Wet skid resistance prediction with broadband dielectric spectroscopy

(1)

-60 -40 -20 0 20 0,0 0,2 0,4 0,6 0,8 1,0 Tan 

(DMA)

Temperature / C

E-SBR / BR + Silica / Carbon Black (in phr) Y1 70 / 10

Y2 40 / 40

Y3 10 / 70

WET SKID RESISTANCE PREDICTION WITH

BROADBAND DIELECTRIC SPECTROSCOPY

A. RATHI¹, M. HERNÁNDEZ2_{, S.J. GARCÍA}3_{, C. BERGMANN}4_{, J. TRIMBACH}4_{, J.W.M. NOORDERMEER}1_{, W.K. DIERKES¹,}

A. BLUME1

¹UNIVERSITY OF TWENTE, THE NETHERLANDS; 2_{ICTP-CSIC, SPAIN;} 3_{DELFT UNIVERSITY OF TECHNOLOGY,}

THE NETHERLANDS; 4_{HANSEN & ROSENTHAL, KG, GERMANY}

CONCLUSION

For the three compounds studied, the BDS method delivers a good correlation with the

coefficient of friction μ from the tire test measurements at 65 km/h in wet road condition.

∴

BDS seems to predict the WSR more reliable than the existing DMA method.

Proposal for prediction of WSR : Testing viscoelastic behavior at frequencies related to skidding (104 _-107 _{Hz) with Broadband Dielectric Spectroscopy (BDS)}

The BDS measurements have been done in the range of -120 to 80 °C and 1 to 106 _{Hz in a parallel plate}

geometry. Based on a speed to frequency conversion (Frequency = Speed / micro-roughness of the road), the frequency of the tire test is ca. 3.6*107 _Hz.

-120 -80 -40 0 40 80 0,0 0,2 0,4 0,6 0,8 1,0 1,2 Temperature / C M  / M  max at 10 6 Hz (BDS) Y1 Y2 Y3 0,9 Comparable broadness of Y2 and Y3

BETTER CORRELATION WITH THE BDS METHOD !!!

Correlation with μ from tire testing

ACKNOWLEDGEMENTS

The authors are thankful to Hansen & Rosenthal, KG for the financial and scientific support of this work. Special thanks to the Yokohama Rubber Company for providing the samples, the DMA measurement data and the tire test

measurement data.

Existing method for prediction of Wet Skid Resistance (WSR) : Tan δ at 0 °C / 1-100 Hz from DMA

The DMA measurements have been done in tension mode in the range of -60 to 20 °C at a static strain of 10%, dynamic strain of 0.5% and a frequency of 20 Hz. The coefficient of friction (μ) has been measured under wet road conditions at 65 km/h from real tire tests.

LIMITATION OF THE DMA METHOD !!!

Correlation with μ from tire testing

REFERENCE

Rathi, A., Investigation of safe mineral-based and bio-based process oils for tire tread application, PhD manuscript in preparation, 2019, University of Twente : Enschede, p 191-226.

0,74 0,76 0,78 0,80 0,82 0,84 0,86 0,231 0,242 0,253 0,264 0,275 0,286 0,297 0,308 Y3 Y2

Tan



at 0 C (DMA)

Coefficient of friction  (Tire test)

Y1

No linear correlation with