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8/9/2019 vertical bracing
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Member No. = 398 (PR9 - STRUCTURE 65)
Bolt Strength gr 8.8
Shear strength ps = 375 N/mm2
(Table30, BS5950-1:2000)
Bearing strength pbb = 1000 N/mm2
(Table31, BS5950-1:2000)
Tensile strength pt = 560 N/mm2 (Table34, BS5950-1:2000)
Steel Details S275
Design strength of steel py = 250 N/mm2
Bearing strength of steel pbs = 460 N/mm2
(Table32, BS5950-1:2000)
Weld Strength E70 XX
Design strength of fillet welds pws = 225 N/mm2
(Table37, BS5950-1:2000)
FORCES FROM STAAD ANALYSISAf = 426225 N
GENERAL DATA
UC203X203X46
VERTICAL BRACING CONNECTION
(axial force [Ax])
High Strength Bolt Grade
Structural Steel Grade
Welding Electrode Grade
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Depth of Section Db1 = 203.2 mmWidth of section Bb1 = 203.6 mm
Area of the Section As = 5870 mm²
Flange Thickness Ft1 = 11 mm
Web Thickness Wt1 = 7.2 mm
Root Radius Rr1 = 10.2 mm
Edge Distance A1 = 40 mm >1,4 D
Edge Distance A2 = 40 mm >1,4 D
Nominal Diameter of the Bolt d = 20 mm
Shear area of the Bolt As = 314 mm2
Net area of Bolt Anb 245 mm2 (Ref: BS4190-2001,Table 16)
Diameter of Hole D = 22 mm
Number of Bolts in Web Nbw = 4
Number of Bolts in each Flange Nbf = 2
Number of the bolts in single shear NbS = 4
Number of the bolts in double shear NbD = 4
Effective web thickness
Thickness of shim padding on either side of web = 5 mm
Effective web thickness Wte = 17.2 mm
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Web cover plates
Thickness - web cover plates Wct = 10 mm
Width of cover plate Wcb = 160 mm
Number of Web cover plates = 2Correction factor for steel gr. 275 Ke (pt. 3 .4.3) = 1.2 (BS5950-1:2000,Cl 3.4.3)
Gross area of Web Cover plate Awg = 1600 mm2
Net areaAwn
= 1160 mm
2
Eff. area,Awe = Ke*Awn< Awg (or =Awg) Awe = 1392 mm2
Flange cover plates
Thickness - Flange Cover Plate Fct = 15 mm
Width of Flange cover plate Fcb = 200 mm
Number of cover plates on each flange = 1Correction factor for steel gr. 275 Ke (pt. 3 .4.3) = 1.2 (BS5950-1:2000,Cl 3.4.3)
Gross area of Flange Cover plate Afg = 3000 mm2
Net area Afn = 2340 mm2
Eff. area,Afe = Ke*Afn< Afg (or =Afg) Afe = 2808 mm2
A.) STRESS ON BOLTS
Check for Shear Capacity
Shear force in each bolt shear face Taf =Af/(NbS+2xNbD) = 426225 / (4 + 2 x 4)
35519 N
Shear capacity of one bolt per shear face Ps = ps·Anb = 375 x 245
91875 N
Check for Shear Taf < Ps 35519 < 91875 OK
B.) CHECK FOR TENSILE CAPACITY
Tensile capacity of Cover plates Pt = py(2*Awe + 2*Afe) = 250(2 x 1392 + 2 x 2808)
2100000 N
Pt > Af 2100000 > 426225 OK
C.) CHECK FOR BEARING
Web thk / Web cover plate
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Min thickness for bearing in web Wtb = 17.2 mm
i) Bearing capacity of bolt in web Pbb = d·Wtb·pbb = 20 x 17.2 x 1000344000 N
ii) Bearing capacity of web / cover plate Pbs1 = d·Wtb·pbs = 20 x 17.2 x 460
158240 N
but ≤ 1/2·A1·Wtb·pbs = 0.5 x 40 x 17.2 x 460
158240 N
Pbs1 > 2Taf 158240 > 71038 OK
Flange cover Plate Min thickness for bearing in Flange Ftb = 11 mm
iii) Bearing capacity of bolt in flange Pbb = d·Ftb·pbb = 20 x 11 x 1000
220000 N
iV) Bearing capacity of cover plate / flange Pbs2 = d·Ftb·pbs = 20 x 11 x 460
101200 N
but ≤ 1/2·A2·Ftb·pbs = 0.5 x 11 x 40 x 460
101200 NPbs2 > Taf 101200 > 35519 OK
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