Mikel Abasolo, a researcher of the University of the Basque Country, has built a simplified simulation model for wind turbines. All one has to do is enter the characteristics that the tower and its parts will have, and in a matter of seconds, the model predicts the load that has to be given to each of the bolts, which leads to great advantages in the construction and maintenance process. In installations of such large dimensions, it is customary to have to adjust the bolts over and over again to balance the load. But this model enables these data to be known before the building begins.
Owing to their great height, wind turbine towers are built in two or three parts and are subsequently bolted together. However, joining elements of such dimensions and quantities of bolts is very complex. “The aim is that all the bolts should have the same load so that they all work equally. In an adjustment sequence, when you tighten one bolt, the previous ones lose part of their load,” explained Abasolo.
This is the reason why this simplified model is so valuable, because it can predict what load has to be apportioned to each bolt at the moment when the installation is assembled, so that by the end of the process, the load ends up being uniform. Data like tube geometry, the exterior and interior diameter, the metrics and resistance of the bolts, or the final load to be achieved is entered into the model; this is enough so that in a matter of seconds the result that fits the circumstances is achieved.
This model can also be applied to maintenance tasks. As time goes by, the bolts of the wind turbine towers loosen, and just as when they are built, they have to be adjusted over and over again until the load is uniform once again, which means that here, too, a lot of time and money is lost.
As Abasolo explains, this simplified model is totally pioneering, since until now nothing like it geared towards wind turbines has been done. “Similar things have been done for pressure pipes, but there was nothing with respect to wind turbine joints. So we have taken advantage of a methodology never used before in this area.”
