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Copyright of Electric Power Automation Equipment / Dianli Zidonghua Shebei is the property of Electric Power Automation Equipment Press and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A study on the load characteristics of the modified gear planetary gear systems is conducted to address the issue of uneven loads between planetary gears due to manufacturing and installation errors, which result in deviations between the radial and circumferential installation positions of planetary gears and non-offset values. Based on the theory of rotor dynamics, the time-varying stiffness and the radial and circumferential offsets of the planetary gears are considered, and the five-degree-of-freedom dynamic model of the planetary gear transmission system with addendum modification is established. The response and frequency spectrum of the system are solved by the Runge-Kutta method. The load distribution characteristics of the planet gears under different radial offsets, circumferential offsets, and comprehensive offsets are analyzed. The influence of the radial and circumferential offset of the planetary gear on the load distribution of the planetary gear transmission system is discussed, and the variation law of the load vibration amplitude of the planetary gear transmission system with addendum modification under the time and frequency is obtained. The simulation results show that the load characteristics of the planetary gear train considering the error are quite different from those in theory. Its vibration amplitude of the planetary gear transmission system is greatly affected by the radial offset, and the large radial offset has the greatest impact on the load of the planetary gear. Small deflections of the planetary gear during installation can lead to large changes in the load characteristics. The planetary gear transmission system load test platform is built, the frequency-doubling vibration response signal of the planetary reducer housing is tested, and the relation between the planetary gear transmission system load force and vibration response is obtained. The amplitude variation trend in the experimental results is similar to that in the simulation analysis, and the correctness of the established model and solution method is verified.

Copyright of Journal of Henan University of Science & Technology, Natural Science is the property of Editorial Office of Journal of Henan University of Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The difference in power demand and the driver's operation in various operation stages make the loader have the problem of low energy utilization. Changeable operating objects and drastically changing loads have exacerbated the difficulty of energy-saving research in different operating stages of loaders. Therefore, based on identifying the operation stage and analyzing the load characteristics under typical working conditions of the loader, this paper proposes a shovel-loading cooperative control strategy. Specifically, the Drag Reduction Insertion (DRI) in the shoveling stage is realized based on learning the driving intention. Based on different operation stages, the load characteristics of different materials for shovel-loading are deeply analyzed, and the prediction research of the power output characteristics of the power unit is carried out. The shovel-loading cooperative control solves the problem of the poor economy caused by different power requirements in different operation stages and significantly reduces the impact of the driver's operating experience. • A cooperative control strategy for shovel-loading of loader is proposed. • Accurate identification of the operational stages are completed. • The DRI in the shoveling stage is realized based on learning the driving intention. • The prediction research of the power output characteristics of the power unit is carried out. [ABSTRACT FROM AUTHOR]

Under the dual crisis of energy shortage and environmental pollution, natural gas has become a promising alternative fuel. However, its application in marine engines still has some problems such as knocking and misfire in the cylinder, especially during the harsh transient condition of the main engine, which the transient speed regulation rate should be less than 15%, and the speed recovery time should be less than 15s to meet the corresponding specification requirements. In this paper, the 8M23G marine four-stroke natural gas engine is taken as the research object. And, the harsh transient condition of the engine under two modes of load characteristics and propulsion characteristics was analyzed through experiment and simulation. The results showed that the cooperative control strategy had the best effect, which decreased the Lambda of the engine to less than 3.5. Furthermore, the speed recovery time under load characteristics can be controlled at about 10 s. [ABSTRACT FROM AUTHOR]

Copyright of Engineering Mechanics / Gongcheng Lixue is the property of Engineering Mechanics Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

