EP4784356A1 - A method of making a wind turbine blade component - Google Patents

Abstract

A method of making a wind turbine blade component A method of making a wind turbine blade (10) component. The method comprises providing a sheet (36) comprising a first edge (44a), a first alignment feature (42a) located adjacent to the first edge and defining a first datum feature (46a), a second edge (44b), and a second alignment feature (42b) located adjacent to the second edge and defining a second datum feature (46b). The method further comprises providing a mould (28) defining a mould surface (30), and providing, at a first position along the mould surface, a first position marker (38a) indicating a first position. Additionally, the method comprises providing, at a second position along the mould surface (28), a second position marker (38b) indicating a second position. The method comprises arranging the sheet (36) on the mould surface (28), and aligning the first datum feature (46a) with the first position marker (38a) and aligning the second datum feature (46b) with the second position marker (38b) to thereby align the sheet on the mould. The first alignment feature (42a) is visually different in comparison to the second alignment feature (42b). Additionally or alternatively the first alignment feature (42a) is located at a different portion of the first edge (44a) in comparison to the location of the second alignment feature (42b) at the respective second edge (44b).

Description

A method of making a wind turbine blade component

Technical field

The present invention relates generally to wind turbine blades and more particularly to a method of making a wind turbine blade component.

Background

Modern wind turbine blades are very large structures, and components of a wind turbine blade, such as a blade shell or a shear web may therefore also be very large. Manufacturing components such as blade shells and/or shear webs often includes a moulding process. A moulding process, such as vacuum assisted resin transfer moulding (VARTM), typically involves arranging one or more sheets on a mould surface. However, due to the size of some wind turbine blade components, and the corresponding size of the mould configured to form such a component, accurate alignment of sheets on the mould can be both challenging and time-consuming.

It is against this background that the present invention has been developed.

Summary

In a first aspect of the present invention there is provided a method of making a wind turbine blade component. The method comprises providing a sheet comprising a first edge, a first alignment feature located adjacent to the first edge and defining a first datum feature, a second edge, and a second alignment feature located adjacent to the second edge and defining a second datum feature. The method further comprises providing a mould defining a mould surface, and providing, at a first position along the mould surface, a first position marker indicating a first position. Additionally, the method comprises providing, at a second position along the mould surface, a second position marker indicating a second position. The method comprises arranging the sheet on the mould surface, and aligning the first datum feature with the first position marker and aligning the second datum feature with the second position marker to thereby align the sheet on the mould. The first alignment feature is visually different in comparison to the second alignment feature. Additionally or alternatively the first alignment feature is located at a different portion of the first edge in comparison to the location of the second alignment feature at the respective second edge.

Accordingly, the method facilitates simple alignment of the sheet on the mould using the first and second alignment features of the sheet in combination with the corresponding position markers. The method also facilitates simple orientation of the sheet on the mould surface because the configuration of the first and second alignment features facilitates fast visual identification of the respective edges of the sheet, and the sheet can then be arranged on the mould in the intended orientation.

The first and second alignment features are located adjacent the respective first and second edges and are a feature of the sheet that is in addition to the edges of the sheet. That is the sheet comprises a first edge and the sheet further comprises a first alignment feature located adjacent to the first edge, the first alignment feature defining a first datum feature relative to the first edge; and the sheet comprises a second edge and the sheet further comprises a second alignment feature located adjacent to the second edge, the second alignment feature defining a second datum feature relative to the second edge. In other words, the first alignment feature is a feature of the sheet that is not in itself the first edge and similarly, the second alignment feature is a feature of the sheet that is not in itself the second edge.

In some examples the sheet may comprise a first alignment feature that is visually different in comparison to the second alignment feature and the first alignment feature may also be located at a different portion of the first edge in comparison to the location of the second alignment feature at the respective second edge. Such a configuration facilitates orientation and alignment of the sheet on the mould as previously described, and the provision of multiple visually identifiable indicators (i.e. the different forms of the alignment features and the locations of said alignment features) additionally helps to ensure that that the sheet is arranged on the mould the correct way up, i.e. not upside down.

