# US 2014/0154092 A1 · Wind turbine blade with transition region

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- Number: US 2014/0154092 A1
- Document ID: US20140154092A1
- Status: Published application
- Kind: A1
- Application number: 14/233,558
- Filed: 2012-07-16
- Published: 2014-06-05
- Earliest claimed: 2011-07-20
- Assignees: Lm Wp Patent Holding A/S
- Inventors: Martin Dahl; Bjarne Krab Mortensen; Morten Olesen
- Web page: https://patentgrep.com/patent/US20140154092A1

## CPC

- B29C 70/304: {In-plane lamination by juxtaposing or interleaving of plies, e.g. scarf joining}
- F01D 5/12: Blades ({specially adapted for radial flow machines or engines F01D5/04}; blade roots F01D5/30; rotors with blades adjustable in operation F01D7/00; stator blades F01D9/02)
- F01D 5/147: {Construction, i.e. structural features, e.g. of weight-saving hollow blades (F01D5/148, F01D5/16 and F01D5/20 take precedence; blade shape F01D5/141; blades with cooling or heating channels or cavities F01D5/18; heating, heat-insulating or cooling means on blades F01D5/18)}
- F03D 1/0675: {of the blades}
- F05B 2280/5001: Elasticity
- F05B 2280/6003: Composites; e.g. fibre-reinforced
- F05B 2280/702: Reinforcements
- Y02E 10/72: Wind turbines with rotation axis in wind direction
- B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00)
- F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D)
- F03D: WIND MOTORS
- F05B: INDEXING SCHEME RELATING TO WIND, SPRING, WEIGHT, INERTIA OR LIKE MOTORS, TO MACHINES OR ENGINES FOR LIQUIDS COVERED BY SUBCLASSES F03B, F03D AND F03G
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

## Abstract

A wind turbine blade (1) is formed of a fibre-reinforced composite material comprising a polymer matrix. The blade (1) further comprises a first region (11), a second region (12) and a transition region (13) between the first and the second region (11, 12). The first region (11) is reinforced predominantly with a first reinforcement fibre material (21). The second region (12) is reinforced predominantly with a second reinforcement fibre material (22). The first and the second reinforcement fibre material differ from each other and has differing E-modulus. The transition region (13) additionally comprises a third type of reinforcement fibre material (23) differing from both the first and the second reinforcement fibre material (21; 22) and having an E-modulus between that of the first reinforcement fibre material (21) and that of the second reinforcement fibre material (22).

## Claims

### Claim 1

Wind turbine blade (1) having a longitudinal direction (L) extending from a root region (2) to a tip (4) of the blade, said blade comprising at least one component formed of a fibre-reinforced composite material comprising a polymer matrix and a first fibre material (21) being fibreglass and a second reinforcement fibre material (22) being carbon fibres embedded in the polymer matrix, said blade further comprising a first region (11), a second region (12) and a transition region (13) between the first and the second region (11, 12), the first region (11) being reinforced predominantly with the first reinforcement fibre material (21), the second region (12) being reinforced predominantly with the second reinforcement fibre material (22), the first and the second reinforcement fibre materials differing from each other and having differing E-modulus, characterised in that the transition region (13) additionally comprises a third type of reinforcement fibre material (23) differing from both the first and the second reinforcement fibre material (21; 22) and having an E-modulus between that of the first reinforcement fibre material and that of the second reinforcement fibre material.

### Claim 2 (depends on 1)

Blade according to claim 1, wherein the third reinforcement fibre material (23) is made of metal fibres, preferably steel fibres.

### Claim 3 (depends on 1)

Blade according to claim 1, wherein the amount of third type of fibre material (23) varies in the transition region (13) so as to mitigate a stiffness transition between the fibreglass (21) in the first region (11) and the carbon fibres (22) in the second region (12).

### Claim 4 (depends on 1)

Blade according to claim 1, wherein the transition region (13) is arranged in a longitudinally extending zone between the first region (11) and the second region (12).

### Claim 5 (depends on 1)

Blade according to claim 1, wherein the proportion between the first and the third reinforcement fibre material (21;23) and the proportion between the third and the second reinforcement fibre material (23; 22) vary such in the longitudinal direction of the transition region (13) that the E-modulus of the composite material varies monotonically between the first and the second region (11; 12).

### Claim 6 (depends on 1)

Blade according to claim 1, wherein the proportion between the first and the third reinforcement fibre material (21; 23) decreases monotoni-cally between the first and the second region (11,12) over at least a first portion of the transition region (13) adjacent the first region (11).

### Claim 7 (depends on 1)

Blade according to claim 1, wherein the proportion between the third and the second reinforcement fibre material (23; 22) decreases monotonically between the first and the second region (11;12) at least over a second portion of the transition region (13) adjacent the second region (12).

### Claim 8 (depends on 1)

Blade according to claim 1, wherein the proportion of the third reinforcement fibre material (23) is substantially constant in a longitudinally central portion (17) between the first and the second portion of the transition region (13).

### Claim 9 (depends on 8)

Blade according to claim 8, wherein the central portion (17) of the transition region (13) comprises predominantly reinforcement fibre material of the third type (23).

### Claim 10 (depends on 1)

Blade according to claim 1, wherein fibres or bundles of fibres of the first type of fibres (21) extend with differing lengths from the first region (11) and into the transition region (13), fibres or bundles of fibres of the second type of fibres (22) extend with different lengths from the second region (12) and into the transition region (13,) and fibres or bundles of fibres of the third type of fibres (23) extend in the transition region (13) between the first and the second type of fibres extending from the first and the second region (11; 12), respectively.

### Claim 11 (depends on 1)

Blade according to claim 1, wherein the transition region (13) is formed of a laminate of several fibre layers (14) in which each fibre layer (14) has a first boundary surface (15) at a first position in the longitudinal direction and a second boundary surface (16) at a second position in the longitudinal direction, the fibre layers (14) including reinforcement fibres of the first type (21) on a first side of the first boundary surface (15) and reinforcement fibres of the third type (23) on a second side of the first boundary surface (15), the fibre layer (14) further including fibres of the third type of reinforcement fibres (23) on a first side of the second boundary surface (16) and fibres of the second type of reinforcement fibres (22) on a second side of the second boundary surface (16), i.e. fibres of the third type between the first and the second boundary surface.

### Claim 12 (depends on 1)

Blade according to claim 1, wherein the transition region (13) comprises the third type of reinforcement fibre material (23) over its entire extent.

### Claim 13 (depends on 1)

Blade according to claim 1, wherein the transition region (13) has a length of at least 0.3 metre, such as a length between 0.3 and 20 metres, between 0.3 and 10 metres or between 0.3 and 5 metres.

### Claim 14 (depends on 1)

Blade according to claim 1, wherein the fibres of the first region (11), the second region (12) and the transition region (13) is oriented predominantly in the longitudinal direction (L) of the blade (1).

### Claim 15 (depends on 1)

Blade according to claim 1, wherein the at least one component is a load-bearing part of the blade, such as a spar, a beam or a principal laminate part of a shell structure of the blade.