Abstract
This abstract present a 3D investigation and measurements of stresses in the tyre patch contact. The article will present the research regarding the stress inside the contact spot of tyre from truck and car with the road in the characteristic modes: free run, acceleration, haulage and braking.
This new transducer allows for displaying the curves of the forces acting upon each transducer mounted along the road, in real time. With the help of this transducer it is possible to measure punctually the forces inside the contact spot of the tyre with the rolling track on the contact spot whole width.
The authors developed the 3D force transducer with an active surface, subject of an Invention nr.121354/30.11.2007 file at the Romanian National Invention Office. Thus, with an assembly of transducer mounted along the rolling track, in the Department of Transport, Road Vehicles of the Polytechnic University in Bucharest measurements have been regarding the stress inside the contact spot.
Special Lab View soft has been developed for data acquisition by the computer inside the vehicle and by a stationary computer. The whole complex system of data acquisition is started by an optical barrier crossed by a laser beam.
Pressures inside the tested tires were: 2 bar - 6,5 bar according to the vehicle tires for unloaded vehicles. The 3D transducers have been developed, in order to measure the forces inside the contact spot we have performed several truck runs for each pressure so that, by taking photos and reconstructing images, we could directly represent the forces for each type of tires.
KEYWORDS: tyre patches contact; weigh in motion; solid force transducer; force; pressure.