written 6.1 years ago by |
Given
ISMB 250
bf=125m tf=12.5m tw=6.9
γ1=13m
ISHB 200 at 37.92 bf=200mm tf=9mm
tw=6.1mm
R=85kN(factored load)
ϕ of bolt=16mm
Anb=157mm2
fub=4×100=400N/mm2
fy=250N/mm2
fu=410N/mm2
required no of bolts
shearing capacity of bolt =fub×Anb×nn√3×γmb
=400×157×1√3×1.25
Vdsb=29kN
bearing capacity of bolt=2×K×t×d×fu
Kb=(e3d0,p3d0−1,fybfu,1) min value
Vdpb=2×0.56×9×16×410
Vdps=66.129kN
No .of bolts=factored loadbolt value (min value Vdsb & Vdpb)
=8529=2.39≈4Nos
Shear capacity of seat angle
=bf√3×ymo
=125×10×250√3×1.1
=164>35
Step II length of angle supporting beam(b)=125mm
Step III bearing length of route line of beam(b)
(b)=Rtw×fyhymo==806.9×2501.1=54.2mm
b=54.2mm
Step IV length of out standing leg=54.2+10=64.2
Assume 75mm
provide 150×75×10
b1=b-(tf-γ1)
=54.2-(12.5+13)
b1=28.7mm
b2=(b1+10)-ta-γ2
=(28.7+10)-10-10
b2=18.7mm
Step V bending moment of root angle =Rb1×b2×b22
=8528.7×18.7×18.72
mu=517.83kN/mm
Step VI
moment resisting capacity
md=1.2×2501.1×12.5×1036
md=568.18kN.mm
md>mu hence safe
Step VIII Shear strength of beam
Vd=aw×fyw√3×ymo=250×6.9)×250√3×1.1
Vd=226.35