Static Loads

Wfs= Wc/L

Wrs= Wb/L

Wfs = Static weight on front axle

Wr= Static weight on rear axle

Dynamic Loads

  • Grades (θ)

Wf = Wfs – Whθ/L

Wr = Wrs + Whθ/L

W= Dynamic weight on front axle

Wr = Dynamic weight on rear axle

  • Accelerating

Wf = Wfs – Whax/(Lgc)

Wr = Wrs + Whax/(Lgc)

ax = acceleration in X-direction

gc = acceleration of gravity

 

Acceleration relation

Fx = M.ax = Wax/gc

P = Fx.V

ax = Fx gc/W = Pgc/(VW)

ax / gc = P/(VW)

Acceleration is

  1. Proportional to power to weight ratio.
  2. Inversely proportional to speed.
  3. Efficiency in utilizing available power depends on
  • Minimizing friction losses and
  • Ability to keep engine at peak power.