To improve the load characteristics of the transmission error for helical gears, a gear made of laminated materials is proposed. The gear has three layers in which metals with different rigidities are laminated in the tooth width direction. The layers on both sides are made from the same metal, and a different metal is used for the central layer. A theoretical analysis was performed to investigate the effects of arranging high- and low-rigidity layers and changing the width of the central layer. The laminated gear has load characteristics different from the transmission error for a conventional homogeneous material gear. The transmission error can be reduced with the combination of a high-rigidity central layer and a low-rigidity side layers, and a low transmission error can be maintained over a wide load range by adjusting the central layer width appropriately. The principle of the reduction in the transmission error is that, by changing the rigidity along one-pitch meshing progress with laminated materials, the elastic deformation of the teeth can largely cancel out the rotational fluctuations caused by the tooth flank shape over the wide load range. A pair of laminated gears was manufactured, and testing confirmed that the laminated gear has a transmission error lower than that for a gear made from a homogeneous material. The laminated gear has the potential to achieve the lower vibration/noise generation for the wider load range than the homogeneous gear.

Modern power system is stepping into the era of big data. It is necessary to widely collect multi-source data and mine the load characteristics of load data from different angles. This paper introduces an efficient comprehensive characteristic analysis method of 10 kV bus load based on integrated clustering technology, which includes clustering the load from vertical and horizontal dimensions respectively to obtain the clustering results under the unified time frame. Firstly, K-means clustering and hierarchical clustering are used to establish the load characteristic model for the whole year’s load data, and the daily load characteristics and hourly load characteristics are obtained. Then, the distribution time area of the maximum load and the normal operation threshold of the load are analyzed. Finally, the feasibility of this method is verified through the 24 * 365 load data, which provides convenience for the subsequent power system optimization.

This paper aims to analyze the distribution efficiency of DC power distribution power system in commercial building based on measured data from a typical office building in Hong Kong. In this research, a real-scene comparative testbed was built in a Hong Kong office to compare the energy efficiencies of AC and DC power distribution system. Similar load characteristics and use schedules are set and used in the experiment. The distribution efficiency has been found to be affected by load type, voltage level and the loading conditions. The efficiency of this DC power system is derived, considering the PFC model was working in a good condition. For LED loads, the average distribution efficiencies after converter are 77.7% and 51.8 % under the condition of full lightning and normal lightning mode. The main loss in this system is transmission loss and switching loss. The average AC/DC converter efficiencies of LEDs are 92.21% and 88.85% respectively with the load working under full power and normal power, while the average AC power factors of LEDs are 85.31% and 56.22% respectively with the load working under the same as above. The average AC/DC converter efficiencies of the fan coil are 97.41%, 96.03%, 92.74%, 89.10%, 85.71%, 78.72%, 67.61%, 63.57% respectively with the load working under level 8 to level 1 while the average AC power factors of the fan coil are 98.0%, 99.0% and 99.4% respectively with the load working under low middle and high condition. As the PFC circuit does not have ideal power factor correction when the load is small, it is not recommended to add PFC circuit when the load power is low. Using uncontrollable rectifier circuit is going to lead to a better performance.

The load characteristics of a power grid significantly change with the increase in the number of electric vehicles (EVs). In this study, we present a method for predicting the long-term load characteristics of Hubei Power Grid (A large power grid in China with annual power consumption of 207.1 billion kWh in 2020) up to until year 2030 with the development of EVs. The predicted load characteristics include the annual peak loads and hourly load curves of typical days for different seasons in target years 2025, and 2030. The proposed long-term load forecasting method uses saturated load prediction with grey Verhulst model and Monte Carlo simulation. The future impacts of the charging load of EVs on the grid are discussed in detail.

