Tread with care

Using knowledge gleaned from almost 50 years researching Terramechanics, simulated tyre performance on a number of surfaces is now possible thanks to Japanese technology. Jon Excell reports

One could be forgiven for thinking that tyre design represents one of automotive engineering’s less demanding challenges. But, as vehicle performance is tweaked and enhanced in every possible direction, the tread on the small patches of tyre — which at any given moment provide the only connection between all this technology and the road surface — is the result of exacting design calculations.

Now, new technology for simulating tyre performance on a range of different road surfaces has been developed by scientists at Bridgestone Corporation in Japan.

Known as Comprehensive Road Surroundings Simulation (CROSS), the high-powered software is expected to enable engineers to optimise the design of tyre tread patterns by simulating behaviour on unpaved roads in the sun, rain and snow. The tool is specifically intended for use in the design of tread patterns for 4 x 4s, earthmoving, agricultural and all-terrain vehicles.

Company spokesman, Shinichi Kobori said that until now it has been largely impossible to simulate on a PC such complex interactions between tyres and surfaces, and tyre manufacturers have relied upon field testing. While CROSS is not expected to completely replace testing, it will reduce the dependence on the method.

Kobori claimed that it will also allow engineers to evaluate tyres on a greater range of surfaces than is currently practical. ‘Traditionally, manufacturers have needed to conduct field testing with real prototypes to evaluate the performance of different tread patterns which has been expensive and time consuming,’ said Kobori. ‘CROSS enables engineers to evaluate tyre performance using desktop computers — greatly reducing the number of physical prototypes and the amount of testing required,’ he added.

The software draws on knowledge gleaned from almost 50 years of research into Terramechanics, a term that refers to the behaviour of soil under the influence of vehicles and machinery. The company uses a supercomputer to predict and simulate the movement and response of soil as it is compacted beneath a moving tyre.

Kobori said that there are no specific figures on how much time the software will cut from the tyre design process. He said that this will be down to the type of tyre being designed.

He confirmed that Bridgestone is already using CROSS in the design of tyres for 4 x 4 vehicles and agricultural machinery. He added that the company is looking to apply the technology to a continually broadening range of tyres. It has no plans to make the software commercially available to other manufacturers.