Compression Members MCQ with answer and solution

Concept

Definition of beam-column structural member

Formula

NONE

Step-by-step solution

1. A strut is a structural member subjected purely to axial compression. 2. A beam carries transverse loads, resulting predominantly in bending moments. 3. A structural member simultaneously subjected to axial compression and bending moment is defined as a beam-column. Answer: C

Explanation

Structural elements that carry both bending moments like a beam and axial compressive loads like a column are classified as beam-columns. In real structures, pure columns or pure beams are rare because connections typically transfer both force types simultaneously. Consequently, design codes evaluate beam-columns under combined stress interaction equations.

Why the other options are wrong

A) A strut is subjected predominantly to axial compression without significant bending. B) A purlin is a roof beam subjected primarily to bending loads. D) A lintel is a horizontal beam designed to carry gravity masonry loads above wall openings.

Shortcut

Bending (Beam) + Axial Load (Column) = Beam-Column.

Common mistake

Confusing a beam-column with a simple strut that only carries axial compression load.