According to IS 800:2007, the design compressive strength of an axially loaded compression member is based on the: 

Explanation:

As per clause no 7.1, IS 800:2007, The design compressive strength P_d of an axially loaded member is based on the Perry Robertson Formula and is given by;

\(P_{d}= A_{e}f_{cd}\) , 

where A_e = Effective sectional area , f_cd = Design compressive stress 

The design compressive stress of axially loaded compression member shall be calculated using following equation:

 \(f_{cd} = \frac{\frac{f_{y}}{\gamma _{mo}}}{\Phi +\left [ \Phi ^{2}-\lambda ^{2} \right ]^{0.5}}=\chi \frac{f_{y}}{\gamma _{mo}}\leq \frac{f_{y}}{\gamma _{mo}}\),

where \(\phi= 0.5\left [ 1+\alpha \left ( \lambda -.2 \right )+ \lambda^{2}\right ]\) , \(\lambda\)= non-dimensional effective slenderness ratio \(=\sqrt{\frac{f_{y}}{f_{cc}}} \) , where f_cc = Euler's buckling class\(=\frac{\pi ^{2}E}{(\frac{KL}{r})^{2}} \)

Where \(\frac{KL}{r}\)= Effective slenderness ratio , \(\alpha\) = Imperfection factor , \(\chi\) = stress reduction factor , \(\gamma_{mo}\)= partial safety factor for material strength