Copyright of Journal of Beijing University of Technology is the property of Journal of Beijing University of Technology, Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Heilongjiang University of Science & Technology is the property of Journal of Heilongjiang University of Science & Technology Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Industrial steam heating is a significant aspect of energy consumption in China, playing a crucial role in industrial energy efficiency. Historically, demand response research has predominantly focused on the electricity sector, with limited emphasis on steam supply. This study explores a novel Time-of-Use pricing approach for steam heating systems, anchored in the demand response theory of price incentives. It develops a peak-valley segmentation method by considering both the load differences between supply and demand and the thermal storage capacity of the pipeline system. Additionally, the paper delves into user response characteristics to formulate an optimized Time-of-Use pricing model for steam heating systems. Implemented in a Jiangsu-based case study, the model demonstrates significant efficiency improvements: it reduces the peak-valley load difference by up to 68.3% and cuts steam purchasing costs by ¥135,000. Furthermore, the alignment between the users' total steam load curve and the heat source's steam supply is enhanced by 18.8%, illustrating the model's effectiveness in balancing demand and supply. • Cluster analysis to extract steam user load characteristics. • Divide peak/valley times based on network storage and user traits. • Create a multi-objective Time-of-Use model for steam pricing optimization. • Carry out a case validation in an actual industrial park in Jiangsu. [ABSTRACT FROM AUTHOR]

Support insert run-flat tire is a kind of safety tire based on common tire structure. It has the advantages of simple structure, easy disassembly and strong bearing capacity. However, when driving under zero-pressure condition, it can not meet the requirements of heavy load, high mobility and long-distance. Aiming at this problem, the finite element model is established. The load and contact patch characteristics of the model are simulated by ABAQUS. The radial stiffness curve and the contact pressure distribution under zero-pressure are obtained. The results show that the radial stiffness curve presents a certain nonlinearity in the sidewall loading stage. When the insert contacts the tire, it is approximately linear. The contact pressure distribution cloud diagram under zero-pressure condition shows that there is warpage. The tire test bench was set up and the relevant test scheme was formulated. The radial stiffness curve and the footprint of the support insert run-flat tire under zero-pressure condition were obtained. The research results show that the simulation and test results are in good agreement. This research is of great significance to the performance analysis of whole support insert run-flat tire under zero- pressure condition. [ABSTRACT FROM AUTHOR]

In order to investigate the load-sharing performance of the 2K-H planetary gear transmission system， a translation-torsion coupling dynamics model is established with considering the nonlinear factors of time-varying meshing stiffness and the overall meshing error and so on， the dimensionless differential equations with 18 degrees of freedom of the system are deduced in this model. By solving the differential equations， the influences of the support stiffness of the center component and the clearance floating on the load-sharing performance of the planetary gear train are analyzed. It is shown that the floating amount of the component increases with the reduction of the support stiffness of the center component and the increase of the clearance of the shaft hole within a certain range， the load-sharing factor of the system decreases when the floating amount of the component increases.

P‐I diagrams are widely used for structures subjected to blast loads. In the same manner, structures subjected to vehicle impact load, such as bridge columns, could potentially take advantages of the P‐I diagram if the dynamic characteristics of vehicle impact load and bridge columns are well considered. In the paper, the performance of bridge columns and hence the use of P‐I diagram is evaluated under vehicle impact load. The main tasks of the paper are (1) to determine the dynamic characteristics of vehicle impact load through finite element method, and three simplified load shapes are obtained including isosceles triangle, right triangle, and rectangular shapes; (2) to investigate structural failure modes under various shear‐bending ratios and impact loads; (3) to establish the damage index based on the residual axial capacity of bridge columns and to obtain P‐I diagrams at different damage levels of bridge columns under vehicle impact load; (4) to parametrically analyze the effects on the impulse asymptotic and the peak load asymptotic of P‐I diagrams, including column diameter, stirrup reinforcement ratio, longitudinal reinforcement ratio, and strength of the concrete. Finally, a simplified calculation method of P‐I diagrams is proposed to evaluate the performance of bridge columns under vehicle impact load. [ABSTRACT FROM AUTHOR]