It should be appreciated that the first and second position markers indicate pre-determined positions on the mould surface where accurate alignment of the alignment features of the sheet with said position markers results in the manufacture of a wind turbine blade component to the intended design.

In some examples, the wind turbine blade component may be a laminated composite component. In such an example the sheet may form at least part of a laminate layer of the wind turbine blade component. As such, the sheet may be a sheet of fibrous material, for example comprising reinforcing fibres such as glass fibres or carbon fibres. Accordingly, in some examples the sheet may be a sheet of glass fibre material, such as biaxial glass fibre material. In some other examples, the sheet may be a sheet of consumable or sacrificial material used in a moulding process when making a wind turbine blade component in accordance with an example of the invention. For example, the sheet may be a sheet of transfer film, peel-ply material, flow-controlling material, release material, or sealing material.

In some examples, providing the first and/or second position marker may comprise providing the respective position marker on the mould surface. For example, the first and/or second position marker may comprise a line or other marker painted or taped onto the mould surface, in some examples.

In some other examples, providing the first position marker may comprise projecting the first position marker onto the mould surface and/or sheet using a visible light projection system. Additionally or alternatively, providing the second position marker may comprise projecting the second position marker onto the mould surface and/or sheet using a visible light projection system.

For example, a visible light projection system may comprise a laser projection system. Accordingly, the first and/or second position markers may comprise laser projections. Projecting the or each position marker onto the mould surface and/or sheet is an effective and time efficient method for aligning one or more sheets on the mould. In particular, such a method facilitates the alignment of opaque or substantially opaque sheets on the mould. Further, such a method may facilitate alignment of a plurality of sheets on top of one another on the mould surface, where the plurality of sheets may otherwise obscure a view of a position marker on the mould surface itself. A visible light projection system also facilitates simple reconfiguration of the first and/or second position markers such that the same apparatus can be used to align sheets of different layers in the wind turbine blade component, or even for making different designs of the wind turbine blade component using the same apparatus by indicating different positions for aligning the or each sheet on the mould.

In some examples, the mould may be a male mould and the mould surface may therefore be a substantially convex mould surface. Accordingly, in some examples the mould may be configured to form a shear web of a wind turbine blade, and the method may therefore be a method of making a shear web of a wind turbine blade.

In some examples, the convex mould surface may comprise a main mould surface and one or more side surfaces extending transverse to the main mould surface. In such examples, the first and second position markers may be provided on the main mould surface. Accordingly, arranging the sheet on the mould may comprise arranging the sheet such that the first and second alignment features are located on the main mould surface, in some preferred examples. Such a configuration may be advantageous for ensuring that the first and second position markers, and the first and second alignment features are all visible from either side of the mould. Additionally, such a configuration facilitates the use of an overhead visible light projection system located above the mould for projecting the first and/or second position markers onto the mould surface and/or sheet because the main mould surface is within the field of view of such a projection system.

In some examples the main mould surface may be a substantially flat, upwards-facing surface of the mould. Conversely, the one or more side surfaces may extend transversely downwards from the main mould surface. For example, the main mould surface may be shaped to form a web panel of a shear web, and the or each side surface may be shaped to form at least part of a shear web mounting flange that extends transverse to the web panel for connecting the shear web to a blade shell.

In some examples, the sheet may comprise a third edge and a fourth edge. The third and fourth edges may extend between mutually opposed first and second edges of the sheet. The method may comprise arranging the sheet on the mould surface such that at least one of the third edge and/or fourth edge is positioned on a side surface of the mould. It follows that in some examples, a projection line extending between the third edge and the visible light projection system, and/or between the fourth edge and the visible light projection system, may be intercepted by the main mould surface. Accordingly, in examples where the mould comprises a convex mould surface it may not be possible to project a reference line onto the side surface of the mould for aligning the third and/or fourth edges of the sheet. The method described herein advantageously facilitates alignment of the sheet without requiring projection of a reference line onto the or each side surface of the mould.

In some other examples the mould may be a female mould and the mould surface may therefore be a concave mould surface. Accordingly, in some examples the mould may be configured to form at least a portion of a wind turbine blade shell, and the method may therefore be a method of making at least a portion of a wind turbine blade shell.

