8D.D.2.1 Axial Stress
Tensile Stress
The allowable tensile stress, as calculated in STAAD.Pro as per IS:802 is described below.
The estimated tensile stresses on the net effective sectional area in various members, multiplied by the appropriate factor of safety shall not exceed minimum guaranteed yield stress of the material.
Thus, the permissible stress in axial tension, σ_{at} in MPa on the net effective area of the sections shall not exceed
σ_{at} = F_{y}
where= 
Compressive Stress
The estimated compressive stresses in various members multiplied by the appropriate factor of safety shall not exceed the value given by the formulae described below.

Condition: when (b/t) ≤ [ (b/t)_{lim} = 210/√F_{y}]:

When KL/r ≤ C_{c}, the allowable compressive stress is (in N/mm^{2})
F_{a} = F_{y}{1  0.5[(KL/r)/C_{c}]^{2}}

When KL/r > C_{c}, the allowable compressive stress is (in N/mm^{2})
F_{a} = π^{2}E/(KL/r)^{2}


Condition: when (b/t)_{lim} < (b/t) ≤ 378/√F_{y}:
The equations in condition 1 shall be used, substituting for F_{y} the value F_{cr} given by:
F_{cr} = F_{y}[1.677  0.677·(b/t)/(b/t)_{lim}]

Condition: when (b/t) > 378/√F_{y}
The equations in condition 1 shall be used, substituting for F_{y} the value F_{cr} given by:
F_{cr} = 65,550/(b/t)
=  
=  
=  
=  
=  
=  
=  
=  
= 