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1

Methods of hydrodynamic calculation oil pipeline sequential transportation of small batches of various oil

Serediuk M.D.

Archives of Materials Science and Engineering

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2022

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Vol. 117, nr 1

25--33

EN

Purpose: To improve the technologies of different oil types of sequential pumping through the pipeline by establishing the laws of changing the throughput and energy efficiency of the oil pipeline operator in the process of pumping and displacing oil batches. The identified regularities would contribute to more effective management of the mixture realisation process at the end of the oil pipeline and reliable forecasting of the results of the different oil types of mixture formation. Design/methodology/approach: Carrying out theoretical studies and applying mathematical modelling methods in order to establish the regularities of hy-drodynamic processes during the injection into the oil pipeline and the displacement of oil different grades from it. Findings: The regularities of changes in oil pipeline capacity and specific electricity costs for transportation as a function of the coordinates of different oil types of batches contacts and the time of sequential pumping cycle implementation they have been established. Research limitations/implications: The next stage of the research is to establish the influence of the hydrodynamic processes features on the intensity of the oil different grades mixture formation in the process of their successive pumping in the oil pipeline. Practical implications: A method and software have been developed that make it possible to predict the throughput and energy efficiency of oil pipeline operation for each moment of the sequential pumping cycle of small batches of different grade oil. The application of the method for the conditions of an operating oil pipeline proved that during the cycle of four types of sequential oil pumping, the change in throughput exceeds 20%, and the change in energy consumption exceeds 10%. Originality/value: The originality of the method consists in taking into account the regularities of the hydrodynamic process of the movement of several batches of oil of different grades in the pipeline, the features of the profile of the pipeline route and the physical properties of the liquid that fills the cavity of the pumps.

2

Failure characteristics and strength model of composite rock samples in contact zone under compression

Wang Qihu, Wang Jie, Ye Yicheng, Jiang Wei, Yao Nan

Archives of Mining Sciences

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2020

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Vol. 65, no. 2

347--361

EN

Significant differences in the physical and mechanical properties exist between the rock masses on two sides of an ore-rock contact zone, which the production tunnels of an underground mine must pass through. Compared with a single rock mass, the mechanical behavior of the contact zone composite rock comprising two types of rock is more complex. In order to predict the overall strength of the composite rock with different contact angles, iron ore-marble composite rock sample uniaxial compression tests were conducted. The results showed that composite rock samples with different contact angles failed in two different modes under compression. The strengths of the composite rock samples were lower than those of both the pure iron ore samples and pure marble samples, and were also related to the contact angle. According to the stress-strain relationship of the contact surface in the composite rock sample, there were constraint stresses on the contact surface between the two types of rock medium in the composite rock samples. This stress state could reveal the effect of the constraint stress in the composite rock samples with different contact angles on their strengths. Based on the Mohr-Coulomb criterion, a strength model of the composite rock considering the constraint stress on the contact surface was constructed, which could provide a theoretical basis for stability researches and designs of contact zone tunnels.

3

Damage risk of the raceway edge arise in four-point slewing bearing

Krynke Marek, Mielczarek Krzysztof

System Safety : Human - Technical Facility - Environment

|

2019

|

Vol. 1, nr 1

632--638

EN

In the article some forms of damage to raceway of slewing bearings for single-row ball bearing slewing ring with four-point contact and their causes were shown. Changes of the contact angle and its influence on the geometry for contact zone of the rolling elements raceway were analyzed. An identification of changes for contact angle of individual balls for different parameters of the contact was received. It was showed that contact angles of some rolling elements were increasing. It can cause damage to the raceway by spalling or rolling out of edge of the bearing ring. Ways of avoiding too early damage to the raceway at the stage of the design and the selection of coronary bearings were suggested.

4

The Opoka-Rock from the Mesozoic/Neogene Contact Zone in the Bełchatów Lignite Deposit – Characteristics of a Petrographic Nature and as a Raw Material

Pękala Agnieszka

Journal of Ecological Engineering

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2019

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Vol. 20, nr 8

232--237

EN

During the exploitation of the Bełchatów lignite deposit at the point of contact between the Mesozoic substrate and Neogene deposits, the rocks of different petrographic composition were found. The group of rocks with transitional features between carbonate and silica rocks were called opoka-rock. This article presents the current state of knowledge on the geological conditions pertaining to the occurrence of the Bełchatów opoka-rock, and on its petrographic and chemical characteristics. An analysis was also carried out to determine the physical, mechanical as well as raw-material properties, as well as the related issue of potential utilisation.

