Link to YouTube Video Part 1: http://www.youtube.com/watch?v=649LuQEjjdg
Many architects are unleashing evermore complex geometry and pushing the boundaries of physics, materials and the natural laws that govern all of us. With today’s 3D digital creation tools the creative minds are virtually unlimited and often the engineer has to tame and rationalise the geometry to create an affordable, buildable structure from the Architects design intent without compromising the original forms. This is often where the Revit Structure Suite comes into its own allowing the Engineer to use a surprisingly diverse set of tools to help solve the above problems.
For the above example we will take a look at a conceptual roof modelled in AutoCAD 2012 using the NURBS surfacing tools that are available. The Architect can very quickly create a lofted surface and then use the CV tools and surface associativity to create some interesting forms.
This geometry will result in Splines which are not really suitable for the fabrication of structural frames due to the complex curves and expense and complexity involved in rolling and forming the structural sections. Quite often these forms will need to be rationalised into faceted panels made from straight sections that will give the impression of a curved roof.
This can be achieved in a number of ways either using split solid geometry or mesh modelling which will automatically facet the surfaces. You can control the number of facets using two system variables SURFTAB1 and SURFTAB2. In the below example the mesh has been exploded into flat regions. This can then be imported into Revit Structure and used to create a structural framing system.
If anyone is interested in seeing more in depth tutorials and YouTube videos then let me know and I will take the time to create a full tutorial on the various techniques that can be used with AutoCAD 2012, ASD and Revit Structure?