Structural Information Modelling
The structural engineering domain is not often discussed when talking about BIM-based working and IFC. It may seem that it is not as attractive as other domains such as Architecture, HVAC or Facilities Management. So it may come as a surprise to find that structural engineering has a long tradition in IFC development.
IFC may not be the first choice for use with structural analysis.There are not many data exchange scenarios for numerical data. Very special analysis methods as well as huge and highly optimized date sets make data exchange a problem. But thatís not the focus of IFC developments. Instead, the BIM approach enables the capture of design decisions and the relationship to the architectural model, i.e. the physical elements and all related information that enables structural data such as load bearing structures, element properties, loading assumptions etc. or be derived. Consequently, structural information modeling enables better cooperation with other domains and supports the idealization processes as shown in the figure below.
|Figure 1: Idealization process within the structural analysis domain|
AEC3 is a founding member of the Structural Engineering Group and acts as the Technical Coordinator. Leading software companies in the field of structural engineering actively support IFC model extensions for sharing structural data and are implementing IFC interfaces. As well as structural analysis and dimensioning, detailing of steel structures was the focus of the first structural developments. Later developments included support for timber and concrete constructions.
In the long-term, IFC and suggested structural extensions will replace the German standards PSS (Produktschnittstelle Stahlbau) and DtH (Datentransfer im Holzbau) to improve data integration with other domains and to strengthen capabilities for pre-fabrication. Furthermore, the converter from the National Institute of Standards and Technologies (NIST) has shown that IFC and the CIMsteel Integration Standards (CIS/2), which focuses on steel structures and is predominantly used in the US and UK markets, can be used together.
As structural information modeling is based on architectural data it extends current data sharing scenarios and defines new IFC model views. Structural analysis developments have been used by AEC3 to extensively test the IDM methodology and the buildingSMART Model View Defintion format. These will provide significant improvements for IFC implementation. In November 2007, thanks to the support from Statsbygg, the integration of both approaches was shown by the University of Tampere and AEC3 at an international meeting in Brisbane, Australia. As these examples are tackling a lot of upcoming problems they will guide further developments for extending the use cases of IFC.