5

Porównanie sekwencji deformacji fałdowych w północnej i południowej okrywie granitoidów Karkonoszy

Gaidzik K., Żaba J.

Przegląd Geologiczny

|

2017

|

Vol. 65, nr 12

1548--1554

EN

We applied the detailed structural analysis to 394 outcrops in the southern and northern metamorphic cover of the Karkonosze Intrusion. We recognised five generations of fold structures: F1 -poorly preserved tight intrafoliation folds; F2 - the most common generation, with the whole variety of fold geometries, W-E and WSW-ENE-oriented fold axes in the northern contact zone, and W-E and WNW-ESE-oriented fold axes in the southern contact zone; F3 - chevron folds; F4 - kinkfolds observed only in the Stara Kamienica schist belt; and F5 - wide open folds, locally transformed into monoclinal kinkfolds, probably formed during the Variscan intrusion of the Karkonosze pluton. Similarity observed in the structural style in the northern and southern contact zones prove that these lithostratigraphic units had formed a single unit - the Izera-Kowary Unit - and had undergone the same deformational stages before the Karkonosze granitoid intrusion took place.

6

Strength Analysis of the Drive Unit of the Wheeled Mobile Platform Including the Contact Phenomena

Jaskot A., Posiadała B., Śpiewak S.

Machine Dynamics Research

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2017

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Vol. 41, No. 1

163--174

EN

Original structure of the powertrain, between the electric drive motor and the drive wheel, has been described in this work. The platform is designed in order to provide the analysis of dynamic interactions and their impact on motion which will be a base in defining the control settings of drive units of the powertrain and the steering system. Solution of the powertrain shown in the work provides the ability to uncouple selected drive units and to study motion trajectory in follower motion when the stub axles are immobilized. In this work the contact conditions between the ground and the tread with the simulation of the torque generated by centrifugal forces has been presented. The consequence of the adopted solution is a specific distribution of contact pressures in the contact zone between the tread and the ground and is included in the paper. In the article the FEM model used in the analysis has been introduced. The results obtained from the performed research contained in this publication will be used in developing analytical models with simulation studies about the four-wheeled mobile platform motion with taking into account the friction and slippage.

7

Effect of Manner of Coupling Powertrain of Prototype Mobile Platform on Conditions of Rolling Friction Between Drive Wheel and Ground

Jaskot A., Posiadała B., Śpiewak S.

Machine Dynamics Research

|

2017

|

Vol. 41, No. 4

111--120

EN

The research subject is an author’s design solution of a wheel transporter. Original structure of a powertrain, between an electric drive motor and a drive wheel, has been described in this work. A design solution of the powertrain shown in the work provides the ability to uncouple selected drive units and study of a motion trajectory in follower motion when the stub axles are immobilized. The consequence of the adopted solution is a specific distribution of contact pressures in a contact zone between the drive wheel and the ground, which is dependent both on a load of the platform, but primarily on whether a wheel is coupled to the drive unit and will be the follower system. This effect appropriately reflects both a resistance of the rotational motion of the drive wheel and the resistances associated with positioning of a steering system of the platform. The article describes the FEM model used in the analysis. Results obtained from performed research, contained in this publication will be used in developing analytical models with simulation studies about the four-wheeled mobile platform motion with taking into account a friction and a slippage.

8

Wpływ kierunku działania sił promieniowych na przebieg charakterystyk nośności statycznej łożyska wieńcowego jednorzędowego

Śpiewak S.

