Tire heating changing with compounds

Discussion in 'Car Modding' started by rigodon, Dec 18, 2019.

  1. rigodon

    rigodon Registered

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    Hi everybody,

    I'm trying to make different tyre compounds to heat in a different way when sliding. That is, when a hard rubber is sliding it won't get the same heat because of friction as a soft one doing the same slide. We see an effect like: "hard tyre slides more because it hass less grip, the more it's sliding, the more it gets heatened, the more it gets heatened, it will has less grip because it will eventually overheaten, less grip means more sliding... ". So in the end hard tyres will give you more or less the same duration with less performance compared to softer compounds. I've read a lot before writing this post, but I can't get a clear idea of which tyre parameters will allow you to change the amount of heat you get based on sliding friction. SlidingAdhesionCurve? DampingHeatEnergy? I tried DryTerrainEffect=(0,1,0.90), but it doesn't seem to have an effect on normal corner sliding, only when you spin.

    Thanks a lot in advance
     
  2. mantasisg

    mantasisg Registered

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    I am not sure about softer rubber heating less when sliding. Softer rubber would produce stronger sliding friction as a result of energy being spent by rubber being sheared off, that's kinda last resort of how tire can give friction. I would say that harder rubber would heat up more only because /if it slides a lot, and it would likely slide way more than silly soft compounds

    I am still learning the TGM myself... You can give more friction to rise energy levels. You can modify rubber rolling resistance with bristle damping, will also change the sliding feel a lot. You can modify glass transition temperature, softer rubber will "freeze" at lower temperature. You can modify static curve by making tire more slippery as it heats up, or less. You can change thermal depth of tread, more of it will store more heat making it slower to cool. You can change ground conductance that will also give big difference in the way tire cools down... There are more stuff. Everything works together there as much as I understand.
     
  3. rigodon

    rigodon Registered

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    Thanks for the advices. Maybe I expressed myself badly on first post, but I think harder compounds should get less heat when sliding. I understood all parameters you were mentioning except "give more friction". How do you give it more or less friction?
     
  4. mantasisg

    mantasisg Registered

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    Well, static friction and sliding friction parameters. Static curve, sliding curves, marble, groove, dampness parameters. Also bristle springs and damping... Everything basically :D
     
  5. mantasisg

    mantasisg Registered

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    On the second thought, I am not completely sure if higher friction would influence tire wear a lot, I didn't test it properly, just quick observation. But I suppose that more friction directly translates into ability for a tire to do more work, thus hold more energy. The more there is energy potential before it turns into kinetic energy (sliding) means it will wear more.

    But I don't understand it all too well. I mean: what would be the difference in energy of tire that is rolling one meter and a tire that is sliding one meter. Or what would be the wear/energy difference for a tire that decelerates quicker when sliding. I would suppose in term of energy it would go in this rising order: non sliding rolling tire > slow sliding and slowly slowing tire > slow sliding and quickly slowing tire > fast sliding and slowly slowing tire > fast sliding and fast slowing tire. I also suppose that the amount of heat that accumulates in rubber is also directly proportional to the energy that is put into system. Well.......... I just got a bit into thinking out in text mode...

    I would suppose that tire that has completely no friction at all would never wear a single bit, thats assuming that it would be able to move from stationary position in the first place. Would be fun to try 0 friction values in a sim :D Tires should just spin place not doing anything. Friction is the employer of tire :D
     
  6. rigodon

    rigodon Registered

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    I was asking because I couldn't find any "static / sliding friction parameters". I just could find the "Static/Sliding BaseCoefficient". Obviously, a little bit more of sliding grip would mean less sliding and less heat, but not sure if it is what you're talking about.
     
  7. mantasisg

    mantasisg Registered

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    Those are definitely base friction parameters. More sliding friction does mean quicker slowing when in slide. Worth to mention that when you drive fast and put tires in slip angle and slip ratio, your grip is always a combination of static and sliding friction, because particular piece of tire is always sliding, depending on amount of slip ratio or/and slip angle.

    I don't know, maybe it is not relevant for heat. Maybe it is all about normal force on tire, initial sliding speed and speed delta per time delta. After all tires would heat up sliding on any surface.
     
  8. Emery

    Emery Registered

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    Heating rate should be a function of the carcass construction (ply material, number of plies, orientation of plies, thickness of rubber, and tread patter: slick, ribs, blocks, zig-zag, sipes), load, sliding, and cooling via conductance to the ground and transfer to the air. In theory there is heat transfer from the brakes, but I'm not sure if rF2 models that.

    Compound determines how the tire reacts to the heat. A hard compound wears more slowly at the expense of some grip. A hard compound may or may not have a higher operating temperature for peak grip; AFAIK always, though, peak grip is less than a softer compound.

    Edit: if the harder compound doesn't last longer, then there's no reason to use it unless the regulations require it. When the regulations require it, the usual strategy is to get off the hard compound as soon as possible because it is slower, thus you may have the impression it doesn't last longer.
     
  9. Raintyre

    Raintyre Registered

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    DryTerrainEffect=(0,1,0.90) is the parameter you need. Perhaps you simply need a lower value instead of 0.90. (try 0.30)
    You can also do it with a combination of other parameters, but it is much more complex and difficult to master..
     
  10. Lazza

    Lazza Registered

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    @rigodon be careful you don't try and edit out realistic behaviour to cater for poor driving.

    I've recently been watching some motogp racing and one of the races had someone using the (slightly) harder tyres, and it was assumed they would be stronger at the end. Actually, they spun up the rear tyre more and had less grip by the end.

    People trying to drive a hard tyre like a soft tyre will end up with less grip, and this is how it should be. When driven within their respective limits the hards should last longer.
     

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