Hybrid tower - a tower variant with combination of different materials

 Hybrid tower constructions are referred to, which are composed of two different construction methods or materials, such as eg, concrete and steel. Often they are made of a concrete shaft bottom which is biased and an attached steel shaft with a plurality of tube sections.

Especially with substructure , the tower height is a critical factor for the economy. The higher the turbines can be erected the greater the yield of wind energy. However, it must be increased with increasing hub height and the tower base diameter in order to ensure the stability still can.

The tower base diameter is limited by transport conditions on the road at about D = 4.3m. Therefore, beyond 100m hub height predominantly hybrid towers are used, the lower concrete shaft is manufactured locally or is composed of individual products manufactured in parts.

The hybrid tower illustrated as an example of the type VENTUR has in the area of the concrete shaft an octagonal polygonal cross-section as a ground plan and runs the height to conical. The octagon is composed of several wall-like precast concrete, the steadily taper upwards. The individual wall elements are prefabricated in the factory under controlled conditions and then transported to the construction site.

View of the hybrid tower VENTUR

The on-site installation is carried out with the developed climbing construction by the company Drössler GmbH Umwelttechnik from Siegen. The bias of the precast concrete parts is implemented via external power cable extending along the inner wall of the tower. The high-strength concrete allows shorter production times and an appearance in architectural concrete.

With reference to the figures, the design of the clamping system is illustrated wherein by using a 3D model of each clamping member is checked. The stress changes on the bending pressure and flexural tension side be analyzed in response to the applied bending moment and evaluated in diagram form.

Model of the tower base with foundation
Stress gradients in the tendons

With reference to the figures, the design of the clamping system is illustrated wherein by using a 3D model of each clamping member is checked. The stress changes on the bending pressure side and flexural be analyzed in response to the applied bending moment and evaluated in diagram form.

Services

SKI Ingenieurges. mbH accompanies these onshore developments with

  • Design and dimensioning of supporting structures
  • Calculation of wind loads in combination with other actions
  • Stress and stability proofs for "primary and secondary Steel"
  • Checks in the fatigue limit state
  • Development work in connection with new types of support structures
  • Detailed checks for welded and bolted constructions
  • Verification of prestressed support structures
  • Dimensioning of shallow and deep foundations
  • Concept studies for novel foundation structures of offshore wind turbines
  • Static-constructive assistance in certification 
Installation of a WT with hybrid tower
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