Przegląd Mechaniczny

|

2016

|

nr 3

26--33

PL

Artykuł dotyczy problematyki katalogowego doboru łożysk tocznych wieńcowych obciążonych siłami promieniowymi o dużych wartościach. W pracy zaprezentowano metodykę modelowania łożysk wieńcowych. Obiektem analizy było łożysko wieńcowe jednorzędowe, produkcji krajowej, które jest zastosowane w koparce jednoczerpakowej F250H. W artykule przedstawiono charakterystyki nośności statycznej badanego łożyska zależne od kierunku działania obciążeń promieniowych względem wektora momentu wywrotnego, co w dotychczasowych pracach nie było rozważane. Dodatkowo do oceny własności użytkowych bieżni łożyska zaproponowano wykorzystanie metod statystycznych. Parametry rozpatrywanego łożyska oraz wartości uzyskanych wielkości statystycznych zestawiono w tabelach. Całość badań prezentowana w publikacji obejmuje wykorzystanie metody elementów skończonych, równań opisujących mechanikę kontaktu układu kulka-bieżnia oraz elementy statystyki do rozwiązywania problematyki łożyskowań.

EN

Article concerns the problems related to catalog selection of rolling bearings which are loaded large radial forces. A methodology for modeling of slewing bearing was presented. The object of the analysis was the one row ball slewing bearing, domestic production, which is used in excavator type F250H. The static carrying load curvatures of the slewing bearing which are depend on direction acting the radial loads relative to the vector of tilting moment were shown, what in previous works wasn't considered, Additionally to evaluation of functional properties of the bearing raceway the statistics methods were used, The parameters of the considering bearing and the values obtained of statistic quantity have been contained in the tables. The whole study that are presented in the publication involves the use of finite element method, the equations of contact mechanics for ball-race way and statistic method to solving the bearing problems.

9

The modification of the raceway profile in the double row slewing bearing

Kania L., Śpiewak S., Pytlarz R.

Journal of KONES

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2016

|

Vol. 23, No. 1

139--146

EN

The slewing bearings are applied in heavy working machines and operated in extreme conditions. A characteristic feature of these bearings are a high load which determining a large deflection of a contact zone rolling element - raceway. This phenomenon combined with the effects of a bearing clearance causes a significant increase in a contact angle of the bearing. This in turn causes displacement of the contact zone to an undesirable position. In the construction of slewing bearing is applied of a large value of the osculation ratio. This leads to occur of large sizes of the contact zone identified in a radial cross-section. The sizes are comparable to values of the radius of the ball. The contact zone is type of quasi-linear. Effects of changes the position of the contact zone in the double-row ball slewing bearing has been presented in the paper. The raceway profile for such bearing consists of the arc section changing in the radial section. When the contact zone includes a change point of curvature of the raceway profile it comes to a concentration of a contact stress, and this is unfavourable for operation of the bearing. In order to eliminate this phenomenon to the profile introduced a transition curve. For this purpose was selected a clothoid. The curve ensures a gradual change of curvature from the arc section of the profile to the zero curvature of the straight profile section. The raceway profile becomes the smooth curve of the second rank. In the article are presented a numerical model of the contact zone for the double-row ball slewing bearing and the distributions of a pressure in the contact zone for the ordinary and modified raceway profiles. The calculation results have been presented as graphs of the distributions of the pressure along the contact zone. It has been shown that the introduction modification of the raceway profile eliminates the concentration of the pressure along the contact zone profile. The results obtained can be used during design of the raceway profiles of the double-row ball slewing bearing.

10

Ciśnienie i docisk oraz szerokość strefy kontaktu między cylindrami i wałkami w drukującej maszynie offsetowej – przegląd literatury

Jurkiewicz A., Pyr'yev Y.

Acta Poligraphica

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2016

|

Vol. 8

9--27

EN

The printing literature provides different values of pressure between cylinders in the printing unit and between rollers in the ink unit of the offset printing machine. Very often there is no information on whether a given value of pressure is maximum or average. Another frequent problem referred to in the printing literature is that authors do not reveal the source of theorems, equations or other important information. This article includes a set of values collected for pressure, line pressure, press clamping and the contact zone width that have been presented by other authors in their specific articles and books. It also includes definitions of pressure, line pressure, press clamping, indentation of blanket and metric clamping. In addition, the article briefly presents findings of the experimental research related to the contact zone between cylinders and rollers was carried out in the printing unit and in the ink unit until present. This article also gives publication references which provide for different equations concerned with the clamping force of cylinders, their compression or indentation, the contact zone width and the impact the specific stress-strain has on blankets.