In order to research the new integrity evaluation technology of gas pipeline and promote the mature development of gas pipeline integrity management, this paper deeply analyzes the characteristics of Beijing gas pipeline and combines with the methods of finite element modeling, statistical analysis, mathematical fitting and experimental verification. Based on the Spangler-lowa method, the load effects of gas pipelines with different pressure grades are analyzed, a new method for evaluating the external load carrying capacity of gas pipeline with local corrosion defects was developed, and a method for evaluating the internal pressure carrying capacity of gas pipeline was determined. The research shows that the integrity structure evaluation of gas pipeline should be evaluated according to the pressure level. Medium- and low-pressure gas pipeline is mainly affected by external load, and deformation is the evaluation basis. The sub-high-pressure gas pipeline is affected by both external load and internal pressure, and its deformation and stress are taken as the evaluation basis respectively. High-pressure gas pipeline is mainly affected by internal pressure, and stress is the evaluation basis. [ABSTRACT FROM AUTHOR]

Low-temperature discharged water from thermally-stratified reservoirs in spring and summer will have a negative environmental impact on fish breeding and agricultural irrigation downstream. The temperature-control curtain (TCC) is a selective withdrawal structure that can effectively change the discharged water temperature. Compared with a traditional selective withdrawal project, a TCC project has the advantages of low cost and simple construction and can even be added to operating reservoirs without impacting power generation. Analysis of the load characteristics is the key to the application of TCC engineering. This paper establishes a three-dimensional numerical model simulation and verifies it with physical model experimental results. The crucial parameters affecting the load characteristics of TCC are investigated, including the water blocking rate, area ratio, inclination ratio, inflow velocity, and water temperature stratification ratio. The results show that: (1) This numerical simulation approach can be used to predict the drag coefficient and the load of a TCC; (2) the water blocking rate has the greatest influence on the drag coefficient, and it is the most critical indicator of the TCC load; and (3) the drag coefficient exponentially increases with an increasing water blocking rate, quadratically increases with an increasing area ratio, linearly increases with an increasing inclination ratio, and linearly increases with an increasing water temperature stratification ratio. [ABSTRACT FROM AUTHOR]

This work presents the performance analysis of a single phase interior permanent magnet synchronous generator. The stator magneto motive force (MMF) waveform of the single phase winding function was developed. The mathematical model in phase variables by which the performance of the generator can be investigated under various operating conditions was developed. Self-excitation of the generator was achieved through pre-excitation by the permanent magnet in the rotor, and then regulated by connecting 30µF capacitor across the terminals of the stator winding. The performances of the generator under constant speed, constant capacitor value and varying power factor loads was investigated. The voltage build-up characteristics and dynamic loss of load performance was studied. The magnitudes of the output power, real power, load voltage and load current increases with increase in load power factors while the phase voltage, phase current, capacitor current and the reactive power decreases with increase in power factor loads. The generator has shown to be capable of stand-alone power source. Simulations were carried out using the Simulink® toolkit in MATLAB® software. [ABSTRACT FROM AUTHOR]

Planes are the execution tools of coal plough,the work load directly affecting the planing capacity and production efficiency of the plow. In order to study the load characteristics,developing the coal plow load calculation program based on Matlab and VC,which can calculate the random load of planer at different positions according to the different simulating coal seam occurrence conditions; Planes at different positions were simulated and the strength verified based on ADAMS software. By analyzing the results indicate that : in the same cutting depth,the loads of planes at the different positions are random,in which load short broadsword’s means and standard deviations of the three load are minimum and the cutter force is relatively stable and uniform compared with other positions,followed by long broadsword,knife top and bottom knife; With increasing of planing depth,three forces of planes suffered have varying degrees increased,When the cutting depth exceeds a certain value,cutting resistance will be significantly increased; when the cutter spacing exceeds a certain transversal distance,cutting force increases sharply; In the working process,long and short waist by the maximum stresses are located in knife body thickness position transition connection and the knife body and the lamellar alloy head is embedded,main failure mode for the wear and fracture;the top and bottom knife knife connected with the knife base part chamfer can relax the stress concentration. Analysis results of load planer reliability and structure optimization design provides a theoretical basis for the study of dynamic.

