Wind Loads

Theory of wind load

In structural analysis, wind load denotes the force imposed by wind on a structure. Wind load is influenced by factors like height above the ground and velocity. These forces can profoundly impact the stability and structural integrity of structures and buildings. SimSolid plays a crucial role in modeling wind loads on structures by considering key factors such as wind speed, air density, directionality, frictional drag, and shape factor. By incorporating these parameters, SimSolid facilitates the evaluation of pressure exerted on surfaces exposed to the wind, contributing to accurate calculations of structural deflection.

A pivotal influence on wind load considerations is the wind profile. SimSolid supports two distinct profiles: Uniform and Logarithmic. These profiles serve as mathematical models, elucidating the uniform distribution or logarithmic progression of wind speed concerning the height above the ground (H) within the atmospheric boundary layer.

In the Logarithmic wind profile, the interpolation points along the logarithmic curve between the height above the ground (H) and wind speed (V) are calculated by the following equation.

V (z) = \frac{u}{κ} \ln (H + 1)

Where,

u: Shear velocity (Default = ~0.5)
$κ$: Von Karman constant (Default = ~0.41)
H: Height above ground where velocity was measured

The wind pressure for surfaces that are normal to the wind direction is calculated by the following equation.

P_{w i n d} = \frac{1}{2} ρ_{a i r} V^{2} C

Where,

$P_{w i n d}$: Wind pressure
$ρ_{a i r}$: Air density
V: Speed of the wind
C: Shape factor

For the surfaces which are parallel to the wind direction includes frictional drag ( $C_{f}$ ) is calculated by, the following equation.

P_{w i n d} = \frac{1}{2} ρ_{a i r} C_{f} V^{2} C

The default value of friction drag coefficient is set to 0.01.

Tip: The Enable Shielding checkbox provides capability to protect components from wind load that are obstructed by other parts. When unchecked, wind load is exerted on all components, regardless of whether the surfaces facing the wind source are obstructed by other parts within the assembly.