scholarly journals MATHEMATICAL MODEL OF ESTIMATION THE DYNAMIC PARAMETERS OF MACHINE AND TRACTOR UNIT’S ENGINE UNDER UNSTEAD LOAD

2019 ◽  
Vol 14 (2) ◽  
pp. 106-110 ◽  
Author(s):  
Владимир Медведев ◽  
Vladimir Medvedev ◽  
Станислав Синицкий ◽  
Stanislav Sinickiy
Keyword(s):  
Mathematical Model ◽  
Dynamic Characteristics ◽  
Theoretical Basis ◽  
Theoretical Calculations ◽  
Dynamic Performance ◽  
Transition Process ◽  
Theoretical Studies ◽  
The Mathematical Model ◽  
Regulatory Characteristic ◽  
The Ideal

The article provides an analysis of the existing methods and techniques for assessing the dynamic characteristics of engines of mobile machines, and also presents theoretical calculations for estimating the dynamic performance of an machine and tractor unit’s engine under unsteady load. The proposed mathematical model describes the change in the performance of the engine of machine and tractor unit with a linear law of loading and allows you to compare an engine’s operation at unsteady load with the ideal. The quasi-dynamic characteristic was laid as the theoretical basis for study to assess the dynamic performance of machine and tractor unit’s engine under unsteady load. Comparison of the dynamic performance of engines at unsteady load with ideal performance, which have no dynamic losses. It is proposed to apply the “quasi-dynamic” characteristics. The quasidynamic (ideal) characteristic is called - the change in the performance of machine and tractor unit’s engine, in the transition process, occurring in accordance with the change in the frequency of rotation of the crankshaft on the stationary characteristics. The mathematical model for estimating the dynamic performance of an machine and tractor unit’s engine using a correcting branch with an unsteady load is experimental equations for load buildup. Theoretical relationships have been developed for evaluating the dynamic performance of an engine with an unsteady load on the correcting branch of the regulatory characteristic. Using the proposed theoretical dependences, it is possible to carry out theoretical studies of the effect of load on the dynamic performance of an machine and tractor unit’s engine and determine the total dynamic losses.

Effects of revolute clearance joint on the dynamic behavior of a planar space arm system

2018 ◽  
Vol 233 (5) ◽  
pp. 1629-1644 ◽  
Author(s):  
Huihui Miao ◽  
Bing Li ◽  
Jie Liu ◽  
Anqi He ◽  
Shangkun Zhu
Keyword(s):  
Mathematical Model ◽  
Dynamic Characteristics ◽  
Degrees Of Freedom ◽  
Multibody System ◽  
Dynamic Performance ◽  
Clearance Joint ◽  
Locking Mechanism ◽  
Operation Stability ◽  
Pointing Accuracy ◽  
The Mathematical Model

Space arm system is a typical multibody mechanical system requiring high operation stability and precision connected by kinematic joints. As joint clearance is inevitable during the manufacturing and mounting process, it turns into a critical problem affecting the dynamic characteristics and kinematic accuracy of the mechanism. A space arm system deploying stably and accurately is the prerequisite to guarantee the final satellite pointing accuracy once it is into its working state. Thus, the space arm system needs to have good dynamic characteristics and stability during its deploying process and to have accurate and reliable positioning characteristics during its locking process. For the deploying process, the mathematical model of a multibody system with clearance joint has been established as a foundation to study the influence of clearance properties, including clearance size, clearance joint locations, numbers of clearance joints and lubrication on the dynamic performance and motion stability of a two-degrees-of-freedom space arm system. The mathematical model of a locking mechanism has been established to study the clearance effects on the pointing accuracy of the space arm system during its locking process. The simulation results show that, the clearance has different effects on the dynamic characteristics of the space arm system during its different working processes.

scholarly journals Determination of the Vertical Load on the Carrying Structure of a Flat Wagon with the 18–100 and Y25 Bogies

