The discussion revolves around the effects of heat on friction, particularly in the context of tires and various materials. Participants explore how temperature influences kinetic (dynamic) friction and the coefficient of friction across different states of matter.
The conversation is ongoing, with various perspectives on how heat affects friction being shared. Some participants provide examples from practical applications, such as racing, while others seek clarification on general principles. There is no explicit consensus, but multiple interpretations of the effects of heat on friction are being explored.
Participants mention specific conditions under which friction changes with temperature, such as optimal temperature ranges for different materials. There is an acknowledgment of the complexity involved in understanding these relationships.
Kinetic (dynamic) friction in some cases increases with heat. Take for instance brake pad material in some racing applications. It's fairly common for the driver to have to get heat into the brakes before they work at an optimal level.rcgldr said:Depending on the material, kinetic (dynamic) friction decrease once temperature exceeds some level. This is why overheated brakes can fade, why overheated clutches can slip, and why overheated tires slide easier than cool tires.
There's an optimal range of temperature that varies depending on the material. If below the optimal temperature range, then heat will improve friction, if above the optimal range, then more heat will degrade friction. Once within the optimal temperature range, then the ideal situation would be to dissipate heat at the same rate it's generated (on average) so that temperature remains within the optimal range.dp86 said:But generally speaking, does heat reduce or increase the coefficient of friction?
SammyS said:Kinetic (dynamic) friction in some cases increases with heat. Take for instance brake pad material in some racing applications. It's fairly common for the driver to have to get heat into the brakes before they work at an optimal level.
Operator said:Same goes with tires, which is why drag racers do burn-outs before a race. That's not just for show, the heat makes the rubber a more sticky.