Local buckling of thin-plate elements - The Behaviour and Design of Steel Structures to EC3 - page 146

τ cr = 5.34 × 190000 × ( 10 / 1500 ) 2 = 45.1 N / mm 2

EC3-1-5A.1(2)

λ w = 0.76 × √ ( 355 / 45.1 ) = 2.132 > 1.08 EC3-1-5 5.3(3)

Assuming that there is a non-rigid end post, then

χ w = 0.83 / 2.132 = 0.389 EC3-1-5T5.1

Neglecting any contribution from the flanges,

V b , Rd = V bw , Rd = 0.389 × 355 × 1500 × 10 √ 3 × 1.0 N = 1196 kN. EC3-1-5 2(1)

4.9.6 Example 6 - shear buckling resistance of a
stiffened plate girder web
Problem. DeterminetheshearbucklingresistanceoftheplategirderwebofS355
steel shown in Figure 4.31d if intermediate transverse stiffeners are placed at
1800 mm spacing.

Solution.

t w = 10 mm, f yw = 355 N / mm 2

EN10025-2

ε = √ ( 235 / 355 ) = 0.814 T5.2

h w = 1540 − 2 × 20 = 1500 mm.
a / h w = 1800 / 1500 = 1.20, k τ st = 0 EC3-1-5A.3(1)

k τ = 5.34 + 4.00 / 1.20 2 = 8.12 EC3-1-5A.3(1)

τ cr = 8.12 × 190000 × ( 10 / 1500 ) 2 = 68.6 N / mm 2

EC3-1-5A.1(2)

Assuming that there is a rigid end post, then

λ w = 0.76 × √ ( 355 / 68.6 ) = 1.73 > 1.08

EC3-1-5 5.3(3)

χ w = 1.37 /( 0.7 + 1.73 ) = 0.564 EC3-1-5T5.1

Neglecting any contribution from the flanges,

V b , Rd = V bw , Rd = 0.564 × 355 × 1500 × 10 √ 3 × 1.0 N = 1734 kN.

EC3-1-5 5.2(1)