Bolt Cross

Wheel bolt dimensions?

Hi,

I am trying to figure out the diameter of the wheel bolt in a car wheel, a car that breaks with locking it's wheels in these conditions:
- the mass of the car is 1500 kg
- all the weight of the car is shifted on the front wheels
- only the front wheels brake
- the friction coefficient between tire and road is 0.5
- a wheel has 5 bolts that are placed on a circle of 50 mm radius centered in the wheel center
- the total radius of the wheel+tire is 316 mm
- the car produces a torque of 285Nm at 1800 rpm
- the modulus of shearing (I'm not sure if the translation is correct, I'm not a native English speaker) is 100 MPa (the maximum effort that the steel can hold before breaking)

Thank you!

Kind of abusive on the car, maybe?

first lets find the force the road applies to the wheels
normal force is mg
so frictional force is 0.5mg
F = 0.5(1500)(9.81)
F = 7360 N

summing forces about the center of the locked up tire we can determine the force the wheel bolts create to resist the braking load. I'll assume the friction force between the wheel and hub is zero so that all force is carried by the bolts.

7360(316) - Fb(50) = 0
Fb = 46500 N

Assume each bolt is equally loaded on two tires (10 bolts)
each bolt carries
46500/10 = 4650 N

so each bolt cross sectional area is found by dividing by the shear modulus (good job on the english)

A = 4650/100x10^6
A = 4.65x10^-5 m^2

as area for a circle is (pi)r^2
(pi)r^2 = 4.65x10^-5
r = 0.00385 m
so round up to
r = 4 mm
d = 8 mm

This is a minimum and has no factor of safety.

Find Bolt Cross On eBay Below:

NEW Mission MXB 400 Cross Bow With Pro Package W Scope Quiver Bolts Case Rope
NEW Mission MXB 400 Cross Bow With Pro Package W Scope Quiver Bolts Case Rope
$1,599.00
Barnett Razr Cross Bow Game plan X Bolt Bag Carbon Express Kit
Barnett Razr Cross Bow Game plan X Bolt Bag Carbon Express Kit
$899.99
BladesUSA Eagle2 D Crossbow Bolts 14 Inch Aluminum Dart For 150 Pound S Cross
BladesUSA Eagle2 D Crossbow Bolts 14 Inch Aluminum Dart For 150 Pound S Cross
$18.05
5 PCS 15 150 180 lb Aluminum Hunting Crossbow Bow Bolts Arrows Scope Cross Bow
5 PCS 15 150 180 lb Aluminum Hunting Crossbow Bow Bolts Arrows Scope Cross Bow
$8.48
Self Cocking ALUMINUM PISTOL SYSTEM 80 lb CROSSBOW CROSS BOW W 3 BOLTS
Self Cocking ALUMINUM PISTOL SYSTEM 80 lb CROSSBOW CROSS BOW W 3 BOLTS
$49.00
MINI 80 LB ARCHERY HUNTING Gun METAL PISTOL CROSSBOW W 15 BOLTS ARROWS Cross
MINI 80 LB ARCHERY HUNTING Gun METAL PISTOL CROSSBOW W 15 BOLTS ARROWS Cross
$24.93
180LB CAMOUFLAGE HUNTING CROSSBOW + 4x20 SCOPE + 14 BOLTS camo cross bow 180 lb
180LB CAMOUFLAGE HUNTING CROSSBOW + 4x20 SCOPE + 14 BOLTS camo cross bow 180 lb
$139.89
SPORTSMAN 80 POUND CROSSBOW ARROWS bolts ARCHERY cross bow hunting pistol new LB
SPORTSMAN 80 POUND CROSSBOW ARROWS bolts ARCHERY cross bow hunting pistol new LB
$29.99
BARNETT CROSS BOW WITH 12 NEW BOLTS COME SEE ROBINHOOD
BARNETT CROSS BOW WITH 12 NEW BOLTS COME SEE ROBINHOOD
$95.00
20 PCS 15 150 180 lb Aluminum Hunting Crossbow Bow Bolts Arrows Scope Cross Bow
20 PCS 15 150 180 lb Aluminum Hunting Crossbow Bow Bolts Arrows Scope Cross Bow
$32.48
Crossbow Self Cocking with Hunting Scope KingsArchery Cross Bow Hunt Arrow Bolts
Crossbow Self Cocking with Hunting Scope KingsArchery Cross Bow Hunt Arrow Bolts
$96.44
NEW 50 POUND CROSSBOW with ARROWS bolts ARCHERY cross bow hunting pistol new lb
NEW 50 POUND CROSSBOW with ARROWS bolts ARCHERY cross bow hunting pistol new lb
$12.99
120LB DRAW CROSSBOW +2 BOLTS ADJUSTABLE CROSS BOW + 2 ARROWS LAST ONE HUNTING
120LB DRAW CROSSBOW +2 BOLTS ADJUSTABLE CROSS BOW + 2 ARROWS LAST ONE HUNTING
$87.00
Self Cocking Crossbow 80lb Draw Mini Pistol Cross Bow With 15 Arrows Bolts
Self Cocking Crossbow 80lb Draw Mini Pistol Cross Bow With 15 Arrows Bolts
$39.59
6 Pack Excalibur 22CAV 6 Cross Bow Bolts Nocks NOT Included
6 Pack Excalibur 22CAV 6 Cross Bow Bolts Nocks NOT Included
$37.97


Recently Purchased Bolt Cross:


barnett razr cross bow game plan xbolt bag carbon express kit, 120lb draw crossbow 2 bolts adjustable cross bow 2 arrows last one hunting, mini 80 lb archery hunting gun metal pistol crossbow w15 bolts arrows cross , bladesusa eagle2d crossbow bolts 14inch aluminum dart for 150pound s cross, 6 pack excalibur 22cav 6 cross bow bolts nocks not included, self cocking crossbow 80lb draw mini pistol cross bow with 15 arrows bolts, self cocking aluminum pistol system 80 lb crossbow cross bow w3 bolts, new mission mxb 400 cross bow with pro package w scope quiver bolts case rope , barnett cross bow with 12 new bolts come see robinhood, crossbow selfcocking with hunting scope kingsarchery cross bow hunt arrow bolts, 20 pcs 15 150 180 lb aluminum hunting crossbow bow bolts arrows scope cross bow, 5 pcs 15 150 180 lb aluminum hunting crossbow bow bolts arrows scope cross bow, new 50 pound crossbow with arrows bolts archery cross bow hunting pistol new lb, sportsman 80 pound crossbow arrows bolts archery cross bow hunting pistol new lb, 180lb camouflage hunting crossbow 4x20 scope 14 bolts camo cross bow 180 lb



Comments are closed.