The figure below shows the column buckling which has the ratio of design compressive stress to yield stress on Y-axis and non-dimensional slenderness ratio on X-axis. On the basis of this curve, which of the following statements is correct?
- AThe imperfection factor, for the Buckling Class a, b, c, & d has the order as a > b > c > d
- BThe imperfection factor, for the Buckling Class a, b, c, & d has the order as d > c > b > aCorrect
- CThe imperfection factor, for the Buckling Class a, b, c, & d has the order as b > c > d > a
- DThe imperfection factor, for the Buckling Class a, b, c, & d has the order as c > d > a > b
Solution
Concept
Buckling classes and imperfection factors
Formula
α: a = 0.21, b = 0.34, c = 0.49, d = 0.76
Step-by-step solution
1. IS 800 imperfection factors: class a 0.21, b 0.34, c 0.49, d 0.76. 2. Curve a is the highest (best), curve d the lowest in the figure. 3. Imperfection factor order: d > c > b > a.
Explanation
The lower the curve, the larger the imperfection factor.
Why the other options are wrong
The other orders contradict the factor values.
Shortcut
Lowest curve = largest α.
Correct answer: B) The imperfection factor, for the Buckling Class a, b, c, & d has the order as d > c > b > a