The ratio of the effective length of a member to the radius of gyration of the cross-section about the axis under consideration.
Use of Slenderness Ratio:
It is used to find out the design load as well as in classifying various columns in short/intermediate/long. The slenderness ratio of a column gives an indication of buckling failure in the column. The more the slenderness ratio, the more the tendency of the column to fail by buckling effect in that direction.