Size effect in contact fatigue

The results of special experiments on the size effect in contact fatigue are presented. It is established that under constant contact loading conditions the durability is higher, the larger is the diameter of a tested element. The methods for estimation of contact fatigue resistance of gear wheels,...

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Published in:Проблемы прочности
Date:2009
Main Authors: Sosnovskii, L.A., Zhmailik, V.A., Komissarov, V.V.
Format: Article
Language:English
Published: Інститут проблем міцності ім. Г.С. Писаренко НАН України 2009
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Online Access:https://nasplib.isofts.kiev.ua/handle/123456789/48468
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Cite this:Size effect in contact fatigue / L.A. Sosnovskii, V.A. Zhmailik, V.V. Komissarov // Проблемы прочности. — 2009. — № 1. — С. 113-120. — Бібліогр.: 22 назв. — англ.

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Digital Library of Periodicals of National Academy of Sciences of Ukraine
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author Sosnovskii, L.A.
Zhmailik, V.A.
Komissarov, V.V.
author_facet Sosnovskii, L.A.
Zhmailik, V.A.
Komissarov, V.V.
citation_txt Size effect in contact fatigue / L.A. Sosnovskii, V.A. Zhmailik, V.V. Komissarov // Проблемы прочности. — 2009. — № 1. — С. 113-120. — Бібліогр.: 22 назв. — англ.
collection DSpace DC
container_title Проблемы прочности
description The results of special experiments on the size effect in contact fatigue are presented. It is established that under constant contact loading conditions the durability is higher, the larger is the diameter of a tested element. The methods for estimation of contact fatigue resistance of gear wheels, which is based on the statistical model for a deformable solid body having a critical volume, are proposed. The limiting stresses of a gear wheel are estimated using a regulated base for this machine parts. Представлены экспериментальные результа­ты по исследованию масштабного эффекта при контактной усталости. Установлено, что при постоянной контактной нагрузке долго­вечность испытываемого конструкционного элемента цилиндрической формы тем выше, чем больше его диаметр. Предложены мето­ды оценки сопротивления контактной уста­лости зубчатых колес, основанные на исполь­зовании статистической модели критичес­кого объема деформируемого твердого тела. Предельные значения напряжений для натур­ных элементов оцениваются с использова­нием расчетных нормативов, разработанных специально для зубчатых колес.
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fulltext UDC 539.4 Size Effect in Contact Fatigue L. A. Sosnovskii,a V. A. Z hm ailik ,b and V. V. K om issarovc a Scientific and Production Group “Tribofatigue Ltd.,” Gomel, Belarus b Production Group “Gomselmash,” Gomel, Belarus c Belarusian State University of Transport, Gomel, Belarus The results o f special experiments on the size effect in contact fatigue are presented. It is established that under constant contact loading conditions the durability is higher, the larger is the diameter o f a tested element. The methods fo r estimation o f contact fatigue resistance o f gear wheels, which is based on the statistical model fo r a deformable solid body having a critical volume, are proposed. The limiting stresses o f a gear wheel are estimated using a regulated base fo r this machine parts. K e y w o r d s : size effect, contact fatigue, gear wheels. The durability and fatigue resistance o f components operating under cyclic loading by bending, tension, compression, twisting, etc. appear to be the lower, the larger are the component dimensions [1 ,2 ] Since the phenom ena o f contact fatigue are based on the same processes as those occurring under other types of fatigue, it is natural to expect that increasing the absolute dimensions o f a component w ould decrease its contact fatigue limit. However, by analyzing the available results o f studies on the size effect in contact fatigue it is impossible to get a definite opinion on this problem [2-13]. Some researchers state that the size effect in contact fatigue undergoes inversion, i.e., as the diameter o f contacting