Structural design of hybrid-towers for wind energy converters

verfasst von
Peter Schaumann, Christian Keindorf
Abstract

The structural design of sandwich towers for wind energy converters is presented in this paper. This new kind of hybrid tower consists of two steel shells which are bonded together with a core material. Compared to a steel tower section the shell thickness is splitted to an inner and outer steel face. The core between the inner an outer steel face increases the stability of the shells. It works together like a sandwich or composite shell. Different composite shell theories are used to estimate the stability of such double skin shell constructions. A model scale test series with sandwich cylinders is carried out to analyse the shell buckling and the influence of different core materials. The test specimens are loaded by uniform axial compression. The deformations and strains are measured online by optical 3D sensors to localize critical zones. The experimental results are compared to numerical simulations including measured geometrical imperfections. The FEmodel is validated by a composite shell theory. Within a numerical pre-design the use of high strength steels for the inner and outer steel face is also considered to compare various types of tower configurations. The goal is to find the best combination of steel faces with a core material in the ultimate limit state. However, the fatigue limit state must be also considered. Therefore, a method for post weld treatment will be presented to increase the fatigue strength of the steel faces. Furthermore, new joint techniques are also suggested for hybrid tower constructions with sandwich sections.

Organisationseinheit(en)
Institut für Stahlbau
Typ
Aufsatz in Konferenzband
Seiten
1045-1056
Anzahl der Seiten
12
Publikationsdatum
2008
Publikationsstatus
Veröffentlicht
Peer-reviewed
Ja
ASJC Scopus Sachgebiete
Energieanlagenbau und Kraftwerkstechnik, Erneuerbare Energien, Nachhaltigkeit und Umwelt
Ziele für nachhaltige Entwicklung
SDG 7 – Erschwingliche und saubere Energie