Patent Publication Number: US-2022234319-A1

Title: Method for producing a wind turbine blade

Description:
The present disclosure relates to wind turbine blades and manufacture of wind turbine blades. More specifically, the present disclosure pertains to the field of joining of parts of a wind turbine blade, such as joining of interfaces, such as a leading edge glue line or a trailing edge glue line, or part thereof. In particular, the present disclosure is related to joining of a trailing edge joint of a flatback wind turbine blade. 
     BACKGROUND 
     Wind turbine blades of fibre-reinforced polymer and in particular the aerodynamic shells of wind turbine blades are usually manufactured in moulds, where the pressure side and the suction side of the blade are manufactured separately by arranging glass fibre mats and/or other fibre-reinforcement material, such as carbon fibre, in each of the two moulds. Afterwards, one of the two halves is turned upside down and positioned on top of the other of the two halves, and the two halves are adhered together. The blade parts may be positioned on top of each other by turning and repositioning the complete half mould. 
     A wind turbine blade may be manufactured by infusing fibres, such as glass fibre mats and/or carbon fibre mats with a resin, such as polyester or epoxy. Infusion of the fibres may be provided by vacuum assisted resin transfer moulding (VARTM). 
     As wind turbines and wind turbine blades increase in size, the blade loads, i.e. strains, bending moments, peel loads etc., in particular along the trailing edge, increase. For this and other reasons, the design of the trailing edge is an important factor for the efficiency of the wind turbine. Wind turbine blades comprising a flatback profile at the trailing edge may have an increased efficiency. An optimized profile comprises a varying geometry of the trailing edge along the airfoil region of the blade. 
     However, it may be complicated to assemble a wind turbine blade with a flatback trailing edge. In particular, it may be challenging to sufficiently bond together trailing edge interfaces between the pressure side and suction side blade shell when the blade comprises a flatback profile. 
     SUMMARY OF THE INVENTION 
     It is an object of the present disclosure to provide a wind turbine blade and a method for manufacturing a wind turbine blade, which overcomes at least some of the disadvantages of the prior art. 
     In particular, it is an object of the present invention to provide a wind turbine blade and a method for manufacturing a wind turbine blade, which enhance mechanical properties as well as manufacturing convenience of bonding between blade parts, such as a suction side blade half shell and an pressure side blade half shell, in particular throughout the trailing edge of a wind turbine blade with a flatback profile. However, the present disclosure may equally be applied to bonding of other blade components which could benefit from the application of a glue flange, as disclosed. 
     Thus, the present disclosure relates to a method for assembling a wind turbine blade, such as a wind turbine blade comprising a first blade component, e.g. a first blade half shell, and a second blade component, e.g. a second blade half shell. 
     The first blade component comprises a first contact area configured to be connected to a second contact area of the second blade component, e.g. to form a leading edge and/or a trailing edge, such as a flatback trailing edge, of the wind turbine blade. The first contact area has a first contact surface. The second contact area has a second contact surface. The first contact area may comprise a first contact edge of the first blade component. The second contact area may comprise a second contact edge of the second blade component. The first contact edge and the second contact edge may be configured to be adjacently arranged during assembly of the wind turbine blade, e.g. to form a bond line of the wind turbine blade, e.g. along the leading edge and/or the trailing edge of the wind turbine blade. The first blade component may be a suction side half shell of the wind turbine blade or a pressure side half shell of the wind turbine blade. The second blade component may be the opposite blade half shell, such as the pressure side half shell of the wind turbine blade or the suction side half shell of the wind turbine blade. 
     The method comprises providing a flange element having a first flange surface configured to face the first contact surface and a second flange surface configured to face the second contact surface. The flange element comprises a flexible part along the first flange surface allowing a first primary flange surface of the first flange surface to be angled relative to a first secondary flange surface of the first flange surface. The first flange surface may join the second flange surface e.g. along a flange surface interface. 
     The method further comprises positioning the flange element against the first blade component and/or the first contact surface, such that the first flange surface is facing the first contact surface. 
     The flange element may be positioned such that the first primary flange surface is closer to the first contact edge than the first secondary flange surface. 
     The method further comprises: bonding the first secondary flange surface to the first contact surface with a first adhesive substance; pivoting the first primary flange surface to open the cavity between the first flange surface and the first contact surface; bonding the first primary flange surface to the first contact surface with a second adhesive substance, wherein the second adhesive substance and the first adhesive substance are different types of adhesive substances; and bonding the second contact surface of the second blade component to the second flange surface. 
