LRFD: ( \phi_t = 0.75 ) → ( P_d = 0.75 \times 129.5 = 97.1 \text{ kips} ) ASD: ( \Omega_t = 2.00 ) → ( P_a = 129.5 / 2.00 = 64.8 \text{ kips} )
[ A_n = A_g - \sum (d_h \cdot t) + \sum \left( \frac{s^2}{4g} \cdot t \right) ] solution manual steel structures design and behavior
Thickness ( t = 0.5 \text{ in} ). Two hole diameters in the failure path (assuming worst path goes through both holes in the same leg – check path 1-2-3). LRFD: ( \phi_t = 0
Better to follow AISC manual example: For L4×4×½ connected with 3 bolts, block shear strength: For angles, net section often through holes in
Path 1: straight line through both holes (no stagger effect since in same leg, but stagger formula still applies if line zigzags – here, holes are in same leg, so stagger not applied unless crossing to other leg? For angles, net section often through holes in same leg, stagger effect negligible for two holes on same line. However, typical solution uses two holes: ( A_n = A_g - 2 \cdot (d_h \cdot t) ) = ( 3.75 - 2 \cdot (1.0 \cdot 0.5) = 3.75 - 1.0 = 2.75 \text{ in}^2 ).
Gross shear length = ( 1.5 + 3 + 3 = 7.5 \text{ in} ) (from edge to last bolt). Net shear length = ( 7.5 - 2.5 \times d_h = 7.5 - 2.5 = 5.0 \text{ in} ) (since 2.5 holes along shear path? Actually 2.5 holes for two lines? Need precise – typical simplified: net shear area = ( (7.5 - 2.5*(1.0))*0.5 = 2.5 \text{ in}^2 ) per plane, two planes = 5.0 in²).