This paper presents the construction of the two-point and three-point block methods with additional derivatives for directly solving y″′=f(t,y,y′y″). The proposed block methods are formulated using Hermite Interpolating Polynomial and approximate the solution of the problem at two or three-point concurrently. The block methods obtain the numerical solutions directly without reducing the equation into

A detailed investigation of damage and failure mechanisms of composite laminates under low-velocity impact (LVI) by experimental tests and numerical modeling is presented. Five impact energy levels were investigated on composite laminates by drop-weight tests. Permanent indentations were measured, and delamination areas of each interface induced by each LVI event were captured using an ultrasonic C-scan

In this study, the integrated MSOT (M-Multi-dimensional factor autobody model, S-Screening autobody component, O-Optimization of plate thickness, T-Testing, and validation) integration method is adopted to optimize the automobile body structure design for weight reduction. First, a multi-dimensional factor body model is established, then components of the vehicle are screened for the most important

A radial thrust hydrodynamic sliding bearing (RTHSB) with special shaped cavity had been designed. Taking the instantaneous temperature rise characteristics of RTHSB as an analysis object, considering the influence of inlet lubricating oil velocity and transmission shaft speed, a dynamic simulation method of variable viscosity temperature field is proposed, and the mathematical model of instantaneous

A heat pump in the aerospace industry can significantly reduce the area of radiator by elevating the rejection temperature. Especially for a Lunar base, the heat pump can improve the heat rejection capability of the thermal control system to adapt the high-temperature environment. However, gravity on the Lunar (about 1/6 g) may have an adverse impact on a gas-oil separator of the heat pump, and solving

As for the batch process, it is needed to carry out a unique simulation for each group of parameters. The simplest method to achieve this goal is to uses the Simulink as the integration space. It cannot solve some complicated dynamic model set up in dynamic software. This paper introduces an intelligent batch program to enable the model solved in the dynamic software during the simulation. This paper

In order to increase efficiency and reliability of hub motor power device for distributed driving electric vehicle, a novel hub motor with an external rotor PM (permanent magnet) is designed and optimized. The performance parameters of hub motor are computed and selected based on vehicle dynamics indicators and the driving equations. This paper determines the optimum primary size of hub motor by choosing

Ultrasonic-assisted transient liquid phase bonding of pure Cu with Sn-In solder was realized at 140°C in air. Shear test was carried out on the weldment. The effect of ultrasonic vibration on microstructure and mechanical properties of the weld seam was studied. The relationship between the formation of intermetallic compounds and their mechanical properties was analyzed by means of electronic scanning

The concept of tunnel boring machine (TBM) disc cutter rock breaking coupled with high-pressure water jets has been proposed to overcome the difficulties that occur when TBMs encounter extremely hard rocks. Thus, to meet actual engineering requirements for the TBM construction of tunnels as part of the Wan’anxi water diversion project in Longyan City (Fujian Province, China), experiments were conducted

The rapid development of low-power electronic sensors and integrated circuits has made the energy supply module complex and costly to a greater extent. The traditional energy supply method is based on external wiring or built-in batteries, which gives rise to a series of problems such as high costs of installation and maintenance, and environmental pollution. Mini-type energy generators absorb the

For the problem of relatively severe lateral vibration found in the vertical electrodynamic shaker experiment, an electromechanical coupling dynamic model of the electrodynamic shaker considering low-frequency lateral vibration is proposed. The reason and mechanism of the lateral vibration is explained and analyzed through this model. To establish this model, an electromagnetic force model of overall

The article presents theoretical and experimental studies of tribosystems operating under conditions of normal and abnormally low friction and wear when changing the external conditions of their operation. A comparative analysis of self-organization mechanisms of tribosystem operating under conditions of normal mechanochemical and abnormally low friction and wear is performed to determine the conditions

4SPRR-SPR parallel robot is a novel closed-loop mechanism. The research of kinematics is the basis of real-time and robust robot control. This paper aims to proposing a method to address a surrogate model of forward kinematics for PMs (Parallel Mechanisms). Herein, the forward kinematics model is derived by training the VQTAM (Vector-Quantified Temporal Associative Memory) network, which originates

During the past several decades, cement-based building materials have been used widely in the area of civil engineering. Among all kinds of cement-based building materials, concrete has the largest consumption and production output because of its low production cost, easily available raw materials sources, and simple construction. The most famous advantage of concrete is its high compressive strength

A power-split hybrid electric vehicle with a dual-planetary gearset is researched in this paper. Based on the lever analogy method of planetary gearsets, the power-split device is theoretically modeled, and the driveline simulation model is built by using vehicle modeling and simulation toolboxes in MATLAB. Six operation modes of the vehicle are discussed in detail, and the kinematic constraint behavior

