'Purlins' in a roof truss system are designed as:
Choose the correct answer
Compression members (columns)
Biaxial bending members — gravity load resolved along roof slope and normal to it, plus wind in/out of plane
Tension-only rods
Only for resisting horizontal wind load
Correct Answer
B. Biaxial bending members — gravity load resolved along roof slope and normal to it, plus wind in/out of plane
Why is this the answer?
Purlins: secondary members spanning between roof trusses, carrying roof sheets/cladding. Subjected to biaxial bending because: (1) Major axis bending from vertical (gravity) loads resolved along and perpendicular to slope; (2) Wind suction/pressure. IS 800: Z-section or C-section purlins common. Designed as beam in biaxial bending; can use IS 800 method for bending about both axes.
Related Steel Structures MCQs
More solved Steel Structures questions for AE/JE Civil Engineering exams.
- The 'residual stresses' in hot-rolled steel sections arise from:
- The 'effective slenderness ratio' for a single angle compression member (IS 800)...
- 'Fatigue failure' in steel structures occurs under:
- The 'tension field action' in a plate girder web after buckling means:
- Bolts in 'slip-critical' (HSFG) connections resist load by:
- The 'portal frame analysis' approximation for multi-storey frames under horizontal load...
Practice more Civil Engineering questions
This MCQ belongs to JE Level Premium Test Series. Full tests include timed attempts, rank comparison and subject-wise analysis.