parts is increased, the durability grows [4-6]. However, others assert that increase in a component size leads to reduction o f bending and contact fatigue limits [7, 10]. For the basic regularities o f the size effect in contact fatigue to be elucidated, special experimental studies have been made. The test scheme is shown in Fig. 1. Cylindrical sample 2 serves as a tooth o f a gear wheel. A counterbody - roller 1 - is pressed to the surface o f sample 2 by a contact load F N in the contact zone x. Roller 1 serves as a tooth o f the second gear wheel that transmits the contact load F n to sample-model 2 . Sample 2, which is fastened in spindel 3, is rotated with an angular velocity « 1. Counterbody 1 is rotated with an angular velocity « 2 , its rotation axis being parallel to that o f sample 2. Regulating the ratio o f the velocities «1 and « 2 allows one to obtain the required slip coefficient, im itating the slip in gearing. The contact load F N provides a simultaneous excitation both o f contact and bending stresses in the corresponding zones, whereas the distance between these zones is chosen tobe equal to that between the pitch point and the tooth root. Using the counterbody (roller) with a constant diameter D =100 mm and sample-models o f various diameters d (Fig. 2) makes it possible to change two m ain curvatures and to obtain the size ratio o f the contact area (a /b) within the range 0.4-0.8, which is satisfactory for practical purposes. © L. A. SOSNOVSKII, V. A. ZHMAILIK, V. V. KOMISSAROV, 2009 ISSN 0556-171X. Проблемы прочности, 2009, № 1 113 L. A. Sosnovskii, V. A. Zhmailik, and V. V. Komissarov Fig. 1. Testing scheme for a toothed gearing model: (1) sample-model of the tooth; (2) counterbody (roller); (3) testing machine spindle. Fig. 2. Tested tooth models. a b c Samples 10, 20, and 30 mm in diameter were made from steel 18KhGT, invoking the technology o f m anufacturing gear wheels at the Production Group “Gomselmash.” Working surfaces o f counterbodys and samples were cemented at a depth o f 1.0-1.5 m m with subsequent hardening up to 59-63 H R C and polished (R a > 0.32 ^m ). The run-out o f the samples in the working zone was not more than 10 ^m . Tests were perform ed using a wear fatigue testing m achine o f UIM type [20] at a constant linear velocity in the contact v circ = 1.57 m/s. The error of keeping the shaft rotation frequency w ithin the steady regime is ± 3 % o f the m easured value [2 0 ]. W hen the sample and the counterbody are tested in the contact zone, the slip degree is controlled to be equal to 3%. In the course o f tests, a lubricant (oil TAD-17 I) is supplied to the contact zone w ith a feeding speed o f 2 -4 drops per minute. The tests were interrupted after occurrence o f the limiting state conditions corresponding to the real service ones for a particular gearing (limiting convergence o f the axes o f the sample and the counterbody d iim = 100 ^m ). The contact load F n (see Fig. 3) serves as a param eter controlling the m odel loading. 114 ISSN 0556-171X. npo6n.eMH npounocmu, 2009, N 1 Size Effect at Contact Fatigue I, t, t , min Fig. 3. Loading program scheme. The basic test results are shown in Figs. 4 and 5. From Fig. 4 it is seen that under constant contact loading conditions the durability is higher, the larger is the diameter o f a tested element. For the base of N b = 4 -1 06 cycles, we have established the dependences o f limiting contact stresses p f and limiting contact load F Um on the diameter o f the tested models, d (Fig. 5). The analysis o f Fig. 5 yields that: 1) in terms o f the limiting contact load, i f the tested model diameter is increased from 10 to 30 mm, this load grows from 780 to 1520 N. 2 ) in terms o f the limiting contact fatigue, i f the tested m odel diameter is increased from 10 to 30 mm, the contact fatigue limit decreases from 5150 MPa to 4900 MPa. F„, N 1600 1500 1400 1300 1200 1100 1000 900 800 700 600 500 ------------------------------------------------------------ J------------------------------- 400------— I I 1111-------— LLLLLl------- — III 10* 10s 10’ N, cycles Fig. 4. The size effect on the contact fatigue resistance [(/) log F = 7.8009 — 0.7434 log N ; (2) log F = 5.9047 — 0.4266logN ; (3) logF = 5.2255 — 0.3097logN]. ISSN 0556-171X. npoôëeMbi npounocmu, 2009, N 1 115 L. A. Sosnovskii, V. A. Zhmailik, and V. V. Komissarov P„ MPa 5200 5100 5000 4900 4S0D 5 10 15 20 25 30 rf.mm 0.1 0.3 0.5 0.7 0.9 mm3 a b Fig. 5. Limiting contact stresses and limiting contact load vs. sample diameter (a) and critical volume size (b). Based on the above experimental results, it is possible to formulate the following basic regularity o f the size effect in friction: under constant contact loading conditions the durability is higher, the larger is the diameter o f a tested component. For the size effect in contact fatigue to be analyzed theoretically, the model o f a solid body w ith a critical volume [14] was used. According to this model, i f a deformable solid body is characterized by such a stressed state that its fatigue failure is possible, then it is composed o f two regions: safe and critical volumes. Similarly, assume that in contact deformation by a critical volume Vint is understood the region o f a loaded body, at each point o f which the value o f the stress intensity o int is less than the limiting value o f o ) (~ P f m)) V int = f f f dxdy d z ( 1) o in t (x, y, z )so l2 The critical volume is an absolute m easure o f damage; it is statistical in character and contains the geometrical sizes o f tested elements. This permits using it as the param eter controlling the size effect in contact fatigue. The proposed procedure is applied for the assessment o f critical (limiting) stresses as a limitation criterion for the corresponding critical regions [15]. It (* lim)consists in determining the limiting intensity o f stresses o int when the tested system is subjected to the limiting load F * lim : 0 f j m) = max( o in t(F * lim , d V ),) (2) dV where d V is the elementary volume o f the loaded body. = 5294. !v 33-12.25 d 4 / / / / ' / / / / / A ­ v 465.33 +36.1 d 116 ISSN 0556-171X. npo6n.eMH npounocmu, 2009, N9 1 Size Effect at Contact Fatigue Then the criterial condition for limitation o f critical volumes will be o f the form Vint = { d v j o iM > a \ d V C Vk }, (3) where Vk is the working volume o f a deformable solid body. As critical volumes can have arbitrary and complex shapes, it is difficult to determine them by formula (1). Therefore, calculations were made using the program package “M athem atics” by the num erical M onte-Carlo method. Figure 6 presents the calculation results on the critical volumes formed due to norm al and tangential contact stresses. -1.5 -1 -0,5 0.5 1 x/a -1.5 -1 -0.5 d 1 y/a Fig. 6. The critical volume (a) developed due to normal and tangential contact stresses: (b) section by the plane y = 0; (c) section by the plane x = 0; (d) section by the plane z = 0.5a. c Since critical volumes are used as the damage measure o f deformable bodies, the analysis o f Fig. 6 specifies the particular regions (zones) where internal cracks can initiate and propagate. Using the proposed method, the dependences o f limiting contact stresses p f and limiting contact load F lim on the critical volume size (V int) (Fig. 5) are constructed for the base N b = 4 -106 cycles. The obtained dependences are seen to have a qualitatively similar character both in analyzing the tested models in terms o f the diameter and the critical volume in terms o f size. Thus, the proposed m odel is valid and does not contradict the results obtained. In this case, a critical volume to be calculated includes the geometrical dimensions o f tested components and has a statistical character [limiting contact stresses p f m) serve as a limitation criterion]. In this respect, this is a more preferable param eter for description o f the size effect in contact fatigue. ISSN 0556-171X. npoôëeMbi npounocmu, 2009, N 1 117 L. A. Sosnovskii, V. A. Zhmailik, and V. V. Komissarov Using the given approach, it is possible to execute a settlement estimation of rolling fatigue resistance o f particular toothed gear wheels. The input data for calculations are given in Table 1. T a b l e 1 Input Data for Calculation of Gear Wheels Gear Combined torque M k , N-m Reference diameter d , mm Radius of tooth profile evolvent in a pitch point Effective face width B, mmp 1, mm p 2 , mm PKK 0135684 