In some examples, the first and/or second alignment feature may be provided on a surface of the sheet. For example, the alignment feature may be drawn or printed onto a surface of the sheet. In some other examples, the first alignment feature may be formed as part of the sheet. Additionally or alternatively, the second alignment feature may be formed as part of the sheet. For example, the sheet may be manufactured with the first and/or second alignment feature integrally formed in the sheet. For example the sheet may be a moulded or pressed sheet comprising the first and/or second alignment feature. In some examples the sheet may be a sheet of woven fibrous material into which the first and/or second alignment feature are woven during manufacture of the sheet.

In some examples, the first alignment feature may be cut into the sheet. Additionally or alternatively, the second alignment feature may be cut into the sheet. For example, the or each alignment feature may be cut into the sheet at the same time that the sheet is cut from a larger stock of material. A plurality of sheets as described herein may be cut simultaneously from a stack of stock material. Accordingly, in some examples respective first and/or second alignment features may be cut into a plurality of sheets simultaneously.

In some preferred examples the first and/or second alignment feature of a sheet may extend into the sheet from the first and/or second edge respectively. Such a configuration may result in an alignment feature that is particularly clearly visible to a technician when arranging the sheet on the mould. Further, in examples where the sheet is cut from stock material, such a configuration facilitates a particularly efficient cutting process when cutting the sheet from the larger stock material because the alignment feature can be cut in the same process step in which the respective edge of the sheet is cut.

In some examples, the first and/or second alignment feature may comprise a notch, or cutout, extending into the sheet from a respective edge. Such an alignment feature may comprise a straight edge identifiable as the respective datum feature. For example, the alignment feature may comprise a triangular cut-out, and the datum feature may be an edge of the triangular cut-out that extends substantially perpendicular to the respective edge of the sheet. In some other examples, the first and/or second alignment feature of a sheet may be a simple slit extending into the sheet from the respective edge of the sheet. Such a slit may comprise a straight cut and may itself define the respective datum feature.

In some examples, the first and second edges of the sheet may be mutually opposed. For example, the sheet may be substantially quadrilateral shaped, such as substantially square, rectangular, trapezoidal, or rhomboidal. Accordingly, the first and second edges may be left and right edges, or top and bottom edges of the sheet in some examples. In some examples, the first alignment feature may be visually different in comparison to the second alignment feature, and the first and second alignment features may be respectively located at the same portion of the respective first and second edges of the sheet. Accordingly, in such an example the orientation of the sheet may be primarily identified by the visual difference between the first and second alignment features.

In some such examples, the first and second position markers may be aligned with one another in a first direction, and the first and second datum features may also be aligned with one another in the first direction. For example, the first and second position markers may be defined by the same line, i.e. a reference line such as a centreline of the mould surface or a single projected laser line for example. Such a configuration may simplify the provision of the first and second position markers whilst still facilitating accurate alignment and orientation of the sheet on the mould by aligning the datum features of the visually different first and second alignment features with the respective position markers, i.e. with the reference line.

In some other examples, the first alignment feature may be visually the same as the second alignment feature, and the first alignment feature may be located at a different portion of the first edge in comparison to the location of the second alignment feature at the respective second edge. For example, the first and second alignment features may each be a simple slit cut into the sheet. Accordingly, the first and second alignment features may be visually the same as one another. Identification of the correct orientation of the sheet may therefore be achieved primarily by observing the location of the respective alignment feature. For example, an alignment feature located at a central portion of an edge may indicate that the edge is the first edge, and an alignment feature located at a side portion of an edge may indicate that the edge is a second edge. This may facilitate a simple and efficient process for manufacturing the sheet whilst still enabling accurate alignment and orientation of the sheet on the mould.

