Joining device for hybrid wind turbine towers
View Patent ↗A joining device ( 8 ) for hybrid wind turbine towers ( 5 ) intended for the fixation of a metal portion ( 6 ) of a wind turbine tower ( 5 ) to a concrete portion ( 7 ) of said wind turbine ( 1 ) which comprises a metal body ( 9 ) having a generally tubular configuration that is suitable to be fixed to the metal portion ( 6 ) of the tower ( 5 ) which in use is adjacent to the concrete portion ( 7 ), and suitable for being at least partially embedded into said concrete portion ( 7 ), said metal body ( 9 ) being provided with a number of anchoring openings ( 11 ) adapted such that the material of the concrete portion ( 7 ) passes therethrough. A hybrid wind turbine tower ( 5 ) comprises such a joining device ( 8 ) provided between one metal portion ( 6 ) and one concrete portion ( 7 ).
1. A joining device for a hybrid wind turbine tower, said hybrid wind turbine tower comprising a concrete portion and a metal portion located adjacent to said concrete portion, said joining device being adapted to join said metal portion to said concrete portion, wherein the joining device comprises a metal body having a generally tubular configuration that is adapted to be fixed via a connecting edge to said metal portion of the hybrid wind turbine tower and is adapted to be at least partially embedded into said concrete portion of the hybrid wind turbine tower, said metal body having a number of anchoring openings adapted such that the material of the concrete portion passes through said anchoring openings, and wherein the metal body includes at least one plate projecting therefrom, the at least one plate serving as a carrier for at least some of said anchoring openings.
2. A joining device as claimed in claim 1 , wherein said one or more plates are provided with a number of said anchoring openings adapted so that a portion of the material of said concrete portion passes therethrough.
3. A joining device as claimed in claim 1 , wherein said one or more axial plates are arranged at an outer portion of the metal body.
4. A joining device as claimed in claim 2 , wherein said one or more plates provided with a number of said anchoring openings are arranged at an outer portion of said metal body.
5. A joining device as claimed in claim 1 , wherein said one or more plates are arranged at an inner portion of said metal body.
6. A joining device as claimed in claim 2 , wherein said one or more plates are arranged at an inner portion of said metal body.
7. A joining device as claimed in claim 6 , wherein one or more of said anchoring openings of said one or more plates are circular or elliptical in shape.
8. A joining device as claimed in claim 2 , wherein one or more of said anchoring openings of said one or more plates are drop-shaped.
9. A joining device as claimed in claim 2 , wherein said anchoring openings have a size decreasing in a direction towards the top of said hybrid wind turbine tower.
10. A joining device as claimed in claim 2 , wherein said anchoring openings have a size increasing in a direction towards the top of said hybrid wind turbine tower.
11. A joining device as claimed in claim 2 , wherein at least some of said anchoring openings widen from said edge of a plate in a direction towards said metal body.
12. A joining device as claimed in claim 1 , wherein said one or more plates project substantially perpendicular to said metal body.
13. A joining device as claimed in claim 1 , wherein said metal body is cylindrical in shape.
14. A joining device as claimed in claim 1 wherein said metal body is polygonal in shape.
15. A joining device as claimed in claim 1 , wherein said metal body is frusto conical in shape.
16. A hybrid wind turbine tower, comprising;
(a) at least one concrete portion;
(b) at least one metal portion located adjacent to said concrete portion; and
(c) a joining device provided between one metal portion and one concrete portion, wherein said joining device comprises a metal body, wherein said metal body: comprises a tubular configuration adapted to be fixed via a connecting edge to said metal portion of said hybrid wind turbine tower and the metal body is adjacent to said concrete portion; the metal body being adapted to be at least partially embedded into said concrete portion of the hybrid tower; having one or more anchoring openings adapted such that the material of said concrete portion passes through said anchoring openings; and wherein the metal body includes at least one plate projecting therefrom, the at least one plate serving as a carrier for at least some of said anchoring openings.
17. A joining device according to claim 1 , wherein the minimum plate length of said plates is determined according to the following formula:
L
min
≥
(
n
o
·
ϕ
·
t
·
6
·
f
ck
·
3
·
β
2
·
a
·
f
yk
)
where:
L min is the minimum opening length, in mm;
n° is the number of anchoring openings formed in the plate;
φ is the opening diameter, in mm;
t is the plate thickness, in mm;
f ck is the characteristic concrete compressive strength, in MPa;
f yk is the characteristic metal tensile strength of the plates or the metal portion, in MPa;
β is a coefficient corresponding to the type of the plate steel; and
a is the welding-neck thickness.
18. A joining device according to claim 1 , wherein the minimum opening centre-to-centre distance of said anchor openings is according to the formula:
s
min
≥
(
1
+
3
2
·
6
·
f
ck
f
y
d
·
1
1.25
)
·
ϕ
where:
S min is the minimum opening centre-to-centre distance, in mm);
f ck is the characteristic concrete compressive strength, in MPa;
f yk is the characteristic metal tensile strength of the plates or the metal portion, in MPa; and
φ is the opening diameter in mm.