Design software harnesses the wind

The world's major design house for the supporting structures for wind turbines says it has achieved enormous efficiency and quality improvements by adopting one of the mainstream 3D CAD packages and by taking advantage of parameterisation and making full use of the what the software can do, has substantially improved quality, accuracy and detail. Rambøll, headquartered in Denmark, but with a substantial design office in London, designs the foundation parts of most of the world's offshore wind turbines. Far from being just steel tubes, they have to not only support the main structure, but accommodate access from the sea to the mechanical parts of the machine, while resisting the effects of wind, waves and currents as well as the wind load on the turbine. "Every one is different", according to project engineer, Filipe Duarte Matias Ângelo, because the nature of the sea bed, what is to be attached on top, and the local nature of sea waves make each design problem unique. The company previously used a dedicated structural civil engineering package, Tekla Structures, but in 2008, embraced SolidWorks. Ângelo says that the designs involved "extremely large files", to the point that "simple updates were taking almost a day and it was taking around 30 minutes just to open a file". He said that, in contrast to what they were using before, "The modelling interface is quite easy to learn". "It's very easy to make drawings, has good exportation possibilities and has a rendering capability." The company design offices are in Copenhagen, Esbjerg and London and coordination and revision management is undertaken using PDM Vault, which, "always allows us to go back to previous revisions, improving traceability and collaboration", Ângelo explained. At first, changing the model updated all drawings, destroying previous versions, which was overcome by creating a configuration for each drawing. There is also a direct plug in to ANSYS in three clicks, which is vital for analysing structural integrity. The designers make full use of the parameterisation capability in designing access platforms since changing the diameter of the main pipe changes all the structural beams. Ângelo said they were "Working to do this a bit better." They also made use of the welds feature, which was described as "very useful", as was the ability to locate the centre of gravity and total mass, since it is necessary to know these in order to work out installation procedures. The external platform also has to include a crane, and the software is used to ensure that the crane can be rotated and doors opened without problem. The bottom line is that tendering now, "Has taken a step forward in terms of detail, accuracy and flexibility, allowing the client to ask for changes at a much earlier stage than before, making final cost much lower. Furthermore, in the detailed phases, robust models can now be taken to risk assessment meetings making it easier to identify risks and increase the safety of the foundation." He said that "Challenges" included the modelling of welds, something that has been specifically addressed in SolidWorks 2011, now officially launched. This version includes automated weld placement and documentation and includes enhanced fillet and groove features. Other enhancements include new sheet metal bend calculation tables, new drawing detailing functions, allowing the automatic alignment, staggering and centring of dimensions and 2D simplification to accelerate static, nonlinear, pressure vessel and thermal studies. There is a new electronics cooling module and a new HVAC module with new fan models and curves. PhotoView 360 is fully integrated, there are walk-through capabilities and DriveWorks Xpress is embedded as a task pane. Mechatronic designing has been enhanced. A Defeature tool facilitates the removal of unnecessary detail, such as the internals of a gearbox, while retaining the relationship between input and output shafts, to assist collaboration without risk of compromising intellectual property.