Tension member with rivet/bolt holes not in a single line: the governing strength of the net section depends on which geometric parameters?
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APitch (fastener spacing along the line of force)
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BGauge (transverse spacing between fastener lines)
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CDiameter of the rivet/bolt holes along the critical path
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DAll the above
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ENone of these
Answer
Correct Answer: All the above
Explanation
Introduction / Context:When holes do not lie on a single straight line, the critical rupture path can be zig-zag. Net-section strength must therefore consider both longitudinal and transverse spacing as well as hole sizes.
Given Data / Assumptions:
- Tension member with multiple fastener lines.
- Potential straight and zig-zag failure paths.
- Standard deductions for holes and stagger corrections.
Concept / Approach:Net width is computed by deducting hole diameters along the path, but zig-zag paths allow a stagger correction that adds back an amount proportional to gauge^2 / pitch for diagonal segments. Hence pitch, gauge, and hole diameters all influence the least net area.
Step-by-Step Solution:
Identify all plausible failure paths (straight and zig-zag).For each path, compute net width: b_net = b_gross − Σ(d_h) + Σ(stagger correction).Select the least net area A_net, then strength = A_net * f_t (or design value).Verification / Alternative check:Check block shear if applicable; confirm that the chosen path indeed gives the smallest net area.
Why Other Options Are Wrong:Each single parameter alone is insufficient; the interaction among pitch, gauge, and hole size governs the net section.
Common Pitfalls:Using nominal hole size instead of standard hole diameter; forgetting stagger correction; ignoring minimum pitch/gauge requirements causing tear-out.
Final Answer:All the above