     The present disclosure may facilitate more accurate placement of adhesive flanges as well as other features influential to the blade design and manufacturing tolerances, thereby stronger wind turbine blades may be provided, production time may be reduced, and/or necessity of service and repair of the wind turbine blade may be reduced. 
     Although the present disclosure is focused towards the assembly of a flatback trailing edge, i.e. the joining of a suction side half shell and a pressure side half shell at the trailing edge, it is emphasized that the principles as described herein may be applied alternatively or additionally to joining of other components of a wind turbine blade. 
     The present disclosure is specifically advantageous, when the first contact surface and the second contact surface in the assembled wind turbine blade is not parallel, e.g. wherein the first contact surface and the second contact surface forms an angle, such as an angle more than 10 degrees, such as more than 30 degrees, such as more than 45 degrees, such as more than 60 degrees. In such situations, it may be difficult to sufficiently bond, e.g. with an adhesive substance, such as a glue, the first contact surface and the second contact surface. The present disclosure facilitates sufficient bonding between the first blade component and the second blade component, in these situations. 
     The first adhesive substance may be of a first type of adhesive substance, such as a fast curing glue. The first adhesive substance may have a first curing time. The first curing time may be less than 300 seconds, such as less than 180 seconds, such as less than 120 seconds, such as less than 60 seconds. The first type of adhesive substance may be incompliant with required mechanical properties for joining of the first blade component and the second blade component. The first adhesive substance may be a tacky tape. 
     The second adhesive substance may be of a second type of adhesive substance. The second type of adhesive substance may be different than the first type of adhesive substance. The second adhesive substance may have a second curing time. The second curing time may be more than 120 seconds, such as more than 180 seconds, such as more than 300 seconds, such as more than 600 seconds. The second curing time may be longer than the first curing time. The second type of adhesive substance may be compliant with required mechanical properties for joining of the first blade component and the second blade component. 
     Bonding of the first secondary flange surface to the first contact surface may comprise applying the first adhesive substance between the first secondary flange surface and the first contact surface. Bonding the first secondary flange surface to the first contact surface may comprise, e.g. after applying the first adhesive substance between the first secondary flange surface and the first contact surface, applying a first pressure to the flange element to press the first secondary flange surface against the first contact surface. Bonding the first secondary flange surface to the first contact surface may comprise curing the first adhesive substance while applying the first pressure. Bonding the first secondary flange surface to the first contact surface may comprise, e.g. after the first adhesive substance has been cured, releasing the first pressure. 
     Bonding the first primary flange surface to the first contact surface may comprise applying the second adhesive substance between the first primary flange surface and the first contact surface. Bonding the first primary flange surface to the first contact surface may comprise, e.g. after applying the second adhesive substance between the first primary flange surface and the first contact surface, applying a second pressure to the flange element to press the first primary flange surface against the first contact surface. Bonding the first primary flange surface to the first contact surface may comprise curing the second adhesive substance while applying the second pressure. Bonding the first primary flange surface to the first contact surface may comprise, e.g. after the second adhesive substance has been cured, releasing the second pressure. 
     Bonding the second contact surface to the second flange surface may comprise applying a third adhesive substance onto the second flange surface. Bonding the second contact surface to the second flange surface may comprise, e.g. after applying the third adhesive substance onto the second flange surface, positioning the second blade component such that the second contact surface is positioned against the third adhesive substance and the second flange surface. Bonding the second contact surface to the second flange surface may comprise curing the third adhesive substance. Bonding the second contact surface to the second flange surface may comprise positioning the second blade component such that the second contact edge is arranged adjacently the first contact edge, e.g. to form a bond line, e.g. along the leading edge and/or the trailing edge of the wind turbine blade. 
     The third adhesive substance may be of a third type of adhesive substance. The third adhesive substance may have a third curing time. The third curing time may be more than 120 seconds, such as more than 180 seconds, such as more than 300 seconds, such as more than 600 seconds. The third curing time may be longer than the first curing time. The third type of adhesive substance may be compliant with required mechanical properties for joining of the first blade component and the second blade component. The third adhesive substance and the second adhesive substance may be the same type of adhesive substance, such as the second adhesive substance. For example, the third adhesive substance may be the second type of adhesive substance. 
