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Radius of gyration

For column design, the radius of gyration incorporates area and the moment of inertia. This value represents the resistance of a cross-section to buckling, which in columns happens under a load parallel to its lesser dimension. The slenderness ratio is the ratio of a column's effective length (modified by K-value to account for its end conditions) to its least radius of gyration.
For a W12x16 A36 steel column with a least radius of gyration of 0.773, whose ends are both free to rotate but fixed in translation (K=1), what is it's slenderness ratio?

AnswerKl/r = (1)(12feet)(12in/ft) / 0.773 = 186.3

ARE 4.0 exam prep: SS

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