11

Influence of Radial Forces Positively, Negatively and Perpendiculary Directed on the Static Carrying Capacity of the one Row Ball Slewing Bearing

Jaskot A., Śpiewak B., Śpiewak S.

Machine Dynamics Research

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2015

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Vol. 39, No. 3

33-47

EN

Problems of determining the static limiting load curves of slewing bearings where were taken into account all possible directions of radial forces have been presented in the paper. The object of the analysis was the one row ball slewing bearing, domestic production, which is used in excavator type F250H. In order to carry out the evaluation of functional properties of the bearing raceway the statistics methods were used. The parameters of the considering bearing and the values obtained of statistic quantity have been contained in the tables. Calculations were performed by using the finite elements method (FEM), ADINA program, analytical Eschmann's formulas and classical mechanics equations.

12

Influence of Radial Forces on Change of Friction Torque in Twin Slewing Bearing

Kania L., Śpiewak S.

Machine Dynamics Research

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2014

|

Vol. 38, No. 2

121-131

EN

A method of numerical conduct research of phenomena which occur in slewing bearing has been presented in the paper. The basic problems concerning technical peculiarity of slewing bearing were defined. The object of the analysis was twin slewing bearing for which a model of contact zone ball-raceway was developed. Results of calculations which are presented in the paper were obtained by using a model of twin slewing bearing described in a separate publication. Nascent conditions of rolling resistance in slewing bearing were specified. The paper presents importance of radial forces as a component of the external load of slewing bearing. The results of numerical analysis of changing friction torque of twin slewing bearing caused by external load were submitted. In especially action of radial forces on the slewing bearing has been taken into account. The values of fraction torque were shown on the background of static limiting load curve for the slewing bearing which was considered. The original numeric method was used to determine the fraction torque for slewing bearing. Calculations were performed by using the finite element method, ADINA program, analytical Eschmann formulas and classical mechanics equations.

13

Wyznaczanie oporów ruchu łożyska tocznego wieńcowego w oparciu o rozkład obciążenia wewnętrznego

Kania L., Śpiewak S.

Tribologia

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2013

|

nr 1

59--68

PL

W artykule zaprezentowano oryginalną metodę wyznaczania momentu tarcia w łożyskach wieńcowych. Do analizy przedstawionych problemów wykorzystano metodę elementów skończonych i analityczny model tarcia tocznego. Obliczenia potrzebne do wyznaczenia rozkładu obciążenia wewnętrznego w łożysku i maksymalnej wartości siły obciążającej elementy toczne łożyska były przeprowadzone za pomocą procedur wykorzystujących system ADINA L. 8, 9]. Zamieszczono autorski model pozwalający na wyznaczanie współczynnika tarcia tocznego dla układu kulka–bieżnia łożyska. Przyjęte modele uwzględniają uwarunkowania techniczne przekazywania obciążenia zewnętrznego na elementy składowe łożysk wieńcowych podwójnych. Wyznaczono charakterystyki momentu tarcia, które zaprezentowano na tle charakterystyk nośności statycznej, odpowiadających zadanej wartości luzu łożyskowego.

EN

The original method to determine the friction torque for twin slewing bearings is presented in the article. The finite element method and analytic model of rolling friction has been used for the analysis of presented problems. The calculation to determine the maximum contact force on the rolling element was done using a ADINA program 8, 9]. The copyrighted model that made it possible to determine the various friction coefficients for contact zone ball–bearing race in slewing bearings is attached. Accepted models allow the estimation of the technical conditions of acting external load on component parts of twin slewing bearings. The profile of the carrying capacity and friction torque of twin slewing bearing for a constant value of bearing clearance is presented.

14

Porównanie wybranych parametrów łożysk wieńcowych podwójnych i łożysk wieńcowych jednorzędowych

Kania L., Śpiewak S.