A composite sliding mode control based on the load characteristic of the permanent magnet direct-driven system is presented for a mining scraper conveyor. First, the mathematical model of a permanent magnet synchronous motor is established based on the coordinate transformation theory. Subsequently, the soft switching sliding mode observer (SS-SMO) is designed to observe the change of load torque in real time. The composite sliding mode speed controller of PMSM is designed on the basis of non-singular terminal sliding mode control, in which the observed load torque is used for feed-forward compensation. The chain characteristics of a scraper conveyor are described by the Kelvin-Vogit model, and the dynamic model of the overall scraper conveyor system is established with the distinct element method. Next, according to the coupling relationship between the permanent magnet direct-driven system and the scraper conveyor, the electromechanical coupling simulation model is established using the MATLAB/Simulink module. The simulation results demonstrate that the composite sliding mode controller of the permanent magnet direct-driven system can achieve smooth starting of the scraper conveyor, and the effectiveness of the designed controller is illustrated by comparing the controller with the related reference. In addition, the designed SS-SMO can estimate the load torque precisely, enhance system robustness and suppress the chattering of the control system caused by the load change.

Helical magnetic flux compression generators (HFCGs) are widely used to generate extremely highpower pulses. Two most important output characteristics of HFCGs in their use as pulsed power generators are maximum value of load current and the rise time of that current. In this paper, an approach is proposed to improve the output characteristic of a Cascaded-HFCG. The approach is based on time-varying primary winding of dynamic transformer and addition of a gradually incremental resistance in series with the first stage winding. It is demonstrated analytically using simulation results that the output current and its rise-time improve by minimizing energy returned from secondary winding to primary winding of dynamic transformer. The results are compared to conventional Cascaded-HFCG that has a non-destructive winding in its structure. A finite element model is considered to calculate the selfinductances, mutual inductance and resistances of the generator. A new approach is proposed to gradually increase in the resistance of primary winding of dynamic transformer. [ABSTRACT FROM AUTHOR]

The object of research in the work is hydrodynamic processes in the high pressure fuel system of the ship’s medium-speed engine on variable modes. Variable regimes constitute a significant part of the operational time of a number of types of ships (tugs, fishing vessels, etc.), and for transport fleets they are characteristic for maneuvering. In the latter case, reliability and environmental safety for sanitary control zones are of particular importance. Studies of fuel supply processes in variable modes are important, since they largely determine all the operating characteristics of a diesel engine and are not well studied The article presents an experiment in which the task is obtaining the load characteristics and the study of transients in the fuel equipment of the ship’s medium-speed diesel engine under dynamic testing conditions. In the course of the research, a developed hardware and software complex is used to ensure the implementation of the experiment plan, fixation, processing and oscillography of the obtained data. An electromechanical system is developed by rack displacement of a high-pressure fuel pump with programmed computer control. The experiment program provides for changing the rack position in the whole range covering the operational load characteristic. The discrete displacement includes five fixed rack positions with a step transition between them. During testing, the high-pressure fuel pump completes 80 injection cycles over 44 s. The transition time between the individual fixed positions of the racks is 0.44 s. The stabilization period of hydrodynamic processes in the fuel supply system is close to 0.22 s. In the investigated range of rack positions mr = 25–5 mm the main parameters of the fuel injection are as follows: рn.с = 474–232 bar; рn.i = 457–222 bar; рp = 445–162 bar. The possibility of obtaining load characteristics by dynamic tests is shown, which significantly reduces the test time and increases the reliability of the data, eliminating the influence of the time trend parameters. [ABSTRACT FROM AUTHOR]

The load（ working condition） coefficient is one of the important original inputs in the design of chain transmission system,it is directly related to design variables of the chain bearing capacity,especially for the timing silent chain system,the chain plate thickness or number are all related to it. Through a engine timing chain system design,ignoring the torsional vibration and engine cylinder to work,the load characteristics of the timing silent chain system are analyzed qualitatively. By using the cylinder head anti drag system test bench,through static and dynamic load torque test,the load coefficient and the method of determining under different speed conditions of the timing silent chain system are proposed,which is of great reference value to the design of the multi axis and high speed silent chain system.

