Surface Pressure Profiling
Surface Pressure Profiling is a process whereby one maps the distribution of pressure across any given surface. The resulting surface pressure profiling map highlights pressure variations at a glance.
One can readily obtain surface pressure profiling maps using Fujifilm Prescale®. Fujifilm Prescale® is an easy to use tool that reveals the distribution and magnitude of pressure between any two contacting, mating, or impacting surfaces. Bram van de Sande of the Eindhoven University of Technology in The Netherlands used Fujifilm Prescale® for surface pressure profiling of tires against road surfaces.
Fujifilm Prescale® is a Mylar-based film that contains a layer of tiny microcapsules. The application of force upon the film causes the microcapsules to rupture, producing an instantaneous, permanent, high-resolution, surface pressure profiling image across the contact area. Like Litmus paper, the color intensity of the film is directly related to the amount of pressure applied to it, the color intensity being directly proportional to the pressure.
Mr. Sande’s measurements utilized a flat-plank, tire testing machine. On this machine, all forces acting on the tire could be applied under realistic tire–road boundary conditions. For each test, a sheet of Fujifilm Prescale® was placed beneath the tire to record the surface pressure profiling readings. Figure 1 shows a typical Fujifilm Prescale® image. Figure 2 shows the image after it has been scanned, digitized, and colorized.
Fig 1: Fujifilm Prescale® Image of Tire Pressure at 5000 N Applied Force and 2.3 bars Inflation Pressure
Fig 2: Fujifilm Prescale® Image after Further Processing. Image Has Been Digitized and Colorized.
Image processing, as shown in Figure 2, can be performed using Topaq®. Topaq® consists of a specially calibrated, densitimetric scanner and Windows® software. Fujifilm Prescale® can be scanned and analyzed using Topaq® to obtain high-resolution, color-calibrated images and a wealth of statistical information pertaining to the analyzed film.
“Assessment of Fuji Prescale® films in tyre/road contact surface measurements,” Bram van de Sande (s040433), DCT 2007.083, DCT Bachelor Final Project, Eindhoven University of Technology, Department of Mechanical Engineering, Dynamics and Control Technology Group, August, 2007