scholarly journals FEATURES OF STRENGTH TESTING OF PASSENGER WAGON AUTOMATIC REGULATORS

2020 ◽  
Vol - (1(16)) ◽  
pp. 20-27
Author(s):  
К. Boriak ◽  
◽  
О. Lymarenko ◽  
N. Peretiaka ◽  
◽  
...  
Keyword(s):  
Stress State ◽  
Tensile Load ◽  
Longitudinal Direction ◽  
Load Force ◽  
Bench Test ◽  
Passenger Cars ◽  
Brake Pads ◽  
Automatic Regulator ◽  
Allowable Range ◽  
Residual Deformations

The automatic regulator РКЗТ-675 (РТПР-675) and РТПР-675M is installed in the brake lever transmission of the passenger car and used for automatical maintenance of gaps between the surfaces of rolling of wheel pairs and brake pads within the established limits irrespective of the wear of the rolling surfaces of wheels. The design of auto regulators allows you to change the stroke of the piston rod and the brake cylinder and to manually release and tighten the regulator. Scope of auto regulators: freight, passenger cars and electric trains of the main railways. The article is devoted to solving the problem of contradictions in clause 15.5.7 of the current departmental Ukrainian instruction ЦЛ-0013 for repairing brake equipment of the railway carriage of the existing requirement for mandatory compliance with screw unscrewing in size "a" within 300-350 mm when testing automatic regulators on an automatic test stand for strength under load a normalized force of 8t in the longitudinal direction, provided that there are no residual deformations of the automatic regulator screw along its length. The article aims to refute the dependence of the values of the stress state of an automatic regulator when testing its strength on a test bench from a change in its length in the entire possible range of screw unscrewing by size "a" in the allowable range of 0-600 mm. The problem is solved by calculation using two different methods, and the results of the stress state values of the automatic regulator with different lengths of screw unscrewing by size “a” are compared with each other. Based on this, the general conclusion is made that the size “a” (within the range of 0–600 mm) of the automatic regulator screw unscrewing when testing it for strength with the same load force (N = 8t ≈ 80 кН) in the longitudinal direction does not affect the calculated value of the screw tension σ = 113.23 MPa when tested on an automatic bench. The developers of the departmental Ukrainian instruction ЦЛ-0013 are invited to make in clause 15.5.7 corresponding changes regarding the requirement of optional observance of the value of the size "a" within 300-350 mm at the bench test of the automatic regulators for the tensile load under the standardized force of 8t.

scholarly journals Impact of Operating Time on Selected Tribological Properties of the Friction Material in the Brake Pads of Passenger Cars

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 884
Author(s):  
Andrzej Borawski
Keyword(s):  
Tribological Properties ◽  
Operating Time ◽  
Friction Material ◽  
Operating Conditions ◽  
Direct Impact ◽  
Passenger Cars ◽  
Wear Factor ◽  
Brake Pads ◽  
Road Users ◽  
The Coefficient Of Friction

Braking systems have a direct impact on the safety of road users. That is why it is crucial that the performance of brakes be dependable and faultless. Unfortunately, the operating conditions of brakes during their operating time are affected by many variables, which results in changes in their tribological properties. This article presents an attempt to develop a methodology for studying how the operating time affects the value of the coefficient of friction and the abrasive wear factor. The Taguchi method of process optimization was used to plan the experiment, which was based on tests using the ball-cratering method. The results clearly show that the degree of wear affects the properties of the friction material used in the production process of brakes.

Research on the relationship between transmission efficiency and input torque of manual transmission

2019 ◽  
Vol 20 (6) ◽  
pp. 611
Author(s):  
Shu Yan ◽  
Geng Li ◽  
Shaopeng Tian ◽  
Qingxing Zheng
Keyword(s):  
Test Bench ◽  
Transmission Efficiency ◽  
Calculation Model ◽  
Manual Transmission ◽  
Bench Test ◽  
Theoretical Simulation ◽  
Factors Affecting ◽  
Allowable Range ◽  
Dc Bus ◽  
Input Torque

Based on the manual transmission of a micro car, this paper would present the analysis of the factors affecting the transmission efficiency (TE) and the calculation formula of TE. Accordingly, the calculation model of Matlab/Simulink TE would be built to figure out how TE varies with input torque. Meanwhile, a set of manual transmission test bench would be designed and used to verify the theoretical simulation results. It adopts a common DC bus energy feedback closed system which can feedback the power generated by the load motor to the grid through the DC bus so as to save the electricity and produce less pollution. Therefore, while the test bench can reflect the variation trend of TE about the manual transmission truly, it is comparatively reliable. Apart from being energy-saving, its unique versatility could definitely predict its exceptional potential. The data of TE obtained from the test bench are compared with the simulation result. It showed that the TE of bench test and simulation result are similar, though companied by less than 2% error difference which is within the allowable range. Most importantly, the bench test results proved the validity of the theoretical analysis statistically, which is of great necessity and significance to the research of TE.

