# 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 seven 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 $10mm$.