Influence of Shock-Absorber Parameters on Vehicle Vibrations during Braking

2006 ◽  
Vol 113 ◽  
pp. 235-240 ◽  
Author(s):  
Robertas Pečeliūnas ◽  
Olegas Prentkovskis
Keyword(s):  
Mathematical Model ◽  
Shock Absorber ◽  
Research Results ◽  
Vehicle Suspensions ◽  
Emergency Braking ◽  
Vibration Theory ◽  
Braking Distance ◽  
Braking Process ◽  
Vehicle Movement

The main goals of the work are to define consistent patterns of impacts exercised by vibration of the vehicle in emergency braking on the vehicle’s movement mode and on the braking distance and to analyze the formation of oscillation. Besides, it is aimed to extend expert’s opportunities for modeling vehicle movement for investigation of accidents’ circumstances related to vehicle braking with the aid of the developed models. A mathematical model of impact exercised by bumper’s characteristics on the vehicle’s braking process has been designed, enabling the determination of coefficients of longitudinal relative forces of the vehicle’s front and rear axles, which depend on the road’s pavement and its condition. The obtained research results extend the vehicle vibration theory in transitional movement modes, which are used in the design and improvement of vehicle suspensions, as well as in traffic accident’s investigation and improvement of methodology of their expertise calculations.

scholarly journals Assessment of the functional functionality of passenger car brake systems by changing the braking distance during operation

2021 ◽  
Vol 13 (1) ◽  
pp. 78-86
Author(s):  
Alexander Nazarov ◽  
◽  
Vitalii Kashkanov ◽  
Ivan Nazarov ◽  
Yevhen Ivanchenko ◽  
...  
Keyword(s):  
Operating Conditions ◽  
Passenger Cars ◽  
Passenger Car ◽  
Emergency Braking ◽  
Braking System ◽  
Braking Distance ◽  
Braking Force ◽  
Braking Process ◽  
Relative Change

The article discusses a methodology for assessing the functional suitability of brake systems to change the braking path of passenger cars, taking into account various operating conditions. The goal is achieved by using the method of mathematical modeling of the emergency braking process, taking into account the possible operating conditions of cars performing emergency braking at certain initial speeds, in particular, exceeding 100 km / h. Based on the analysis of scientific sources, it has been established that the determination of the braking efficiency of a vehicle classically occurs on the verge of blocking all wheels with known methods of distributing braking forces between the axles of the vehicle. In this case, the standards set the maximum value of the minimum deceleration and braking distance. In addition, the jump in the maximum possible value of the braking force between the wheels of each axle makes it possible to compare it with the requirements of DSTU 3649: 2010, and the assessment of the magnitude of this jump for each braking of the car is to establish its functional suitability. As a result, according to the magnitude of the jump in the maximum possible value of the braking distance, the change in the maximum allowable braking force of the car sets, and according to the magnitude of its jump, it is possible to assess the functional suitability of its braking system. As a result, the use of expert information on the value of jumps in the maximum possible value of the braking force of a car, affecting the braking torques and braking coefficient, can reduce the amount of experimental research and significantly reduce the time to reach an objective decision on the functional suitability of the brake systems of operated cars. The paper presents the results of theoretical studies of passenger cars Chevrolet Aveo, Lada Priora and Forza with different loads, performing emergency braking at an initial speed of 40-150 km / h on a road with dry asphalt concrete. The boundaries of the coefficient of the relative change in the braking distance of the tested passenger car, at which it is possible to make a conclusion about the functional suitability of its braking system, have been established.

scholarly journals Simulation of the rotary-screw vehicle motion on snow

2018 ◽  
Vol 245 ◽  
pp. 17003
Author(s):  
Yan Arlauskas ◽  
Yuri Molev ◽  
Valentina Obrezkova ◽  
Valery Naumov
Keyword(s):  
Vibration Characteristics ◽  
Rough Terrain ◽  
Road Vehicle ◽  
Research Results ◽  
Suspension Parameters ◽  
Vehicle Motion ◽  
Vehicle Movement ◽  
Rotary Screw

The article presents the determination of oscillation parameters of the rotor-screw vehicle during motion on rough terrain. The study presented the dynamics of off-road vehicle movement. The dependence of the vehicle vibration characteristics on the mover geometry and suspension parameters was found. The experiment with the vehicle was performed. Analysis of the research results allows to conclude that the use of the suspension increases speed of the rotary-screw vehicle by 1.5 - 2.5 times. The developed model and obtained results will be useful in design of all-terrain vehicles.

