D12.A.6.1 Double symmetric wide flange profile

The von Mises stress is checked at four stress points as shown in figure below.

Section Properties

• Ax , Ix , Iy, and Iz are taken from STAAD.Pro database
• Ay = h × s Applied in STAAD.Pro print option PRINT MEMBER STRESSES

Az = (2/3)· b · t · 2

τy = Fy/Ay

τz = Fz/Az

• Ay and Az are not used in the code check
• $C w = ( h − t ) 2 b 3 t 24$ref. NS app. C3

Ty = dA × z

Tz = dA × y

Stress calculation

General stresses are calculated as:

 $σ = σ x + σ b y + σ b z = F x A x + M y I y z + M z I z y$

 $τ = τ x + τ y + τ z = M x I x c + V y T z I z t + V z T y I y t$

Where the component stresses are calculated as shown in the following table:

Table 1. Stress calculations at selected stress points for a wide flange section
Point No σx σby σbz τx τy τz
1 $F x A x$ $M y I y b 2$ $M z I z b 2$ $M x I x t$ 0 0
2 " 0 " " $F y I z b t h 2 2 t$ $F z I y t b 2 8 t$
3 " 0 $M z I z h 1$ $M x I x s$ $F y I z b t h 2 s$ 0
4 " 0 0 " $F y I z ( b t h 2 + 0.5 h 1 2 s ) s$ 0

In general wide flange profiles are not suitable for large torsional moments. The reported torsional stresses are indicative only. For members with major torsional stresses a separate evaluation has to be carried out. Actual torsional stress distribution is largely dependent on surface curvature at stress point and warping resistance.