Apparatus, system, and method for simulating resin infusion in a wind turbine blade mould

Abstract

A test apparatus (60) for resin infusion of a test specimen (66) that simulates resin infusion in one or more materials in a wind turbine blade mould (44) during manufacture of a wind turbine blade (20) is disclosed. The test apparatus (60) includes a base frame (62) and a test bed (64) mounted to the base frame (62), where the test bed (64) is configured to receive the test specimen (66) during resin infusion testing. The test apparatus (60) is configured to simulate at least one of: i) a geometric condition; and ii) a thermal condition of the one or more materials in the wind turbine blade mould (44) during manufacture of a wind turbine blade (20). A test system (130) and a method of resin infusion of a test specimen (66) that simulates resin infusion in one or more materials in a wind turbine blade mould (44) during manufacture of a wind turbine blade (20) is also disclosed.

Description

[0001] APPARATUS, SYSTEM, AND METHOD FOR SIMULATING RESIN INFUSION IN A WIND TURBINE BLADE MOULD

[0002] Technical Field

[0003] The invention relates generally to wind turbines, and more particularly to a simulation or test table and a test system for simulating resin infusion within materials in a wind turbine blade mould during the manufacture of a wind turbine blade. The invention also relates to a method of using the test table and test system to simulate resin infusion within the mould for a wind turbine blade.

[0004] Background

[0005] Wind turbines are used to produce electrical energy using a renewable resource and without combusting a fossil fuel. Generally, a wind turbine converts kinetic energy from the wind into electrical power. A horizontal-axis wind turbine includes a tower and an energy generating unit positioned atop of the tower. The energy generating unit typically includes a nacelle to house mechanical and electrical components, such as a generator, and a rotor operatively coupled to the components in the nacelle through a main shaft extending from the nacelle. The rotor, in turn, includes a central hub and a plurality of blades extending radially therefrom and configured to interact with the wind to cause rotation of the rotor. The rotor is supported on the main shaft, which is either directly or indirectly operatively coupled with the generator which is housed inside the nacelle. Consequently, as wind forces the blades to rotate, electrical energy is produced by the generator.

[0006] Modem wind turbines use multiple blades, with a popular standard using three wind turbine blades per wind turbine. Such blades are very long and getting increasingly longer with newer wind turbine designs. For example, the length of some modern wind turbine blades may be in the vicinity of approximately 100 meters (m) or greater and have a root diameter of approximately 5 m or greater. Modem wind turbine blades have a construction that typically includes an outer shell and a spar structure located inside the outer shell. The outer shell provides the aerodynamic aspect of the blade and includes a profile configured to generate lift from the oncoming wind that ultimately causes the wind turbine blades to rotate. The outer shell typically has a laminate composite construction of a plurality of fiber layers, one or more core materials embedded within the fiber layers, and a resin matrix, and includes a windward half shell and a leeward half shell bonded together at leading and trailing edges of the wind turbine blade. The spar structure on the inside of the blade provides the load-bearing aspects of the blade. In one known arrangement, the spar structure includes a pair of spar caps and one or more shear webs extending therebetween. The spar caps may be arranged in opposing relation across the height of the blade, with one spar cap being associated with the windward half shell and the other spar cap being associated with the leeward half shell. The spar caps may be integrated into the outer shell such that the spar caps form a portion of the outer shell. Alternatively, the spar caps may be adhesively bonded to an inner surface of the outer shell. The spar caps extend longitudinally along the majority of the length of the wind turbine blade, and in one arrangement may be formed from a stack of pultruded strips of carbon-fiber reinforced plastic.

