scholarly journals INTEGRATED STATE VARIABLE OF PERSISTENT CONTACT JOINTS OF PARTS OF CUTTERS WITH BLOCK-MODULAR STRUCTURE

2020 ◽  
pp. 31-34
Author(s):  
A. Kravtsov
Keyword(s):  
Surface Layer ◽  
Surface Profile ◽  
Operating Mode ◽  
Normal Pressure ◽  
Relative Speed ◽  
Complex State ◽  
Saturation Phenomenon ◽  
State Variable ◽  
Elastoplastic Deformations ◽  
Operational Characteristics

The increase in the health of block cutters when achieving the operational characteristics of persistent contact joints of their elements is considered. The results of changes in the regulated parameters of the surface profile of the block housing using the saturation phenomenon are presented. The operational characteristics of block cutters change their values during operation, due to wear of frequently replaced parts (for example, 100 changes of cutting blocks correspond to the operating mode of contacting surfaces when normal pressure is applied at Pn = 10 MPa and relative speed of 10 m/min per 1 minute), as well as elastoplastic deformations of their elements. By these characteristics we mean the performance (rigidity of the structure, the flexibility of its parts, etc.) tools. Their change causes deviations of the specified properties of the surfaces of the parts of the cutters from the set values. Preset properties include the state of contact when irregularities in the profile of the deformable surface fill the depressions of the contacted surface. In order to minimize such deviations, it is necessary to achieve a state of the surface layer of contact pairs of elements so that these parameters stabilize (reach equilibrium values) during operation. For this, it is proposed to use the complex state variable of the surface layer for contact compounds with saturation.

Effect of Thermal Distortion on Wear of Composites

1995 ◽  
Vol 117 (4) ◽  
pp. 622-628 ◽  
Author(s):  
Shingo Obara ◽  
Takahisa Kato
Keyword(s):  
Elastic Deformation ◽  
Composite Structure ◽  
Frictional Heating ◽  
Tetragonal Zirconia ◽  
Surface Profile ◽  
Normal Pressure ◽  
Oxide Ceramic ◽  
Thermal Distortion ◽  
Test Results ◽  
Worn Surface

The worn surface profile of a composite structure was experimentally and numerically investigated focusing on the effects of sliding conditions. Wear tests on composites made of an oxide ceramic and an amorphous metal against a tetragonal zirconia polycrystals-alumina were carried out under various mean contact pressures, P, and sliding velocities, V. The test results showed that the worn surface profiles of the composites changed with the PV value. A new numerical method for simulating the worn surface profile of a composite structure has been developed. The present method is based upon the assumption that the profile of a worn surface is changed by thermal distortion of the sliding bodies due to frictional heating and by elastic deformation due to normal pressure and friction traction. The calculated results were compared with the test results, and the comparison showed that the elastic deformation plays an important role in forming the worn surface profile and that the effect of thermal distortion becomes remarkable with an increase in PV values. The numerical results clarified the contribution of the thermal distortion to the change in the worn surface profile of the composite.

Bearing profile of sliding tribological systems

2021 ◽  
pp. 53-56
Author(s):  
Keyword(s):  
Hydrodynamic Lubrication ◽  
Surface Profile ◽  
Experimental Methods ◽  
Hydrodynamic Characteristics ◽  
Bearing Surface ◽  
Tabular Data ◽  
Sliding Bearing ◽  
Friction Process ◽  
Operational Characteristics ◽  
Wide Range

The main contours of the bearing surfaces of friction pairs with hydrodynamic lubrication are considered. Analysis of tabular data and graphs obtained by experimental methods made it possible to establish additional parameters of influence on the hydrodynamic characteristics of the friction process and the operational characteristics of tribological systems, in a wide range of load-speed modes. Keywords: sliding bearing, hydrodynamics, bushing, bearing surface, profile, circle, ellipse, wavy contour, wear. [email protected]

scholarly journals Strain/Damage in Crystalline Materials Bombarded by MeV Ions: Recrystallization of GaAs by High-Dose Irradiation

1984 ◽  
Vol 35 ◽  
Author(s):  
C. R. Wie ◽  
T. Vreeland ◽  
T. A. Tombrello
Keyword(s):  
Surface Layer ◽  
Energy Loss ◽  
Ion Irradiation ◽  
Stopping Power ◽  
High Dose ◽  
Double Crystal ◽  
Saturation Phenomenon ◽  
Nuclear Stopping ◽  
X Ray ◽  
Dose Irradiation

