Influence of stress state of brake disk on parameters of microgeometry of its surface that is out of contact area

2021 ◽  
pp. 35-39
Author(s):  
Yu. V. Krivosheya ◽  
◽  
D. S. Krivosheya ◽  
Keyword(s):  
Stress State ◽  
Contact Area ◽  
Surface Deformation ◽  
Disk Surface ◽  
Main Trend ◽  
Brake Disc ◽  
Brake Disk ◽  
Coverage Area ◽  
Tensile Stresses ◽  
Disc Surface

The paper shows results of the study dedicated to influence of contact area stress state on a trend of changes for roughness and waviness parameters of brake disc surface located on the periphery of contact with a brake pad in the coverage area of preferred compression and tensile stresses. It also displays that the main trend of surface deformation under the influence of growing mechanical compression stresses consists in increase of altitude and decrease of step parameters of roughness and waviness. The authors have established that in the coverage area of tensile stresses the roughness and the waviness of the brake disk surface returns to initial values determined in condition of absence of external power influence. On the basis of the results, the authors have explained the process of waviness appearance on the brake disc surface. Results of the study are recommended for the application at solving tasks on friction and wear.

Investigation of Friction Temperature in Railway Disc Brake

2012 ◽  
Vol 479-481 ◽  
pp. 202-206
Author(s):  
Wan Hua Nong ◽  
Fei Gao ◽  
Rong Fu ◽  
Xiao Ming Han
Keyword(s):  
Finite Element ◽  
Contact Pressure ◽  
Friction Pair ◽  
Brake Disc ◽  
Finite Element Software ◽  
Disc Surface ◽  
Friction Temperature ◽  
Steel Disc ◽  
Braking Force ◽  
Braking Process

The distribution of temperature on the rubbing surface is an important factor influencing the lifetime of a brake disc. With a copper-base sintered brake pad and a forge steel disc, up-to-brake experiments have been conducted on a full-scale test bench at a highest speed of 200 Km/h and a maximum braking force of 22.5 KN. The temperature distributions on brake disc surface have been acquired by an infrared thermal camera, and the contact pressure on the contact surface of the friction pair has been calculated by the finite element software ABAQUS. The results show that the area and thermal gradient of the hot bands increase with the increase of braking speed and braking force. The hot bands occur in priority at the radial location of r=200 mm and r=300 mm, and move radially in the braking process. The finite element modelling calculation indicates that the distribution of the contact pressure on the disc surface in radial direction is in a "U"-shape. The maximum contact pressure occur at the radial locations of r=200 mm and r=300 mm, and the minimum contact pressure occur in the vicinity of the mean radius of the disc. The conformity of contact pressure distributions with the practical temperature evolutions indicates that the non-uniform distribution of the contact pressure is the factor resulting in the appearance of hot bands on the disc surface.

A study of brake disc modal behaviour during squeal generation using high-speed electronic speckle pattern interferometry and near-field sound pressure measurements

2000 ◽  
Vol 214 (3) ◽  
pp. 285-296 ◽  
Author(s):  
M Reeves ◽  
N Taylor ◽  
C Edwards ◽  
D Williams ◽  
C. H. Buckberry
Keyword(s):  
High Speed ◽  
Sound Pressure ◽  
Surface Deformation ◽  
Speckle Pattern ◽  
Near Field ◽  
Electronic Speckle Pattern Interferometry ◽  
Brake Disc ◽  
Pressure Measurements ◽  
Near Field Sound ◽  
Field Sound

The out-of-plane surface vibration of a brake disc during naturally excited squeal has been investigated using a combination of high-speed electronic speckle pattern interferometry (ESPI) and near-field sound pressure measurements. Both techniques provide visualization and quantification of the time-resolved surface velocity. A mathematical description of disc brake squeal modal behaviour is proposed that predicts accurately all of the experimentally observed interferometry and sound field measurements. The complex mode description proposed here is in agreement with that proposed by others for drum brake squeal. This assumes that two identical diametral modes are excited simultaneously, identical except for a spatial and temporal phase shift. The use of a near-field microphone array provided a convenient multipoint, non-contacting vibration probe which may find use in the study of other vibrations characterized by high surface amplitudes and efficient sound radiation. The high-speed ESPI provided a real-time visualization of surface deformation analogous to double- pulsed holographic interferometry, with the benefit of giving a true time series of the surface deformation during a single vibration cycle.

The Effect of Higher Prestress on Concrete Railroad Tie Behavior

2015 ◽  
Author(s):  
N. D. Catella ◽  
R. A. Mayville
Keyword(s):  
Stress State ◽  
Prestressed Concrete ◽  
Three Dimensional ◽  
Negative Consequences ◽  
Premature Failure ◽  
Model Interaction ◽  
Tensile Stresses ◽  
Prestressing Force ◽  
Consistent Performance ◽  
Three Dimensional Finite Element

Prestressed concrete crossties are used extensively by North American railroads because they offer improved service life and consistent performance. Recent industry trends have encouraged manufacturers to effectively increase concrete ties’ prestressing force to improve their structural performance in flexure and shear. This paper presents the results of linear and nonlinear three-dimensional finite element analyses of typical concrete crossties to study the stress state of crossties at prestress transfer and to identify potential negative consequences of increasing effective prestressing force. The analyses utilize finite-sliding contact with Coulomb friction to model interaction between prestressing strands and adjacent concrete. Variation of several parameters that affect stress state at prestress transfer are considered, including magnitude of prestressing force, stiffness of concrete, crosstie geometry, and strand configuration. The analyses indicate that tensile stresses develop near the ends of the crossties at prestress transfer and their magnitudes increase with decreasing transfer length and increasing prestress force. These tensile stresses may account for widespread longitudinal cracking that has been observed in premature failure of concrete crossties in the last ten years.

