Mohammad “Mehran” Motamedi, Chuang Su, Michael Craft, Saied Taheri and Corina Sandu, Center for Tire Research (CenTiRe) Mechanical Engineering Department Virginia Tech

1. 12/20/2013
Development of a Laboratory Based
Dynamic Friction Tester
Mohammad “Mehran” Motamedi, Chuang Su,
Michael Craft, Saied Taheri and Corina Sandu
Center for Tire Research (CenTiRe)
Mechanical Engineering Department
Virginia Tech
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2. 12/20/2013
Content
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Background/Introduction
Need and Industrial Relevance
Objectives
Computer-Aided Design
Velocity and Slip Control, and Force Measurement
Fabricate dominant wavelengths onto disks
Applications
Summary
References
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Background/Introduction
• Friction between tire and road
• Pavement texture – Tire/Road Interactions
• Road Surface Texture Wavelengths:
– Micro-texture
– Macro-texture
• Friction Components:
– Adhesion
– Hysteresis
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Need and Industrial Relevance
Addressing issues faced by tire designers:
 Ability to predict the pavement surface characteristics (e.g., rolling
resistance, friction and tire wear) as they relate to the tire interaction in
terms of the pavement surface features (e.g., texture, roughness).
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Outdoor testing:
 Weather conditions.
 Time -- Money -- Human resources.
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Indoor Testing:
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Reduced cost
Controlled laboratory environment
Improved data accuracy and reproducibility.
Ease of data accessability and processing
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Objectives
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Develop a laboratory based rubber friction test
equipment.
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Investigate frictional effect of texture wavelengths
with respect to slip ratio.
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Validate the multi-scale rubber/road contact model
using rubber samples from compounds that make
up the tire.
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Computer-Aided Design
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Machine Shop Drawings:
Dimensions and Tolerances, Material, and Weldments
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Velocity and Slip Control
• AKM42H Sevomotor
AKD-P00606 Servodrive
VT075-007-0-RM075-40 Gearheard
• AKM44J Sevomotor
AKD-P01206 Servodrive
VT010-025-0-RM100-40 Gearhead
AKD Drive configuration and
programming software.
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Force Measurement and Data Acquisition
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Dominant Wavelengths of Pavement Texture
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Spectral Analysis
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Dominant wavelengths
onto disks.
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Investigate the contributions of macro- and micro-texture constituents.
Model the rubber-surface contact and adhesion on multiple scales.
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Surfaces with decomposed characteristics:
Rapid Prototyping
• Methods
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Inkjet-based 3D printing systems
Ridges etched away on silicon wafer
Selective Laser Sintering
Stereolithography
• Trade-off
– Size, Resolution, Precision and Reliability, Material
Properties, HDT, Cost
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Applications
Multi-Scale Correlations
• Friction stems from the contribution of several scales of
macro- and micro-texture.
– Measure friction for each scale in the lab.
– Calculate the mean friction for each surface at each scale.
– The friction coefficient of the profile: A linear combination of
the scale friction coefficients by scale.
– Maximize the correlation between the measured friction and
the calculated friction.
– The scales that account for friction.
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Applications
Anti-Lock Braking Systems
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Slip Ratio
– Maintained
at
the
tire’s
maximum longitudinal force and
bounded as close to this region
as possible.
• Brake Cylinder Pressure
– Preventing wheel lock
• Maximize braking potential
– Minimize stopping distance
– Provide some degree of lateral
stability to the vehicle.
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Applications
Icy Road
• Climate control
– Chamber
– Temperature sensor and humidity sensor
– Control unit
• Sprinkle water to the disk
• Adjust temperature to below zero and generate ice
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Summary
• Need, industrial relevance and objectives
• Design the Dynamic Friction Tester
• Velocity and slip control and force measurement
• Surfaces with desired features
• Applications in ABS braking, test on icy road and
multi-scale correlations
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Acknowledgements
Industry Advisory Board of the Center for Tire Research
(CenTiRe) for financial support.
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References
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American Society for Testing and Materials, “Measuring Surface Friction Properties Using the British
Pendulum Tester,” ASTM Standard Test Method E- 303-93 (2003), Book of ASTM Standards, Volume
04.03, Philadelphia, PA, 2005.
Bredell, L.J., Johnson, L.B., Kuhlmann-Wilsdorf, Jr. D., “Teaming measurements of the coefficient of
friction and of contact resistance as a tool for the investigation of sliding interfaces”, Wear, 120
(1987) 161 – 173.
American Society for Testing and Materials, “Measuring Pavement Surface Frictional Properties
Using the Dynamic Friction Tester,” ASTM Standard Test Method E 1911-98 (2002), Book of ASTM
Standards, Volume 04.03, Philadelphia, PA, 2005.
Berres, R., “High-speed linear friction testing”, Tire Technology International, July 2011, pp. 22-24
Berritta, R., Cossalter, V., Doria, A., & Ruffo, N. (2002, June). Identification of motorcycle tire
properties by means of a testing machine. In Proc. 2002 SEM Annual Conference and Exposition on
Experimental and Applied Mechanics (pp. 116-119).
American Society for Testing and Materials, “Skid Resistant of Paved Surfaces Using a Full-Scale
Tire,” ASTM Standard Test Method E 274-97, Book of ASTM Standards, Volume 04.03, Philadelphia,
PA, 2005.
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Thank you
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