Curb Climbing Calculation

[krue0101]

Hello,
I am building a utility vehicle and am trying to determine if I will be able to climb curbs with it. I am having a tough time calculating the required force/tractive effort to get up a 6" curb with a 21" tire.

Can anyone help?

Thanks

 

[mloew]

What equations did you get from a statics calculation?

Best regards,

Matthew Ian Loew


Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[krue0101]

I have a 20inch diameter wheel and would like to climb a 6inch curb so I just did a fbd of a tire up against a curb and summed the moments about the point that the tire meets the curb.

I came up with [F(axle forward)*4 inches]- [Weight(vehicle)*10inches] = 0.

It seems pretty simple, but I am not sure if this is correct?

Any comments??

Thanks

 

[magnograil]

You need to consider more factors such as whether it is being driven into the curb by the rear wheel or the front wheel is supplying the torque to climb the curb. What is the expected coefficient of friction at the road and curb? Momentum will supply some of the force required. Suspension will reduce some of the apparent weight on the tyre.

 

[krue0101]

Hello,

It is a real wheel drive vehicle.

I will use the coefficient of traction for concrete.

What else can I do analytically to determine the rear wheel torque required to climb this curb?

Thanks,

 

[mloew]

Statics, to start. You will need to figure out what the peak torque is while trying to climb the curb. There will be a combination of forces acting at the tire/curb contact point. One acting longitidinally and one vertically from gravity.

Best regards,

Matthew Ian Loew


Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.