     After bonding the first flange surface, e.g. the first primary flange surface and/or the first secondary flange surface, to the first contact surface and bonding the second flange surface with the second contact surface, the first flange surface, e.g. the first primary flange surface and/or the first secondary flange surface, the second flange surface and/or the flange surface interface may be covered, such as completely covered, by adhesive substance, e.g. including the first adhesive substance, the second adhesive substance and/or the third adhesive substance. 
     The method may comprise, e.g. prior to bonding the first secondary flange surface to the first contact surface and/or prior to positioning the flange element against the first blade component, positioning a barrier element to maintain the first adhesive substance between the first secondary flange surface and the first contact surface. The barrier element may be coupled to the flange element. The barrier element may be positioned onto the first contact surface. The barrier element may be fastened to the first contact surface, e.g. by tacky tape, or by an adhesive, such as an adhesive similar to the first adhesive substance. The barrier element may be a foam element, such as a foam strip. The barrier element may be positioned more distant from the first contact edge than the flange element, e.g. the barrier element may be positioned such as to allow the flange element to be positioned between the barrier element and the first contact edge. 
     The method may comprise, e.g. prior to bonding the first primary flange surface to the first contact surface and/or prior to bonding the first secondary flange surface to the first contact surface and/or prior to positioning the flange element against the first blade component, positioning a spacer between the first contact surface and the first primary flange surface to maintain a controlled distance between the first contact surface and the first primary flange surface. The spacer may be fastened to the first contact surface, e.g. by tacky tape, or by an adhesive, such as an adhesive similar to the first adhesive substance. The spacer may comprise a plurality of spacer elements, such as cylindrical elements, e.g. having a diameter between 5 and 15 mm, such as approximately 10 mm. The spacer may have a height between 5 and 15 mm, such as approximately 11 mm. The spacer may have a height lower than a height of the barrier element, such as 50% of the height of the barrier element. 
     It is envisaged that any embodiments or elements as described in connection with any one aspect may be used with any other aspects or embodiments, mutatis mutandis. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       Embodiments of the invention will be described in more detail in the following with regard to the accompanying figures. Like reference numerals refer to like elements throughout. Like elements may, thus, not be described in detail with respect to the description of each figure. The figures show one way of implementing the present invention and are not to be construed as being limiting to other possible embodiments falling within the scope of the attached claim set. In addition, an illustrated embodiment needs not have all the aspects or advantages shown. An aspect or an advantage described in conjunction with a particular embodiment is not necessarily limited to that embodiment and can be practiced in any other embodiments even if not so illustrated, or if not so explicitly described. 
         FIG. 1  is a schematic diagram illustrating an exemplary wind turbine, 
         FIG. 2  is a schematic diagram illustrating an exemplary wind turbine blade, 
         FIG. 3  is a schematic diagram illustrating an exemplary wind turbine blade, 
         FIG. 4  is a schematic diagram illustrating a cross section of an exemplary wind turbine blade, 
         FIGS. 5-12  illustrates exemplary instances of an exemplary method for assembling a wind turbine blade, 
         FIGS. 13 a - k    show parts of cross sections a wind turbine blade at various positions, and 
         FIG. 14  is a block diagram of an exemplary method. 
     
    
    
     DETAILED DESCRIPTION 
     In the following figure description, the same reference numbers refer to the same elements and may thus not be described in relation to all figures. 
       FIG. 1  illustrates a conventional modern upwind wind turbine  2  according to the so-called “Danish concept” with a tower  4 , a nacelle  6  and a rotor with a substantially horizontal rotor shaft. The rotor includes a hub  8  and three blades  10  extending radially from the hub  8 , each having a blade root  16  nearest the hub and a blade tip  14  furthest from the hub  8 . 
       FIG. 2  shows a schematic view of an exemplary wind turbine blade  10 . The wind turbine blade  10  has the shape of a conventional wind turbine blade with a root end  17  and a tip end  15  and comprises a root region  30  closest to the hub, a profiled or an airfoil region  34  furthest away from the hub and a transition region  32  between the root region  30  and the airfoil region  34 . The blade  10  comprises a leading edge  18  facing the direction of rotation of the blade  10 , when the blade is mounted on the hub, and a trailing edge  20  facing the opposite direction of the leading edge  18 . 