Low-temperature discharged water from thermally-stratified reservoirs in spring and summer will have a negative environmental impact on fish breeding and agricultural irrigation downstream. The temperature-control curtain (TCC) is a selective withdrawal structure that can effectively change the discharged water temperature. Compared with a traditional selective withdrawal project, a TCC project has the advantages of low cost and simple construction and can even be added to operating reservoirs without impacting power generation. Analysis of the load characteristics is the key to the application of TCC engineering. This paper establishes a three-dimensional numerical model simulation and verifies it with physical model experimental results. The crucial parameters affecting the load characteristics of TCC are investigated, including the water blocking rate, area ratio, inclination ratio, inflow velocity, and water temperature stratification ratio. The results show that: (1) This numerical simulation approach can be used to predict the drag coefficient and the load of a TCC; (2) the water blocking rate has the greatest influence on the drag coefficient, and it is the most critical indicator of the TCC load; and (3) the drag coefficient exponentially increases with an increasing water blocking rate, quadratically increases with an increasing area ratio, linearly increases with an increasing inclination ratio, and linearly increases with an increasing water temperature stratification ratio.

Based on the coal rock cutting theory,simulated the load characteristic of the roller in the process of during coal rock; with the flexible-body dynamics as the theoretical basis to establish rigid-flexible coupling model of cutting unit,simulate the process of height adjustment by ADAMS and get the load response of link point; used Workbench to get the stress distribution of ranging arm when the link point force is maximum during the process of height adjustment; with linear cumulative damage rule as the theoretical basis,used Workbench to estimate the fatigue life of the ranging arm to verify the results of the reliability analysis and load response analysis.This paper provides a new method to research on dynamic characteristic and reliability of shearer cutting unit.

Copyright of Technical Electrodynamics / Tekhnichna Elektrodynamika is the property of National Academy of Sciences of Ukraine, Institute of Electrodynamics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Circuit breakers are one of the most widespread electrical devices in control and distribution systems that use electric energy fluxes, providing protection from short circuits and current overloads. First and foremost, circuit breakers should provide a high operation speed at shutdown, which can be achieved with low weight and significant electromagnetic forces. For approximate determination of magnetic system dimensions, network analysis methods are used. In addition, the model of magnetic field structure can be substantially simplified. The conductivity of air gaps between the ferromagnetic elements of a magnetic system can be described by a modified method of probable paths of magnetic flux, and the resistance of ferromagnetic elements (magnetic potential drop) is taken into account by means of a mathematically expressed magnetization curve (for steel of 10895 grade). [ABSTRACT FROM AUTHOR]

The static magnetization curves and load characteristics of dc single-winding plunger shell-core magnet system with a flat cylindrical pole have been determined using the FEMM software environment. The methods of similarity theory and experiment planning have been used to represent these characteristics as the generalized polynomial nondimensional models in the form that is convenient for solving the synthesis problems. The limit of linearity of the magnet system has been defined. [ABSTRACT FROM AUTHOR]