In some examples, the method may comprise providing a plurality of sheets, each sheet comprising a respective first edge, a respective first alignment feature located adjacent to the first edge and defining a respective first datum feature, a respective second edge, and a respective second alignment feature located adjacent to the second edge and defining a respective second datum feature. In such an example the method may further comprise arranging each sheet on the mould surface in the same orientation such that each first alignment feature is located on the same side of the respective sheet and each second alignment feature is located on the same side of the respective sheet. The first edge of each sheet may define a first edge region, and the second edge of each sheet may define a second edge region. In some examples, the method may comprise arranging a first sheet and second sheet on the mould such that a first edge region of the first sheet overlaps a second edge region of the second sheet. In such an example the respective first alignment feature is preferably located at a different portion of the respective first edge in comparison to the location of the respective second alignment feature at the respective second edge. Such a configuration may help to further minimise confusion when aligning the first and second datum features of each sheet with the respective position markers.

Additionally, in examples where the alignment features are cut or otherwise formed in the sheet by an absence of sheet material, offsetting the alignment features helps to ensure that the resultant wind turbine blade component, formed in part by the sheets, is not weakened by a close arrangement of discontinuities, i.e. the alignment features, in the constituent sheets. For example, if the sheets comprise fibre material for forming a composite wind turbine blade component, offsetting the alignment features, i.e. providing first and second sheets having respective alignment features located at different portions of the respective edges of the sheets, may help to ensure that sufficient load paths are formed in the component and thereby minimise the risk of stress concentrations forming in the component. In some preferred examples, overlapping sheets may be arranged such that the first alignment feature of the first sheet is spaced apart from the second alignment feature of the second sheet by at least 10 mm, preferably at least 20 mm, more preferably at least 30 mm in all directions.

In some examples, the first position marker may be provided at a first position along the mould surface in a first direction, and the second position marker may be provided at a second position along the mould surface in the first direction. The first and second position markers each indicate a respective position across the mould surface in a second direction. It follows that the method may therefore comprise aligning the first and second datum features of the sheet with the first and second position markers in the second direction. The second direction may be transverse to the first direction, for example, in some preferred examples the second direction may be orthogonal to the first direction.

It will be appreciated than in some examples where the first and second position markers are aligned with one another, the first and second position markers may be provided at different positions in the first direction and aligned with one another in the second direction. For example, the first and second position markers may be provided at different positions along a reference line that extends in the first direction and may therefore be at different positions in the first direction whilst being aligned in the second direction. As described previously, the sheet may be arranged such that the first and second datum features are aligned with the respective first and second position markers in the second direction.

Conversely, in some other examples the first and second position markers may not be aligned, and the first and second position markers may instead be offset from one another in both the first and second direction. It should be appreciated that in such an example the method may still comprise arranging the sheet such that the first and second datum features are aligned with the respective first and second position markers in the second direction.

The second direction may be transverse to the first direction, for example, in some preferred examples the second direction may be orthogonal to the first direction. For example, the first direction may be a spanwise direction of the resultant wind turbine blade component, and the second direction may be one of a chordwise direction, a widthwise direction or a thickness direction of the resultant wind turbine blade component. In some examples, the mould surface defined by the mould may therefore extend longitudinally in the first direction, i.e. in the spanwise direction of the resultant wind turbine blade component. It follows that the mould surface defined by the mould may therefore also extend in the second direction transverse to the first direction, i.e. in a chordwise, widthwise, or thickness direction of the resultant wind turbine blade component.

In some examples, the method may comprise arranging the sheet on the mould surface by hand. The provision of position markers and alignment features in accordance with the examples described herein is particularly advantageous for observation by technicians during the manufacture of the wind turbine blade component on the mould.

The first and/or second alignment features may be a cut in the sheet. In other examples, the first and/or second alignment features may be a marker on the sheet. For example, the first and/or second alignment features may be drawn or painted onto a surface of the sheet or may be provided on an adhesive sticker attached to the sheet. The first and/or second alignment features may be formed as part of the sheet by weaving or stitching the alignment feature into the sheet. The alignment features may comprise a portion, such as a straight line or edge, that is identifiable as the datum feature for arrangement with the corresponding position marker. It should be appreciated that references to arranging sheet “on the mould” or “on the mould surface” are not limited to the arrangement of a sheet directly on, i.e. in direct contact with, the mould or mould surface. In some examples the method may comprise arranging the sheet on the mould surface on top of an intermediate component or material, such as a release layer or film for example.

In another aspect of the present invention there is provided shear web manufactured in accordance with an example of the method described herein.