[0007] The shear web is connected between the spar caps and includes an intermediate web and first and second flanges provided at respective first and second ends of the intermediate web. As such, the shear web is substantially l-shaped in cross section and bridges the gap between the windward and leeward sides of the outer shell. The flanges are oriented transversely to the intermediate web when viewed in cross section and provide a means for mounting the shear web between the opposed spar caps. In this regard, the flanges are configured to be bonded to the spar caps by means of adhesive. In one known arrangement, the first and second flanges may be formed from a T-shaped pultrusion of carbon-fiber reinforced plastic and include a foot and an upstand, where the foot forms the flange and the upstand facilitates a connection of the foot to the intermediate web. The intermediate web typically has a laminate composite construction of a plurality of fiber layers, one or more core materials embedded within the fiber layers, and a resin matrix. Depending on the size of the blade and expected loads, the spar structure may include more than one shear web extending between the opposed spar caps.

[0008] The outer shell is typically made through a moulding process using a windward half mould and a leeward half mould. In this regard, the fiber layers, such as glass and / or carbon fiber layers, and the core material, such as various foam and / or wood cores, may be laid in the moulds (along with the spar caps when such spar caps are integrated into the outer shell) and resin is admitted into the moulds in a vacuum- assisted resin infusion process. The half shells are then cured within their respective half moulds. The shear web, and more particularly at least the intermediate web thereof, is also typically made through a moulding process using a separate mould tool. In a similar manner, fiber layers, core material, and the T-shaped pultrusions may be laid in the mould tool and resin is admitted into the mould in a vacuum- assisted resin infusion process. The shear web is then cured within the mould. To form the wind turbine blade, the shear web may be positioned within one of the blade half moulds and one of the flanges of the shear web adhesively bonded to the spar cap associated with the respective half shell. The other half shell (not having the shear web) may then be juxtapositioned relative to the half mould including the shear web. The outer shell may be adhesively bonded along the leading and trailing edges of the wind turbine blade and the other flange of the shear web may be adhesively bonded to the spar cap associated with the other half shell.

[0009] As noted above, a common method for infusing resin within the layers of material in the windward and leeward half moulds is by using vacuum-assisted resin infusion processes. In this type of moulding process, the open end of each of the half moulds is sealed by an outer cover or bag. A vacuum pump is then placed into communication with the mould cavity between the mould surface and the outer vacuum bag of the respective half moulds. When the vacuum pump is activated, the pressure within the cavity decreases and the outer vacuum bag is pressed toward the mould surface due to the higher atmospheric pressure on the external side of the vacuum bag. In addition, resin tap points may be distributed about the half moulds to introduce resin into the materials being consolidated within the half moulds. The resin is drawn into the half moulds by the vacuum pump to wet the materials within the half moulds with resin. The half moulds are typically heated during resin infusion to reduce the viscosity of the resin and allow the resin to be more easily transferred or distributed throughout the materials in the half moulds. The half moulds are also heated to facilitate curing of the composite material after resin infusion.

[0010] While moulding processes for manufacturing wind turbine blades have been generally successful, there are technological challenges as the size of wind turbine blades continue to increase. By way of example, in some instances the resin does not fully infuse within the various materials in the half moulds, ultimately producing localized “dry spots” within the half shells that form the wind turbine blade. Left unattended, these dry spots operate as points of structural weakness in the wind turbine blade during use. Thus, these dry spots must then be addressed in various post-processing procedures that are time consuming and expensive. Moreover, if the dry spots are significant, the entire wind turbine blade may have to be scrapped.

[0011] In many instances, the development of dry spots within the various materials of the half moulds is not a very well understood phenomena. Thus, the fundamental physics behind the behavior of the resin infusion front as the resin penetrates into the various materials in the half moulds is not advanced enough where corrective or prophylactic measures may be taken during the resin infusion process to avoid the dry spots. One factor for a lack of understanding of dry spot formation is that technicians cannot see the formation of dry spots in real time. It is only after the fact, i.e. , after the blade half shell is moulded and cured that localized dry spots are detected through various non-destructive testing techniques (e.g., ultrasonic testing).

[0012] It is expected that this problem will be exacerbated as wind turbine blades continue to grow in size and complexity. By way of example, as the twists and surface curvatures of wind turbine blades, as well as the verticality of the surfaces (i.e., effect of gravity on resin infusion on inclined and highly inclined surfaces) become more prevalent in larger blades, it is believed that the development of dry spots in the composite half shells may similarly become more prevalent.