2021 ◽  
Vol 11 (9) ◽  
pp. 4130
Author(s):  
Oleksij Fomin ◽  
Alyona Lovska ◽  
Václav Píštěk ◽  
Pavel Kučera
Keyword(s):  
Mathematical Model ◽  
Fatigue Strength ◽  
Service Life ◽  
Dynamic Characteristics ◽  
Dynamic Load ◽  
Field Tests ◽  
Vertical Load ◽  
Mathcad Software ◽  
The Mathematical Model

The study deals with determination of the vertical load on the carrying structure of a flat wagon on the 18–100 and Y25 bogies using mathematic modelling. The study was made for an empty wagon passing over a joint irregularity. The authors calculated the carrying structure of a flat wagon with the designed parameters and the actual features recorded during field tests. The mathematical model was solved in MathCad software. The study found that application of the Y25 bogie for a flat wagon with the designed parameters can decrease the dynamic load by 41.1% in comparison to that with the 18–100 bogie. Therefore, application of the Y25 bogie under a flat wagon with the actual parameters allows decreasing the dynamic loading by 41.4% in comparison to that with the 18–100 bogie. The study also looks at the service life of the supporting structure of a flat wagon with the Y25 bogie, which can be more than twice as long as the 18–100 bogie. The research can be of interest for specialists concerned with improvements in the dynamic characteristics and the fatigue strength of freight cars, safe rail operation, freight security, and the results of the research can be used for development of innovative wagon structures.

The static and dynamic characteristics of a pressure relief valve with a proportional solenoid-controlled pilot stage

2002 ◽  
Vol 216 (2) ◽  
pp. 143-156 ◽  
Author(s):  
R Maiti ◽  
R Saha ◽  
J Watton
Keyword(s):  
Mathematical Model ◽  
Dynamic Characteristics ◽  
Dynamic Behaviour ◽  
Practical Experience ◽  
Pressure Relief Valve ◽  
Relief Valve ◽  
Pressure Relief ◽  
Static And Dynamic Characteristics ◽  
Good Comparison ◽  
The Mathematical Model

The steady state and dynamic characteristics of a two-stage pressure relief valve with proportional solenoid control of the pilot stage is studied theoretically as well as experimentally. The mathematical model is studied within the MATLAB-SIMULINK environment and the non-linearities have been considered via the use of appropriate SIMULINK blocks. The detailed modelling has resulted in a good comparison between simulation and measurement, albeit assumptions had to be made regarding the solenoid dynamic characteristic based upon practical experience. The use of this characteristic combined with additional dynamic terms not previously considered allows new estimations of internal characteristics to be made such as the damping flowrate. The overall dynamic behaviour has been shown to be dominated by the solenoid characteristic relating force to applied voltage.

scholarly journals Study on the Mathematical Model of Vacuum Breaker Valve for Large Air Mass Conditions

Water ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1358
Author(s):  
Zhang ◽  
Fan ◽  
Yu ◽  
Zhang ◽  
Lv ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Theoretical Basis ◽  
Isothermal Process ◽  
Air Mass ◽  
Protection Scheme ◽  
Calculation Results ◽  
Air Valve ◽  
The Mathematical Model ◽  
Valve Model ◽  
Derivation Process

The mathematical model of vacuum breaker valve is significant to the protection scheme. The more accurate the vacuum breaker valve model, the more reliable the calculation results. In this study, the application conditions of the air valve model are analyzed according to the assumptions used in the derivation, and the contradictions between these assumptions are proposed. Then, according to the different working characteristics between the vacuum breaker valve on the siphon outlet pipe and the air valve, the vacuum breaker valve model is deduced based on the modified assumptions. In the derivation process, the thermodynamic change of the gas in the vacuum breaker valve is assumed to follow the isentropic process rather than an isothermal process, and the water level in the vacuum breaker valve is considered to be changeable. An engineering case is introduced, and the results calculated according to the vacuum breaker valve model are compared with those resulting from the air valve model. The results indicate that the vacuum breaker valve model is suitable for large air mass conditions and can provide a theoretical basis for the numerical simulation and settings of vacuum breaker valves.