In another aspect of the present invention there is provided a wind turbine blade shell manufactured in accordance with an example of the method described herein.

Brief description of the drawings

Examples of the present invention will now be described by way of non-limiting example only, with reference to the accompanying figures, in which:

Figure 1 is a schematic exploded view of a wind turbine blade;

Figure 2 is a schematic perspective view of a mould for making a wind turbine blade component;

Figure 3 is a schematic cross-sectional view of the mould and a visible light projection system for providing position markers on the mould;

Figure 4a is a schematic perspective view of a sheet arranged on the mould;

Figure 4b is an enlarged view of an alignment feature of the sheet arranged with a corresponding position marker to align the sheet on the mould; and

Figures 5a to 5c are schematic plan views of different examples of sheets comprising differently-configured alignment features.

Detailed description

Figure 1 is a schematic exploded view of an example of a wind turbine blade 10. The blade extends longitudinally in a spanwise direction (S) between a root end 12 and a tip end 14, and in a chordwise direction (C) between a leading edge 16 and a trailing edge 18. The blade 10 also extends in a thickness direction (T) orthogonal to the spanwise direction (S) and the chordwise direction (C). The blade 10 comprises a shell which may be formed of a first half shell 20a and a second half shell 20b which are joined together. The wind turbine blade 10 may also comprise a shear web 22 which extends longitudinally in the spanwise direction (S) inside the shell. The shear web 22 may comprise a longitudinally-extending web panel 24 and one or more web flanges 26 configured for connecting the shear web 22 to the shell of the blade 10.

Wind turbine blade components such as half shells 20a, 20b and shear webs 22 may be formed using a moulding process, such as vacuum assisted resin transfer moulding (VARTM). A method of manufacturing a wind turbine blade component will now be described with reference to the remaining figures.

Reference is made initially to Figure 2, which shows a schematic perspective view of a portion of a mould 28 that defines a mould surface 30. In the example shown in Figure 2, the mould 28 is a male mould meaning that the mould surface 30 is a substantially convex mould surface. For example, the mould surface 30 may comprise a main mould surface 32 and one or more side surfaces 34 extending transverse to the main mould surface 32. Accordingly, the mould 28 may be configured to form a shear web 22 such as that shown by way of example in Figure 1 . The main mould surface 32 may be shaped to form the web panel 24 and the side surfaces 34 may be shaped to form the web flanges 26.

The mould surface 30 extends longitudinally in a first direction X which may be the spanwise direction (S) of the resultant wind turbine blade component formed on the mould 28. The mould surface 30 also extends in a second direction Y that is transverse to the first direction X. In some examples the second direction Y may be orthogonal to the first direction X, for example the second direction Y may be the thickness direction (T) of the resultant wind turbine blade component. It should be appreciated that in other examples the second direction Y may be a chordwise direction (C), of a resultant wind turbine blade component.

Arrangement of a sheet 36 on the mould 28 will be described later in more detail with reference to Figures 4a - 5c. However, to facilitate accurate arrangement of the sheet 36 on the mould 28, the method includes providing position markers 38a, 38b as shown in Figures 2 and 3. For example, a first position marker 38a is provided at a first position along the mould surface 30 to indicate the first position. Similarly, a second position marker 38b is provided at a second position along the mould surface 30 to indicate the second position. The first and second position markers 38a, 38b may be provided at separate positions along the mould surface 30 in the first direction X and each marker 38a, 38b may indicate a respective position across the mould surface 30 in the second direction Y.

The position markers 38a, 38b may be provided in different ways in different examples. With reference still to Figures 2 and 3, in some preferred examples the first and second position markers 38a, 38b may be projected onto the mould surface 30 using a visible light projection system 40. In examples where the mould surface 30 is convex, the first and second position markers 38a, 38b are preferably provided on the main mould surface 32. Designing the manufacturing process such that the markers 38a, 38b are provided on the main mould surface 32 helps to ensure that the desired location of the markers 38a, 38b is within the field of view 41 of a visible light projection system 40 arranged above the mould 28. Providing position markers 38a, 38b on the main mould surface 32 also helps to ensure that the markers are visible to assembly technicians from all sides of the mould 28 when manufacturing the component.