     The airfoil region  34  (also called the profiled region) has an ideal or almost ideal blade shape with respect to generating lift, whereas the root region  30  due to structural considerations has a substantially circular or elliptical cross-section, which for instance makes it easier and safer to mount the blade  10  to the hub. The diameter (or the chord) of the root region  30  may be constant along the entire root area  30 . The transition region  32  has a transitional profile gradually changing from the circular or elliptical shape of the root region  30  to the airfoil profile of the airfoil region  34 . The chord length of the transition region  32  typically increases with increasing distance r from the hub. The airfoil region  34  has an airfoil profile with a chord extending between the leading edge  18  and the trailing edge  20  of the blade  10 . The width of the chord decreases with increasing distance r from the hub. 
     A shoulder  40  of the blade  10  is defined as the position, where the blade  10  has its largest chord length. The shoulder  40  is typically provided at the boundary between the transition region  32  and the airfoil region  34 . 
     It should be noted that the chords of different sections of the blade normally do not lie in a common plane, since the blade may be twisted and/or curved (i.e. pre-bent), thus providing the chord plane with a correspondingly twisted and/or curved course, this being most often the case in order to compensate for the local velocity of the blade being dependent on the radius from the hub. 
     The wind turbine blade  10  comprises a blade shell comprising two blade shell parts or half shells, a first blade shell part  24  and a second blade shell part  26 , typically made of fibre-reinforced polymer. The wind turbine blade  10  may comprise additional shell parts, such as a third shell part and/or a fourth shell part. The first blade shell part  24  is typically a pressure side or upwind blade shell part. The second blade shell part  26  is typically a suction side or downwind blade shell part. 
     The first blade shell part  24  and the second blade shell part  26  are fastened together with adhesive, such as glue, along bond lines or glue joints  28  extending along the trailing edge  20  and the leading edge  18  of the blade  10 . Typically, the root ends of the blade shell parts  24 ,  26  has a semi-circular or semi-oval outer cross-sectional shape. 
       FIG. 3  shows a wind turbine blade  10  with a flatback profile at the trailing edge  20 . The trailing edge  20  has a flattened profile. The flattened profile may increase the aerodynamic efficiency and also may reduce the chord width, thereby making it easier to transport the wind turbine blade  10 . Furthermore, it also may reduce required manufacturing space. 
       FIG. 4  is a schematic diagram illustrating a cross sectional view of an exemplary wind turbine blade  10 , e.g. a cross sectional view of the airfoil region of the wind turbine blade  10  as described in relation to  FIG. 3 . The wind turbine blade  10  comprises a leading edge  18 , a trailing edge  20 , a pressure side  24 , a suction side  26  a first spar cap  74 , and a second spar cap  76 . The trailing edge  20  has a flattened profile for forming a flatback profile. The wind turbine blade  10  comprises a chord line  38  between the leading edge  18  and the trailing edge  20 . The wind turbine blade  10  comprises shear webs  42 , such as a leading edge shear web and a trailing edge shear web. The shear webs  42  could alternatively be a spar box with spar sides, such as a trailing edge spar side and a leading edge spar side. The spar caps  74 ,  76  may comprise carbon fibres, e.g. in combination with glass fibres, while the rest of the shell parts  24 ,  26  may comprise glass fibres. 
     The wind turbine blade  10 , such as the shell parts  24 ,  26  may comprise sandwich panels, e.g. comprising lightweight materials such as balsa or foam sandwiched between fibre-reinforced layers. The trailing edge  20  forming the flattened profile may be provided as a third shell part, or as an integral part of the first shell part  24  or the second shell part  26 . Alternatively, the trailing edge  20  may be provided by parts of both the first shell part  24  and the second shell part  26 . 
     A glue joint for assembling the first shell part  24  and the second shell part  26  may be provided near the trailing edge  20 , such as between a first trailing edge part of the trailing edge  20  and a second trailing edge part of the trailing edge  20 . Alternatively, the glue joint may be provided between the trailing edge  20  and the first shell part  24  or between the trailing edge  20  and the second shell part  26 . 
