Block shear rupture strength (AISC Eq J4-5):
A single-angle tension member, L4×4×½ (A36 steel), is connected to a gusset plate with 7/8-inch diameter bolts as shown in Figure P2.17 (three bolts in one leg, staggered: 3" on center along length, 2" gage). Compute the design tensile strength (LRFD) and allowable tensile strength (ASD).
Tension net area across last bolt row = (gage distance – one hole) * t = ( (2.0 - 1.0)*0.5 = 0.5 \text{ in}^2 ) per plane? Two planes? For single angle, block shear occurs in the connected leg only.
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 ).
Given edge distance = assume 1.5 in (standard), spacing = 3 in, hole diameter = 1 in, thickness = 0.5 in.
[ U = 1 - \frac{1.13}{6} = 0.812 ]
Tension member connected to gusset plate – check block shear along bolt group.
Check alternative staggered path through first hole in one leg then to hole in opposite leg? For L4×4, gage between legs (distance from back of one leg to center of holes in other leg) ≈ 2.5 in (AISC gage for angles). But given gage = 2.0 in, stagger term: ( s^2/(4g) = 3^2/(4 2) = 9/8 = 1.125 ). For one diagonal path: ( A_n = A_g - 2 (d_h t) + (1.125 t) ) = ( 3.75 - 1.0 + 0.5625 = 3.3125 \text{ in}^2 ) → larger than 2.75, so critical net area = 2.75 in².
Block shear rupture strength (AISC Eq J4-5):
A single-angle tension member, L4×4×½ (A36 steel), is connected to a gusset plate with 7/8-inch diameter bolts as shown in Figure P2.17 (three bolts in one leg, staggered: 3" on center along length, 2" gage). Compute the design tensile strength (LRFD) and allowable tensile strength (ASD).
Tension net area across last bolt row = (gage distance – one hole) * t = ( (2.0 - 1.0)*0.5 = 0.5 \text{ in}^2 ) per plane? Two planes? For single angle, block shear occurs in the connected leg only. solution manual steel structures design and behavior
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 ).
Given edge distance = assume 1.5 in (standard), spacing = 3 in, hole diameter = 1 in, thickness = 0.5 in. Block shear rupture strength (AISC Eq J4-5): A
[ U = 1 - \frac{1.13}{6} = 0.812 ]
Tension member connected to gusset plate – check block shear along bolt group. Two planes
Check alternative staggered path through first hole in one leg then to hole in opposite leg? For L4×4, gage between legs (distance from back of one leg to center of holes in other leg) ≈ 2.5 in (AISC gage for angles). But given gage = 2.0 in, stagger term: ( s^2/(4g) = 3^2/(4 2) = 9/8 = 1.125 ). For one diagonal path: ( A_n = A_g - 2 (d_h t) + (1.125 t) ) = ( 3.75 - 1.0 + 0.5625 = 3.3125 \text{ in}^2 ) → larger than 2.75, so critical net area = 2.75 in².