scholarly journals About Application the Tyre-Road Adhesion Determination of a Vehicle Equipped with an Automated System of Brake Proportioning

2019 ◽  
Vol 18 (5) ◽  
pp. 401-408 ◽  
Author(s):  
D. N. Leontiev ◽  
I. N. Nikitchenko ◽  
L. A. Ryzhyh ◽  
S. I. Lomaka ◽  
O. I. Voronkov ◽  
...  
Keyword(s):  
Traffic Accidents ◽  
High Efficiency ◽  
Road Traffic ◽  
Rolling Force ◽  
Automated System ◽  
Experimental Investigations ◽  
Efficiency Estimation ◽  
Braking Distance ◽  
Braking Process

The paper considers a method for calculation and evaluation of an automated brake proportioning system and it also describes assessment of efficiency while using cohesion forces of an automated system during vehicle braking process (MAZ 256200 taken as an example). A method for efficiency estimation of the vehicle braking equipped with an automated brake proportioning system is graphically presented in the paper. A comparable analysis has been made in order to evaluate vehicle braking efficiency in three various conditions of its wheel motion during braking process. The paper contains description of braking processes for a vehicle at its idealized braking, at braking with an operating automated system and at braking with blocked wheels. Mathematical dependences have been proposed and they make it possible to calculate a coefficient of cohesion forces used by an automated brake proportioning system on the basis of time parameters for vehicle braking process. The proposed mathematical dependences take into account design peculiarities of the automated system, i.e. a diagram of modulator arrangement on axes of the vehicle. The executed analysis for calculation accuracy of the coefficient pertaining to use of cohesion forces of the automated system with and without taking into accout rolling force resistance of the vehicle wheels has demonstrated a possibility to apply the proposed calculation methods for carrying out auto-technical expertise while investigating road-traffic accidents involving transport facilities equipped with such systems as ABS. The paper proposes a dependence for identification of a vehicle braking distance on the basis of the coefficient on use of cohesion forces by the automated brake proportioning system. The executed experimental investigations on both test and serial models of the automated brake proportioning system have allowed to justify theoretical discussions concerning application of tyre-road adhesion in the operational process of the vehicle brake proportioning system. The investigation results have shown high efficiency of the test automated brake proportioning system developed by Chair of Automobiles in the name of A. B. Hredescul at Kharkiv National Automobile and Road University under the following braking conditions: dry road surface and compacted snow cover.

Simulation of the Free Piston’s Movement from the Single Regime Running Thermo-Hydraulic Generator

2014 ◽  
Vol 659 ◽  
pp. 171-176
Author(s):  
Nicolae Chioreanu ◽  
Tudor Mitran ◽  
Stelian Tarulescu ◽  
Horia Beles ◽  
Adrian Soica
Keyword(s):  
Mathematical Model ◽  
Thermal Energy ◽  
Diesel Fuel ◽  
Main Part ◽  
Kinematic Parameters ◽  
Research Results ◽  
Hydraulic Generator ◽  
The Mathematical Model ◽  
Engine Cycle

The paper presents the research results regarding the determination of the calculus relations necessary to simulate the free piston’s movement from the single regime thermo-hydraulic generators. The thermo-hydraulic generator is the main part of the single regime running thermal engines (absolute novelty-pioneer invention), that transforms the thermal energy obtained by burning the fuel (gasoline, diesel fuel, unconventional fuels), in hydrostatic energy. The hydrostatic energy produced by the generator is stored in a hydro-pneumatic accumulator. In the paper are presented the variation functions of the forces acting on the piston in one engine cycle and the variation functions of the kinematic parameters (speeds and accelerations). Because the thermo-hydraulic generator is an absolute novelty, the mathematical model for the piston’s movement developed by the authors is an original one, but is based on classical equations that describe the phenomena that take place in the system.

