### Column Design (Part 3)

Let's continue from the previous post ...

The criteria to select whether we should use the Euler formula or the J. B. Johnson formula to calculate for the critical load (Pcr) of the column is related to the value of the actual slenderness ratio or

where: E = Modulus of elasticity of the material of the column Sy = Yield strength of the column material

The use of the above column constant (Cc) is as follows, Determine the

The criteria to select whether we should use the Euler formula or the J. B. Johnson formula to calculate for the critical load (Pcr) of the column is related to the value of the actual slenderness ratio or

**column constant**, Cc. It is defined aswhere: E = Modulus of elasticity of the material of the column Sy = Yield strength of the column material

The use of the above column constant (Cc) is as follows, Determine the

**length**and**end fixity**of the columnDefine the value of the**constant (K)**according to the type of end fixityCompute the**effective length (Le)**from**Le = KL**From the cross section shape and dimensions, compute the**radius of gyration (r)**from**r = sqrt(I/A)**Compute the slenderness ratio from**Slenderness ratio = Le/r_min = KL/r_min**From the material of the column, compute the**column constant (Cc)**as per the above formulaCheck whether**KL/r > Cc?**If yes, the column is Long: Use the Euler formulaIf no, the column is Short: Use the J. B. …