Measurement and Real Time Analysis of Local Damage in Wear-and-Fatigue Tests

In rolling fatigue tests the approach of the axes is usually measured once per cycle or for several loading cycles because of the difficulties of processing a large amount of data in multi-cycle testing. The aim of this work was the development and tests of smoothing model for measured by the SZ-01 center time series experimental data using wavelet transform.

With the help of the SZ center, the frictional moment in the roller/shaft system was measured allowing for studying the change in the coefficient of rolling resistance as a function of the level of the contact and non-contact bending load during wear-fatigue tests. Also the axes approach of the contacting bodies (roller and shaft) was measured at eight points on the raceway circumference in one cycle. This allowed studying the heterogeneity of local damages under conditions of rolling and mechano-rolling fatigue. When developing a software module for smoothing a large amount of experimental data from the test center, various methods of time series smoothing were used: moving average; exponential moving average; wavelet transform and moving average applied to the differences of the wavelet coefficients; wavelet transform and exponential moving average applied to the difference of the wavelet coefficients.

The results of numerical simulation showed that the best approximation to the original series was provided by the wavelet transform using an exponential moving average to smooth the differences between the coefficients of the wavelet transform.

The use of a software module based on this model in SZ-01 center allowed smoothing the time series characterizing the change of roller and shaft axes approach and torque.

1. Myshkin N.K., Petrakovets M.I. Tribologiya. Printsipy i prilozheniya [Tribology. Principles and applications]. Gomel, MPRI NASRB, 2002, 304 p.

2. Sosnovskii L.A. Osnovy tribofatiki [Fundamentals of tribo-fatigue]. Gomel, BelSUT, 2003, vol. 1, 246 p., vol. 2, 234 p.

3. Sosnovskii L.A. Mekhanika iznosoustalostnogo povrezhdeniya [Mechanics of wear-and-fatigue damage]. Gomel, BelSUT, 2007, 434 p.

4. Sherbakov S.S. [On one requirement for the choice of coeffi of friction in the power system]. Zavodskaya laboratoriya [Factory laboratory], 2005, vol. 71, no. 2, pp. 46–48 (in Russian).

5. Sosnovskiy L.А., Bogdanovich А.V., Yelovoy O.M., Tyurin S.А., Komissarov V.V., Sherbakov S.S. [Methods and main results of Tribo-Fatigue tests]. International Journal of Fatigue, 2014. vol. 66. pp. 207–219. DOI: 10.1016/j.ijfatigue.2014.04.006

6. Tyurin S.A. [Investigation of plasticity waves in contact-mechanical fatigue]. Vestnik BrGTU [BrSTU Bull.], 2001, no. 4, pp. 11–14 (in Russian).

7. Eadie D.T., Santoro M., Oldknow K., Oka Y. Field studies of the effect of friction modifiers on short pitch corrugation generation. Proceedings of 7th international conference on contact mechanics and wear of rail/wheel systems. Brisbane, 2006, vol. 1, pp. 235–243.

8. Kouanga C.T., Jones J.D., Revill I., Wormald A., Nowell D., Dwyer-Joyce R.S., Araújo J.A., Susmel L. On the estimation of fi lifetime under fretting fatigue loading. Int. J. of Fatigue, 2018, no. 112, pp. 138–152. DOI: 10.1016/j.ijfatigue.2018.03.013

9. Tyurin S.A., Sherbakov S.S. [Experimental investigation of residual wave-like damages at initiated initial distortion of the sample shape]. Vestnik BelGUT [BelSUT Bull.], 2005, no. 2 (11), pp. 88–93 (in Russian).

10. Yansong Wang, Weiwei Wu, Qiang Zhu and Gongqi Shen. Discrete Wavelet Transfom for Nonstationary Signal Processing. Theory and Applications, InTech., 2011, pp. 21–42.

11. Akansu A.N., Serdijn W.A., Selesnick I.W. Emerging applications of wavelets: A review. Phys. Communication, 2010, no. 3, pp. 1–18. DOI: 10.1016/j.phycom.2009.07.001

12. Mirotin E.A. [Forecasting time series using non-decimated wavelet transform and one-sided fi ]. Vestnik BSU [BSU Bull.], Ser. 1., 2011, no. 2, pp. 127– 132 (in Russian).