are a few researches on

The reduction of agglomeration of particulate reinforcement in friction stir processing and elimination of joint line remnant in friction stir welding depends on stirring ability of friction stir tool. The magnitude of stirring is indicated by the intensity of material inter-mixing in tool interacted region. Present investigations analyse the influence of geometrical aspects of classical friction stir

A data-driven finite element method that accounts for more than two material state variables has been presented in this work. Data-driven finite element method framework can account for multiple state variables, viz. stresses, strains, strain rates, failure stress, material degradation, and anisotropy which has not been used before. Data-driven finite element method is implemented in the context of

The detection of the symmetry axis from discrete axially symmetric surfaces is an interesting topic, which is transversal to various fields: from geometric inspection to reverse engineering, archeology, etc. In the literature, several approaches have been proposed for estimating the axis from high-density triangular models of surfaces acquired by three-dimensional (3D) scanning. The axis evaluation

It is essential to optimize the support structures in rotating machinery to reduce the vibration, (i.e. decreasing forces transmitted to the whole dynamic system). Lots of vibration alleviation methods were applied in rotary machines, such as squeeze film dampers were used in aero-engine. In this paper, a theoretical model of an active floating squeeze film damper was studied in a vibration control

In this work, it is aimed to study the effects of dry machining and minimum quantity lubrication application on machinability in turning AISI 4140 steel by utilizing different cutting parameters. Also, this study contains effects and optimization of cutting conditions (dry and minimum quantity lubricating), feed rate, and cutting speed on surface roughness (Ra) and main cutting forces (Fc) determined

In this paper, a piezoelectric energy harvesting application on a portal frame of two-degrees-of-freedom considering a quadratic coupling between the coordinates with two-to-one internal resonance is considered. The piezoelectric material is considered as a linear device using a voltage and a charge mathematical model. The equations of motion of the system were obtained by applying the energy method

This paper investigates the dynamic behavior of a geometrically nonlinear nanobeam resting on the fractional visco-Pasternak foundation and subjected to dynamic axial and transverse loads. The fractional-order governing equation of the system is derived and then discretized by using the single-mode Galerkin discretization. Corresponding forced Mathieu-Duffing equation is solved by using the perturbation

Effects of porosity, profile of thickness and angular deceleration on the stress and deformation of a fluid-saturated functionally graded porous magneto-electro-elastic rotating disc are investigated in this article. Since the angular velocity is taken to be variable, the disc is subjected to Lorentz force in two directions: radial and circumferential. It is assumed that material properties of the

The purpose of the paper is to study stability and free vibrations of laminated plates and shallow shells composed of functionally graded materials. The approach proposed incorporates the Ritz method and the R-functions theory. It is assumed that the shell consists of three layers and is loaded in the middle plane. The both cases of uniform as well as non-uniform load are possible. The power-law distribution

Partial emission pumps or open impeller pumps or tangent pumps with very low specific speed at either fast or conventional speed have found extensive applications in aircraft, liquid rockets, cryogenic fluid systems, chemical and petroleum-chemical industries, energy and food processing systems, etc. Usually, impeller trimming of rotodynamic pumps serves as an effective tool to meet required hydraulic

The current paper deals with the studies of heat transfer and pressure drop through a horizontal, adiabatic pipe, having gas–solid flows. The inlet air temperature is 443 K, whereas the inlet solid temperature is 308 K. The numerical results are compared with the benchmark experimental data and are agreed satisfactorily. The influences of solid loading ratio, solid diameter and gas velocity on Nusselt

The horizontal bubbly two-phase flow is preferably used in various industrial applications because it provides high interfacial areas which enhance the heat and mass transfer. In the present research, the phase distribution of controlled air-water flow in a horizontal acrylic round pipe with 60 mm inside diameter (D) has been investigated experimentally and modeled numerically. The modeled differential

As a new kind of active flow control technology, plasma flow control has a bright future, for its simple structure, fast response, and wide frequency band. The wind tunnel and flight tests were conducted with microsecond dielectric barrier discharge on a glider. For the tests, the microsecond pulse power supply and remote control system were designed and built. In the wind tunnel test, the flow separation

The aerodynamic performance of axial turbines depends significantly on profile losses, secondary flow losses, and clearance gap losses of vanes and blades. In modern high-efficiency turbomachinery operating at various working conditions, profile losses are very important criteria for the development of vanes and blades, and turbine designers strive to minimize the losses, based on better understandings

An analytical approach based on a hydrodynamic lubrication model is presented to understand the bearing capacity, leakage, and friction moment of the slipper–swash-plate interface in a swash-plate-type axial piston pump. Furthermore, how the shaft speed, load pressure, and slipper attitude influence the lubrication performance of the interface is analyzed. The research shows that the slipper attitude

Due to the existence of coupling relationships, quality characteristics form a variation propagation process, which increases the risk possibility of product quality. In order to improve the robustness of quality characteristics, this paper proposes a fuzzy clustering-based key quality characteristics decoupling planning considering risk criticality. Firstly, based on the design structure matrix, a

To meet the needs of large load and high reliability measurement under complex working conditions and downsize the outline of six-axis force sensor as much as possible, the design concept of hybrid limb is proposed to the design of parallel six-axis force sensor. A kind of heavy-load-bearing flexible integrated six-axis force sensor with hybrid limbs is proposed. The proposed force sensor adopts a

In engineering applications, angular contact ball bearings are usually mounted in pairs to accommodate the high-speed and heavy-load conditions. The usability, security, and stability of rotating machinery systems are heavily dependent on the mechanical behaviors of matched angular contact ball bearings. However, few related works about matched bearings have been reported. Consequently, it is of great