Przegląd Mechaniczny

|

2013

|

nr 1

27--33

PL

W artykule porównano wybrane parametry łożysk wieńcowych podwójnych i jednorzędowych. W analizie uwzględniono wpływ luzu osiowego na zmianę charakterystyk nośności statycznej obu typów analizowanych łożysk. Przedstawiono wykresy momentu tarcia łożysk w odniesieniu do ich nośności statycznej. Do analizy przedstawionych problemów wykorzystano metodę elementów skończonych i analityczny model tarcia tocznego. Zamieszczono wykresy rozkładów obciążenia wewnętrznego w analizowanych łożyskach.

EN

The chosen selected parameters of twin slewing bearings and slewing bearing single-row ball have been presented in the article. The effect of bearing clearance on change of static carrying capacity of both analyzed types has been considered. Diagrams of carrying capacity and friction torque have been created. The finite element method and analytic model of rolling friction has been used to the analysis of presented problems. The diagrams of distribution the internal load in analyzed beadings has been presented.

15

Wpływ luzu łożyskowego na nośność statyczną łożysk tocznych wieńcowych podwójnych w odniesieniu do oporów toczenia

Kania L., Śpiewak S.

Pomiary Automatyka Kontrola

|

2012

|

R. 58, nr 1

119-122

PL

W artykule przedstawiono analizę wpływu luzu łożyskowego na przebieg charakterystyki nośności statycznej łożyska wieńcowego podwójnego. Wyznaczono w oryginalny sposób charakterystyki momentu tarcia, które zaprezentowano na tle charakterystyk nośności statycznej, odpowiadających wybranym wartościom luzu łożyskowego. Uzyskane wyniki przedstawiono w formie graficznej. Przeprowadzone analizy wykonano z użyciem metody elementów skończonych.

EN

The effect of selected bearing clearances in twin slewing bearing on their static carrying capacity is presented in the paper. Basic parameters of analyzed bearing are presented in the Tab. 1. The finite element method and analytic model of rolling friction has been used to the analysis of presented problems. Obtained results of profile static carrying for selected values of bearing clearance are presented as graph (Fig. 5). It is claimed to be a possibility to single out the range of bearing clearance which optimal profile of static limiting load curves is obtained. The way of determining (modeling) the effect of bearing clearance on the static carrying capacity of twin slewing is based on works [1, 5] and it is introduced in chapter 2. The original method to determining the friction torque for twin slewing bearings is presented (chapter 3) in the article. The calculation which is needed to calculate the maximum contact force on the rolling element has been done using the ADINA program [2, 7]. Profile of carrying capacity and friction torque of twin slewing bearing for selected values of bearing clearances have been presented (Fig. 6). It was thought that the permissible tension force for the fixing bolts should be predicted to the selection of construc-tional bearing clearances. The proposed method of determining of friction torque can be used to the selection of engine power which drive has been transmitted with using slewing bearing. The method presented in the article can be used to the analysis of twin- and other kinds of slewing bearings.

16

Wpływ wybranych parametrów konstrukcyjnych na nośność statyczną łożysk tocznych wieńcowych podwójnych

Kania L., Śpiewak S.

Pomiary Automatyka Kontrola

|

2010

|

R. 56, nr 8

930-933

PL

W artykule przedstawiono analizę wpływu luzu między-pierścieniowego i kształtu zakończenia bieżni łożyska wieńcowego podwójnego na jego nośność statyczną. Wykorzystano modelowanie numeryczne za pomocą metody elementów skończonych. Uzyskano oryginalne wyniki, które zaprezentowano w formie graficznej. Określono pewne wytyczne odnośnie luzu między pierścieniowego i kształtu zakończenia bieżni łożyska wieńcowego podwójnego, które mogą być wykorzystane w projektowanych strukturach łożysk wieńcowych podwójnych a także innych typów łożysk wieńcowych.

