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Indian standard angle 100×100×6mm is used as strut iin roof truss the length of strut between entrane section at each end 8m cal the strength 1) connect two halts at each end
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2) 1 bolt at each end 3) welded at each end

Given ISA=100×100×6

l=3m=3000mm

rvv=19.2mm

off length =0.854lenght of strut(0.821)

Leff=KL=1×3000=3000mm

Area=1167mm2

  1. Pd=Ae×fcd       Ae=1167mm2

fcd=fy/ymoϕ+[ϕ2λ2]0.5

ϕ=0.5[1+α(λ0.2)+λ2]

α=0.49 .. . .. . .class c for angle

λe=K1+K2λvv2+K3λ2ϕ

λw=L/rvvϵϕ2E250& λϕ=b1+b2/2tϵϕ2E250

λvv=1.73 λϕ=0.188

Case I-considering tow bolt at each end

Table 12 IS Pg48

fixed condition

K1=0.2 K2=0.35 K3=20

λe=0.2+0.35(1.73)2+20(0.188)2

λe=1.397

ϕ=0.5[1+0.49(1.3970.2)+(1.397)2

ϕ=1.79

fy=250

fcd=79.55mpa =79.55N/mm2

Pd=92.84kN

Hindge condition

K1=0.7 K2=0.6 K3=5

λe=0.7+0.6(1.73)2+5(0.188)2

λe=1.63

ϕ=0.5[1+0.49(1.6370.2)+1.632]

ϕ=2.1788

fcd=250/1.12.1788[2.175521.632]0.5=62.72Kn

Pd-Ae×fcd

=1167×62.72

Pd=73.19KN

angles is connected by two bolts Pd=73.19KN

Case II Consider one bolt at each end fixed

K1=0.75 K2=0.35 K3=20

λe=0.75+0.35(1.73)2+20(0.188)2

λe=1.58

ϕ=0.5[1+0.49(1.580.2)+1.582]

ϕ=2.09

fcd=250/1.12.09[2.0921.58)0.5

fcd=65.72

Pd=1167×65.72

Pd=76.69×103N

Hinde end

K1=1.25

K2=0.5

K3=60

λe=1.25+0.5(1.75)2+60(0.188)2

λe=2.206

λ=0.5[1+0.49(2.2060..2)+2.2062]

ϕ=3.424

fcd=250/1.13.424+[3.42422.2062]0.5

fcd=37.67

Pd=1167×37.67

Pd=43.89KN

Whenangle is connected by each end Pd=43.89 KN

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