No. 1, 1998 - Tribology in Industry

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UDK 62r.179.6.891.22
T. F. KALfuM{OYA, T. M. MOISEEVA, O.Y. KHOLODILOY
On Statistical Description
of Solids Friction
A method is propo'setl of es-tintaling the poranteters of a .rpecial class conclation Jiurctiott. II i,s based ott
meQsurements of statistic of the sndied phenomenon or FSFC. The only conrlitiort o.f applying lhe statistics
is the reqrdrement that the protluct 9f freQuency range of the recordad railiatiott b), tirie irJ i"rirAi"g is vastly
laryer than utity. A contbinerl arutlysis of acorctic tlata antl those oJ' F'SFC (roighness, size ctistibtttion of
wear debris, etc.) hat,e showtt that the statislics a.rc rcsponsive to pinctically'oll lihenomerrn ,rrorrpn,rr-urg
frictiort antl wear. The depenrlenc-ie.s obtained of the staiistics r:niat^iort with evenialfacton hat,e enable; trcw
citeia to estirnate durability of frictitn joints to be formrilated.
Keywords: frictiort, wear, su(ace roughness, tvear rrebris, acowtic inadiation
l.INTRODUCTION
A number of tribological problems rvhose solutions are
important for understanding solids friction require investigation
of both statistical properties accompanying friction
and wear (acoustic irradiation, heat generation,
etc.), and study of fixed states of a friction conracr
(FSFC) involving surface rolrghness, '"vear debris ancl so
on. It turns so, that separate parameters of these pheno_
mena (intensity of acoustic irradiation, contact temper:r_
ture) and FSFC realization (rough surface profile, wear
debris size) are insufficient for unambiguous identifica_
tion of a tribosystem state.
2. PROBLEI\{ FORN{ULATION
Friction to proceed from the fact that the majority of the
phenomena and FSFC can be presented as reiilization of
a random field (r, y/, so a number of the tribological
characteristics would depencl on its correlation function
behavior about zero. In this connectictn the problem of
estrmation and sirnulation of the function secrns quitc
actual. A nrethod has been proposecl earlier to estinratc
correlation function pararneters of a certain class random
fields. The method is based on the use of functionals
(statistics) belonging to the studied phenomena or FSFC
[7,2):
T. F. Kolm.v-kot,n,7-. M. Moiseu,a, O. tr/. Kholodilov
Mctal- Polyrner Resaarclt lrrstitLttc tnned o,ftcr V.A. Bctvi
of Ilehntssiatt Acaclcmy of Scicttct:s,
Gorncl, Rcpublic o.[ I]clorus
24
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- is the
tabulated function; A - transmi'Ssion band; 1; - frecluency
range of the recorded field; I - time of recording; T _
sampling length. The only condition for their application
is Al>1.
Obiects of the present investigation are the foilorving:
1 - to substantiate invariance of proposed functionals for
any nature randorn fields; 2 - to prove their stabiliry for
stationary fields and substantial sensitivity to variations
in stability.
These problems can be traced on the exanrple of the
studied in friction contact acoustic fields ancl in case with
mechanically induced random states of the friction con_
tact (aspelities of contact surfaces, stl-ucture of actulrl
conterct spots, fields of wear debr-is distributiou).
l,et us dwell on acoustic frictional phenomena and show
the probability of the suggested functionals use to estirnlrte
the mechanisrn of frictional contact rvearing by
characteri.stic parameter r(a, b) in the space o[ statistics
(a, b).
triboloSy in i nrhrrry Votumc 20, No. l, lggg.