EN

The effect of selected constructional parameters of twin slewing bearings on their static carrying capacity is presented in the paper. The radial gap between internal and external bearing rings and shape of bearing race profile is analyzed. To the analysis of the problem, the finite element method has been used. The bearing balls are modeled with superelements [7]. Computation was realized in two stages. In the first computation stage the models of contact zone ball - bearing race in elastic-plastic state of material have been developed. The meshing zones of balls and segments of bearing rings are presented in Fig. 1. The method presented in work [8] has been used. In particular models, values of radial gap between bearing rings and shape of edge of bearing race have been changed as in the Tab. 2. To obtain equivalent characteristics of ball - bearing race system, the iteration computations have been used. These characteristics have been used to specify characteristics of elastic truss elements which are being used in superelements. In the second computation stage, the characteristics of the carrying capacity of slewing bearing have been computed. The numerical model of twin slewing bearing presented in Fig. 3 has been used. Exemplary computations have been made for the twin slewing bearing SL023.50.2000 produced by Wuxi Lida Gear Manufacturing Co. (China). Parameters of analyzed bearing are presented in Tab. 1. The results of computation are presented in graphical form in Fig. 4 and Fig. 7. The effect of radial gap between bearing rings on equivalent characteristic of contact zone and on characteristic of bearing carrying capacity has been proved, recommended values of radial gap have been given. The method presented in the article can be used to the analysis of twin- and other kinds of slewing bearings.

17

Technologiczne podstawy montażu połączeń wciskanych termicznie z wykorzystaniem regularnego mikroreliefa w strefie kontaktu

Oborski I.

Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika

|

2009

|

z. 76 [261]

229-234

EN

The ways of the technological maintenance of the high-quality joint assembly with tightness by the thermal methods are suggested, and the analytical dependences for defining of the separate efficient process variables to ensure the decrease of energy and time (temporary) during the combined thermal method of assembly are also given.

18

Wyznaczanie charakterystyk zastępczych kulek w numerycznym modelowaniu łożysk tocznych wieńcowych

Kania L., Śpiewak S.

Pomiary Automatyka Kontrola

|

2009

|

R. 55, nr 6

334-337

PL

Charakterystyki zastępcze części tocznych umożliwiają ich modelowanie za pomocą elementów prętowych w modelach numerycznych łożysk wieńcowych wykonanych przy użyciu metody elementów skończonych. W pracy omówiono sposób wyznaczania charakterystyki zastępczej kulek w łożysku wieńcowym kulkowym jednorzędowym. Wykorzystano w tym celu model strefy styku kulki z bieżnią łożyska oraz segment modelu numerycznego pierścienia łożyska z tzw. superelementem. Przedstawiono założenia budowy modelu i przykładowe wyniki obliczeń numerycznych. Obliczenia wykonano przy założeniu sprężysto-plastycznego stanu materiału z uwzględnieniem tarcia na powierzchniach styku.

EN

Equivalent characteristics of rolling elements enable their modelling with help of truss elements in finite element method based numerical models of slewing bearings [2, 3, 4]. A new method for determination of equivalent characteristics of balls in a single-row ball slewing bearing (Fig. 1) is presented in the paper. At the first stage of calculations the numerical model of the ball contact zone with the bearing raceway was developed (Fig. 2). The model is divided into sections. In the 2 and 3 contact sections There was used a material in elastic-plastic state with bilinear characteristic (Fig. 3) in 2 and 3 contact sections, while in 1 and 4 sections - an elastic one. At the second stage the numerical model of a bearing ring segment (Fig 4.) with a super-element (Fig. 5) was developed. The super-element consists of two pairs of rigid beam elements (2) and an elastic truss element (1) with nonlinear characteristic ??-?. The model was loaded with a force calculated by formula (2) with the material hardness coefficient according to [9]. Numerical calculations were carried out with ADINA software [7]. Table 1 and Fig. 6. present the equivalent characteristic of the ball. The calculations results were approximated by power function (4). The new method for calculation of the bearing ball equivalent characteristic allows for accurate simulation of the bearing contact zone. It can be applied to all types of ball slewing bearings. Accurate estimation of the ball equivalent characteristic will have positive influence on accuracy of calculating the bearing capacity.

19

The numerical determination of contact zone tool and work-pieces in burnishing rolling process

Patyk R., Patyk S., Kukiełka L.