The main purpose of this study is to investigate the influence of tool geometry (cutting edge angle, rake angle, and inclination angle) and to optimize tool wear and surface roughness in hard turning of AISI 1055 (52HRC) hardened steel by using TiN coated mixed ceramic inserts. The results show that the inclination angle is the major factor affecting the tool wear and the surface roughness in hard

To understand the effect of internal leakage on the torque field and characteristics of a torque converter (TC), a transient analysis was performed on the internal flow of a TC and the pressure pulsation characteristics of monitoring points in the convection channel. It was found that dividing the leakage area of the TC into a separate watershed improved simulation accuracy by 4%. When there was a

The in-situ observation of the phase transformation processes of weld metal during high-heat input welding were carried out by a high temperature laser confocal microscope. The influences of Ti content on the phase transformation process were investigated. It was found that the Ti inclusions could act as the nucleation sites for α→γ transformation during the heating stage of welding thermo cycle and

The performance characteristics of the engine and the emission levels with Copra Oil (CPO), Virgin Coconut (cocos nucifera) Oil (VCO), Tamanu (calaphyllum inopyllum) Oil (TMO), and Nangae (canarium indicum) Oil (NGO) are presented. The oils, obtained from naturally grown trees in Vanuatu, were tested as straight vegetable oils (SVOs) in a Diesel engine and the results are compared with those of neat

In order to study the influence of blade outlet cutting width on hydrodynamic excitation noise of the centrifugal pump with low specific speed, five schemes are used to perform V-shaped cutting on the outlet of the impeller blade are studied in this study. Based on Lighthill acoustic analogy, combining computational fluid dynamics and computational acoustics, RNG k-ε turbulence model is used to calculate

A model-driven fault diagnosis method for slant cracks in aero-hydraulic straight pipes is presented in this paper. First, fracture mechanics theory and the principle of strain energy release are used to derive an expression for the local flexibility coefficient of straight pipes with slant cracks. The inverse method of total flexibility is used to calculate the stiffness matrix of straight pipe elements

An improved instantaneous frequency estimation algorithm for rotating machines based on a kernel-based fuzzy C-means clustering (KFCM) algorithm used in association with a spectral centroid algorithm is proposed in this study. The clustering algorithm is used first to discriminate the time-frequency points from the sources of the reference axis and other points. The discrete time-frequency points related

To reduce maintenance costs, it is important to carry out probabilistic analyses on railway vehicle components. In this work, a data-driven approach based on a Gaussian process for regression is developed to determine the probability of axle failure caused by crack growth in railway axles. For complicated failure modes, it is difficult or even impossible to build a reliable analytical or simulation

Surfaces of gears under combined rolling and sliding motions may suffer a complicated wear process due to the transient time-varying effect along the meshing path. In this paper, a methodology for predicting the wear of tooth surfaces is developed for the spiral bevel gears. In the wear model, the machined surface roughness, mixed lubrication, friction, flash temperature and the dynamic behavior of

In this article, a free convection flow of Cu−Al2O3−H2O hybrid Maxwell nanofluids through a channel formed by two infinite vertical plates have been studied. Together with the the energy balance and heat source, a fractional model of Maxwell fluid is considered. To develop an analytical exact solution for velocity field, only the Caputo-Fabrizio definition of non-integral derivative together with application

Nonlinear dynamics behavior of the roller follower is discussed for different follower guides’ internal dimensions and cam angular speeds. A dynamic tool such as Wolf algorithm is used to extract largest Lyapunov exponent parameter. Positive value of Lyapunov exponent parameter indicates non-periodic motion and chaos. The influence of flank curvature of the cam profile on the nonlinear dynamic behavior

In order to improve the working stability of brushless direct current motors (BLDCM), a diagonal recursive neural network (DRNN) control strategy based on Q-learning algorithm is proposed in this paper which is called as Q-DRNN. In Q-DRNN, DRNN iterates over the output variables through a unique recursive loop in the hidden layer, and its key weight is optimized to speed up the iteration. Moreover

Research on optimization of control strategy for hybrid energy storage system (HESS) of the electric vehicle (EV), a new adaptive control strategy based on particle swarm optimization (PSO) algorithm is proposed in this paper. The steady-state power of the filtered power is used as the ideal output power of the battery. For the steady-state current output of the battery, the output power of the ultracapacitor

This study investigated a novel adaptive output feedback control scheme for non-strict feedback nonlinear systems with uncertainties, disturbances, and asymmetric time-varying output constraints. Because that the states of the system are unmeasurable, we used an adaptive fuzzy state observer to obtain the estimated values of the states. To make the output and tracking error satisfy their asymmetric

Numerous ground-based observatories are using small sized ground telescopes for scientific research purposes. The telescopes that are available on the market have three main problems. These issues can be listed as: positioning repeatability, tuning requirement according to different wind speeds for different seasons, and the mass changing via different scientific equipments added to the telescope.

