scholarly journals Directional stability of an agricultural tractor

2021 ◽  
Vol 49 (2) ◽  
pp. 456-462
Author(s):  
Irina Troyanovskaya ◽  
A. Zhakov ◽  
O. Grebenshchikova ◽  
S. Voinash ◽  
E. Timofeev
Keyword(s):  
Mathematical Theory ◽  
Shear Force ◽  
Lateral Displacement ◽  
Lateral Forces ◽  
Straight Line ◽  
The Difference ◽  
External Forces ◽  
Agricultural Tractor ◽  
Line Movement ◽  
Moldboard Plow

The discrepancy between the plow width and the tractor width leads to the asymmetry of plowing units. The geometry of the plowshare surface of the moldboard plow contributes to the generation of lateral forces on the working tool. All this leads to the imbalance of the tool and the deviation of the tractor from straight-line movement during plowing. To maintain straight-line movement, the driver has to adjust the machine every 5-10 meters, which is highly tiresome. To study the causes of lateral slips of the plowing unit, we constructed a mathematical model, which consists of the equations of controlled movement and equations of the tractor's uncontrolled shear under the action of external forces from the plow. The description of the force interaction of the drive with the ground is based on the mathematical theory of friction, taking into account anisotropy and elastic properties in contact. Based on the passive shear model, we constructed a hodograph diagram of the maximum tractor shear force from the side of the working tool. We found that the shear force reaches its maximum friction value only in the case of a translational shear, when its line of action passes through the tractor's center of gravity. In all other cases, the shift (slip) of the tractor is caused by a lower force. We formulated the features and assumptions of the model as applied to caterpillar and wheeled tractors. As a result, we found that, regardless of the direction of the lateral displacement of the plow's traction resistance, the tractor is slipped towards the plowed field. The result of the numerical experiment showed that the main reason for the slip of the wheeled plowing unit is the difference in soils along the sides of the tractor but not the deviation of the plow traction resistance.

scholarly journals Road holding ability of machine-tractor unit during plowing

2020 ◽  
Vol 1 (6) ◽  
pp. 41-49
Author(s):  
I.P. Troyanovskaya ◽  
◽  
A.O. Zhakov ◽  
Keyword(s):  
Mathematical Theory ◽  
Shear Force ◽  
Lateral Displacement ◽  
Lateral Forces ◽  
Straight Line ◽  
Controlled Motion ◽  
Draft Resistance ◽  
External Forces ◽  
Vehicle Movement ◽  
Line Movement

The discrepancy between the working width of the plow and the width of the tractor leads to asymmetry of the arable units. The geometry of the share surface of the reversible plow contributes to the generation of lateral forces on the working tool. All this contributes to the imbalance of the working body and the deviation of the tractor from straight-line movement during plowing. To maintain a straight line, the driver has to correct the vehicle movement every 5-10 meters, which makes him more tired. To study the causes of lateral slip of the plowing unit, a mathematical model was built. It consists of the equations of controlled motion and equations of uncontrolled shift of the tractor under the action of external forces from the plow. The description of the force interaction of the propeller with the ground is based on the mathematical theory of friction, taking into account anisotropy and elastic properties in contact. On the basis of the passive shear model, the hodograph of the maximum force shifting the tractor from the side of the working tool is constructed. It has been established that the shear force reaches its maximum adhesion value only in the case of trans-lational shear, when its line of action passes through the center of gravity of the tractor. In all other cases, the shift (pull) of the tractor is carried out by a force of a lower value. The features and as-sumptions of the model are formulated in relation to the tracked and wheeled tractors. As a result, it was found that regardless of the direction of the lateral displacement of the plow draft resistance, the tractor is pulled towards the plowed field. The result of the numerical experiment showed that the main reason for the drift of the wheeled arable unit is the different type of soil along the sides of the tractor, but not the displacement of the plow traction resistance.