Exact Solutions of the Vibration Problem of Beam Structures

2013 ◽  
Vol 390 ◽  
pp. 242-245 ◽  
Author(s):  
Alexander V. Chekanin
Keyword(s):  
Mathematical Model ◽  
Exact Solutions ◽  
Dynamic Characteristics ◽  
Natural Frequencies ◽  
Numerical Solutions ◽  
High Accuracy ◽  
Displacement Method ◽  
Actual Problem ◽  
Beam Structures ◽  
The Mathematical Model

The article deals with the actual problem of improving the accuracy of determining the dynamic characteristics of beam structures. To solve such problems the displacement method is used. Defining matrices are calculated with the Godunovs scheme. Numerical solutions in this case can be obtained practically with any accuracy within accepted hypotheses of the mathematical model of the calculated object. This suggests that the resulting solutions are standard. The examples of determining the natural frequencies of vibrations of beam structures that demonstrate an extremely high accuracy of the proposed algorithm are given.

Study on Control Characteristics of Driving and Lifting System for Logistics and Loading Machinery

2012 ◽  
Vol 268-270 ◽  
pp. 1517-1522 ◽  
Author(s):  
Guo Jin Chen ◽  
Ting Ting Liu ◽  
Ni Jin ◽  
You Ping Gong ◽  
Huo Qing Feng
Keyword(s):  
Mathematical Model ◽  
Dynamic Characteristics ◽  
Optimization Design ◽  
Integrated System ◽  
Operating Conditions ◽  
Control Methods ◽  
Lifting System ◽  
The Mathematical Model ◽  
Power Match

The logistics and loading machinery is the typical hydromechatronics integrated system. How to solve the reasonable power match in the driving and lifting process of the logistics and loading machinery, we need to establish the mathematical model of the driving and lifting system, and analyze their control characteristics. Aiming at the load requirements for different operating conditions, this paper studies respectively the dynamic characteristics of the driving and lifting system. Through simulation and computation, the control methods and strategies based on the best performance are proposed. That lays the foundation for the optimization design of the logistics and loading machinery.

scholarly journals Improving the Dynamic Characteristics of Precision Lathes Used in the Repair of Agricultural Machinery

2021 ◽  
pp. 36-39
Author(s):  
D.E. Molochnikov ◽  
◽  
R.Sh. Halimov ◽  
N.P. Ayugin ◽  
I.R. Salakhutdinov ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Dynamic Characteristics ◽  
Low Frequency ◽  
Frequency Component ◽  
Honeycomb Structure ◽  
Friction Unit ◽  
Agricultural Machinery ◽  
Longitudinal Vibrations ◽  
Model Of Friction ◽  
The Mathematical Model

A model of a friction unit of a lathe in the form of a thin layer of material of a honeycomb structure is described to determine the dynamic characteristics of a movable carriage to guide joint. The analysis of the mathematical model of friction for different sliding pairs with varying load and sliding speed is performed. It is shown that the presence of an abrasive impurity in the lubrication of the guide enhances the effect of the low-frequency component of the carriage vibrations on the dynamics of the machine tool and the presence of pockets for retaining the lubricant in the joint of the guide makes it possible to reduce the amplitude of the longitudinal vibrations of the carriage to 30-50 %.

scholarly journals Modeling of T-16M self-propelled chassis’ diesel engine starting motor energy capacity

2018 ◽  
Author(s):  
Д.Н. Маничев ◽  
Д.Г. Мясищев
Keyword(s):  
Mathematical Model ◽  
Fuel Consumption ◽  
Theoretical Calculations ◽  
Target Function ◽  
Energy Capacity ◽  
Logical System ◽  
Winter Conditions ◽  
The Mathematical Model ◽  
The Given ◽  
Tractor Engine