DETERMINATION OF PERFORMANCE INDICATORS OF THE TRUCK KrAZ-6510TE

2020 ◽  
pp. 19-26
Author(s):  
Olexandr Pavlenko ◽  
Serhii Dun ◽  
Maksym Skliar
Keyword(s):  
Mathematical Model ◽  
Surface Friction ◽  
Building Structures ◽  
Maximum Torque ◽  
Military Equipment ◽  
Military Vehicles ◽  
Force Magnitude ◽  
Vehicle Mobility ◽  
The Mathematical Model

In any economy there is a need for the bulky goods transportation which cannot be divided into smaller parts. Such cargoes include building structures, elements of industrial equipment, tracked or wheeled construction and agricultural machinery, heavy armored military vehicles. In any case, tractor-semitrailer should provide fast delivery of goods with minimal fuel consumption. In order to guarantee the goods delivery, tractor-semitrailers must be able to overcome the existing roads broken grade and be capable to tow a semi-trailer in off-road conditions. These properties are especially important for military equipment transportation. The important factor that determines a tractor-semitrailer mobility is its gradeability. The purpose of this work is to improve a tractor-semitrailer mobility with tractor units manufactured at PJSC “AutoKrAZ” by increasing the tractor-semitrailer gradeability. The customer requirements for a new tractor are determined by the maximizing the grade to 18°. The analysis of the characteristics of modern tractor-semitrailers for heavy haulage has shown that the highest rate of this grade is 16.7°. The factors determining the limiting gradeability value were analyzed, based on the tractor-semitrailer with a KrAZ-6510TE tractor and a semi-trailer with a full weight of 80 t. It has been developed a mathematical model to investigate the tractor and semi-trailer axles vertical reactions distribution on the tractor-semitrailer friction performances. The mathematical model has allowed to calculate the gradeability value that the tractor-semitrailer can overcome in case of wheels and road surface friction value and the tractive force magnitude from the engine. The mathematical model adequacy was confirmed by comparing the calculations results with the data of factory tests. The analysis showed that on a dry road the KrAZ-6510TE tractor with a 80 t gross weight semitrailer is capable to climb a gradient of 14,35 ° with its coupling mass full use condition. The engine's maximum torque allows the tractor-semitrailer to overcome a gradient of 10.45° It has been determined the ways to improve the design of the KrAZ-6510TE tractor to increase its gradeability. Keywords: tractor, tractor-semitrailer vehicle mobility, tractor-semitrailer vehicle gradeability.

KEBIJAKAN MODERASI PIDANA MATI

2017 ◽  
Vol 10 (2) ◽  
pp. 193
Author(s):  
Mei Susanto ◽  
Ajie Ramdan
Keyword(s):  
Human Rights ◽  
Death Penalty ◽  
Capital Punishment ◽  
Criminal Code ◽  
Right To Life ◽  
Life Imprisonment ◽  
Research Results ◽  
Moderation Model ◽  
The Right

ABSTRAKPutusan Nomor 2-3/PUU-V/2007 selain menjadi dasar konstitusionalitas pidana mati, juga memberikan jalan tengah (moderasi) terhadap perdebatan antara kelompok yang ingin mempertahankan (retensionis) dan yang ingin menghapus (abolisionis) pidana mati. Permasalahan dalam penelitian ini adalah bagaimana kebijakan moderasi pidana mati dalam putusan a quo dikaitkan dengan teori pemidanaan dan hak asasi manusia dan bagaimana kebijakan moderasi pidana mati dalam RKUHP tahun 2015 dikaitkan dengan putusan a quo. Penelitian ini merupakan penelitian doktrinal, dengan menggunakan bahan hukum primer dan sekunder, berupa peraturan perundang-undangan, literatur, dan hasil-hasil penelitian yang relevan dengan objek penelitian. Penelitian menyimpulkan, pertama, putusan a quo yang memuat kebijakan moderasi pidana mati telah sesuai dengan teori pemidanaan khususnya teori integratif dan teori hak asasi manusia di Indonesia di mana hak hidup tetap dibatasi oleh kewajiban asasi yang diatur dengan undang-undang. Kedua, model kebijakan moderasi pidana mati dalam RKUHP tahun 2015 beberapa di antaranya telah mengakomodasi amanat putusan a quo, seperti penentuan pidana mati di luar pidana pokok, penundaan pidana mati, kemungkinan pengubahan pidana mati menjadi pidana seumur hidup atau penjara paling lama 20 tahun. Selain itu masih menimbulkan persoalan berkaitan dengan lembaga yang memberikan pengubahan pidana mati, persoalan grasi, lamanya penundaan pelaksanaan pidana mati, dan jenis pidana apa saja yang dapat diancamkan pidana mati.Kata kunci: kebijakan, KUHP, moderasi, pidana mati. ABSTRACTConstitutional Court’s Decision Number 2-3/PUU-V/2007, in addition to being the basis of the constitutionality of capital punishment, also provides a moderate way of arguing between retentionist groups and those wishing to abolish the death penalty (abolitionist). The problem in this research is how the moderation policy of capital punishment in aquo decision is associated with the theory of punishment and human rights and how the moderation policy of capital punishment in the draft Criminal Code of 2015 (RKUHP) is related with the a quo decision. This study is doctrinal, using primary and secondary legal materials, in the form of legislation, literature and research results that are relevant to the object of analysis. This study concludes, firstly, the aquo decision containing the moderation policy of capital punishment has been in accordance with the theory of punishment, specificallyy the integrative theory and the theory of human rights in Indonesia, in which the right to life remains limited by the fundamental obligations set forth in the law. Secondly, some of the modes of moderation model of capital punishment in RKUHP of 2015 have accommodated the mandate of aquo decision, such as the determination of capital punishment outside the main punishment, postponement of capital punishment, the possibility of converting capital punishment to life imprisonment or imprisonment of 20 years. In addition, it still raises issues regarding the institutions that provide for conversion of capital punishment, pardon matters, length of delay in the execution of capital punishment, and any types of crime punishable by capital punishment. Keywords: policy, criminal code, moderation, capital punishment.

