NASCLA Accredited Commercial General ContractorMetalsHard
A steel fabricator receives a shipment of ASTM A500 Grade B hollow structural sections (HSS). What is the primary advantage of using HSS in structural applications compared to traditional open sections like W-shapes, particularly in columns or truss members subjected to axial compression?
- AHSS connections are inherently simpler and require fewer bolts or welds.
- BHSS provides superior resistance to local buckling due to its closed shape.
- CHSS offers lighter weight per linear foot for the same strength.
- DHSS is significantly less expensive to produce and procure.
Show answer & explanationAnswer & explanation
Correct answer: B. HSS provides superior resistance to local buckling due to its closed shape.
The closed, box-like shape of HSS provides excellent torsional stiffness and significantly improved resistance to local buckling compared to open sections, making them highly efficient for members subjected to axial compression or torsion. While weight and cost can vary, and connection design can be complex, local buckling resistance is a primary structural advantage.
Why the other options are wrong
- A. Connections for HSS can often be more complex than for open sections, especially for moment connections, requiring specialized welding or fitting.
- C. While HSS can be efficient, it is not universally lighter for the same strength; efficiency depends on the specific design and loading conditions.
- D. The cost of HSS can be comparable to, or sometimes more than, open sections depending on market conditions, material grade, and fabrication complexity.
Hollow Structural Sections (HSS)
Closed structural steel shapes (squares, rectangles, rounds) used in construction, offering high strength-to-weight ratios, excellent torsional stiffness, and resistance to local buckling.
- ASTM A500 is a common specification for cold-formed HSS.
- Efficient for columns, truss members, and architectural exposed structures.
- Superior resistance to local buckling and torsion due to closed shape.
- Connections can sometimes be more complex than for open sections.
Memory trick: HSS: Closed Shape, Stronger Against Buckling.