Reference is now made to Figure 4a which shows a sheet 36 arranged on the mould surface 30. As previously described, the position markers 38a, 38b are provided to facilitate accurate alignment of the sheet 36. The sheet 36 therefore comprises a plurality of alignment features 42a, 42b configured to correspond to the position markers 38a, 38b to facilitate alignment of the sheet 36 on the mould 28. The sheet 36 comprises a first alignment feature 42a located adjacent to a first edge 44a of the sheet 36, and a second alignment feature 42b located adjacent to a second edge 44b of the sheet 36. As shown in Figure 4a the first and second edges 44a, 44b may be mutually opposed. In some examples the sheet may comprise third and fourth edges 44c, 44d which may be located on the side surfaces 34 of the mould 28.

The first alignment feature 42a defines a first datum feature 46a for aligning the sheet 36 with the first position marker 38a and the second alignment feature 42b defines a second datum feature 46b for aligning the sheet 36 with the second position marker 38b. A detailed view of the first alignment feature 42a is provided in Figure 4b. In this example the first alignment feature 42a comprises a triangular cut-out extending into the sheet 36 from the first edge 44a. The datum feature 46a in this example is defined by a side of the triangular cut-out which is substantially perpendicular to the first edge 44a. The sheet 36 is positioned by aligning the first datum feature 46a with the first position marker 38a, and in particular the sheet 36 may be arranged to align the datum feature 46a with the position marker 38a in the second direction Y. Whilst not shown in a separate detail view, it will be appreciated that the second datum feature 46b is aligned with the corresponding second position marker 38b in a similar manner. By aligning both the first and second datum features 46a, 46b with their respective position markers 38a, 38b, the sheet 36 is aligned on the mould 28 both rotationally and in the second direction Y. Accurate positioning of the sheet 36 in the first direction X may be achieved by aligning the first or second edge 44a, 44b of the sheet 36 with a reference line or marker (not shown), such as a projected reference line, which indicates a desired position along the mould surface 30 in the first direction X.

Figures 5a to 5c show different examples of a sheet 36 comprising first and second alignment features 42a, 42b configured to correspond to first and second position markers 38a, 38b to facilitate alignment of the sheet 36 on the mould 28. In each of these examples the alignment features 42a, 42b may be formed as part of the sheet 36. For example, the alignment features 42a, 42b, and therefore also the respective datum features 46a, 46b, may be formed by cutting the features into the sheet 36.

Figure 5a shows an example of a sheet 36 comprising a first alignment feature 42a that is visually different in comparison to the second alignment feature 42b. For example the first alignment feature 42a may be a triangular cut-out, whereas the second alignment feature 42b may be a linear slit cut into the sheet 36. A technician can easily identify which alignment feature is the first or second alignment feature 42a, 42b based on the visual differences between the alignment features. As such, the technician can easily determine the correct orientation of the sheet 36 on the mould 28.

As shown in Figure 5a, in some examples the first and second alignment features 42a, 42b may be located at the same portion of the respective first and second edges 44a, 44b of the sheet 36, for example a central portion as shown in Figure 5a. The first and second datum features 46a, 46b may be aligned with one another in the first direction X in such an example. It follows that the corresponding first and second position markers 38a, 38b may therefore also be aligned with one another, and in some examples the first and second position markers 38a, 38b may be defined by different portions of the same reference line, such as a centreline, extending in the first direction X. Such a configuration may be simpler for a technician to observe when arranging the sheet 36. Despite the alignment features 42a, 42b being located in the same portion of the respective edges 44a, 44b, simple orientation of the sheet 36 is facilitated by the visual differences between the alignment features 42a, 42b as previously described. Referring now to Figure 5b, in some other examples, the first alignment feature 42a may be located at a different portion of the first edge 44a in comparison to the location of the second alignment feature 42b at the respective second edge 44b. In such an example the first alignment feature 42a may be visually the same as the second alignment feature 42b. The identification of which alignment feature is the first or second alignment feature 42a, 42b may therefore be based on the position of the respective alignment feature in such examples. For example, as shown in Figure 5b, an alignment feature located in a central portion of an edge may indicate that the alignment feature is the first alignment feature 42a and the edge is therefore the first edge 44a. Conversely, an alignment feature located outside of the central portion, for example nearer to the third or fourth edge 44c, 44d, may indicate that the alignment feature is the second alignment feature 42b and the respective edge is the second edge 44b. The position of the alignment feature 42a, 42b therefore provides an indication of which position marker 38a, 38b the respective alignment feature should be arranged with.