scholarly journals Determination of Optimum Position of Shear Wall in an Irregular Building for Zone III & IV

2019 ◽  
Vol 9 (1) ◽  
pp. 174-183
Keyword(s):  
Comparative Study ◽  
Lateral Displacement ◽  
Shear Walls ◽  
Shear Wall ◽  
Lateral Stiffness ◽  
Base Shear ◽  
Modeling And Analysis ◽  
Lateral Forces ◽  
Optimum Position ◽  
External Forces

Stiffness is the property of the structure that is responsible for absorbing the external forces. For the case a multistory building, when the height of the building increases, the lateral stiffness of the building decreases. With low lateral stiffness, the building becomes more vulnerable to lateral forces like wind and earthquake. In order to prevent the structure from damage from the lateral forces, lateral stiffness is induced in the structure by means of shear walls. With the introduction of shear wall, we observe a considerable decrement in lateral displacement and increase in base shear. The resistance of lateral forces in terms of magnitude by shear wall depends on its location in the building. In this paper, a G+15 storey building is considered. The building is irregular in nature (T shaped). A comparative study is done to obtain the optimum position of shear wall in the structure. For optimization, the total length of the shear wall in the structure is kept constant. The whole modeling and analysis is done by ETABS v. 2016. The comparative study is done on the basis of base shear, storey displacement & storey drift. The above values are calculated by the dynamic approach of analysis of building subjected to seismic loading.

Automatic Tread Gaging Machine

1979 ◽  
Vol 7 (1) ◽  
pp. 31-39
Author(s):  
G. S. Ludwig ◽  
F. C. Brenner
Keyword(s):  
Experimental Tests ◽  
Automatic Machine ◽  
Wear Rates ◽  
Handling Device ◽  
Straight Line ◽  
Component Systems ◽  
Before And After ◽  
Good Repeatability ◽  
The Difference ◽  
Straight Lines

Abstract An automatic tread gaging machine has been developed. It consists of three component systems: (1) a laser gaging head, (2) a tire handling device, and (3) a computer that controls the movement of the tire handling machine, processes the data, and computes the least-squares straight line from which a wear rate may be estimated. Experimental tests show that the machine has good repeatability. In comparisons with measurements obtained by a hand gage, the automatic machine gives smaller average groove depths. The difference before and after a period of wear for both methods of measurement are the same. Wear rates estimated from the slopes of straight lines fitted to both sets of data are not significantly different.

scholarly journals Elastic Simulation of Joints with Particle-Based Fluid

2021 ◽  
Vol 11 (15) ◽  
pp. 6900
Author(s):  
Su-Kyung Sung ◽  
Sang-Won Han ◽  
Byeong-Seok Shin
Keyword(s):  
Principal Stress ◽  
Human Body ◽  
Yield Condition ◽  
Maximum Principal Stress ◽  
Human Motion ◽  
The Difference ◽  
The Moment ◽  
External Forces ◽  
Physical Changes ◽  
Elastic Simulation

Skinning, which is used in skeletal simulations to express the human body, has been weighted between bones to enable muscle-like motions. Weighting is not a form of calculating the pressure and density of muscle fibers in the human body. Therefore, it is not possible to express physical changes when external forces are applied. To express a similar behavior, an animator arbitrarily customizes the weight values. In this study, we apply the kernel and pressure-dependent density variations used in particle-based fluid simulations to skinning simulations. As a result, surface tension and elasticity between particles are applied to muscles, indicating realistic human motion. We also propose a tension yield condition that reflects Tresca’s yield condition, which can be easily approximated using the difference between the maximum and minimum values of the principal stress to simulate the tension limit of the muscle fiber. The density received by particles in the kernel is assumed to be the principal stress. The difference is calculated by approximating the moment of greatest force to the maximum principal stress and the moment of least force to the minimum principal stress. When the density of a particle increases beyond the yield condition, the object is no longer subjected to force. As a result, one can express realistic muscles.