Приведена разработка математической модели расхода топлива в режиме пуска двигателя пусковым устройством. Проведено сравнение с результатами исследовательских испытаний. Целевой функцией в математической модели является часовой расход топлива всей рассматриваемой системы МП-5 «Урал-2Т ЭЛЕКТРОН» – двигатель Д-21А1. Целью работы является описание математической модели для данной логической системы. При данном подходе также использованы основы оценки топливной экономичности колесных малогабаритных лесотранспортных систем. После проведения математических расчетов получили часовой расход топлива В = 1,24 кг/ч. Проведение исследовательских испытаний запуска двигателя трактора Т-16М при помощи ПУ в зимний период показали, что часовой расход топлива В = 1,28 кг/ч. Таким образом, погрешность теоретических расчетов и исследовательских испытаний составляет 6%. Сравнение теоретических и практических результатов позволяет сделать следующие выводы: теория, построенная на математической модели, дает результаты, наиболее близкие к экспериментальным с расхождением 6%; разработанная теоретическая модель входит в постановку задачи оптимизации компонентов пускового привода. The article is devoted to development of mathematical model of fuel consumption of the engine started by a starter as well as comparison with the results of the researches. Hourly fuel consumption of the MP-5 «Ural-2T ELECTRON» – engine D- 21A1 system represents the target function of the mathematical model. The aim of the article is to describe a mathematical model for the given logical system. As a result of mathematical calculations the hourly fuel consumption is B = 1.24 kg/h. Research tests of starting the T-16M tractor engine by the starter in winter conditions showed that the hourly fuel consumption B = 1.28 kg/h. Thus, discrepancy between theoretical calculations and research tests is 6%. Comparison of theoretical and practical results leads to following conclusions: theory based on the mathematical model gives results closest to experimental ones with a discrepancy of 6%; the developed theoretical model can be included into the task of starting drive components' optimization.

Modeling and Simulation of Educational Linear Motion Module

2009 ◽  
Author(s):  
Dian-sheng Chen ◽  
Yu-xin Chen ◽  
Tian-miao Wang
Keyword(s):  
Mathematical Model ◽  
Dynamic Performance ◽  
Linear Motion ◽  
Motion Model ◽  
Load Case ◽  
Know How ◽  
Working Principle ◽  
And Control ◽  
The Mathematical Model ◽  
Control Accuracy

In order to let the student understand the linear motion module’ principles and know how to improve the dynamic performance and control accuracy, a mathematical model is established based on the analysis of the composition and working principle of linear motion module. On the load and unload conditions, we simulate and analyze the system respectively. In the load case, PID parameters are obtained after the PID regulation. The correction of establishing the mathematical model and simulating the system are verified so that the linear motion model’ precision is effectively enhanced.

Mathematical modeling of articulated passenger train spatial vibrations

2021 ◽  
Vol 2021 (2) ◽  
pp. 91-99
Author(s):  
O. Markova ◽  
◽  
H. Kovtun ◽  
V. Maliy ◽  
◽  
...  
Keyword(s):  
Mathematical Model ◽  
Differential Equations ◽  
Dynamic Characteristics ◽  
High Speed ◽  
Ride Quality ◽  
Railway Transport ◽  
Passenger Train ◽  
Wide Range ◽  
Random Track Irregularities ◽  
The Mathematical Model

The problem of high-speed railway transport development is important for Ukraine. In many countries articulated trains are used for this purpose. As the connections between cars in such a train differ from each other, to investigate its dynamic characteristics not a separate car, but a full train vibrations model is necessary. The article is devoted to the development of the mathematical model for articulated passenger train spatial vibrations. The considered train consists of 7 cars: one motor-car, one transitional car, three articulated cars, one more transitional car and again one motor-car. Differential equations of the train motion along the track of arbitrary shape are set in the form of Lagrange’s equations of the second kind. All the necessary design features of the vehicles are taken into account. Articulated cars have common bogies with adjoining cars and a transfer car and the cars are united by the hinge. The operation of the central hinge between two cars is modeled using springs and dampers acting in the horizontal and vertical directions. Four dampers between two adjacent car-bodies act as dampers for pitching and hunting and are represented in the model by viscous damping. The system of 257 differential equations of the second order is set, which describes the articulated train motion along straight, curved, and transitional track segments with taking into account random track irregularities. On the basis of the obtained mathematical model the algorithm and computational software has been developed to simulate a wide range of cases including all possible combinations of parameters for the train elements and track technical state. The study of the train self-exited vibrations has shown the stable motion in all the range of the considered speeds (40 km/h – 180 km/h). The results obtained at the train motion along the track maintained for the speedy motion have shown that all the dynamic characteristics and ride quality index insure train safe motion and comfortable conditions for the travelling passengers.

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