2.1 Karamba3D Entities

Grasshopper (GH) is an object oriented, visual scripting environment. It provides items like points, curves, surfaces, . . . for geometric computing. The full range of geometric items can be inspected in the subcategory “Geometry” of the toolbar section “Params”. Karamba3D adds eight entities for building structural models:

Entity	Typology
Model	contains all the information related to a structure
Element	can be a beam, truss, shell or spring
Element Set	groups together elements in a given order, makes them accessible under a common name
Joint	defines the connectivity between neighboring elements
Load	external action which is imposed on the structure
Cross-section	defines a structural element’s geometry in section
Material	provides information regarding the physical behavior of what a cross section is made of
Support	defines how a structure connects to the ground.

Karamba3D objects behave like GH entities.

• They can be stored in containers (see the “Params” subcategory of the “Karamba3D” toolbar).

• When converted into text by plugging them into a panel they provide textual output regarding their fundamental properties.

Default Settings

In order to build a structural model not all of the above entities need to be present. Karamba3D assumes default settings for materials and cross sections:

• If no material is given, Karamba3D chooses steel (S235 according to EC3 with$f_{yk} = 23.5 kN/cm^2$) for all cross sections.

• For beams the default is a circular hollow cross sections (CHS) with an outer diameter of$114.4mm$and a wall thickness of $4mm$. The default thickness of shells amounts to $10mm$.

Graphical User Interface

Some Karamba3D components come with graphical user interface components like radio-buttons, drop-down lists and sub-menus.

Sliders on Karamba3D components have a preset number-range. Double-click on the knob to change the precision and range to your specific need.

In some cases the user can select between different options at a component input (e.g. the Load-Case at a result component, or the degrees of freedom at a support-component). To select these options via ValueList-components right-click on the Karamba3D-component and select "Expand ValueLists" from the context menu or plug a ValueList into the corresponding input-plug. The selection of dynamic content that depends on the upstream model (e.g. selection of load-cases) works only after the component executed at least once. So one needs to connect the mandatory input-plugs before expanding dynamic value-lists.

The ModelView-, BeamView- and ShellView-components provide a short-cut for selecting color-ranges for result display: Right-click on the components and select 'Colors' from the context menu.