scholarly journals XXIII.—On the Disruptive Discharge of Electricity: An Experimental Thesis for the Degree of Doctor of Science, Department A

1878 ◽  
Vol 28 (2) ◽  
pp. 633-671 ◽  
Author(s):  
Alexander Macfarlane
Keyword(s):  
Copper Wire ◽  
Late Summer ◽  
The Other ◽  
Straight Line ◽  
Summer Session ◽  
The Difference ◽  
A Chain ◽  
The One ◽  
Metallic Parts ◽  
The University

The experiments to which I shall refer were carried out in the physical laboratory of the University during the late summer session. I was ably assisted in conducting the experiments by three students of the laboratory,—Messrs H. A. Salvesen, G. M. Connor, and D. E. Stewart. The method which was used of measuring the difference of potential required to produce a disruptive discharge of electricity under given conditions, is that described in a paper communicated to the Royal Society of Edinburgh in 1876 in the names of Mr J. A. Paton, M. A., and myself, and was suggested to me by Professor Tait as a means of attacking the experimental problems mentioned below.The above sketch which I took of the apparatus in situ may facilitate tha description of the method. The receiver of an air-pump, having a rod capable of being moved air-tight up and down through the neck, was attached to one of the conductors of a Holtz machine in such a manner that the conductor of the machine and the rod formed one conducting system. Projecting from the bottom of the receiver was a short metallic rod, forming one conductor with the metallic parts of the air-pump, and by means of a chain with the uninsulated conductor of the Holtz machine. Brass balls and discs of various sizes were made to order, capable of being screwed on to the ends of the rods. On the table, and at a distance of about six feet from the receiver, was a stand supporting two insulated brass balls, the one fixed, the other having one degree of freedom, viz., of moving in a straight line in the plane of the table. The fixed insulated ball A was made one conductor with the insulated conductor of the Holtz and the rod of the receiver, by means of a copper wire insulated with gutta percha, having one end stuck firmly into a hole in the collar of the receiver, and having the other fitted in between the glass stem and the hollow in the ball, by which it fitted on to the stem tightly. A thin wire similarly fitted in between the ball B and its insulating stem connected the ball with the insulated half ring of a divided ring reflecting electrometer.

scholarly journals Determination of Multilayer Soil Strength Parameters Using Genetic Algorithm

2018 ◽  
Vol 4 (10) ◽  
pp. 2383 ◽  
Author(s):  
Seyyed Mohammad Hashemi ◽  
Iraj Rahmani
Keyword(s):  
Genetic Algorithm ◽  
Lateral Displacement ◽  
Error Function ◽  
Back Analysis ◽  
Soil Strength ◽  
Strength Parameters ◽  
Analysis Process ◽  
Project Monitoring ◽  
The Difference ◽  
Python Programming

This paper employs a back analysis method to determine soil strength parameters of the Mohr-Coulomb model from in situ geotechnical measurements. The lateral displacement of a soil nailed wall retaining an excavation in Tehran city used as a criterion for the back analysis. For this purpose, a genetic algorithm is applied as an optimization algorithm to minimize the error function, which can perform the back analysis process. When the accuracy of modeling is verified, the back analysis is performed automatically by creating a link between genetic algorithm in MATLAB and Abaqus software using Python programming language. This paper demonstrated that the genetic algorithm is a particularly suitable tool to determine 9 soil strength parameters simultaneously for 3 soil layers of the project site to decrease the difference of lateral displacement between the results of project monitoring and numerical analysis. The soil strength parameters have increased, with the most changes in Young's modulus of the first to third layers as the most effective parameter, 49.45%, 61.67% and 64.35% respectively. The results can be used in advanced engineering analyses and professional works.

scholarly journals Das Leben ist ein Spiel

2000 ◽  
Vol 43 (4) ◽  
pp. 315-326
Author(s):  
A. Grauvogl
Keyword(s):  
Sexual Reproduction ◽  
Mathematical Theory ◽  
Social Aspects ◽  
Genetic Elements ◽  
The Social ◽  
The Difference

