For steel compression members, the maximum permissible slenderness ratio for single-angle discontinuous struts connected by a single rivet or bolt is limited to which value?

Introduction / Context:Slenderness ratio (effective length/radius of gyration) limits prevent excessive buckling susceptibility and serviceability problems. Discontinuous single-angle struts connected by a single fastener behave less effectively in compression, so codes specify lower slenderness limits than for well-braced members.

Given Data / Assumptions:

• Member type: single angle, discontinuous strut.
• Connection: single rivet/bolt (less restraint).
• We seek the upper limit of slenderness ratio for such a member class.

Concept / Approach:

Poor end restraint and eccentricity in single-angle connections reduce compression capacity and stiffness. Hence the allowable slenderness is capped at a more stringent value (≈130) compared to more robust compression members.

Step-by-Step Solution:

Verification / Alternative check:

Design handbooks list varying limits based on member use; values around 120–130 are commonly associated with lightly connected discontinuous struts, lower than 150–180 used elsewhere.

Why Other Options Are Wrong:

• 110: Unduly restrictive relative to standard allowances.
• 150 or 180: Too permissive for single-angle, single-fastener struts.
• 95: Far too low and impractical for typical steelwork.

Common Pitfalls:

• Applying limits for main compression members to lightly connected angle struts without adjustment.
• Ignoring eccentric fastener effects which reduce effective buckling resistance.

Final Answer:

130