     In the example described with respect to the following figures, a glue joint or bond line  28  between the trailing edge  20  (forming part of the second shell part  26 ) and the first shell part  24  is described. The second shell part  26  constitutes a first blade component  90  and the first shell part  24  including the trailing edge  20  constitutes a second blade component  92 . The first blade component  90  comprises a first contact area  100  configured to be connected to a second contact area  110  of the second blade component  92 . The first contact area  100  may form part of the trailing edge  20 . In an alternative, non-illustrated, example, the second contact area  110  forms part of the trailing edge  20 . 
       FIGS. 5-12  illustrates exemplary instances of a method for assembling a wind turbine blade, such as the wind turbine blade  10 , e.g. of  FIG. 3 , comprising a first blade component  90 , such as the first shell part  24  or the second shell part  26 , and a second blade component, such as the other shell part, e.g. the first shell part  24  or the second shell part. The first blade component  90  comprises a first contact area  100  configured to be connected to a second contact area  110  of the second blade component  92 . Although the illustrated examples are described with reference to the first blade component and the second blade component being respective shell parts, it will be understood that the method may be utilized similarly in assembling other blade components. 
     The first contact area  100  has a first contact surface  102 . The second contact area  110  has a second contact surface  112 . The first contact area  100  comprises a first contact edge  101  of the first blade component  90 . The second contact area  110  comprises a second contact edge  111  of the second blade component  92 . The present disclosure is specifically advantageous, when the first contact surface  102  and the second contact surface  112  in the assembled wind turbine blade is not parallel, such as will be the case when assembling the shell parts of a flatback wind turbine blade near the trailing edge. 
       FIG. 5  illustrates a first blade component  90  comprising a first contact area  100  configured to be connected to a second contact area of a second blade component. The first contact area  100  has a first contact surface  102 . The first contact area  100  comprises a first contact edge  101 . 
     Also illustrated is that the first blade component  90 , e.g. being a first shell part or a second shell part, comprises sandwich structure. For example, the first blade component  90  comprises a shell core  82 , e.g. of balsa wood or foam, and an inner and outer fibre reinforced layer  80 . Also illustrated is an insert  84  provided between the trailing edge part  20  and the remaining shell part of the first blade component  90 . The insert  84  is provided to give the flatback profile of the trailing edge a relatively sharp corner. 
     A first adhesive substance  130  is applied to the first contact surface  102 . A barrier element  142  is positioned to maintain the first adhesive substance  130  at the applied position, e.g. to prevent the first adhesive substance  130  to flow by act of gravity along the first contact surface  102  to the bottom of the blade shell. The first adhesive substance  130  is applied closer to the first contact edge  101  than the barrier element  142 . In some examples, the barrier element  142  may not be needed, e.g. if the slope of the first contact surface  102  is not very steep, or if the first adhesive substance is substantially stiff, has a high viscosity, or in other ways not prone to substantial flow. 
     A spacer  144  is positioned onto the first contact surface to maintain a controlled distance between the first contact surface  102  and the flange element to be bonded to the first contact surface  102 . The spacer  144  may facilitate that the correct amount of adhesive substance is provided between the first contact surface  102  and the flange element of the following figures, such as to attain the required mechanical properties of the bonding. 
       FIG. 6  illustrates the first blade component  90 , wherein a flange element  120  has been provided and positioned against the first blade component  90 , e.g. against the first contact surface  102 . 
     The flange element  120  has a first flange surface  122  configured to face the first contact surface  102  and a second flange surface  126  configured to face the second contact surface of the second blade component. The first flange surface  122  joins the second flange surface  126  along a flange surface interface  128 . The flange element  120  comprises a flexible part  124  along the first flange surface  122  allowing a first primary flange surface  122   a  of the first flange surface  122  to be angled relative to a first secondary flange surface  122   b  of the first flange surface  122 . The flexible part  124  may be a hinge element or may be a relatively thin part of material allowing the angling between the first primary flange surface  122   a  and the first secondary flange surface  122   b.    
     The first adhesive substance  130  is applied between the first secondary flange surface  122   b  and the first contact surface  102 . The first adhesive substance  130  may be applied between the first secondary flange surface  122   b  and the first contact surface  102  after the flange element  120  is positioned or be applied prior to positioning the flange element  120  as exemplified by  FIG. 5 . 
     The flange element  120  is positioned such that the first primary flange surface  122   a  is closer to the first contact edge  101  than the first secondary flange surface  122   b.    