In response to the requirement for population increase, the cross-section area of the urban subway is enlarged, resulting in that one-time excavation technology cannot be directly applied to the excavation of large-section tunnels. Consequently, how to partition the cross-section of the large-section tunnels and optimize the corresponding construction parameters is of great significance. In this paper

Throwing device is an important factor that directly affects the performance of chaff cutter. In this work, the dynamic analysis linked with the problem of low efficiency and residue blockage of disc knife chaff cutter is executed. Based on this perspective, the mathematical model, simulation, and testing of the material movement have been carried out. Simulations are performed in MATLAB/Simulink environment

A methodology for combustion modeling with complex mixing and thermodynamic conditions, especially in thrusters, is still under development. The resulting flow and propulsion parameters strongly depend on the models used, especially on the turbulence model as it determines the mixing efficiency. In this paper, the effect of the sigma-type turbulent diffusion coefficients arriving in the diffusion term

A damage phenomenon called fretting fatigue frequently takes place when two contact bodies are clamped together under a normal contact load along with a small-scale oscillatory motion due to cyclic loading. In contrast to the constant contact loading, less attention has been paid to variable contact loading which was technically reviewed in this study. Emphasis was placed on the efforts made over the

We designed a stable gait pattern and posture-control balance system to enable a biped humanoid robot to maintain balance and avoid falling when walking on uneven ground or slopes. In this study, we first examined the problem of gait generation and the balance of a humanoid robot and then proposed a posture-control balance system using the inertial sensors of a gyroscope and accelerometer to sense

This study proposes a method to improve the manufacturing process of a surface anchor structure for the injection molding along with bonding properties of the plating layer for antennas, which can be applied to the Laser Direct Plating (LDP) process for the production of a three-dimensional antenna integrated with a mobile device case. By adjusting parameters such as the output of the laser processing

When light alloys used in coal mine, the sparks generated by mechanical friction and impacts are the main effective ignition source. While the hot surfaces are concomitant in friction process, prior to the occurrence of mechanical sparks, whether the hot surfaces will be an effective ignition source. Then this paper focuses on the development of hot surfaces generated by TC4 titanium alloy at the low

The purpose of this work is to investigate the heat transport on water suspended by aluminium alloy nanomaterials. The analysis is conducted by incorporating the influence of imposed magnetic field and viscous dissipation over convective surface. The self-similar version of the model is treated numerically and the results for the flow field are presented. It is perceived that the velocity of AA7072-H2O

The paper investigated the effect of localized friction on sheet thinning under lubricated conditions in the deep-drawing process. The Finite Element Analysis (FEA) was used to evaluate the sheet thinning of the AISI 304 sheet under six segmented blank-sheet interfaces. Different values of variable coefficient of friction (VCOF) in each segmented area were investigated, and the sheet thickness values

The power-split hybrid electric vehicle (PS-HEV) has multiple working modes to maintain high operation efficiency according to different conditions. The main modes involved in the vehicle driving process are pure electric mode and the hybrid driving mode. Because the electromechanical coupling problem is involved in the above two working modes, the transmission system exhibits strong non-linear characteristics

Legged robots demand to keep the balance under required durations when performing standing and locomotion. It may be a challenge for legged robots to maintain balance during standing without actuation from ankle joints and involvement of support polygon plane to estimate the center of mass (CoM). In order to maintain the standing balance of legged robots under such a scenario, we propose a virtual

The autonomous vehicle can recognize and understand environment, self-control, and achieve the driving level of the human driver. To create this kind of system, the following work was carried out: (a) a real time lane detection system is proposed, based on vision system functions, using webcam camera; (b) In order to detect curve lanes, deep learning is applied for lane detection, based on fully Convolutional

In order to develop an electrical continuously variable transmission (E-CVT) to replace mechanical power coupling equipment applied in series-parallel hybrid electric vehicle (HEV), this paper proposes a magnetic-field modulated brushless dual-mechanical port motor with Halbach array permanent magnets, which has a more compact structure. The operating characteristics are analyzed by the lever analogy

The digital rod control system (DRCS) is an important component in nuclear power plants. Thus, the structural integrity of the isolation cabinet of the DRCS should be verified, considering the seismic loading and cooling performance of the heating source of electric equipment. In general, the structural safety and functionality of the DRCS are verified through ground excitation and flow experiments

The aim of the current investigation is to discuss the behavior of mixed convection magnetohydrodynamic flow of Eyring–Powell nanoliquid subjected to gyrotactic microorganisms over a stretchable cylinder. Energy communication is developed through the first law of thermodynamics and deliberated in the manifestation of viscous dissipation. Furthermore, Brownian motion and thermophoresis effects are also

