NUMERICAL SIMULATION ON A JOINT SEGMENT OF A PRESTRESSED PREFABRICATED SECTIONAL WIND TURBINE BLADE MODEL

Transcription

1 33 2 Vol.33 No Feb ENGINEERING MECHANICS (2016) ,2 1 ( ( ) ) 16 m ABAQUS 4 4 TK83 A doi: /j.issn NUMERICAL SIMULATION ON A JOINT SEGMENT OF A PRESTRESSED PREFABRICATED SECTIONAL WIND TURBINE BLADE MODEL XU Bin 1,2, HAN Ji-long 1 (1. College of Civil Engineering, Hunan University, Changsha, Hunan , China; 2. Hunan Provincial Key Laboratory of Damage Diagnosis for Engineering Structures (Hunan University), Changsha, Hunan , China) Abstract: As high-power wind turbines develop, the length of the turbine blades tends to increase, and thus the difficulties, risk, and cost involved in transportation increase, especially for those wind farms located in mountainous areas. Dividing a traditional blade into several prefabricated segments and assembling them on-site is an efficient solution to overcome the above problems. In this study, a new prefabricated sectional wind turbine blade assembled by connecting the sectional blades with prestressed high-strength bolts is proposed and a stress analysis on the joint segment of the prefabricated blade model is carried out using a finite element method. The joint segment of a typical wind turbine blade is modeled with ABAQUS. The stress distribution of the joint segment is analyzed under four different design load cases in both flatwise and edgewise directions. Numerical simulation results show that the stress of the wind turbine blade and prestressed bolts under the four design load cases are all within the materials acceptable stress range. In conclusion, the proposed prefabricated sectional blade using prestressed bolts is proven feasible and can be an alternative approach of traditional wind turbine blades. Key words: prefabricated sectional wind turbine blade; finite element method; prestressed bolt connection; stress analysis; glass fiber reinforced plastic (2013FJ2010) (1972 )( binxu@hnu.edu.cn). (1988 ) ( hanjilong23@qq.com).

2 210 [1 2] 40 m Vestas V MW 55 m [3] 6.0 m/s Hahn [4] [5 7] 2 MW 46.5 m 16 m m 2 2(a) 2(b) (a) (b) 2 Fig.2 Prefabricated sectional blade and cross section ~7 13 ~20 26 ~32 36 mm 8 ~12 21 ~25 39 mm mm Fig.1 Whole prefabricated wind turbine blades 3 Fig.3 Connection scheme of sectional blade

3 211 4 Fig.4 Distribution of bolts in section 5 Fig.5 Connection of high strength bolt ABAQUS [8 9] Auto CAD ABAQUS 6 (b) 8 Fig.8 Model of connection section ABAQUS ABAQUS mm 75 mm 40 mm 70 mm 500 mm 590 mm 1 2 ABAQUS 9~ Fig.9 Model of screw 10 1 Fig.10 Model of connector Fig.11 Model of connector 2 6 Fig.6 Model of general section 12 Fig.12 Whole model of joint segment 7 Fig.7 Model of transition section (a)

4 212 1 Table 1 Performance parameters of glass fiber reinforced plastic 2 x /MPa 99.2 E x /GPa 13 G xy /GPa 4.64 cx /MPa x /MPa E x /GPa 41 y /MPa E y /GPa Т xy /MPa 51.1 G xy /GPa 5.3 cx /MPa cy /MPa x /MPa E x /GPa y /MPa E y /GPa Т xy /MPa G xy /GPa 9.74 cx /MPa x /MPa E x /GPa y /MPa E y /GPa Т xy /MPa G xy /GPa 7.6 cx /MPa Table 2 Performance parameter of high-strength bolt /MPa /MPa /GPa [9] Table 3 Type and number of the elements C3D8R 418 C3D8R 1691 C3D C3D C3D C3D C3D8R C3D8R C3D8R Fig.13 The FEM mesh of the joint segment P [10] P Aefu (1) 1.2 A e f u fu 1040 N / mm 4 4 Table 4 Prestress of the connection bolts /mm A e /mm 2 f u /(N/mm 2 ) P/kN m 5 IEC [11] 5 Table 5 Load case at the sectional division / (kn m) / (kn m) /kn /kn

5 [12] 3 4 [13] Mises S, S33 ( : 75%) z y x 14 z Fig.14 z-direction stress of connection section for the prestressed load 15~ 23 x y z x y z z Mises x Fig.15 x-direction stress of general section 16 y Fig.16 y-direction stress of general section 17 z Fig.17 z-direction stress of general section S, S11 ( : 75%) x Fig.18 x-direction stress of transition section 19 y Fig.19 y-direction stress of transition section 20 z Fig.20 z-direction stress of transition section

6 214 6 /MPa Table 6 Results of the max flapwise bending moment 21 x Fig.21 x-direction stress of connection section 22 y Fig.22 y-direction stress of connection section 23 z Fig.23 z-direction stress of connection section zmax zmin /MPa Table 7 Results of the min flapwise bending moment zmax zmin /MPa Table 8 Results of the max edgewise bending moment zmax zmin 24 Mises Fig.24 Mises stress distribution of prestressed bolts 3 4 6~ (1) /MPa Table 9 Results of the min edgewise bending moment zmax zmin (2)

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