Theoretical Model of Plastic Hysteresis in Spherical Contact Under Combined Normal and Tangential Loading

2008 ◽  
Author(s):  
Yuri Kligerman ◽  
Izhak Etsion
Keyword(s):  
Theoretical Model ◽  
Stress State ◽  
Friction Force ◽  
Contact Area ◽  
Contact Condition ◽  
Experimental Results ◽  
Tangential Displacement ◽  
Elastic Plastic ◽  
Plastic Sphere ◽  
Good Agreement

The behavior of an elastic-plastic contact between a deformable sphere and a rigid flat under combined constant normal and reciprocating tangential loading is investigated in the present work. The theoretical model is based on the assumptions of full stick contact condition and two kinds of the sphere material hardening. Hysteretic change of friction force versus tangential displacement during reciprocating tangential loading is investigated along with the study of the change of the contact area and stress state in the elastic-plastic sphere. Good agreement between theoretical and experimental results is obtained.

Rough Contact Between Elastically and Geometrically Identical Curved Bodies

1982 ◽  
Vol 49 (2) ◽  
pp. 345-352 ◽  
Author(s):  
M. D. Bryant ◽  
L. M. Keer
Keyword(s):  
Maximum Principle ◽  
Brittle Fracture ◽  
Contact Area ◽  
Yield Criterion ◽  
Failure Criteria ◽  
Tensile Stresses ◽  
Potential Failure ◽  
Elliptical Contact ◽  
Normal And Tangential Loads ◽  
Von Mises

Surface and subsurface stresses and displacements are obtained when two geometrically and elastically identical rough bodies are pressed together by normal and tangential loads. The theories of Cattaneo and Mindlin, who introduce zones of slip and stick within an elliptical contact area, are used. Von Mises yield criterion and maximum principle tensile stresses are used as failure criteria to assess potential failure due to shear or brittle fracture.

scholarly journals Computer simulation of railway wagon brake disc casting

2018 ◽  
Vol 235 ◽  
pp. 00026
Author(s):  
Peter Futáš ◽  
Alena Pribulová ◽  
Gabriel Fedorko ◽  
Vieroslav Molnár ◽  
Nikoleta Mikušová
Keyword(s):  
Solidification Process ◽  
Production Costs ◽  
Brake Disc ◽  
Brake Disk ◽  
Casting And Solidification ◽  
Railway Wagon ◽  
Cad System ◽  
Product Manufacturing ◽  
Made In

CAD systems serving as the model for real industrial processes are almost an inseparable part of manufacturing in many industry branches. The use of simulation programs in the foundry industry is perceived as a tool for the visualization of the processes involved in the production of castings. They are also used to resolve possible issues and imperfections before the production begins. Consequently, it enhances the quality and reduces product-manufacturing-related financial costs. The paper tackles the issue of how to resolve the occurrence of defects – shrinkages in the railway wagon disc casting while using a simulation program. The 3D model of the casting and of the system of gates was constructed in the CATIA CAD system. The mere simulation of the casting and solidification process was done in the NovaFlow&Solid program. After evaluating the results of the simulation, the correction of the casting and gates was made in order at once to enhance the quality of the casting and reduce the production costs in the manufacturing of this casting. In the production of the brake disk casting, the main issues are little usage of molten metal during casting and the considerable occurrence of shrinkages, which causes the increased economic costs of its production.

Thermal Analysis of Two Wheeler Brake Disc Using ANSYS

2015 ◽  
Vol 787 ◽  
pp. 301-305
Author(s):  
V. Ganesh ◽  
T. Abinaya
Keyword(s):  
Thermal Analysis ◽  
Stainless Steel ◽  
Computer Software ◽  
Frictional Resistance ◽  
Brake Disc ◽  
Conventional System ◽  
Disc Surface ◽  
Braking Force ◽  
Transient Thermal ◽  
Two Wheeler

This paper deals with the transient thermal analysis of brake disc of Variable Braking Force (VBF) system using computer software ANSYS. Generally, brake system is designed to apply frictional resistance to stop the vehicle. In VBF system the frictional resistance applied to the brake disc can be varied by changing the effective disc radius based on the pillion load. The rotor disc is commonly manufactured using cast iron (CI) or stainless steel (SS). In this work, these materials are taken for analysing the temperature distribution of VBF system. In addition to, an effort has been made here to suggest the best suited material for brake disc. By the way, it is evident that the rise in disc surface temperature is higher for VBF system compared with conventional system (constant effective disc radius (r) = 110mm).

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