     The barrier element  142  may be provided as a part of the flange element  120  or, as exemplified by  FIG. 5 , be positioned onto the first contact surface  102  prior to positioning the flange element  120 . 
       FIG. 7  illustrates the first blade component  90 , wherein a first pressure is applied to the flange element  120  to press the first secondary flange surface  122   b  against the first contact surface  102 . In the illustrated example, the first pressure is applied by a clamp  140 . The first pressure may be applied while curing the first adhesive substance  130 , which may be a fast curing type of adhesive. After the first adhesive substance  130  is cured, bonding the first secondary flange surface  122   b  and the first contact surface  102 , the pressure may be released. 
       FIG. 8  illustrates the first blade component  90 , wherein the first primary flange surface  122   a  is pivoted relative to the first secondary flange surface  122   b  about the flexible part  124  to open the cavity between the first flange surface  122 , in particular the first primary flange surface  122   a , and the first contact surface  102 . 
       FIG. 9  illustrates the first blade component  90 , wherein a second adhesive substance  132  is applied between the first primary flange surface  122   a  and the first contact surface  102 , while the flange element  120  is pivoted to open the cavity between the first flange surface  122  and the first contact surface  102 . Thereby it may be ensured, e.g. by visual inspection, that the cavity is sufficiently filled with the second adhesive substance  132 . The bonding between the first secondary flange surface  122   b  and the first contact surface  102  ensures that the position of the flange element  120  is not changed during this process. 
       FIG. 10  illustrates the first blade component  90 , wherein a second pressure is applied to the flange element  120  to press the first primary flange surface  122   a  against the first contact surface  102 . In the illustrated example, the second pressure is applied by a clamp  140 , e.g. the same clamp  140  as used to apply the first pressure as described with respect to  FIG. 7 . The second pressure may be applied while curing the second adhesive substance  132 . After the second adhesive substance  132  is cured, bonding the first primary flange surface  122   a  and the first contact surface  102 , the pressure may be released. Thereby, the first primary flange surface  122   a  may be bonded to the first contact surface  102  with the second adhesive substance  132 . The second adhesive substance  132  may be a different type of adhesive substance than the first adhesive substance  130 . For example, the second adhesive substance may comply with structural requirements for the joining between the first blade component and the second blade component. The second adhesive substance  132  may have a longer curing time than the first adhesive substance  130 . 
       FIG. 11  illustrates the first blade component  90 , wherein a third adhesive substance  134  is applied onto the second flange surface  126 . The third adhesive substance  134  may be the same type of adhesive substance as the second adhesive substance  132 . 
       FIG. 12  illustrates the first blade component  90 , wherein the second blade component  92  is positioned in its desired position relative to the first blade component  90 . The second blade component comprises a second contact area  110  configured to be connected to the first contact area  100  of the first blade component  90 . The second contact area  110  has a second contact surface  112 . The second contact area  110  comprises a second contact edge  111 . 
     The second blade component  92  is positioned such that the second contact surface  112  is positioned against the third adhesive substance  134  and the second flange surface  126 . The second blade component  92  is positioned such that the second contact edge  111  is arranged adjacently the first contact edge  101 , to form the bond line  28 . The first adhesive substance  134  is cured. Pressure may be applied while curing the third adhesive substance  134 . However, the weight of the second blade component  92  may provide sufficient pressure. 
     Thereby, the second contact surface  112  of the second blade component  92  may be bonded to the second flange surface  126  as well as to the first blade component  90 . The first flange surface  122 , e.g. including the first primary flange surface  122   a  and the first secondary flange surface  122   b , the second flange surface  126  and the flange surface interface  128  may be covered by the adhesive substance, e.g. including the first adhesive substance  130 , the second adhesive substance  132  and/or the third adhesive substance  134 . 
       FIGS. 13 a - k    show parts of cross sections a wind turbine blade at various positions along the length of the blade. In particular, it is seen how the shape of the flange element  120  may vary along the length of the wind turbine blade to accommodate the different angles of the joining blade components  90 ,  92 . 
       FIG. 14  is a block diagram of an exemplary method  200  for assembling a wind turbine blade comprising a first blade component, e.g. a first blade half shell, and a second blade component, e.g. a second blade half shell. 
     The method  200  comprises providing  202  a flange element. The provided  202  flange element has a first flange surface configured to face a first contact surface of a first contact area of the first blade component. The provided  202  flange element has a second flange surface configured to face a second contact surface of a second contact area of the second blade component. 