ABSTRACTMeV ion irradiation effects on semiconductor crystals, GaAs(100) and Si (111) and on an insulating crystal CaF2 (111) have been studied by the x-ray rocking curve technique using a double crystal x-ray diffractometer. The results on GaAs are particularly interesting. The strain developed by ion irradiation in the surface layers of GaAs (100) saturates to a certain level after a high dose irradiation (typically 1015/cm2), resulting in a uniform lattice spacing about 0.4% larger than the original spacing of the lattice planes parallel to the surface. The layer of uniform strain corresponds in depth to the region where electronic energy loss is dominant over nuclear collision energy loss. The saturated strain level is the same for both p-type and n-type GaAs. In the early stages of irradiation, the strain induced in the surface is shown to be proportional to the nuclear stopping power at the surface and is independent of electronic stopping power. The strain saturation phenomenon in GaAs is discussed in terms of point defect saturation in the surface layer.An isochronal (15 min.) annealing was done on the Cr-doped GaAs at temperatures between 200° C and 700° C. The intensity in the diffraction peak from the surface strained layer jumps at 200° C < T ≤ 300° C. The strain decreases gradually with temperature, approaching zero at T ≤ 500° C.The strain saturation phenomenon does not occur in the irradiated Si. The strain induced in Si is generally very low (less than 0.06%) and is interpreted to be mostly in the layers adjacent to the maximum nuclear stopping region, with zero strain in the surface layer. The data on CaF2 have been analysed with a kinematical x-ray diffraction theory to get quantitative strain and damage depth profiles for several different doses.

Synchronization in complex dynamical networks coupled with complex chaotic system

2015 ◽  
Vol 26 (06) ◽  
pp. 1550060 ◽  
Author(s):  
Qiang Wei ◽  
Cheng-Jun Xie ◽  
Bo Wang
Keyword(s):  
Chaotic System ◽  
Scaling Function ◽  
Complex Function ◽  
Complex Dynamical Networks ◽  
Real Field ◽  
Complex State ◽  
Dynamical Networks ◽  
State Variable ◽  
System A ◽  
Complex Chaotic System

This paper investigates synchronization in complex dynamical networks with time delay and perturbation. The node of complex dynamical networks is composed of complex chaotic system. A complex feedback controller is designed to realize different component of complex state variable synchronize up to different scaling complex function when complex dynamical networks realize synchronization. The synchronization scaling function is changed from real field to complex field. Synchronization in complex dynamical networks with constant delay and time-varying coupling delay are investigated, respectively. Numerical simulations show the effectiveness of the proposed method.

scholarly journals Partial Control of a Continuous Bioreactor: Application to an Anaerobic System for Heavy Metal Removal

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
M. I. Neria-González ◽  
P. A. López-Pérez ◽  
R. Aguilar-López
Keyword(s):  
Heavy Metal ◽  
Metal Removal ◽  
Cadmium Concentration ◽  
Heavy Metal Removal ◽  
Operating Mode ◽  
Successful Implementation ◽  
Cadmium Removal ◽  
Partial Control ◽  
State Variable ◽  
Continuous Bioreactor

This work presents a control strategy for a continuous bioreactor for heavy metal removal. For this aim, regulation of the sulfate concentration, which is considered the measured and controlled state variable, allowed diminishing the cadmium concentration in the bioreactor, where the corresponding controller was designed via nonlinear bounded function. Furthermore, a nonlinear controllability analysis was done, which proved the closed-loop instability of the inner or uncontrolled dynamics of the bioreactor. A mathematical model, experimentally corroborated for cadmium removal, was employed as a benchmark for the proposed controller. Numerical experiments clearly illustrated the successful implementation of this methodology; therefore, cadmium removal amounted to more than 99%, when the initial cadmium concentration was up to 170 mg/L in continuous operating mode.

Experimental studies of the effect of electrochemical sizing on the contact fatigue of forming rolls

2021 ◽  
Vol 2021 (9) ◽  
pp. 8-10
Author(s):  
Alexander Boldyrev ◽  
Aleksandr Boldyrev ◽  
Vladimir Grigorash ◽  
Vladimir Suhorukov
Keyword(s):  
Surface Layer ◽  
Sample Preparation ◽  
Experimental Studies ◽  
Contact Fatigue ◽  
Comparative Tests ◽  
Operational Characteristics ◽  
Study Results

The study results of the influence of the surface layer of forming rolls on their operational characteristics are presented, the results of comparative tests for contact fatigue of samples machined by grinding and electrochemical sizing are presented, the sequence of sample preparation for experimental studies is considered, recommendations on the choice of final machining method are formulated.

An Overview on Control Algorithms for Automated Highway Systems

2001 ◽  
Vol 13 (4) ◽  
pp. 381-386
Author(s):  
Sadayuki Tsugawa ◽  
Keyword(s):  
Feedback Control ◽  
Vehicle Control ◽  
Control Algorithms ◽  
State Variables ◽  
Relative Speed ◽  
Automated Highway Systems ◽  
Vehicle Communication ◽  
State Variable ◽  
Preceding Vehicle ◽  
Automated Highway

This paper surveys lateral and longitudinal vehicle control algorithms in automated highway systems. In the lateral control, an onboard sensing system detects or captures a reference on a roadway indicating the path of an automated vehicle, and PID control and state variable feedback control based on the modern control theory with deviation from a planned path are mainly used to drive the vehicle along the path. In the longitudinal control, an inter-vehicle gap and relative speed to a preceding vehicle are measured, and feedback control with state variables including deviations in the gap, relative speed, and relative acceleration, some of which are obtained by the transmission over inter-vehicle communication rather the measurement, is used to maintain a predetermined gap in a platoon. Lateral and longitudinal vehicle control algorithms are explained with references to some systems developed since 1960's.

