Slenderness control under load reversal: A tension member that may be subjected to stress reversal due to wind (i.e., may experience compression at times) should have its slenderness ratio limited to which maximum value?

Civil Engineering Steel Structure Design Difficulty: Easy
Choose an option
  • A
    180
  • B
    200
  • C
    250
  • D
    300
  • E
    350

Answer

Correct Answer: 180

Explanation

Introduction / Context:Tension members designed primarily for tension can sometimes experience compression under wind or seismic load combinations. Codes place a stricter slenderness limit in such cases to avoid excessive flexural buckling susceptibility.

Given Data / Assumptions:

  • Member is usually in tension but may see compression due to load reversal.
  • Slenderness ratio is L/r (effective length over radius of gyration).

Concept / Approach:Where reversal of stress is possible, the member must satisfy not only tensile limit states but also the serviceability and stability requirements applicable to compression. A commonly used upper limit for such “tension members liable to reversal” is about 180 to provide adequate stiffness against buckling in compression.

Step-by-Step Solution:Recognize potential compression under wind.Adopt conservative slenderness limit to control buckling risk.Select 180 as the maximum recommended value.

Verification / Alternative check:Historic working stress provisions and many exam references cite 180 as the limit for tension members subject to reversal; pure tension members may be allowed higher limits for appearance or vibration only.

Why Other Options Are Wrong:

  • 200–350: too slender, offering inadequate compression stability under reversal.

Common Pitfalls:

  • Treating potentially reversible members as pure tension without checking buckling.

Final Answer:180

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