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.
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).
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). solution manual steel structures design and behavior
Block shear rupture strength (AISC Eq J4-5):
Better to follow AISC manual example: For L4×4×½ connected with 3 bolts, block shear strength: Check alternative staggered path through first hole in
This manual provides detailed step-by-step solutions for end-of-chapter problems. Solutions follow the AISC Specification for Structural Steel Buildings (ANSI/AISC 360) – current edition. References to provisions (e.g., Section D2, Table D3.1) refer to the AISC Specification. Chapter 2: Tension Members Problem 2.17 (Sample Problem)
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. For one diagonal path: ( A_n = A_g - 2 (d_h t) + (1
[ A_{gv} = 2 \times ( \text{shear length along bolt line}) \times t = 2 \times 7.5 \times 0.5 = 7.5 \text{ in}^2 ] [ A_{nv} = A_{gv} - 2 \times (2.5 \times d_h \times t) \quad \text{(2.5 holes per shear plane)} = 7.5 - 2 \times (2.5 \times 1.0 \times 0.5) = 7.5 - 2.5 = 5.0 \text{ in}^2 ] [ A_{nt} = ( \text{gage} - d_h) \times t = (2.0 - 1.0) \times 0.5 = 0.5 \text{ in}^2 ]