Abstract. Title of the paper: Life is a game Sexual reproduction causes the independent combination of genetic elements. But not only the physiology of reproduction but also behavioural physiology is familiär with independent combinations; in this case the behavioural elements while playing. An attempt is made to analyse and discover the difference between the playing behaviour of animals versus the playing behaviour of humans during childhood. The mathematical theory of game also is based upon selective choice. The social aspects of play in animal and human collectives is explained as well as the possibilities of therapeutical games.

scholarly journals Evaluación de la motilidad espermática a través del sistema C.A.S.A de semen caprino criopreservado bajo diferentes medios diluyentes

Respuestas ◽  
2013 ◽  
Vol 18 (2) ◽  
pp. 16-27
Author(s):  
Leonardo Hernández-Corredor ◽  
Alexander Nivia-Osuna ◽  
Daniel Hernández-Villamizar ◽  
Jorge Alexander Rubio-Parada ◽  
Armando Quintero-Moreno
Keyword(s):  
Lateral Displacement ◽  
Egg Yolk ◽  
Computer Assisted ◽  
Complete Medium ◽  
Sperm Analysis ◽  
Straight Line ◽  
Nitrogen Vapor ◽  
Computer Assisted Sperm Analysis ◽  
The University ◽  
Casa System

 El estudio evaluó la motilidad espermática y su efecto postdescongelación en semen caprino, en dos medios comerciales (Andromed® y TwoStep®) y diferentes protocolos de congelación (medio completo, con adicción del 10% de yema de huevo, semen centrifugado y sobrenadante seminal), se utilizaron machos de la raza alpina de la Universidad Francisco de Paula Santander Ocaña, el semen fue colectado con electroeyaculador, una vez los medios terminados y parte de los contenidos seminales enteros o centrifugados mezclados, se estabilizó por 2 horas, se envasó en pajillas de 0,5 cc y se congela en vapores de nitrógeno por 10 minutos, las pajillas se llevaron al laboratorio de Andrología de la Universidad del Zulia y por medio del sistema C.A.S.A.(Computer Assisted Sperm Análisis) se evaluaron los parámetros de motilidad como velocidad curvilínea (VCL), velocidad rectilínea (VSL), velocidad lineal (VAP), índice de linealidad (LIN), índice de rectitud (STR), índice de oscilación (ALH), Amplitud media del desplazamiento lateral de la cabeza del espermatozoide (BCF), los datos fueron analizados por medio del procedimiento GLM de SAS versión 9.0; los mejores índices de motilidad (VCL, ALH, BCF) fueron expresados enel tratamiento de contenido seminal centrifugado en medio Andromed®. (p≤0,001))La mejor progresividad espermática (VSL,LIN,STR)se presentó el tratamiento de Semen completo de caprino, criopreservado en medio comercial TwoStep®. ABSTRACT  The study evaluated the effect sperm motility and sperm post-thawing in goats, two commercial means (Andromed ® and Two Step ®) and different freezing protocols (complete medium with 10% addition of the egg yolk, semen centrifuged supernatant and seminal ), we used males of the Alpine race of the University Francisco de Paula Santander Ocaña, semen was collected with electroejaculator once finished media and part of the whole and centrifuged seminal contents mixed, stabilized by two hours, packed in 0.5 cc straws and frozen in nitrogen vapor for 10 min, the straws were taken to the laboratory of Andrology at the University of Zulia and through CASA system (Computer Assisted Sperm Analysis) were evaluated motility parameters such as curvilinear velocity (VCL), straight line velocity (VSL), linear velocity (VAP), linearity index (LIN), straightness index (STR) Oscillation Index (ALH ) average amplitude of the lateral displacement of the sperm head (BCF), the data were analyzed by the GLM procedure of SAS version 9.0, the highest rates of motility (VCL, ALH, BCF) were expressed in the treatment of seminal content centrifugation Andromed ® medium. (p ≤ 0.001)) The best progressive sperm (VSL, LIN, STR) will present the full Semen treatment goats, cryopreserved at Two Step ® commercial medium.Keywords: semen, buck, Andromed, Two step.

