The critical buckling load of a slender column with both ends closed to both ends hinged is in the ratio of 4:1. The theoretical critical buckling load formula isPcr=Leff2π2EI where L is the effective length of the column depends on the end condition. For both ends fixed, Pcr,1=(L/2)2πEI and for both ends hinged, Pcr,2=L2π2EI,The required ratio is Pcr,2Pcr,1 =(L/2)2π2EI×π2EIL2=4