Double-angle tension member connected by one leg each – effective net area to be taken for design A pair of equal angles placed back-to-back in tension is connected to a gusset by one leg of each angle (single-sided connection). What should be taken as the net effective area of the section for strength calculations?

Introduction / Context:Shear lag reduces the effectiveness of outstanding legs in angle tension members. When two angles are placed back-to-back and each connects by only one leg to one side of a gusset, the load transfer path is primarily through the connected legs.

Given Data / Assumptions:

• Two equal angles, back-to-back.
• Each angle is connected by one leg to the gusset on the same side.
• Tension member design under working-stress concepts.

Concept / Approach:Only the connected legs have direct, efficient load transfer. Outstanding legs are prone to shear lag and are generally ignored in basic effective-area evaluation, unless a refined factor is applied. The simplest conservative approach is to use the sum of net areas of the two connected legs only.

Step-by-Step Solution:Identify load path → through connected legs adjacent to the gusset.Compute net area of each connected leg (deduct hole areas).Add the two net connected-leg areas; ignore outstanding legs.

Verification / Alternative check:Advanced provisions may allow a shear-lag factor on outstanding legs, but baseline conservative practice is to neglect them for design simplicity and safety.

Why Other Options Are Wrong:

• Gross area or all-leg area overestimates capacity by ignoring shear lag.
• Using only one leg is too conservative for a double-angle member.

Common Pitfalls:Forgetting to deduct bolt/rivet-hole areas when computing the net area of the connected legs.

Final Answer:Sum of the net areas of the two connected legs only; outstanding legs neglected