scholarly journals The Level of Specific Endurance and Technical and Tactical Efficiency of Young Football Players of Different Level of Competition / Nivo specifične izdržljivosti i tehničko-taktičke efikasnosti mladih fudbalera različitog stepena takmičenja

2016 ◽  
Vol 10 (2) ◽  
Author(s):  
Toplica Stojanović ◽  
Slobodan Goranović ◽  
Aleksandar Šakanović ◽  
Darko Stojanović
Keyword(s):  
The Other ◽  
Measuring Instruments ◽  
Football Players ◽  
Five Factors ◽  
Straight Line ◽  
Specific Performance ◽  
The Difference

In order to determine at which level is the specific performance and technical and tactical efficiency of young players of different level of competition, and whether the level of competition can be an indicator of level differences of these abilities, a research was conducted on the sample of young football players aged 14 to 16 from the eight clubs, half of them competing in the higher and the other half in the lower level of competition. A sample of measuring instruments consisted of 13 tests for evaluation of five factors of specific endurance: starting endurance, stamina in maintaining the shallow formation, endurance during fast dribbling, ball pressing endurance, and evaluation of technical and tactical efficiency of football players. The results of the research showed that the young players of higher level of competition had significantly greater technical and tactical efficiency, as well as specific performance in tests which included curvilinear movement and dribbling, as well as control and passing the ball in motion, but the difference is not recorded with straight-line movements and sprints.

Side wind and tank speed influence on lateral displacement of the projectile

2021 ◽  
pp. 24-29
Author(s):  
M. Sorokatiy ◽  
M. Voytovych ◽  
L. Velychko ◽  
O. Moskalova
Keyword(s):  
Mathematical Model ◽  
Wind Speed ◽  
Lateral Displacement ◽  
Longitudinal Section ◽  
Projectile Velocity ◽  
Air Density ◽  
Dimensionless Coefficient ◽  
Air Resistance ◽  
The Difference ◽  
Firing Distance

This article indicates the scope of the formula for determining the magnitude of the lateral displacement of the projectile under the action of crosswind, which is used in the compilation of firing tables. This formula is valid under the following conditions: the force of frontal air resistance to the motion of the projectile is proportional to the its velocity squared; wind speed components are much smaller than the horizontal component of projectile velocity; the projectile velocity projections on the Oy and Oz axes are much smaller than the projections on the Ox axis; the dimensionless coefficient of resistance and the magnitude of the crosswind are constant values. However, in reality, the force of frontal air resistance to the motion of the projectile is only sometimes proportional to the its velocity squared; the projectile velocity projections on the Oz axis may be are much smaller than the projections on the Ox axis and may even be greater than it; the coefficient of resistance is depends on the value of the Makh number, so it can be considered constant only when shooting at short distances. The authors propose a mathematical model for determining the magnitude of the lateral displacement of the projectile under the action of crosswinds. It is believed that the force of the crosswind on the projectile depends on the following factors: air density; the maximum area of the longitudinal section of the projectile; the difference between the value of the lateral component of the wind speed and the speed of the lateral displacement of the projectile, which is raised to a certain power. The magnitude of the values of the lateral displacement of the projectile under the action of the crosswind when shooting at short distances, determined based on the proposed mathematical model, slightly differ from the values of the lateral displacement specified in the firing tables. However, with increasing firing distance, the difference between these values is constantly increasing and the value of the lateral displacement of the projectile determined theoretically is much larger than indicated in the firing tables. In addition, in this research the influence of the tank velocity on the value of the projectile lateral displacement taking into account the action of the crosswind is studied.

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