Wheel skidding due to braking
Wheel skidding due to braking
(OP)
I would like to work out if my wheels are going to skid, but am a bit stuck
We have wheel diameter = 460
Speed = 50kph, 13.9m\s
Weight on wheel = 3600kg
Effective braking force = 300Nm (worked out from brake radius & brake clamp force Cf of pads)
CF wheel to rail = 0.5
Can any one help with this, do I need to provide further info
Regards Brendon
We have wheel diameter = 460
Speed = 50kph, 13.9m\s
Weight on wheel = 3600kg
Effective braking force = 300Nm (worked out from brake radius & brake clamp force Cf of pads)
CF wheel to rail = 0.5
Can any one help with this, do I need to provide further info
Regards Brendon





RE: Wheel skidding due to braking
RE: Wheel skidding due to braking
3600 kg on earth at normal surface conditions gives 3600 x 9.807 = 35,305 N
1304 / 35305 = 0.037
That is the minimum coefficient of friction necessary to avoid skidding. More than that (which is virtually certain, even on ice) and there is no skid.
The other information that was provided, is irrelevant.
Mind you, with such little braking force being applied, the vehicle is going to take a loooooong time to stop. If your numbers are wrong, I can't help it.
Not sure why that was so hard.
RE: Wheel skidding due to braking
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way
RE: Wheel skidding due to braking
RE: Wheel skidding due to braking
kg is not weight. It is mass.
Nm is not force. It is torque or moment.
If I assume this is a 4 wheeled contraption, then we can extrapolate it to be 14,400kg.
Stopping distance becomes 268m. A long way.
It can run away on an incline greater than 2.1 deg.
The basic nature of the question and the confusion over elementary units leads me to believe either:
1) This is a student posting.
2) The original poster may be in over his head. I don't know that forum guidance is a good way to design 14 Ton carts.
RE: Wheel skidding due to braking
Re. Imcjoek's comments. hay, sorry for asking, and for mixing my P's & Q's.
I'm not designing by forum, there are hundreds of calcs in our design, just got a little stuck on that one and our guru was away that day, so I thought I could ask here..
But you are right, I should be more careful with my units, lesson learned, thanks
Cheers Brendon