Influence of Hydrodynamic Fluid Pressure and Shoe Tread Depth on Available Coefficient of Friction

Details

• Personal Author:
  Beschorner K ; Singh G
• Description:
  Slip and fall accidents are a major occupational health concern. Identifying the lubrication mechanisms affecting shoe-floor-contaminant friction under biofidelic (testing conditions that mimic human slipping) conditions is critical to identifying unsafe surfaces and designing a slip-resistant work environment. The purpose of this study is to measure the effects of varying tread design, tread depth and fluid viscosity on underfoot hydrodynamic pressure, the load supported by the fluid (i.e. load carrying capacity), and the coefficient of friction (COF) during a simulated slip. A single vinyl floor material and two shoe types (work shoe and sportswear shoe) with three different tread depths (no tread, half tread and full tread) were tested under two lubrication conditions: 1) 90% glycerol and 10% water (219 cP) and 2) 1.5% Detergent-98.5% (1.8cP) water solutions. Hydrodynamic pressures were measured with a fluid pressure sensor embedded in the floor and a forceplate was used to measure the friction and normal forces used to calculate coefficient of friction. The study showed that hydrodynamic pressure developed when high viscosity fluids were combined with no tread and resulted in a major reduction of COF (0.005). Peak hydrodynamic pressures (and load supported by the fluid) for the no tread-high viscous conditions were 234 kPa (200.5 N) and 87.63 kPa (113.3 N) for the work and sportswear shoe, respectively. Hydrodynamic pressures were negligible when at least half the tread was present or when a low viscosity fluid was used despite the fact that many of these conditions also resulted in dangerously low COF values. The study suggests that hydrodynamic lubrication is only relevant when high viscous fluids are combined with little or no tread and that other lubrication mechanisms besides hydrodynamic effects are relevant to slipping like boundary lubrication. [Description provided by NIOSH]
• Subjects:
  Accidental Falls Accidents Biomechanical Phenomena Occupational Health Occupational Injuries Safety
• Keywords:
  Biomechanics Floors Occupational Accidents Slips, Trips, And Falls STF Walking Surfaces
• ISBN:
  9780791845080
• Publisher:
  The American Society of Mechanical Engineers
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Proceedings
• Place as Subject:
  Colorado ; OSHA Region 3 ; OSHA Region 5 ; OSHA Region 8 ; Pennsylvania ; Wisconsin
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  49-51
• NIOSHTIC Number:
  nn:20055611
• Citation:
  Proceedings of the ASME/STLE 2012 International Joint Tribology Conference, October 7-10, 2012, Denver, Colorado. New York: The American Society of Mechanical Engineers, 2012 Oct; :49-51
• Federal Fiscal Year:
  2013
• NORA Priority Area:
  Manufacturing ; Services
• Performing Organization:
  University of Pittsburgh at Pittsburgh
• Peer Reviewed:
  False
• Start Date:
  20100801
• Source Full Name:
  Proceedings of the ASME/STLE 2012 International Joint Tribology Conference, October 7-10, 2012, Denver, Colorado
• End Date:
  20140731
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:3443da8a6d072ee4e8d5a99c21a3b9e161b42c3ec805929ad214c4b192fd337d181e842276aad2169a0031f3a2b2a39140104db5a4b73dc1ab9c2c5d29e8ec1b
• Download URL:
  https://stacks.cdc.gov/view/cdc/213422/cdc_213422_DS1.pdf
• File Type:
  [PDF - 220.42 KB ]