Innovative precast concrete component concept with optimized joint design for especially tall wind turbines

Figure: Garg et al.

Fig. 1 The development in size of newly installed wind turbines in Germany from 1990 to 2015

Figure: Garg et al.

Fig. 3 General tower assembly and precast component geometry

Figure: Garg et al.

Fig. 2 Design of a possible horizontal joint between the corner elements

Figure: Garg et al.

Fig. 4 Opened test specimen

Figure: Garg et al.

Fig. 5 Test specimen and testing environment

Figure: Garg et al.

Fig. 6 Test specimen with prestressing unit

Figure: Garg et al.

Fig. 7 Overview of test specimens in installation condition

Figure: Garg et al.

$Fig. 8 Preliminary test 1 fracture pattern after load failure: 1,535 kN$ Figure: Garg et al.

Fig. 8 Preliminary test 1 fracture pattern after load failure: 1,535 kN

Figure: Garg et al.

Fig. 9 Approximation function of force-dependent deformation

Figure: Garg et al.

Fig. 10 Progression of test specimen shear stiffness

Figure: Garg et al.

Fig. 11 Installation of the fourth precast component on the second tier of the mockup tower

Figure: Garg et al.

Fig. 12 Influence of shear stiffness on the maximum bolt load in the horizontal joints at the corner and wall area

Figure: Garg et al.

Fig. 13 Comparison of optimization goals with a load around the 45° axis (see fig. on the left)

Figure: Garg et al.

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Fig. 14 Comparison of optimization goals with a load around the 0° axis (see fig. on the right)

Figure: Garg et al.ww

Hybrid structures of precast concrete components and superimposed steel tube tower are economical for very tall wind turbines. The Tubularis PCC Tower concept is suitable for the international wind market and relies on small-format precast concrete components that can be manufactured in non-specialized plants close to the construction site. The Mainz University of Applied Sciences developed the concept of segment joints.

1. Introduction

Wind energy is the driving force in the implementation of the energy revolution and already produced 49% of total renewable energy in 2017. In the process, they ensure 16% of gross electricity generation in Germany. Onshore wind energy accounts for 83% of the wind energy produced [1][2]. The average hub height of newly installed wind turbines throughout Germany amounted to 129.1 m in 2017. On average, these turbines were equipped with a rotor diameter of 113.8 m and provided an output of 2.9 MW [3].

The experience of the last years has shown that the energy yield with increasing...