Frames - The Behaviour and Design of Steel Structures to EC3 - page 384

Section resistance.

t f = 12.5 mm, f y = 275 N / mm 2

EN10025-2

ε = ( 235 / 275 ) = 0.924 T5.2

c f /( t f ε) = ( 204.3 / 2 − 7.9 / 2 − 10.2 )/( 12.5 × 0.924 ) = 7.62 < 9 T5.2

and the flange is Class 1. T5.2
The worst case for the web classification is when the web is fully plastic in
compression, for which

c w /( t w ε) = ( 206.2 − 2 × 12.5 − 2 × 10.2 )/( 7.9 × 0.924 ) = 22.0 < 33

T5.2

and the web is Class 1. T5.2

Thus the section is Class 1.

γ M 0 = 1.0 6.1
N c , Rd = 66.3 × 10 2 × 275 / 1.0 N = 1823 kN = N pl , Rd 6.2.4(2)
0.25 N pl , Rd = 0.25 × 1826 = 455.8 kN > 137.2 kN = N Ed , 6.2.9.1(4)
0.5 h w t w f y = 0.5 ( 206.2 − 2 × 12.5 ) × 7.9 × 275 N = 196.8 kN 6.2.9.1(4)
> 137.2 kN = N Ed ,

and so no allowance need be made for the effect of axial force on the plastic
resistance moment. 6.2.9.1(4)

M N , Rd = M pl , Rd = 567 × 10 3 × 275 / 1.0 Nmm
= 155.9 kNm > 144.8 kNm = M Ed

6.2.9.1(5)

and the section resistance is adequate. 6.2.9.1(2)

Member resistance.
Becausethememberiscontinuouslybracedout-of-plane,beamlateralbuckling
and column minor axis and torsional buckling need not be considered.
Thus M z , Ed = 0, χ LT = 1.0, and

λ 0 = 0, C mLT = 1.0, a LT = 0, and b LT = 0 TA.1

L cr = 5000 5.2.2.(7b)