Tuesday, 13 October 2020

Pangolin Section guide

In this brief tutorial, we will look at the two main ways of defining sections in Pangolin for your structural model.

1. Loading them from a predefined section bank

Pangolin provides 7000+ predefined sections collected in the section bank, these include standard profiles like IPE and HEA from various continental regions (Europe, American (imperial), American, British, Chinese, Continental Steel, Russian) and also some manufacturers like Lindab, SBE, Brausa and so on.

First, we have to filter out the section we are interested from the bank so as to avoid loading all 7000+ of them and bogging Grasshopper down.

Here I use the Section Bank Previews component, which outputs a list of “Section Previews” based on the provided filters from the bank (as seen in the rightmost text box). After we are satisfied with the filtering, we have to actually load in the sections by providing the preview and material to the Section From Bank component as seen below:

2. Defining them with parametric section macros

We can also define custom sections with a slew of parametric section macros. For this, first place the Macro Section component, then choose which kind of section you wish to create using the Select Macro button on the placed component (eg.: hot rolled I profile, welded maltese cross, cold-formed sigma and so on).

After this, we have to specify the name of the new custom section, its material. Finally, specify any parameters that you wish to change like the height or web thickness of the section. You can preview the defined custom section in the Rhino Viewport to get an idea about the section your parameters resulted in.

For cold-formed sections, Pangolin and Consteel provide the unique ability to accurately model and calculate custom intermediate and edge stiffeners. For these cases, you have to first define the stiffeners using the Intermediate Stiffener and Edge Stiffener components with their own parameters then connect these stiffeners into the Macro Section components corresponding input parameters like below:

Deconstructing Sections

Finally note that these objects are not just the surface denoting the cross-section, but complex objects containing design parameters for Consteel as well as other information. You can access some of these extra attributes using the Deconstruct Section component.

You can use this to for example parametrize the eccentricity between beams based on their sections' geometry. In the below example, I deconstruct a section, pull its outline into the deconstruct box component (where it gets converted into a bounding box before deconstruction) and use the Y domain of this box to get the actual height of the current section. This unlike just using the macro’s input height also takes into account possible additional height gained by a protruding stiffener.

You can download the example file here.