Analyzing and creating forms : rapid generation of graphic statics solutions through RhinoScript

Abstract

Graphic statics is a method of structural analysis which relies solely on geometric constructions to determine axial forces within members. Accordingly, any computer-aided drafting (CAD) program may be utilized in the pursuit of a graphic statics solution. This thesis presents a methodology which employs Rhinoceros 4.0 (Rhino) in its capacity as such a program. Using RhinoScript, which provides access to Visual Basic Scripting, or VBScript, within Rhino, the basic steps of graphic statics are automated as scripts. The scripts are then compiled into RhinoStatics, a plug-in module which facilitates graphic statics analyses. The thesis focuses on three applications of graphic statics: determination of simply supported reaction forces, funicular form-finding given restraints on the axial capacity of the material being used, and determination of axial forces within a pin-jointed truss loaded at its nodes. While only these three applications are explored in detail, the developed scripts may be used in the pursuit of a wide range of graphical equilibrium solutions, transforming Rhino into a highly specialized tool in the hands of a user with knowledge of graphic statics techniques. Such users will be able to easily analyze a host of two-dimensional cross-sections and forms, as well as generate new shapes given loading and geometric constraints. Users familiar with VBScript could easily expand on the documented script files to add functionality to suit their own needs. In addition to providing worked examples of how to utilize the RhinoStatics plugin module, this thesis provides a brief overview of graphic statics in general. The developed scripts are explained in detail, with fully documented RhinoScript code provided in the appendices.