3 ms·

I thought it was roughly to the 4th power of the vehicle? At least that's what this chart [1] suggests and I've heard in a few engineering podcasts [1] https:/

I thought it was roughly to the 4th power of the vehicle? At least that's what this chart [1] suggests and I've heard in a few engineering podcasts [1] https://streets.mn/2016/07/07/chart-of-the-day-vehicle-weight-vs-road-damage-levels/ https://streets.mn/2016/07/07/chart-of-the-day-vehicle-weigh...

marcosdumay 6y ago
It's a complicated function that behaves like different powers at different depths. But superficial wear (this study) should have a higher power than deep wear (your link). Civil engineers normally used the 3rd power for deep wear... Maybe the people on your link got a table from something different than what they though it was.
LeifCarrotson 6y ago
Vehicle weight is not directly proportional to axle count - a 9 axle semi with trailer can weigh 80,000 lbs or 9000 lbs/axle, a 2-axle car weighs 3500 or 1750 lbs/axle. Alternatively, multiplying axle count by 4.5 increases vehicle weight by 25x - so the two can both be true at the same time, the power just changes whether you use vehicle weight or axle load.
- yread 6y ago
  What effect does tire width have? Very narrow (<165mm) tires vs dual tires of trucks for example. Smaller area of friction versus lower pressure
  - serf 6y ago
    >What effect does tire width have? probably quite an effect, but reducing damage via width will also decrease vehicle efficiency and increase rolling resistance, so the gains at the road may be lost in an overall loss of efficiency at the vehicle, not to mention manufacturing and materials cost, when finagling the tire-width variable. I don't have any numbers, though.
    - derefr 6y ago
      > will also decrease vehicle efficiency and increase rolling resistance Not necessarily; one could formulate the tread rubber for such wider tires so they're less grippy per square cm of tread contact-surface, and so exactly as grippy as before per fully-loaded tire. Basically making every change in the opposite direction from what dragster tires do (other than the width.)
      - ew6082 6y ago
        That's for peak power. Efficiency is lost in the deformation bending and returning of the walls of each tire as it rolls. i.e. A really highly loaded tire needs to be really well pressurized to prevent overheating and failure due to the losses.
neolog 6y ago
Got a link to engineering podcasts?

marcosdumay 6y ago

It's a complicated function that behaves like different powers at different depths. But superficial wear (this study) should have a higher power than deep wear (your link). Civil engineers normally used the 3rd power for deep wear... Maybe the people on your link got a table from something different than what they though it was.

LeifCarrotson 6y ago

Vehicle weight is not directly proportional to axle count - a 9 axle semi with trailer can weigh 80,000 lbs or 9000 lbs/axle, a 2-axle car weighs 3500 or 1750 lbs/axle. Alternatively, multiplying axle count by 4.5 increases vehicle weight by 25x - so the two can both be true at the same time, the power just changes whether you use vehicle weight or axle load.

yread 6y ago
What effect does tire width have? Very narrow (<165mm) tires vs dual tires of trucks for example. Smaller area of friction versus lower pressure
- serf 6y ago
  >What effect does tire width have? probably quite an effect, but reducing damage via width will also decrease vehicle efficiency and increase rolling resistance, so the gains at the road may be lost in an overall loss of efficiency at the vehicle, not to mention manufacturing and materials cost, when finagling the tire-width variable. I don't have any numbers, though.
  - derefr 6y ago
    > will also decrease vehicle efficiency and increase rolling resistance Not necessarily; one could formulate the tread rubber for such wider tires so they're less grippy per square cm of tread contact-surface, and so exactly as grippy as before per fully-loaded tire. Basically making every change in the opposite direction from what dragster tires do (other than the width.)
    - ew6082 6y ago
      That's for peak power. Efficiency is lost in the deformation bending and returning of the walls of each tire as it rolls. i.e. A really highly loaded tire needs to be really well pressurized to prevent overheating and failure due to the losses.

neolog 6y ago

Got a link to engineering podcasts?