Permitted Maximum Slenderness Ratio of a Steel Column

The permitted maximum slenderness ratio of a steel column under dead load and live load is determined by the following factors:

1. Buckling Strength Ratio

The buckling strength ratio is the ratio of the buckling strength of a column to the axial load applied to the column. The buckling strength of a column is the maximum load that the column can withstand before buckling occurs. The axial load is the load that is applied to the column in the direction of its axis.

2. Effective Length Factor

The effective length factor is a factor that takes into account the effective length of the column. The effective length of a column is the length of the column between its points of lateral support. The effective length factor is used to calculate the buckling strength of the column.

3. Slenderness Ratio

The slenderness ratio is the ratio of the effective length of the column to its least radius of gyration. The radius of gyration is a property of a cross-sectional shape that determines how far the material is distributed from its axis of rotation.

Calculation of Permitted Maximum Slenderness Ratio

The permitted maximum slenderness ratio of a steel column under dead load and live load is calculated as follows:

Permitted Maximum Slenderness Ratio = Buckling Strength Ratio / (Effective Length Factor x Slenderness Ratio)

The value of the permitted maximum slenderness ratio depends on the design code used. For example, the permitted maximum slenderness ratio for a steel column under dead load and live load according to the American Institute of Steel Construction (AISC) code is 180. This means that the slenderness ratio of a steel column should not exceed 180. If the slenderness ratio of a steel column exceeds 180, the column may buckle under the applied load.