Effect of Load Direction on Tensile Yield Properties in Mg-3Al-Zn Alloy

2011 ◽  
Vol 682 ◽  
pp. 145-151 ◽  
Author(s):  
Ran Liu ◽  
De Liang Yin ◽  
Jing Tao Wang
Keyword(s):  
Yield Strength ◽  
Extrusion Direction ◽  
Tensile Load ◽  
Longitudinal Direction ◽  
Az31 Alloy ◽  
Tensile Yield Strength ◽  
Rolled Sheet ◽  
Orientation Factor ◽  
Tension And Compression ◽  
Specimen Orientation

Deformation anisotropy of samples from rolled sheet and extruded rod of AZ31 alloy was investigated in the present work. A strong basal plane texture is detected formed during rolling and extrusion, and both rolled and extruded samples exhibit similar mechanical behavior: tensile yield strength is the highest in the specimens parallel to the longitudinal direction, and decrease continuously as the specimen orientation departs from the longitudinal direction. Using texture analysis and optical microscopy it has been found that, the obvious anisotropy can be explained by texture and orientation factor during tension and compression. Basal slip and twinning are restricted when tensile load is applied in the rolling and extrusion direction, which results in high tensile yield strength along the two directions.

scholarly journals ANALYSIS OF THE STRESSED STATE OF THE AXLE OF A WHEEL PAIR OF A PASSENGER CAR

2021 ◽  
pp. 62-72
Author(s):  
Igor Martynov ◽  
Alena Trufanova ◽  
Vadim Petukhov ◽  
Vadim Shovkun
Keyword(s):  
Finite Element ◽  
Stress State ◽  
Cross Sections ◽  
Geometric Model ◽  
Three Dimensional ◽  
Work Conditions ◽  
Passenger Cars ◽  
Wheel Pair ◽  
Passenger Car ◽  
Finite Element Grid

The paper considers the results of calculations of the axle of the wheel pair of apassenger car for strength and durability from fatigue. The loads acting on the axle of a passengercar during movement at the maximum permissible speed are determined.To solve the problems of studying the stress state of the axle of the passenger car at the firststage, a three-dimensional geometric model of the axis RU1 was developed. The most unfavorableload combination was taken into account in the calculation. The horizontal load was up to 10 kN.The load was applied to the axle necks, respectively, in the vertical and horizontal directions.The calculated model of the car axle RU1 is developed, on the basis of which the finiteelementmodel is created and the stress state of the wheel pair under the action of the main types ofload is investigated. The size of the finite element grid was chosen using a graphoanalytical methodand refined to a size of 2 mm. This feature of the finite element grid allowed to calculate thestresses in the calculated cross sections with greater accuracy and to determine the nature of thestress distribution.It is established that the maximum stresses arising in the axle of the passenger car under the most unfavorable work conditions that are concentrated in the filler in the zone oftransition from the neck to the pre-axle part.The axle was calculated for fatigue. Fatigue tests are usually performed at a uniaxial stressstate, so it is necessary to convert the multiaxial stress state to one scalar value to determine thenumber of cycles to failure at a given voltage amplitude. The load can occur with a constantamplitude.The number of load cycles that the car axle can withstand under operating loads isdetermined. According to the results of the research, restrictions on the service life of the axles ofwheel pairs of passenger cars are proposed.

scholarly journals The Effect of Rigging Angle on Longitudinal Direction Motion of Parafoil-Type Vehicle: Basic Stability Analysis and Wind Tunnel Test

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Takahiro Moriyoshi ◽  
Kazuhiko Yamada ◽  
Hiroyuki Nishida
Keyword(s):  
Stability Analysis ◽  
Wind Tunnel ◽  
Wind Tunnel Test ◽  
Leading Edge ◽  
Longitudinal Direction ◽  
Aerodynamic Characteristics ◽  
Vehicle Stability ◽  
Flexible Wings ◽  
Allowable Range ◽  
Analytical Approaches

The paraglider, a flexible flying vehicle, consists of a parafoil with flexible wings, suspension lines, and a suspended payload. At this time, the suspension lines have several parameters to be designed. Above all, a parameter called Rigging Angle (RA) is sensitive to the aerodynamic characteristics of a paraglider during flight. In this study, the effect of RA is clarified using the two-dimensional stability analysis and a wind tunnel test. The mechanisms about the parafoil-type vehicle stability are clarified through the experimental and analytical approaches as follows. The RA has an allowable range for a stable flight. When the RA is set out of the range, the parafoil cannot fly stably. Furthermore, the behavior of the parafoil wing in the case of lower RA than the allowable range is different from the case of higher RA. The parafoil collapses from the leading edge of the canopy and cannot glide in the case of lower RA.