Excavators are widely used at various construction sites, and they can significantly reduce difficulties during construction and improve construction efficiency. However, conventional excavators still exhibit many shortcomings. In certain construction environments that require precision, the construction accuracy cannot be guaranteed because excavators usually operate in harsh environments. Hence,

In this paper, the effects of linear speed, rotational speed, and tool radius of the pin and shoulder are investigated on the material flow velocity in friction stir welds. To obtain the maximum material flow velocity by an analytical method, a suggested relation is introduced for the rotational speed and tool optimum radius. The derived relation is based on the assumption of a velocity field in the

The tensile-shear strength of AA 5052 single and multi-friction stir spot welding joints were analyzed using experimental, numerical, and analytical approaches. Benchmark specimens were designed and manufactured in a similar manner with respect to industrial practice. Under the fixed welding process condition, the failure mechanism of friction stir spot welded specimens under tensile-shear loading

Perpetual points have been defined recently and their role in the dynamics of mechanical systems is ongoing research. In this article, the nature of perpetual points in natural dissipative mechanical systems with viscous damping, but excepting any externally applied load, is examined. In linear dissipative systems, a theorem and its inverse are proven stating that the perpetual points exist if the

A method for the analysis of amplitude-dependent modal damping factors is developed for the cases when the energy dissipation is caused by the micro-slip motion at friction contacts of blade root joints. The modal damping at root joints for a lone blade and for tuned bladed disc assemblies is studied. Large three-dimensional finite element models and detailed description of friction contacts by surface-to-surface

In the paper, a novel method to improve the uniformity of the temperature distribution on the surface of the hot-plate is presented. Firstly, the effect of magnetic flux density under coupling of the electromagnetic and heat transfer on target surface temperature is studied numerically by using the commercial simulation software COMSOL Multiphysics. To evaluate the uniformity of the temperature distribution

One of the most complicated challenges in submarine rescue operations is how to effectively connect a disabled submarine to a rescue one. Articulated transfer skirt mechanisms are utilized as a means for simplifying the connection process between two submarines. The accuracy of kinematic procedures used for adjusting the mechanism is a substantial aspect of designing transfer skirts. This article commences

This work investigates the use of blast loadings and inverse modeling for the identification of the strain rate hardening model parameters of fibre reinforced polymers. An experimental setup allowing the generation of known and predictable blast waves, leading to repeatable dynamic response in composite plates and the measurement of the displacement and strain fields, is developed. The dynamic response

Over the years, the use of structural adhesive bonding has significantly grown in numerous technological sectors, including the aeronautical, aerospace, medical and automotive industries. The growing need to design lighter and better performing structures has pushed designers to improve their construction techniques, and consequently adhesive joints have appeared as an optimal joining solution, providing

There is a critical limit of thrust force during drilling operation in a composite laminate below which no delamination takes place, which is known as the “critical thrust force”. In this paper, various critical thrust force models have been discussed in detail for circular- and elliptical-shaped delaminations around the drilled hole. Critical thrust force models for circular-shaped delamination for

Animals can obtain excellent locomotion performance as they swim or fly under ground effect in nature. Inspired by this, fluid mechanisms of the flexible bionic wing oscillating and gliding in ground effect are investigated by fluid–solid interaction simulation in this study, respectively. For the oscillation motion, the flexible wing vertically moves up and down at different distances from the ground

The development in manufacturing has insisted upon the fabrication of microdrilled holes on orthopedic implants, with finished side wall (devoid of cracks and burr), thin recast layer, low taper, and improved circularity at entry and exit of the hole. In this study, therefore, a multiobjective optimization of wire electric discharge machining microdrilling response characteristics is addressed in order

Fine finishing entails increased percentage contact area, less friction, and less wear. The magnetorheological finishing is a precision process to obtain the fine finishing on the workpiece surface for improved functional applications. So, the rotary rectangular core-based magnetorheological finishing process is utilized for the precise finishing of the cylindrical external surfaces. The rotary-rectangular

Since the theoretical aeroelasticity for flapping-wing aerodynamics was introduced in the 1920s, the effects of flexibility on aeroelasticity have been paid more attention to aerodynamic design. In recent years, the trait of the wing flexibility is applied for small-scale wings of biomimetic flyers including micro air vehicles and mini unmanned aerial vehicles. Until now, the aerodynamic performance

The mean flow, turbulence characteristics, and dynamics of large-scale vortices are investigated for an offset jet issuing from different nozzle expansion ratios using a four-receiver acoustic Doppler velocimeter. The jet was discharged from sharp-edged rectangular nozzles with expansion ratios of 0.24, 0.49, 0.75, and 1.00 at Reynolds number of 5.3 × 104. The decay rate of the maximum mean velocity

In bio-inspired design, identifying keywords is an important step of biological information searching. Based on existing information retrieval approaches, the amount of relevant biological information in a search result largely depends on the identified keywords. Due to the limitation of biological knowledge, design engineers are difficult to identify the appropriate keywords that can find the biological

The Kriging models which are frequently used in aerodynamic shape optimization may become computationally inefficient when solving problems with large numbers of design variables. One solution to this problem would be the application of gradient-enhanced Kriging model. A gradient-enhanced Kriging and acoustic adjoint-method approach to duct acoustic problems is developed, aimed to improve the efficiency

Various demand response programs have been widely established by many utility companies as a critical load management tool to balance the demand and supply for the enhancement of power system stability in smart grid. While participating in these demand response programs, manufacturers need to develop their optimal demand response strategies so that their energy loads can be shifted successfully according