For a tension member with rivet or bolt holes, the net sectional area is computed as which of the following (relative to gross area)?

Introduction / Context:The presence of fastener holes reduces the effective area that resists tension. Correctly computing net area is essential for capacity checks and to prevent brittle net-section rupture across the line of holes.

Given Data / Assumptions:

• Member contains one or more lines of holes for bolts/rivets.
• Hole diameter used for deduction is the nominal hole size, not the fastener size.
• Staggered patterns may require additional adjustments.

Concept / Approach:Net area A_n = A_g - n * d_hole * t for a straight path through n holes (single plate), where A_g is gross area, d_hole is hole diameter, and t is plate thickness. For staggered lines, a zig-zag correction increases A_n due to longer failure path. The principle remains: subtract the material removed by holes from the gross area along the critical section.

Step-by-Step Solution:Identify the critical failure path (straight or zig-zag).Sum the total hole width crossing the path and multiply by thickness to obtain area removed.Compute A_n by subtracting the hole area from A_g, applying any stagger correction if required.

Verification / Alternative check:Design examples and codes adopt identical logic; capacity in tension is based on the lesser of gross yielding and net-section rupture, the latter using the net area just computed.

Why Other Options Are Wrong:

• Adding, dividing, or multiplying by hole area has no physical basis for section loss.
• None of these: incorrect because the subtraction method is established practice.

Common Pitfalls:

• Using fastener nominal diameter instead of hole diameter (which is larger due to clearance).
• Neglecting stagger correction when applicable.

Final Answer:Gross area minus the area of the rivet holes.