The conventional pneumatic tires have disadvantages in terms of puncture, blowout at high speed, pressure maintenance, and so on. Due to these structural inevitable weaknesses, non-pneumatic tires have been developed and are being investigated. A new non-pneumatic elastic wheel was proposed and studied to solve these problems. As an important bearing member of the non-pneumatic elastic wheel, the force of hinge group is very complex and it has a significant effect on the performance of the wheel. However, in the complex off-road driving, the hinge group has to withstand complex random load and impact load, and inevitably there will be damage failure. In order to explore the performance change of the wheel after the failure of the important bearing parts, it is necessary to study the influence of the hinge group with local damage on the performance of the non-inflated elastic wheel. In this paper, an experimental study on basic characteristics of non-pneumatic elastic wheel with local hinge group fracture damage was conducted in order to enhance the reliability. Based on tire characteristic test-bed, the tests on basic characteristics of static radical stiffness and contact behavior as well as the modal test were conducted. The wheel with local damage, one hinge group of which was disassembled, was used to simulate hinge group fracture condition in this paper. The results show that the effect of the hinge group fracture damage on the wheel load characteristics is the decrease of the radial stiffness, and it is also related to the damage position on the non-pneumatic elastic wheel. The radial stiffness of non-damaged non-pneumatic elastic wheel is 593.06 N/mm, and the corresponding values of the non-pneumatic elastic wheel with fractured hinge group on horizontal position and vertical position are 443.2 and 385.4 N/mm, respectively. Compared with non-damaged non-pneumatic elastic wheel, the numerical value of radial stiffness is reduced by 25% and 35% respectively on horizontal position and vertical position when the fractured hinge group is installed. That is to say the consistency of radial stiffness and deformation uniformity get worse for the wheel with local damage, so the poor performance of riding comfort of non-pneumatic elastic wheel appears. The influence of the hinge group fracture damage on the grounding pressure distribution is the change of grounded imprinting length and grounded area. Under the same vertical load, these 2 indicators of the non-pneumatic elastic wheel with fractured hinge group increase compared with non-damaged non-pneumatic elastic wheel. When the vertical load is 7 262 N, the imprinting length of the non-pneumatic elastic wheel with fractured hinge group on horizontal position is 138 mm, and the numerical value of non-damaged non-pneumatic elastic wheel is 120 mm. The ground imprinting length of the damaged wheel is increased by 15% compared with that of the non-damaged non-pneumatic elastic wheel. The grounded imprinting width does not change, and the value remains at 285 mm. As a result, the total grounded area of the damaged wheel also increases. The area of the non-damaged non-pneumatic elastic wheel is 34 200 mm2, and the area of damaged wheel increases to 39 330 mm2. The contact length and area of the wheel with local damage are greater than corresponding values of the non-damaged non-pneumatic elastic wheel under the same load. The influence of the hinge group fracture damage on the wheel modal test is the change of the natural frequency, the damping coefficient and the modal shape. In addition to a few orders, the natural frequency of non-damaged non-pneumatic elastic wheel is greater than that of non-pneumatic elastic wheel with local damage hinge group, and the damping coefficient of the most of non-damaged non-pneumatic elastic wheel is less than that of non-pneumatic elastic wheel with local damage hinge group. The value of the amplitude of modes gets smaller for the non-pneumatic elastic wheel with local damage hinge group. [ABSTRACT FROM AUTHOR]

Zhang, Z.; Wang, L.; Yao, X., and Lang, J., 2017. Dynamics of an underwater explosion bubble near a rigid wall: Effect of slenderness ratio, installation, and distance parameter. Structural damage of maritime construction ( e.g., dams, warships, etc.) has received considerable international attention in recent years because of underwater explosions from accidental events and terrorist bombing attacks. Therefore, research studies on underwater explosion load characteristics will have a great influence on the future of coastal and maritime engineering. Here, level set-direct ghost fluid-Runge Kutta discontinuous Galerkin method and boundary element method are combined to establish a model of underwater explosion near a rigid wall. First, the hybrid algorithm is used to simulate the process of underwater explosion in free field; the results agree well with experimental data, proving the effectiveness of the algorithm. Second, the process of underwater explosion near a rigid wall is simulated by the presented method. Finally, effects of parameters - slenderness ratio, installation (horizontal and vertical), and distance from the center of the explosive to the rigid wall - are investigated on shock waves and bubble dynamics. It is found that during the detonation process, the ellipsoidal bubble gradually turns into a spherical one. The radial pressure peak value is higher than the axial one. During the collapse phase, the slenderness ratio and the installation have little effect on bubble shape, maximum radius, and pulsation cycle. During the bubble-jet process, a high-speed jet penetrates the bubble toward the rigid wall and generates a high-pressure region on the bubble wall. For the charge placed vertically, the jet velocity rises while the jet width decreases as the slenderness ratio increases; results for horizontal cases are opposite. The jet velocity in the vertical case is lower than that in the horizontal case; on the contrary, the jet width is larger. With the increase of the distance parameter, the pressure on the upper surface of the bubble and the jet velocity are higher, whereas the jet width is smaller. [ABSTRACT FROM AUTHOR]