This paper is concerned with the stability of second-order linear time-varying systems. By utilizing the Lyapunov approach, a generally uniformly asymptotic stability criterion is obtained by adding the system matrices into the quadratic Lyapunov candidate function. In the case of the derivative of the Lyapunov candidate function is semi-positive definite, the stability criterion is also efficient

Thermal performance of Al2O3 nanoparticles dispersed in water was evaluated experimentally in a fully instrumented circular tube under turbulent flow conditions. Thermophysical properties of Al2O3 nanofluids at three different volumetric concentrations (0.38%, 0.81%, and 1.30%) were determined as a function of temperature. Pressure drop and heat transfer experiments were carried out at different volumetric

The strengthening effect and uniformity of residual stress and strain of 7075-T6 aviation aluminum after laser shock peening were investigated. The finite element simulation model of laser shot peening on 7075-T6 aviation aluminum alloy was established and verified. On this basis and combined with experiment, the microstructure, residual stress distribution and equivalent strain distribution of 7075-T6

Natural convection between a cold square porous enclosure and a hot corrugated cylinder is studied numerically in the current article. The enclosure is filled with a water-base nanofluids suspending metal nanoparticles and the porous layer is modelled applying the Brinkman-Forchheimer law. The finite element method has been utilised to solve the governing equations. Analysis in this studies are: the

Entropy generation in bioconvection two-dimensional steady incompressible non-Newtonian Oldroyd-B nanofluid with Cattaneo–Christov heat and mass flux theory is investigated. The Darcy–Forchheimer law is used to study heat and mass transfer flow and microorganisms motion in porous media. Using appropriate similarity variables, the partial differential equations are transformed into ordinary differential

The development of robotic interaction is becoming an increasing topic. The excellent grasp ability of low safety and fragile objects will greatly solve the complex labour of people. Rigid actuation have made significant progress for manufacturing and automation assembly, but it lacks of excellent interaction ability for humans and unstructured environments. Soft manipulator is the basic part of man-machine

In this article, we aim to analyze the dual solutions for the flow of non-Newtonian material (Carreau fluid) over a radially shrinking surface. Magnetohydrodynamics fluid is considered. Concept of Stefan Boltzmann constant and mean absorption coefficient is used in the mathematical modeling of energy expression. Mass transfer is discussed. The upper and lower branch solutions for the Sherwood number

In this research, novel genetic algorithm (nGA) is proposed for Bouc-Wen modle parameters esstimation for magnetorheological (MR) fluid dampers. The optimization efficiency is improved by modifying the crossover and mutation steps of a GA. In the crossover stage, the probability of reproducing offspring from the same parent (same mother and father chromosome) is done to be zero, which may happen in

Mechanical structures always bear multiple loads under working conditions. Topology optimization in multi-load cases is always treated as a multi-objective optimization problem, which is solved by the weighted sum method. However, different weight factor allocation strategies have led to discrepant optimization results, and when ill loading case problems appear, some unreasonable results are obtained

Sediments frequently appear at the bottom of oil and gas wells in the bottom of carbonate rocks during completion or production, seriously affecting the productivity. In order to solve the wellbore cleaning problem, this article applies the Bernoulli equation theory method, the finite element method based on the standard turbulence model and the laboratory test to verify a kind of negative pressure

Pushing coke is an important process in coke oven production. In the process of pushing coke, under the three-body contact state of steel, coke powder, and refractory brick, coke powder plays an important role in lubrication. In this article, a study on the macro- and micro-behavior and mechanism of coke powder lubrication is carried out through tribological tests. The results show that in the process

Rotary ultrasonic machining has been approved as an effective and efficient hole making process for carbon fiber–reinforced plastic composites. Hole quality plays an important role in assembling carbon fiber–reinforced plastic components and can be affected by the carbon fiber reinforcement structures. In this study, experiments are conducted to assess hole quality in carbon fiber–reinforced plastic

In recent years, rehabilitation engineering has played a crucial role in improving the quality of life for individuals with disabilities, by developing innovative devices and assistive technologies. In particular, the population aged over 75 is expected to rise considerably with a corresponding increase in long term conditions and functional and sensory impairments. In addition, people with a range

The study on the effect of cane wood and palm kernel as filler materials on the compressive strength and density of an automobile brake pad has been done. The Central Composite Design tool of the Design Expert 8 software was used to design percentage composition of the test samples for 20 experimental runs. To ascertain how well the factors fit in the design, the lack of fit test was performed. The

The axial and radial temperature distributions of an induction heating workpiece considerably impact the subsequent nitriding process. To obtain a satisfactory temperature distribution, an equal pitch coil, a variable pitch coil, and a variable radius coil were designed. Furthermore, an induction heating model that exhibits electromagnetic and temperature field coupling was established; thus, the effects