An Atomistic Study on the Slip Deformation Mechanism of Crystalline Materials Using a Weak-Plane Model

2012 ◽  
Vol 197 ◽  
pp. 321-326 ◽  
Author(s):  
Takuya Uehara
Keyword(s):  
Plastic Deformation ◽  
Deformation Mechanism ◽  
Tensile Load ◽  
Longitudinal Direction ◽  
Crystalline Materials ◽  
Step Motion ◽  
Weak Plane ◽  
Dynamics Simulations ◽  
Atomistic Study ◽  
Deformation Modes

Molecular dynamics simulations were carried out to investigate the plastic deformation mechanism of fcc crystalline materials using the conventional Lennard-Jones potential. An fcc structure with square cross-section was prepared, and a tensile load was applied in the longitudinal direction. A weak potential was assigned to a specific (111) plane to induce a slip on the specified plane. Accordingly, a slip was initiated in the weak plane following an elastic deformation. The step-by-step motion of the atoms on the slip plane was studied, and a detailed trajectory is presented. The slip then expanded to other planes, and plastic deformation progressed in the whole model. The weak plane was also set as (110) or (100) plane, where different deformation modes were observed: not only slip but also gradual distortion or brittle fracture occurred.

Strain Capacity of X70 Pipeline Steel Subjected to Biaxial Loading Condition

2015 ◽  
Author(s):  
Marcelo Paredes ◽  
Tomasz Wierzbicki
Keyword(s):  
Stress State ◽  
Loading Condition ◽  
Biaxial Loading ◽  
Pipeline Steel ◽  
Tensile Load ◽  
Complex Loading ◽  
Loading Mode ◽  
Coulomb Criterion ◽  
Growing Cracks

In this work the tensile capacity of circumferentially pressurized cracked pipes with varying crack parameters and pipe dimensions are numerically investigated. The biaxial loading mode includes internal pressure and tensile load, which are applied in sequence. The present physics-inspired fracture model based upon the original Mohr-Coulomb criterion enables not only the computation of global fracture response of pipe subjected to complex loading condition but also a thorough determination of the local evolving stress state around the growing cracks.

Dynamic Analysis of Surface Scanning for Tactile Perception

2010 ◽  
Author(s):  
Ramona Fagiani ◽  
Francesco Massi ◽  
Eric Chatelet ◽  
Yves Berthier
Keyword(s):  
Stress State ◽  
Dynamic Analysis ◽  
Bench Test ◽  
Human Hand ◽  
Global Dynamics ◽  
Clear Understanding ◽  
Frequency Range ◽  
Scanning Velocity ◽  
Vibration Spectra ◽  
The Brain

The human hand works in a perfect accord with the brain for an efficient exploration of physical world and objects perception according to man’s purposes. During the haptic sensing, the fingertip slides on a surface activating the receptors located under the skin allowing the brain to identify objects and information about their properties. In fact, in order to create the contact, the hand must exercise a force causing the fingertip to deform, generating a stress-state that contains the information on the object in contact. The information concerning the object surface is represented by the vibrations induced by the friction between the skin and the rubbed object in contact. The mechanoreceptors have the key role of transducing the stress state into an electrical impulse conveyed to the brain. Nevertheless, the vibration spectra induced by the finger/surface rubbing and the consequent activation of the mechanoreceptors on the skin were rarely investigated. A clear understanding of the mechanisms of the tactile sense is basilar for manifold applications, like the development of artificial tactile sensors for intelligent prostheses or robotic assistants, and for the ergonomics. In this context, it is fundamental to realize appropriate dynamic analysis of the signals that characterize the characteristics of the contact. In other words, it is necessary to investigate the vibration spectrum measured on the finger, in order to identify the frequency range of measured spectra (that should correspond to the expected one given by the mechanoreceptors activation frequency range [2–500 Hertz]). An experimental set-up is developed to recover the contact global dynamics by detecting the contact force and the induced vibrations; the bench test has been designed to guarantee the measurements reproducibility and, at cause of the low amplitude of the vibrations of interest, to perform measurements without introducing external noise. In particular, in this paper, the interest will be focused on the changes shown in vibration spectra with respect to variations of the scanning velocity and surface roughness characteristics.

scholarly journals Common Methods in Analysing the Tribological Properties of Brake Pads and Discs – A Review

2019 ◽  
Vol 13 (3) ◽  
pp. 189-199 ◽  
Author(s):  
Andrzej Borawski
Keyword(s):  
Tribological Properties ◽  
New Products ◽  
Dry Sliding ◽  
Passenger Cars ◽  
Friction Materials ◽  
Brake Pads ◽  
Safety Concerns ◽  
Operational Quality ◽  
Disc Brakes

Abstract Disc brakes in passenger cars are extremely important due to safety concerns. Their operational quality largely rests on the conditions of contact between the working elements, which mainly consists offlat and dry sliding. The tribological phenomena thatoccur during braking are, unfortunately, extremely complex and difficult to recreate in laboratory settings. Many scientific institutes conduct research to improve our understanding of these phenomena. The results they present make it possible to continuously simplify the procedures for selecting friction materials and reducing the costs of identifying the properties of new products. This article analyses the methods commonly used by researchers. It also presents different set-ups of research stations, as well as the advantages and drawbacks of each method.

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