Development of Mathematical Model of Ground Unmanned Vehicle Movement

2019 ◽  
Vol 15 (2) ◽  
pp. 618-625
Author(s):  
Nikulin Artem Anatolyevich ◽  
Bychkov Dmitriy Sergeevich ◽  
Generalova Alexandra Alexandrovna
Keyword(s):  
Mathematical Model ◽  
Unmanned Vehicle ◽  
Vehicle Movement

Research on a Generating Method of Spiral Flutes of Hourglass Worm Gear Hob

2017 ◽  
Author(s):  
Yang Jie ◽  
Li Haitao ◽  
Rui Chengjie ◽  
Wei Wenjun ◽  
Dong Xuezhu
Keyword(s):  
Mathematical Model ◽  
Manufacturing System ◽  
Worm Gear ◽  
Virtual Manufacturing ◽  
Transmission Ratio ◽  
Method Of Determination ◽  
Generating Method ◽  
Multiple Threads ◽  
Different Shapes

All of the cutting edges on an hourglass worm gear hob have different shapes and spiral angles. If the spiral angles are small, straight flutes are usually adopted. But for the hob with multiple threads, the absolute values of the negative rake angles at one side of the cutting teeth will greatly affect the cutting performance of the hob if straight flutes are still used. Therefore, spiral flutes are usually adopted to solve the problem. However, no method of determination of the spiral flute of the hourglass worm gear hob has been put forward till now. Based on the curved surface generating theory and the hourglass worm forming principle, a generating method for the spiral flute of the planar double enveloping worm gear hob is put forward in this paper. A mathematical model is built to generate the spiral flute. The rake angles of all cutting teeth of the hob are calculated. The laws of the rake angles of the cutting teeth of four hobs with different threads from one to four threads are analyzed when straight flutes and spiral flutes are adopted respectively. The laws between the value of the negative rake angles of the hob with four threads and the milling transmission ratio are studied. The most appropriate milling transmission ratio for generating the spiral flute is obtained. The machining of the spiral flutes is simulated by a virtual manufacturing system and the results verify the correctness of the method.

Methodology of Estimation of Fire Separation Distances between Construction Facilities by Calculation

2020 ◽  
Vol 1006 ◽  
pp. 93-100
Author(s):  
Vadym Nizhnyk ◽  
Yurii Feshchuk ◽  
Volodymyr Borovykov
Keyword(s):  
Mathematical Model ◽  
Heat Flux ◽  
Linear Regression ◽  
Ignition Temperature ◽  
Oil Products ◽  
Regression Equations ◽  
Fire Load ◽  
Literary Sources ◽  
Tabular Method

Based on analysis of appropriate literary sources we established that estimation of fire separation distances was based of two criteria: heat flux and temperature. We proposed to use “ignition temperature of materials” as principal criterion when determining fire separation distances between adjacent construction facilities. Based on the results derived while performing complete factorial we created mathematical model to describe trend of changing fire separation distances depending on caloric power of fire load (Q), openings factor of the external enclosing structures (k) and duration of irradiation (t); moreover, its adequacy was confirmed. Based on linear regression equations we substantiated calculation and tabular method for the determination of fire separation distances for a facility being irradiated which contains combustible or otherwise non-combustible façade and a facility where liquid oil products turn. We developed and proposed general methodology for estimation of fire separation distances between construction facilities by calculation.

Sign in / Sign up

Export Citation Format

Share Document