Question

The value of φ in the equation of design compressive strength is given by

(a) φ = 0.5[1-α(λ-0.2)+λ^2].

(b) φ = 0.5[1-α(λ-0.2)-+λ^2].

(c) φ = 0.5[1+α(λ+0.2)-λ^2].

(d) φ = 0.5[1+α(λ-0.2)+λ^2].

This question was posed to me in a job interview.

My question is based upon Design of Compression Members in chapter Design of Compression Members of Design of Steel Structures

Answer 1

The correct answer is (d) φ = 0.5[1+α(λ-0.2)+λ^2].

For explanation: The value of φ in the equation of design compressive strength is given by φ = 0.5[1+α(λ-0.2)+λ^2], where α is imperfection factor(depends on buckling class) and λ is non-dimensional effective slenderness ratio.