Surface morphology of wheels in rail vehicles in urban transport

2017 ◽  
Vol 1 (83) ◽  
pp. 12-20
Author(s):  
M. Paczkowska ◽  
Ł. Wojciechowski ◽  
A. Piasecki
Keyword(s):  
Plastic Deformation ◽  
Surface Layer ◽  
Surface Morphology ◽  
Contact Fatigue ◽  
Surface Profile ◽  
Urban Transport ◽  
Rolling Contact ◽  
Dominant Type ◽  
Rolling Surface ◽  
Electron Microscopes

Purpose: The general purpose of presented research was evaluation of surface morphology of chosen tram wheels: LUCCHINI (of Siemens Combino tram), PST (of Moderus Beta tram), and GT no 1 (of Duewag tram) operating in Poznan agglomeration. Design/methodology/approach: 3D surface profile study, macro and microscopic research with light and scanning electron microscopes, and Vickers hardness measurements were done. Findings: Wear effects were observed on the rolling surface, as well on the surface of the top of the wheel flange. Rolling contact fatigue was dominant type of wear. Abrasion was also noticed, especially on the top of the wheel flange. Changes in the surface layer were also noticed, like sever plastic deformation as: overhangs, flattened grains and delamination. Plastic deformation was the reason of hardness increase. Though the rolling surface is the surface responsible for the load transfer, more plastically deformed was the surface layer of the top of the wheel flange. Although investigated wheels was operated in different trams wear effects were similar. Research limitations/implications: The research represents part of a project considering identification of phenomena occurring in the contact zone between tram wheel and the rail funded by the National Centre for Research and Development of the LIDER program. Further research should concentrate on designing of the new wheel (new profile and modified material). Practical implications: On the base of performed research it also was possible to determine some suggestions in the order to extend tram wheel life. Originality/value: The surface morphology of tram wheels has been describe quantitatively on the base of 3D roughness parameters. Main type of wear that dominate in case of chosen tram wheels in Poznan agglomeration was identified. Main material changes in the surface layer were described in those wheels.

Cold Pressure Welding—The Mechanisms Governing Bonding

1979 ◽  
Vol 101 (2) ◽  
pp. 121-127 ◽  
Author(s):  
N. Bay
Keyword(s):  
Surface Layer ◽  
Bond Strength ◽  
Normal Pressure ◽  
Experimental Investigations ◽  
Virgin Material ◽  
Pressure Welding ◽  
Real Contact ◽  
Basic Parameters ◽  
Surface Expansion ◽  
Cold Pressure

Investigations of the bonding surface in scanning electron microscope after fracture confirm the mechanisms of bond formation in cold pressure welding to be: fracture of work-hardened surface layer, surface expansion increasing the area of virgin surface, extrusion of virgin material through cracks of the original surface layer, and establishment of real contact and bonding between virgin material. This implies that normal pressure as well as surface expansion are basic parameters governing the bond strength. Experimental investigations of pressure welding Al-Al under plane strain compression in a specially developed equipment allowing independent variation of normal pressure and surface expansion confirm this. Based upon a slip-line analysis of the extrusion through cracks of the surface layer and upon the establishment of real contact between virgin material, a theory for the bond strength as a function of surface expansion and normal pressure is developed. The theory is in good agreement with the experimental results.

scholarly journals HETEROGENEOUS HARDENING OF MACHINES PARTS BY SURFACE PLASTIC DEFORMATION

2019 ◽  
pp. 106-112
Author(s):  
А. Афонин ◽  
A. Afonin ◽  
Е. Мартынов ◽  
E. Martynov ◽  
А.В. Макаров ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Surface Layer ◽  
Fatigue Loading ◽  
Hardened Layer ◽  
Surface Plastic Deformation ◽  
Surface Plastic ◽  
Heterogeneous Structure ◽  
The Finite Element Method ◽  
Operational Characteristics ◽  
Machine Parts

The main causes of failure of heavily loaded threads are considered. The methods of increasing the efficiency of the equipment due to the method used are proposed. It is found that improving the operational characteristics of the components of mining and metallurgical machinery can be achieved forming heterogeneous-hardened surface layer. Methods of forming heterogeneous structure by surface plastic deformation (SPD are considered). The importance of identifying the nature of the influence of parameters of heterogeneous hardened layer on the performance of machine parts is indicated. Modeling of process heterogeneous hardening of SPD of the finite element method is executed. Recommendations about application of heterogeneous hardening of SPD for hardening the heavy-duty parts are offered. It is found that the use of different methods SPD allows widely vary the degree of depth and the uniformity of the hardening of machine parts. It is found that this increase in life responsible highly loaded parts operating under fatigue loading due to hardening of the heterogeneous surface layer may reach 1.5 times or more.

Sign in / Sign up

Export Citation Format

Share Document