Question

rankins gorden formule

Answer 1

$\frac{1}{P_r} = \frac{1}{P_e} + \frac{1}{P_c}$

Where   
Pe = Euler crippling load 
Pc = Crushing load or Yield point load in Compression
Pr = Actual load to cause failure or Rankine load

Answer 2

$\frac{1}{P_r} = \frac{1}{P_e} + \frac{1}{P_c}$

Where

Pe = Euler crippling load

Pc = Crushing load or Yield point load in Compression

Pr = Actual load to cause failure or Rankine load