# D12.A.6.4 Tube profile

Tube sections are rectangular or quadratic hollow uniform profiles. Critical stress is checked at 5 locations as shown in figure below.

## Section Properties

Ax , Ix , Iy , and Iz are taken from the STAAD.Pro database.

where
 Ay = 2ht, similar as for wide flange profiles, see Section 5.2 Az = 2(2/3)bt, Ay and Az are nto used in code checks Cw = $b 2 h 2 t ( h − b ) 2 24 ( h + b )$ ref. NS app. C3

## Stress calculation at selected stress points

Point No σx σby σbz τx τy τz
1 $F x A x$ $M y I y b 2$ 0 $M x ( h − t ) ( b − t ) I x ( h + b − 2 t )$ $F y I z b t h 2 + t h 1 2 2 t$ 0
2 " $M y I y b 2$ $M z I z h 1$ " $F y I z b t h 2 2 t$ $F z I y 2 h 1 t b 2 2 t$
3 " $M y I y b 2$ $M z I z h 2$ " $F y I z 2 b 2 t h 2 2 t$ $F z I y 2 h 2 t b 2 2 t$
4 " $M y I y b 1$ $M z I z h 2$ " $F y I z 2 b 1 t h 2 2 t$ $F z I y h t b 2 2 t$
5 " 0 $M z I z h 2$ " 0 $F z I y h t b 2 + t b 1 2 2 t$

The general stress formulation is given in sec. 5.2.