290 92 15.73 19.15 20 PKK 0135661 450 108 18.47 21.89 40 For the rolling fatigue limit estimation for a particular type cogwheel it iso necessary to pass to base o f tests equal to 1.2 -1 0 cycles which is regulated for tooth gearings [10, 17]. As a first approximation, such transition can be executed, accepting the slope indicator o f the left branch o f rolling fatigue curve m p = 3 -6 [17] or on the average m p = 4.5. Calculation results are presented in Fig. 7 and in Table 2. T a b l e 2 Results of Calculation of Gear Wheels Gear Vint, mm3 Po, MPa P f , MPa nP aH , MPa ° H PKK 0135684 0.00201 1171.4 2340.8 2.00 1337.8 1.75 PKK 0135661 0.00208 888.6 2340.3 2.63 945.7 2.47 Pf: MPa 2800 2600 2400 2200 2000 1S00 1600 1 _WCi, = U -1 0 s cydes T ~ ~ t r ~ 1 1 1 r — | Gear wheel PK K 0135684 1 1 1 0.01 0.02 0.03 nun Fig. 7. Dependence of rolling fatigue limit on the critical volume value. It is seen from Table 2 that for a gear wheel PKK 0135684 value o f safety factor for the rolling endurance n p is lower by 25% than that o f PK K 0135661. This allows us to conclude that the operational durability o f the PKK 0135684 gear wheel will also be lower than that of PKK 0135661. This conclusion is 118 ISSN 0556-171X. npoôëeMbi npounocmu, 2009, N 1 Size Effect at Contact Fatigue confirmed by data on operation o f a transm ission PKK 0135000 o f a harvest combine “Polesie-3000” m anufactured by Production Group “Gom selm ash” [22]. Conclusions. Inversion o f size effect in rolling fatigue is established and described for particular experimental conditions. The technique o f rolling fatigue resistance assessment on the basis o f statistical m odel o f a deformable solid body w ith critical volume is proposed. The estimation o f a rolling fatigue limit is made for particular types o f gear wheels. 1. L. A. Sosnovskii, M e c h a n ic s o f F a tig u e F a ilu re : H a n d b o o k [in Russian], in 2 Parts, Pt. 2, “SPG Tribofatigue,” Gomel (1994). 2. A. A. Komarovskii, “Size effect: reasons o f the onset, m anifestations and dangerous consequences,” Tekh. D ia g n . N e ra zru sh . C o n tr ., No. 1, 3-8 (2002 ). 3. A. I. Petrusevich, C o n ta c t S tr e n g th o f M a c h in e P a r ts [in Russian], Mashino- stroenie, M oscow (1969). 4. I. M. Sakhonko, “Contact endurance o f quenched steel as a function of geom etrical param eters o f contacting bodies,” in: C o n ta c t S tr e n g th o f M a c h in e -C o n s tr u c tin g M a te r ia ls [in Russian], Nauka, M oscow (1964). 5. B. A. M orozov, V. K. Shashkin, V. T. Firsov, et al., “Contact fatigue strength o f backing-up rolls,” in: S tr e s se s , D e fo rm a tio n , a n d S tr e n g th o f M e ta llu r g ic a l M a c h in e s [in Russian], VNIIM etmash, M oscow (1988). 6 . G. K. Trubin, C o n ta c t F a tig u e o f M a te r ia ls f o r G e a r W h ee ls [in Russian], State Scientific-Technical Publishing House o f M echanical Engineering Literature, M oscow (1962). 7. V. I. Rudnitskii, “Size effect as applied to gear wheels,” V estn . M a s h in o s tr ., No. 7, 24-26 (1958). 8 . A. S. Ivanov, “Size effect in considering bending and contact resistances of fatigue as well as o f friction and wear,” I b id , No. 5, 25-30 (1997). 9. A. V. Orlov, O. N. Chermenskii, and V. M. Nesterov, T e s tin g o f S tr u c tu ra l M a te r ia ls f o r C o n ta c t F a tig u e [in Russian], Mashinostroenie, M oscow (1980). 10. P 5 0 -5 4 -3 0 -8 7 . C a lc u la tio n s a n d S tre n g th T ests . M e th o d s o f T e s tin g C o n ta c t F a tig u e [in Russian], Gosstandart SSSR, VNIIM ash, M oscow (1988). 11. B. I. Kostetskii et al., S u rfa c e S tr e n g th in F r ic t io n [in Russian], Tekhnika, K iev (1976). 12. V. A. Belyaev and I. A. Bolotovskii, “Influence o f the num ber o f teeth o f a gear wheel on its bending supporting,” in: C o n ta c t P r o b le m s a n d T h e ir E n g in e e r in g A p p l ic a t io n s (C o n fe r e n c e P a p e r s ) [in Russian], NIIM ash, M oscow, (1969), pp. 274-284. 13. K. Inoue and T. Masuyama, “Possibilities o f fatigue strength simulation in reliability design o f carburized gears” in: 2nd Int. Conf. on P o w e r T ra n s- m is s io n s ‘0 6 , (Novi Sad, Serbia&M ontenegro, 2006), Novi Sad (2006). 