A further example of a sheet 36 comprising alignment features 42a, 42b is shown in Figure 5c. As shown, in some examples the sheet 36 may comprise alignment features 42a, 42b that are both visually different to one another and located at different portions of the respective sheet edges 44a, 44b. For example, as shown in Figure 5c the first alignment feature 42a may be a triangular cut-out located in the central portion of the sheet 36, and the second alignment feature 42b may be a linear slit located at a portion of the second edge 44b near to the third edge 44c, i.e. outside of the central portion. Such a configuration has the same advantages described previously in terms of the alignment and orientation of the sheet 36 on the mould 28. Additionally, a sheet 36 having both visually different and differently located alignment features 42a, 42b provides a simple means for a technician to determine that the sheet 36 is arranged the right way up on the mould 28.

Whilst Figures 5a to 5c have been described with reference to alignment features 42a, 42b cut into the sheet 36, in some other examples (not shown) the alignment features 42a, 42b may be provided in a different way. For example, the first and/or second alignment feature 42a, 42b may be drawn or painted onto a surface of the sheet 36, or may be provided on an adhesive sticker attached to the sheet 36. In some other examples the or each alignment feature 42a, 42b may be formed as part of the sheet 36 by weaving or stitching the alignment feature 42a, 42b into the sheet itself. Notably, in each example the alignment feature 42a, 42b comprises a portion, such as a straight line or edge, that is identifiable to a technician as the datum feature 46a, 46b for arrangement with the corresponding position marker 38a, 38b. The method of arranging and aligning a sheet 36 described herein may be used to arrange different sheet materials during the manufacture of a wind turbine blade component. For example, the sheet 36 may be a sheet of sacrificial or consumable material used in a moulding process. However, the method is particularly advantageous for arranging a sheet of reinforcing material, such as a sheet of glass fibre material, on or in a mould 28.

In some examples (not shown), the method may include arranging a plurality of sheets 36 such as those described herein on the mould 28. Accordingly, each sheet 36 may comprise a respective first and second edge 44a, 44b, and a respective first and second alignment feature 42a, 42b located adjacent to the corresponding edge. The respective first and second alignment features 42a, 42b may define first and second datum features 46a, 46b as described previously. Each sheet 36 may be arranged on the mould surface 30 in the same orientation. This means that a technician can easily identify which way around each sheet 36 should be oriented by simply observing the first and/or second alignment feature 42a, 42b of each sheet 36. It follows that after correct arrangement of each sheet 36 on the mould 28, the first alignment feature 42a of each sheet 36 may be located on the same side of the respective sheet 36.

Whilst the description above and the accompanying figures are provided with reference to a male mould 28 that defines a convex mould surface 30, for example for making a wind turbine blade shear web 22, it should be appreciated that other examples of the method are equally applicable to manufacturing other wind turbine blade components, such as a wind turbine blade half shell 20a, 20b. It follows that in such other examples, the mould 28 may be configured differently to form the respective wind turbine blade component. For example, to form a wind turbine blade half shell 20a, 20b the mould 28 may define a concave mould surface 30 on which the sheet 36 or sheets are arranged.

In some other examples the mould surface 30 may be substantially flat. The benefits of the method described herein are applicable to the arrangement of a sheet 36 on any mould surface 30 in that the location and/or configuration of the first and second alignment features 42a, 42b provides an easily identifiable indicator for accurately positioning the sheet 36 on a mould 28.

