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6. Strength of the column and the packs

The critical design load case at the ULS will be due to the combination of permanent and unfavourable short-duration variable action:

Direct stress on the latticed column:

Nd 2

Design compression stress, ac.0.d CTc.o.d = -— ^c.o.d = 5.32 N/mm2

Buckling resistance condition for a latticed column (5.3.1 (EC5, 6.3.2))

Xz fc 0k

Relative slenderness about the Xrel z = — • —— Xrel z = 1.29

As relative slenderness ratio is greater than 0.3, conditions in 5.3.1 (EC5,6.3.2(3)) apply:

Instability factor, kz kz = 0 . 5 ■ |_1 + ßc ■ (Xrel .z - 0 . 3) + X2el . J

(equation (5.4b); EC5, kz + y kz2 - X2ielz equation (6.26))

(equation (5.11b); EC5, equation (6.24) - with bending stresses equal to zero)

Combined bending and direct stress condition on latticed column

Md 2

Design bending stress in the latticed amz = — amz = 1.27 N/mm2

column flanges - about the z-z axis, Wz t-. 1- . r i r r kmod.short ' ksys ' fm.o.k

Strength condition when bending about the z-z axis is:

0 0

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