Grasshopper

algorithmic modeling for Rhino

# Massing Design with support of Structural Optimization

Optimization with datas as whole improve 0.03 displacement amount and change a lot for the massing apperance, since Ladybug's wind speed is difficult to understand what fomula to caculate with Karamba point loads. Therefore, this stops at perhaps the part of caculating dead load + some live load.

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Comment by Igor Mitrić Lavovski on June 22, 2015 at 3:43am

Hi Djordje,

Good idea with wind! I will certainly try that!

Comment by Situ on June 18, 2015 at 12:14pm

Hi djordje

I will try to test that optimization with wind load in later future.

Comment by djordje on June 18, 2015 at 6:21am

Hi Situ,

You are doing an amazing work with these optimization karamba projects! Thank you for sharing it.

I thought you understood what I said in here on Ladybug Wind boundary profile component, because no reply was given. Please if something is not clear do not hesitate to comment back, in that way some other user might see your reply and post a solution.

A more in detail continuation of the upper mentioned reply would be:

Find the Z coordinate of area centroid of your curtain wall panels.

Then by using "windProfileHeight_" and/or "distBetweenVec_" inputs from Ladybug Wind boundary profile component find the wind speed (m/s) at each of Z coordinate values from the previous sentence.

Convert those wind speed values into pressure (N/m2):
p = (1.25*(windSpeed^2))/2.
Derive the point load force from the pressure (Newtons):

F = p * A   (A being an area of a curtain wall panel in m2)

Fnode = F/4   ("disposing" the F force to each support-node of your curtain wall panel).

Apply all these Fnode forces to your panels which are somewhat normally oriented to the wind direction. These will be your wind pressure forces. On the opposite side of the building, we can use a rule of a thumb and apply the same Fnode forces/2. These are your wind suction forces.

On lateral panels nodes (lateral in comparison to the wind direction) you can apply Fnode forces, in magnitude Fnode*(1 to 1.5). These are lateral suction forces.

Have in mind that wind load in structural engineering is a complicated subject. Most codes and equations currently used come from a very simplified 2D or 3D (cylinder, box) models. In reality one would need to use CFD software for detailed analysis (Ansys, NX, SolidWorks...), or if the project is actually going to be built then wind tunnel tests.

by June Lee