The accompanying figures have been described with reference to examples in which the first and second position markers 38a, 38b are provided by a visible light projection system 40 which projects the position markers 38a, 38b onto the mould surface 30. It will be appreciated that in some examples, particularly where a plurality of sheets 36 are arranged on the mould 28, the method may involve projecting the first and/or second position markers 38a, 38b onto a sheet 36 that is already arranged on the mould 28. Providing the position markers 38a, 38b on a sheet 36 already arranged on the mould 28 may facilitate accurate arrangement of overlapping sheets 36. In some other examples, the first and second position markers 38a, 38b may be provided in a different way. For example, the position markers 38a, 38b may be defined by markings on the mould surface 30, such as painted or drawn markings, or adhesive markers such as tape or stickers. The position markers 38a, 38b may also be provided by an alignment jig arranged over the mould surface 30 in some examples. The description provided herein serves to demonstrate a plurality of possible examples of the present invention. It will be appreciated that features described in relation to any of the examples above may be readily combined with any other features described with reference to other examples without departing from the scope of the invention as defined in the appended claims.

Claims

CLAIMS:

1. A method of making a wind turbine blade component, the method comprising: providing a sheet comprising a first edge, a first alignment feature located adjacent to the first edge and defining a first datum feature, a second edge, and a second alignment feature located adjacent to the second edge and defining a second datum feature; providing a mould defining a mould surface; providing, at a first position along the mould surface, a first position marker indicating the first position and providing, at a second position along the mould surface, a second position marker indicating the second position; arranging the sheet on the mould surface; and aligning the first datum feature with the first position marker and aligning the second datum feature with the second position marker to thereby align the sheet on the mould; wherein the first alignment feature is visually different in comparison to the second alignment feature and/or the first alignment feature is located at a different portion of the first edge in comparison to the location of the second alignment feature at the respective second edge.

2. The method of claim 1 , wherein providing the first position marker comprises projecting the first position marker onto the mould surface and/or sheet using a visible light projection system; and/or wherein providing the second position marker comprises projecting the second position marker onto the mould surface and/or sheet using a visible light projection system.

3. The method of any preceding claim, wherein the mould is a male mould and the mould surface is a substantially convex mould surface.

4. The method of Claim 3, wherein the convex mould surface comprises a main mould surface and one or more side surfaces extending transverse to the main mould surface, and wherein the first and second position markers are provided on the main mould surface.

5. The method of any preceding claim, wherein the first alignment feature is formed as part of the sheet, and/or wherein the second alignment feature is formed as part of the sheet.

6. The method of Claim 5, wherein the first alignment feature is cut into the sheet and/or wherein the second alignment feature is cut into the sheet.

7. The method of any preceding claim, wherein the first and second edges of the sheet are mutually opposed.

8. The method of any preceding claim, wherein the first alignment feature is visually different in comparison to the second alignment feature, and wherein the first and second alignment features are respectively located at the same portion of the respective first and second edges of the sheet.

9. The method of Claim 8, wherein the first and second position markers are aligned with one another in a first direction, and wherein the first and second datum features are also aligned with one another in the first direction.

10. The method of any of Claims 1 to 7, wherein the first alignment feature is visually the same as the second alignment feature, and wherein the first alignment feature is located at a different portion of the first edge in comparison to the location of the second alignment feature at the respective second edge.

11 . The method of any preceding claim comprising providing a plurality of sheets, each sheet comprising a respective first edge, a respective first alignment feature located adjacent to the first edge and defining a respective first datum feature, a respective second edge, and a respective second alignment feature located adjacent to the second edge and defining a respective second datum feature; and arranging each sheet on the mould surface in the same orientation such that each first alignment feature is located on the same side of the respective sheet and each second alignment feature is located on the same side of the respective sheet.

12. The method of any preceding claim, wherein the first position marker is provided at a first position along the mould surface in a first direction, wherein the second position marker is provided at a second position along the mould surface in the first direction, and wherein the first and second position markers each indicate a respective position across the mould surface in a second direction.

13. The method of Claim 12, wherein the second direction is transverse to the first direction and preferably orthogonal to the first direction.

14. The method of Claim 12 or Claim 13, wherein the first direction is a spanwise direction of the resultant wind turbine blade component, and wherein the second direction is one of a chordwise direction, a widthwise direction or a thickness direction of the resultant wind turbine blade component.

15. The method of Claim 14, wherein the mould surface defined by the mould extends longitudinally in the first direction.