{"id":4688,"date":"2022-09-12T08:32:14","date_gmt":"2022-09-12T06:32:14","guid":{"rendered":"https:\/\/leichtbau.dlr.de\/stronger-in-the-wind-a-new-connection-concept-for-turbine-rotor-blades"},"modified":"2023-04-12T09:32:20","modified_gmt":"2023-04-12T07:32:20","slug":"a-stronger-root-connection-for-wind-turbine-blades","status":"publish","type":"post","link":"https:\/\/leichtbau.dlr.de\/en\/a-stronger-root-connection-for-wind-turbine-blades","title":{"rendered":"A stronger root connection for wind turbine blades"},"content":{"rendered":"

[vc_row][vc_column][vc_column_text]Nowadays, more regenerative energy, especially more wind energy, is the order of the day. Above all else, this can be achieved with ever larger wind turbines. Such developments should lead to a decrease in the cost of energy as well as the space required for wind farms. However, wind turbines cannot simply keep growing without related innovations. <\/strong>Our institute is therefore developing new technologies to avoid an anticipated bottleneck: The blade root, i.e. the bolted connection between rotor blade and hub.<\/strong>[\/vc_column_text][\/vc_column][\/vc_row][vc_row][vc_column width=”1\/2″][vc_empty_space][vc_column_text]<\/p>\n

It’s getting tight<\/h3>\n

Wind turbine manufacturers<\/span> are racing to produce ever larger turbines. In 2021, rotor blades for onshore wind turbines exceeded<\/span> a length of 80 metres; offshore, they have already passed the 100-metre mark. Upscaling rotor blades is no trivial matter. The blade root is currently limiting the development of even longer onshore rotary blades. Conventional blade root connections reach their limit at a blade length of approximately 100 metres. Such a rotary blade requires a diameter of some 4 metres at the blade root. This represents the limit for transportation by road, as clearance under bridges is often capped at 4.5 metres. For offshore rotor blades, this is not an issue: They can usually be produced close to the respective port and loaded directly onto a ship. However, it is only a small number of onshore rotor blades that do not have to contend with a single bridge on the way from the factory to the turbine\u2019s build site.[\/vc_column_text][vc_column_text]<\/p>\n

Strong concepts<\/h3>\n

To overcome this challenge, our institute is currently developing two new technologies: RAX and FML. An innovative bolted connection with r<\/strong>adially and ax<\/strong>ially pretensioned bolts (RAX) and F<\/strong>ibre M<\/strong>etal L<\/strong>aminates (FML) can bear<\/span> significantly greater loads than conventional blade root connections.. Our structural design indicates that this will enable an increase in possible blade length for onshore rotor blades from 100 metres to 150 metres: The outstanding strength means that a connection with RAX and FML requires a root diameter of just 4 metres for a 150-metre blade. As a result, the RAX-FML root allows for much larger onshore turbines and therefore ultimately lower cost of wind energy.[\/vc_column_text][\/vc_column][vc_column width=”1\/2″]