     The method  200  comprises positioning  204  the flange element against the first blade component, such that the first flange surface is facing the first contact surface; and bonding  206  a first secondary flange surface of the first flange surface to the first contact surface with a first adhesive substance. The flange element may be positioned  204  such that the first primary flange surface is closer to a first contact edge of the first blade component than the first secondary flange surface. 
     The flange element comprises a flexible part along the first flange surface allowing a first primary flange surface of the first flange surface to be angled relative to the first secondary flange surface. The method  200  comprises, e.g. after having bonded  206  the first secondary flange surface to the first contact surface, pivoting  208  the first primary flange surface to open the cavity between the first flange surface and the first contact surface, and bonding  210  the first primary flange surface to the first contact surface with a second adhesive substance, wherein the second adhesive substance and the first adhesive substance are different types of adhesive substances. 
     The method  200  comprises, e.g. after having bonded  210  the first primary flange surface to the first contact surface, bonding  212  the second contact surface of the second blade component to the second flange surface. 
     The method  200  may optionally comprise, e.g. prior to positioning  204  the flange element and/or prior to bonding  206  the first secondary flange surface to the first contact surface, positioning  236  a barrier element, e.g. to maintain the first adhesive substance between the first secondary flange surface and the first contact surface. 
     The method  200  may optionally comprise, e.g. prior to positioning  204  the flange element and/or prior to bonding  206  the first secondary flange surface to the first contact surface and/or prior to bonding  210  the first primary flange surface to the first contact surface, positioning  238  a spacer between the first contact surface and the first primary flange surface, e.g. to maintain a controlled distance between the first contact surface and the first primary flange surface. 
     Bonding  206  the first secondary flange surface to the first contact surface may comprise applying  214  the first adhesive substance between the first secondary flange surface and the first contact surface. Bonding  206  the first secondary flange surface to the first contact surface may comprise applying  216  a first pressure to the flange element to press the first secondary flange surface against the first contact surface. Bonding  206  the first secondary flange surface to the first contact surface may comprise curing  218  the first adhesive substance, e.g. while applying  216  the first pressure. Bonding  206  the first secondary flange surface to the first contact surface may comprise releasing  220  the first pressure. 
     Bonding  210  the first primary flange surface to the first contact surface may comprise applying  222  the second adhesive substance between the first primary flange surface and the first contact surface. Bonding  210  the first primary flange surface to the first contact surface may comprise applying  224  a second pressure to the flange element to press the first primary flange surface against the first contact surface. Bonding  210  the first primary flange surface to the first contact surface may comprise curing  226  the second adhesive substance, e.g. while applying  224  the second pressure. Bonding  210  the first primary flange surface to the first contact surface may comprise releasing  228  the second pressure. 
     Bonding  212  the second contact surface to the second flange surface may comprise applying  230  a third adhesive substance onto the second flange surface. The third adhesive substance may be the same type of adhesive substance as the second adhesive substance. Bonding  212  the second contact surface to the second flange surface may comprise positioning  232  the second blade component such that the second contact surface is positioned against the third adhesive substance and the second flange surface. Bonding  212  the second contact surface to the second flange surface may comprise positioning the second blade component such that the second contact edge is arranged adjacently the first contact edge, e.g. to form a bond line. Bonding  212  the second contact surface to the second flange surface may comprise curing the third adhesive substance. 
     Exemplary embodiments of the present disclosure are set out in the following items:
         1. A method for assembling a wind turbine blade comprising a first blade component, e.g. a first blade half shell, and a second blade component, e.g. a second blade half shell, the first blade component comprising a first contact area configured to be connected to a second contact area of the second blade component, the first contact area having a first contact surface, the second contact area having a second contact surface,   the method comprising:
           providing a flange element having a first flange surface configured to face the first contact surface and a second flange surface configured to face the second contact surface, the flange element comprises a flexible part along the first flange surface allowing a first primary flange surface of the first flange surface to be angled relative to a first secondary flange surface of the first flange surface;   positioning the flange element against the first blade component such that the first flange surface is facing the first contact surface;   bonding the first secondary flange surface to the first contact surface with a first adhesive substance;   pivoting the first primary flange surface to open the cavity between the first flange surface and the first contact surface;   bonding the first primary flange surface to the first contact surface with a second adhesive substance, wherein the second adhesive substance and the first adhesive substance are different types of adhesive substances; and   bonding the second contact surface of the second blade component to the second flange surface.   