14. L. A. Sosnovskii, S ta t is t ic a l M e c h a n ic s o f F a tig u e F a ilu r e [in Russian], Nauka i Tekhnika, M insk (1987). ISSN 0556-171X. npoôëeMbi npounocmu, 2009, N 1 119 L. A. Sosnovskii, V. A. Zhmailik, and V. V. Komissarov 15. L. A. Sosnovskii, M e c h a n ic s o f W ea r F a tig u e D a m a g e [in Russian], BelSUT Press, Gomel (2007). 16. O. T. Vavilov, “Concept o f critical volumes in the contact problem ,” Vestn. B r e s t G os. T echn . U n iv e r ., No. 4, 61-65. (2001). 17. I. S. Tsitovich, I. V. Kanonik, and V. A. Vavulo, T ra n sm iss io n o f C a rs [in Russian], Nauka i Tekhnika, M insk (1979). 18. L. A. Sosnovskii and V. V. Komissarov, “Damage in m echanical and contact fatigue,” Z a v o d . L a b ., D ia g n . M a te r . , 71, No. 1, 47-55 (2005). 19. L. A. Sosnovskii, “Contact and bending fatigue o f toothed gearings,” in: Proc. o f the W orld Tribology Congress III (W ashington) (2005). 20. T r ib o fa tig u e . W e a r F a t ig u e T e s t in g M a c h in e s . G e n e r a l S p e c if ic a t io n s : G O S T 3 0 7 5 5 -2 0 0 1 [in Russian], Belarusian State Institute o f Standartization and Certification, M insk (2002). 21. T rib o fa tig u e . M e th o d s o f W ea r F a tig u e T ests . C o n ta c t M e c h a n ic a l F a tig u e T e s ts : G O S T 3 0 7 5 4 - 2 0 0 1 [in R ussian], B elarus S tate In stitu te o f Standartization and Certification, M insk (2002). 22. V. A. Zhmailik, S tre n g th A s p e c ts o f an E s tim a tio n a n d N o r m a liz a t io n o f A c tiv e S y s te m s ’ Q u a lity [in Russian], A uthor’s Abstract o f the D octor’s Degree Thesis (Ph.D.), BelSUT Press, Gomel (2002). Received 11. 06. 2008 120 ISSN 0556-171X. npodxeMbi npounocmu, 2009, N 1
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issn 0556-171X
language English
last_indexed 2025-12-07T18:53:53Z
publishDate 2009
publisher Інститут проблем міцності ім. Г.С. Писаренко НАН України
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spelling Sosnovskii, L.A.
Zhmailik, V.A.
Komissarov, V.V.
2013-08-20T03:41:57Z
2013-08-20T03:41:57Z
2009
Size effect in contact fatigue / L.A. Sosnovskii, V.A. Zhmailik, V.V. Komissarov // Проблемы прочности. — 2009. — № 1. — С. 113-120. — Бібліогр.: 22 назв. — англ.
0556-171X
https://nasplib.isofts.kiev.ua/handle/123456789/48468
539.4
The results of special experiments on the size effect in contact fatigue are presented. It is established that under constant contact loading conditions the durability is higher, the larger is the diameter of a tested element. The methods for estimation of contact fatigue resistance of gear wheels, which is based on the statistical model for a deformable solid body having a critical volume, are proposed. The limiting stresses of a gear wheel are estimated using a regulated base for this machine parts.
Представлены экспериментальные результа­ты по исследованию масштабного эффекта при контактной усталости. Установлено, что при постоянной контактной нагрузке долго­вечность испытываемого конструкционного элемента цилиндрической формы тем выше, чем больше его диаметр. Предложены мето­ды оценки сопротивления контактной уста­лости зубчатых колес, основанные на исполь­зовании статистической модели критичес­кого объема деформируемого твердого тела. Предельные значения напряжений для натур­ных элементов оцениваются с использова­нием расчетных нормативов, разработанных специально для зубчатых колес.
en
Інститут проблем міцності ім. Г.С. Писаренко НАН України
Проблемы прочности
Научно-технический раздел
Size effect in contact fatigue
Масштабный эффект при контактной усталости
Article
published earlier
spellingShingle Size effect in contact fatigue
Sosnovskii, L.A.
Zhmailik, V.A.
Komissarov, V.V.
Научно-технический раздел
title Size effect in contact fatigue
title_alt Масштабный эффект при контактной усталости
title_full Size effect in contact fatigue
title_fullStr Size effect in contact fatigue
title_full_unstemmed Size effect in contact fatigue
title_short Size effect in contact fatigue
title_sort size effect in contact fatigue
topic Научно-технический раздел
topic_facet Научно-технический раздел
url https://nasplib.isofts.kiev.ua/handle/123456789/48468
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