Copyright of Electric Machines & Control / Dianji Yu Kongzhi Xuebao is the property of Electric Machines & Control and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Aiming at the complex conditions of the first shielded bolter miner in the actual work, the mechanical model of bolter miner cutting head was established. Based on cutting mechanism of the conical pick and the cutting head, the cutting head load and torque analysis model under complex coal seam were established. The dynamic characteristics of load and torque in the process of cutting head are analyzed under three different working conditions of cutting roof-coal layers, coal-floor layers and coal seam by finite element method. The results show that when the damage variable D = 1, the coal-rock completely lacks the bearing capacity, and it forms arc-shaped crushing groove on the coal-rock. The large difference of torque between roof-coal layers and the roof-coal layers in the conical pick is 112 Nm, which indicates that the cutting head has the best performance with cutting the coal seam first and then cutting the rock. In the process of excavation, the load fluctuation coefficient of cutting the coal-floor layers and roof-coal layers is about 1.2 times of that of the coal seam. The results can provide a reference for the efficient cutting and performance evaluation of the bolter miner. [ABSTRACT FROM AUTHOR]

The FST2E engine test bed was applied to carry out the simulation tests of the F6L913 diesel engine's plateau performance, to obtain the data of the engine at different altitudes and in various conditions, including torque, power, fuel consumption rate and oil consumption, and to generate the external characteristic curve and the load characteristic curve of the engine by fitting. The test result shows that the engine power and torque is decreased by 15 % to 20 % and the fuel consumption rate is increased by 15 % to 30 % whenever the altitude is increased by 1000 m, and the higher the altitude is, the faster this increase rate becomes. The stable working range of the engine becomes narrower and drifts to the high revolution area.

The results of experimental study of automotive ICE running using biogas with different volume content of CO2 are presented. Recommendations for choosing the values of air-fuel ratios and ignition timings for different operating modes of the automotive biogas engine depending on fuel chemical composition are given.

The new principle of the organisation of working process of the combined supercharging system of transport diesel with the Cascade Pressure Exchanger (CPE) has been described. It allows considerably to raise level of forcing of the engine by supercharging at the expense of expansion of effective air supply area and coolings of supercharging air to temperature below an ambient. Substantive postulates of imitating model of work of combined engine(CICE) have been stated. Some results of calculation-experimental investigations of supercharging system of the engine 6ЧН12/14 have been given. It confirms the possibility of the essential improvement tractive and fuel-economic factors of the transport installations in broad range of the working conditions.

A new method of organization of working cycle of device of direct transformation of heat in the located work of compression of air, based on principle of cascade exchange by pressure, is exposed; the results of pre-selection of basic dimensional and structural parameters of thermal compressor of cascade exchange by pressure are adduced; some special features of its working process are considered; main directions of perfection of working cycle of thermal compressors of cascade exchange of pressure are shown.

Presented paper is dealing with operation load of three-point hitch (TPH) of agriculture tractor in randomly changeable working conditions and their simulation in laboratory. The basic goal was to obtain experimental data, after which we can judge and analyze problematic of dynamic load of wheel tractor at plowing with orientation on TPH. Another goal was using obtained result from operating measures on their simulation in laboratory conditions by hydrostatic simulator. In presented paper is solved power analysis in each elements TPH of agricultural tractor ZTS 160 45URII A. The tractor during exploiting was in set with four-ploughshare carried and five-ploughshare semi-mounted plough. The measuring was realized for 3 varieties of set speed (gear ratio I/2, I/3, I/1), 3 depths of plowing (20, 25 and 27 cm) and 3 varieties of TPH - positional, mixed and draught control.