Computer Methods in Materials Science

|

2009

|

Vol. 9, No. 1

61-65

EN

This work concerns burnishing rolling the shafts with elastic pressing of burnishing elements. One of the most important problems during designing this process is calculate value of technological parameters: principal force of burnishing (F3), feed (fn) and velocity (vn). The principal force of burnishing was calculated by integration the elementary contact pressure over contact zone. It possible to determinate as product of means contact pressures and contact zone. It requires to determinate the both distributions it contact pressures and calculate of mean value and contact zone. The unacquaintance of the contact zone or contact pressures distributions leads to incorrect calculations of principal burnishing force and this can bring to destruction of work-pieces surface layer. In the thermodynamics opinion of continuum medium the burnishing process is triple (geometrical, physical and thermal) non-linear boundary and initial condition problem, with unknown boundary conditions in contact zone of the tool and work-pieces. The basic problem is a knew the mechanism of material plastic deformation and definition of displacement states, strains and stresses that occur in surface layer of processing work-pieces in the force or depth function in burnishing process. These states have significant influence on course of phenomena occurring in the burnishing rolling process, that are deciding on properties of formed work-pieces surface layer. In this work was shown the numerical way of contact zone determinate between burnishing elements and workpieces. In cases, where were analyzed the roughness of surface after previous processing was considered. The modeling was conducted with use of updated Lagrange\'a description and Finite Elements Method. The tool was modeling as rigid, however object as elasto ? visco/plastic (E/VP) body. In aim to variational formulation of the contact problem for this bodies the variational functional, was selected in, are exist one independent field, namely the displacements increment field. Moreover, satisfy that compatibility equations and initial and boundary conditions were fulfilled, was accepted. Such foundations lead to obtain up to the pattern, formulated in displacements increments, model problem for geometrical and physical non-linear dynamics. The movement equations solution was execute with explicit method, in with applauded the differential approximation of displacement partial derivatives. Worked out mathematical models of process were applied was in the author's application in programme Ansys/Ls - Dyna which makes possible the contact automatic detection and calculation the contact zone, and also they calculations the states of deformation and stresses for different material models with regard the influence of elastic strain, friction, strain rate and temperature. The results of simulation are basis to technological operation designing the burnishing rolling. The exemplary results of the contact zone calculations were presented.

PL

Praca dotyczy nagniatania tocznego wałków z elastycznym dociskiem elementów nagniatających. Jednym z najważniejszych problemów w projektowaniu procesu jest obliczenie wartości parametrów technologicznych takich jak główna siła nagniatania, posuw i prędkość. Główną siłę nagniatania oblicza się całkując jednostkowe siły nacisku po obszarze styku. Można tą siłę również wyznaczyć jako iloczyn średnich nacisków jednostkowych i pola styku. Wymaga to określenia zarówno rozkładu nacisków jak i obliczenia wartości średniej oraz pola styku. Nieznajomość jednej z tych wielkości prowadzi do nieprawidłowego obliczania siły nagniatania, a poprzez to przy praktycznym zastosowaniu modelu może doprowadzić do zniszczenia warstwy wierzchniej wyrobu. W pracy przedstawiono sposób numerycznego określania pola styku elementu nagniatającego z przedmiotem obrabianym. Analizowano przypadki, dla których uwzględniono chropowatość powierzchni po obróbkach poprzedzających.

20

Modelowanie korekcji cięciwowo-łukowej w wałeczkach łożysk tocznych wieńcowych

Kania L.

Pomiary Automatyka Kontrola

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2008

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R. 54, nr 7

417-420

PL

W pracy przedstawiono analizę korekcji cięciwowo-łukowej stosowanej w wałeczkach łożysk tocznych wieńcowych. Analizę przeprowadzono wykorzystując metodę elementów skończonych. Przedstawiono model obliczeniowy strefy styku. Wykonano obliczenia rozkładu nacisków wzdłuż tworzącej wałeczka dla różnych wartości parametrów analizowanej korekcji w sprężystym i sprężysto-plastycznym stanie materiałów bieżni i wałeczka. Przedstawiona metoda pozwala na dobór poprawnych parametrów korekcji dla specyfiki łożysk wieńcowych.

EN

In the paper the analysis of cylindrical crowned correction applied for rollers in slewing bearings has been presented. The analysis has been executed with the help a finite element method. Numerical model of contact zone has been presented. Computations of the normal traction across the contact line of the roller with bearing race for different correction parameters at elastic and elastic-plastic state of materials of rollers and bearing rings has been performed. Analysis method presented in paper allows for selection of correct parameters of rollers correction for specific to slewing bearings.