Additionally, EN 1991-1-4 defines cpe,1 for members with a loaded area of 1 m² or less and cpe,10 for members with a loaded area of 10 m² or larger, with linear interpolation used for intermediate values.
：The starting point is the fundamental value of basic wind velocity (v_b,0), determined from maps in a National Annex based on a 50-year return period of a 3-second gust. This basic value is adjusted by two main factors: a directional factor (c_dir) and a seasonal factor (c_season). Since taking a conservative approach by setting both factors to 1.0 is common practice, this simplifies the basic wind velocity to be equal to its fundamental value (v_b = v_b,0).
Let’s walk through a concrete example—a 25m tall rectangular office building in suburban Frankfurt (Terrain Category III), using the German National Annex. wind load calculation excel sheet eurocode verified
| Parameter | Formula Logic | Excel Formula Example | | :--- | :--- | :--- | | | $0.19 \times (z_0 / 0.05)^0.07$ | =0.19*(B18/0.05)^0.07 | | $z_min$ | Look up based on Terrain Category | (Terrain II = 2m, III = 5m, IV = 8m) | | $c_r(z)$ | $k_r \times \ln(\max(h, z_min) / z_0)$ | =B26*LN(MAX(B10, B27)/B18) | | $v_m(z)$ | $c_r(z) \times c_0(z) \times v_b$ | =B28*B19*B23 |
It eliminates the need for expensive software licenses for standard, everyday building geometries. Additionally, EN 1991-1-4 defines cpe,1 for members with
While extremely useful, even the most sophisticated verified spreadsheet has limitations:
A verified spreadsheet must systematically break down EN 1991-1-4 into logical input and output zones. Your sheet must account for these core components: 1. Fundamental Wind Velocity ( Since taking a conservative approach by setting both
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$$I_v(z) = \frack_Ic_0(z) \ln(z / z_0)$$ (Where $k_I$ is the turbulence factor, default 1.0) .