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Bracket angles riveted to column, 180 kN

Short answer

Each angle requires 9 nos. 20 mm rivets at 60 mm pitch and 40 mm end distance, suitable for both hot-driven and cold-driven shop rivets.

Design the connection between the bracket angles 2-IAS 110× 110 × 8 mm and column using (i) power driven (hot) shop rivets (ii) Power driven (cold) shop rivets, as shown in figure below. [Figure: P = 180 K (kN) acting at 275 mm from the column; vertical rivet line with 40 mm end distances at top and bottom and 60 mm pitch between 9 rivets]

Basis: working stress method (IS 800:1984), rivet diameter 20 mm (hole 21.5 mm), P=180P=180 kN (working) at e=275e=275 mm. The load is shared equally by the two angles, 90 kN each. Each angle has one vertical line of 9 rivets, pitch 60 mm, end distance 40 mm, connected to the column flange. The rivets act in single shear, and the 8 mm angle leg governs bearing.

Permissible stresses (IS 800:1984)

RivetShear τvf\tau_{vf}Bearing σpf\sigma_{pf}
(i) Power-driven (hot) shop rivet100 N/mm²300 N/mm²
(ii) Power-driven (cold-driven) rivet, taken at the field value90 N/mm²270 N/mm²

Rivet values (area of hole =363.1=363.1 mm²)

CaseShear value (kN)Bearing value σpf d0 t\sigma_{pf}\,d_0\,t (kN)Rivet value (kN)
(i) hot36.3151.6036.31
(ii) cold32.6746.4432.67

Force in the extreme rivet (one angle)

  • Moment M=90×275=24750M=90\times275=24750 kN·mm
  • Σy2=2(602+1202+1802+2402)=216000\Sigma y^2=2(60^2+120^2+180^2+240^2)=216000 mm²
  • Horizontal force (torsion) at the extreme rivet: Fx=MymaxΣy2=24750×240216000=27.50F_x=\dfrac{M y_{max}}{\Sigma y^2}=\dfrac{24750\times240}{216000}=27.50 kN
  • Direct (vertical) shear: Fd=909=10.00F_d=\dfrac{90}{9}=10.00 kN
  • Resultant: R=27.502+10.002=29.26R=\sqrt{27.50^2+10.00^2}=29.26 kN

Check

  • (i) R=29.26 kN<36.31R=29.26\ \text{kN}<36.31 kN → safe (ratio 0.81).
  • (ii) R=29.26 kN<32.67R=29.26\ \text{kN}<32.67 kN → safe (ratio 0.90).

Answer: provide 9 nos. 20 mm rivets at 60 mm pitch (40 mm end distance) in each of the two angles, for both hot-driven and cold-driven rivets. (18 mm rivets would be marginal and 16 mm rivets unsafe.)

✓ Answer checked by Claude Opus 5.5 (high effort)

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