           2. Method according to item 1, wherein the first adhesive substance has a first curing time, and wherein the first curing time may be less than 300 seconds, such as less than 180 seconds, such as less than 120 seconds, such as less than 60 seconds.   3. Method according to any of the preceding items, wherein the second adhesive substance has a second curing time, and wherein the second curing time may be more than 120 seconds, such as more than 180 seconds, such as more than 300 seconds.   4. Method according to item 3 as dependent on item 2, wherein the second curing time is longer than the first curing time.   5. Method according to any of the preceding items, wherein bonding the first secondary flange surface to the first contact surface comprises:
           applying the first adhesive substance between the first secondary flange surface and the first contact surface   
           6. Method according to the preceding item, wherein bonding the first secondary flange surface to the first contact surface comprises:
           applying a first pressure to the flange element to press the first secondary flange surface against the first contact surface;   curing the first adhesive substance while applying the first pressure;   releasing the first pressure;   
           7. Method according to any of the preceding items, wherein bonding the first primary flange surface to the first contact surface comprises:
           applying the second adhesive substance between the first primary flange surface and the first contact surface;   
           8. Method according to the preceding item, wherein bonding the first primary flange surface to the first contact surface comprises:
           applying a second pressure to the flange element to press the first primary flange surface against the first contact surface;   curing the second adhesive substance while applying the second pressure;   releasing the second pressure;   
           9. Method according to any of the preceding items, wherein bonding the second contact surface to the second flange surface:
           applying a third adhesive substance onto the second flange surface;   positioning the second blade component such that the second contact surface is positioned against the third adhesive substance and the second flange surface;   curing the third adhesive substance.   
           10. Method according to any of the preceding items further comprising, prior to bonding the first secondary flange surface to the first contact surface, positioning a barrier element to maintain the first adhesive substance between the first secondary flange surface and the first contact surface.   11. Method according to any of the preceding items further comprising, prior to bonding the first primary flange surface to the first contact surface, positioning a spacer between the first contact surface and the first primary flange surface to maintain a controlled distance between the first contact surface and the first primary flange surface.       

     The invention has been described with reference to preferred embodiments. However, the scope of the invention is not limited to the illustrated embodiments, and alterations and modifications can be carried out without deviating from the scope of the invention. 
     LIST OF REFERENCES 
     
         
           2  wind turbine 
           4  tower 
           6  nacelle 
           8  hub 
           10  blade 
           14  blade tip 
           15  tip end 
           16  blade root 
           17  root end 
           18  leading edge 
           20  trailing edge 
           24  first blade shell part (pressure side) 
           26  second blade shell part (suction side) 
           28  bond lines/glue joints 
           30  root region 
           32  transition region 
           34  airfoil region 
           40  shoulder 
           42  shear web or spar side 
           74  first spar cap 
           76  second spar cap 
           80  fibre-reinforced layer 
           82  shell core 
           84  insert 
           90  first blade component 
           92  second blade component 
           100  first contact area 
           101  first contact edge 
           102  first contact surface 
           110  second contact area 
           111  second contact edge 
           112  second contact surface 
           120  flange element 
           122  first flange surface 
           122   a  first primary flange surface 
           122   b  first secondary flange surface 
           124  flexible part 
           126  second flange surface 
           128  flange surface interface 
           130  first adhesive substance 
           132  second adhesive substance 
           134  third adhesive substance 
           140  clamp 
           142  barrier element 
           144  spacer 
           200  method 
           202  providing flange element 
           204  positioning flange element 
           206  bonding first secondary flange surface and first contact surface 
           208  pivoting first primary flange surface 
           210  bonding first primary flange surface and first contact surface 
           212  bonding second contact surface and second flange surface 
           214  applying first adhesive substance 
           216  applying first pressure 
           218  curing first adhesive substance 
           220  releasing first pressure 
           222  applying second adhesive substance 
           224  applying second pressure 
           226  curing second adhesive substance 
           228  releasing second pressure 
           230  applying third adhesive substance 
           232  positioning second blade component 
           234  curing second adhesive substance 
           236  positioning barrier element 
           238  positioning spacer