written 6.1 years ago by |
ISMB 350
Area A=6671mm2 bd140 tf=142 tw=81
rxx=r28=142.9
ryy=28.4
length of column =3000mm
leff=k×L=1×3000=3000m
fy=250N/mm2
fa=410N/mm2
E=2×105N/mm2
Design strength of comp member
Pd=Ae×fcd
buckling class(Is pg 44)Is pg 35 table 7
hbf=350140=2.5
hbf=2.5≥1.2
tf=1.42<40
huckling about zz axis class a
buckling about yy axis class b
α=0.21 class a
α=0.34 class b
buckling about z axis a
α=0.21
λz=√fy×(klγzz)2)Π2E
=√250×(2000/28.4)2Π2×2×105
λy=1.189
ϕ=0.5[1+0.34(1.189−0.2)+(1.189)2]
ϕ=1.375
fcd=250/1.10.53+[0.532−0.23622]0.5
fcd=225.2N/mm2
pd=Ae×fcd
6671×225.3
=1.502×106
=15.03×103N
=1503KN
buckling about class b
λ=0.34
λy=√fy×(klrmm)2Π2E
=√250×(2000/rmm)2Π2×2×105
λy=1.189
ϕ=0.5[1+0.34(1.189−0.2)+(1.189)2]
ϕ=1.375
fcd=250/111.375+(1.3752−1.1892)0.5
fcd=110N/mm2
pd=110×6671
pd=733.7 KN
design load of column is 733.7 KN
buckling z Class a
α=0.21 class a
klrxx fcd
20 226
21 fcd
30 220
30−2030−21=220−223220−fcd
fcd=225.3 N/mm2
buckling yy class b
KLryy fcd
100 118
106 fcd
110 104
fcd=110N/mm2