By considering the net area as An, ultimate stress as fu and the partial safety factor as γml, the IS code formula for the preliminary design of a tension member for design strength due to rupture (Tdn) of the critical section is
1
\(T_{dn} = {\alpha A_n f_u\over2\gamma_{ml}}\)
2
\(T_{dn} = {A_n f_u\over\alpha\gamma_{ml}}\)
3
\(T_{dn} = {\gamma_{ml}A_n f_u\over\alpha}\)
4
\(T_{dn}={\alpha A_nf_u\over\gamma_{ml}}\)