Question

The design compressive stress, fcd of column is given by

(a) [fy / γm0]/ [φ – (φ^2-λ^2)^2].

(b) [fy / γm0] / [φ + (φ^2-λ^2)].

(c) [fy / γm0]/[φ – (φ^2-λ^2)^0.5].

(d) [fy / γm0] / [φ + (φ^2-λ^2)^0.5].

This question was addressed to me by my school principal while I was bunking the class.

This intriguing question comes from Design of Compression Members topic in chapter Design of Compression Members of Design of Steel Structures

Answer 1

Right option is (d) [fy / γm0] / [φ + (φ^2-λ^2)^0.5].

Explanation: The design compressive stress, fcd of column is given by fcd = [fy / γm0] / [φ + (φ^2-λ^2)^0.5], where fy is yield stress of material, φ is dependent on imperfection factor, λ is non dimensional effective slenderness ratio.