[0013] Therefore, there is a need in the wind turbine industry to better understand dry spot formation within the composite material of wind turbine blades. More particularly, there is a need to better understand the fundamental physics of the resin infusion process within the materials in the half moulds in order to avoid dry spot formation in wind turbine blades.

[0014] Summary

[0015] To these and other ends, in one aspect of the invention, a test apparatus for resin infusion in a test specimen that simulates resin infusion in one or more materials in a wind turbine blade mould during manufacture of a wind turbine blade is disclosed. The test apparatus includes a base frame and a test bed mounted to the base frame, where the test bed is configured to receive the test specimen during resin infusion testing. The test apparatus is configured to simulate at least one of: i) a geometric condition; and ii) a thermal condition of the one or more materials in the wind turbine blade mould during manufacture of a wind turbine blade.

[0016] In one embodiment, the test apparatus may be configured to simulate the geometric condition of the one or more materials in the wind turbine blade mould during manufacture of a wind turbine blade. In this embodiment, the test bed may be movably mounted to the base frame to change the orientation of the test specimen positioned on the test bed relative to gravity. For example, in one embodiment, the test bed may be rotatably mounted to the base frame so as to be rotatable relative to the base frame about a rotational axis, thereby changing the orientation of the test specimen relative to gravity. In one embodiment, the test apparatus may include a drive mechanism for moving the test bed relative to the base frame. For example, the drive mechanism may include a hand crank or a motor arranged to move the test bed (e.g., rotate the test bed) relative to the base frame.

[0017] In one embodiment, the test apparatus may further include a lock mechanism for locking the position of the test bed relative to the base frame. In addition, the test apparatus may further include at least one support stanchion for supporting the test bed in at least one position relative to the base frame. For example, the at least one support stanchion may include a plurality of support stanchions for supporting the test bed when in a substantially horizontal position.

[0018] In one embodiment, the test apparatus may be configured to simulate the thermal condition of the one or more materials in the wind turbine blade mould during manufacture of the wind turbine blade. This may be in addition to or alternate to simulating the geometrical condition of the one or more materials in the wind turbine blade mould during manufacture of the wind turbine blade. In this embodiment, the test bed may include a test surface configured to receive the test specimen thereon, a backing surface opposite the test surface, and at least one side surface extending between the test surface and the backing surface to define a cavity within the test bed. In one embodiment, at least the test surface and the backing surface of the test bed may each be made from a transparent material. This is configured to allow visualization of the infusion of resin in the test specimen during testing.

[0019] In another aspect of the invention, a test system including the test apparatus of the first aspect above in combination with one or more subsystems to simulate resin infusion in one or more materials in a wind turbine blade mould during manufacture of a wind turbine blade is disclosed.

[0020] In one embodiment, the test system may include the test apparatus of the first aspect and a visualization subsystem including at least one camera for videoing the infusion of resin in the test specimen. The images from the visualization subsystem may be analyzed (e.g., through image analysis and numerical routines) to glean information about the resin infusion process.

[0021] In one embodiment, the test system may include the test apparatus of the first aspect and a heating subsystem to control the temperature of the test surface of the test apparatus which receives the test specimen. In one embodiment, the heating subsystem may include a heater operatively coupled to the cavity of the test bed. For example, the heater may be configured to heat a heat transfer medium to a selected temperature and deliver the heat transfer medium to the cavity of the test bed. In one embodiment, the cavity includes at least one fluid inlet and at least one fluid outlet for respectively introducing the heat transfer medium into the cavity and removing the heat transfer medium from the cavity. In one embodiment, the heat transfer medium may include a gas, such as air. In an alternative embodiment, the heat transfer medium may include a liquid, such as water. In one embodiment, the heating subsystem may be a closed-loop heating system, where the heat transfer medium is continuously directed to and from the cavity in a closed-loop configuration. The heating subsystem is configured to simulate the heating of the half moulds during manufacture of the wind turbine blade.

[0022] In another embodiment, the test system may include the test apparatus of the first aspect and a vacuum subsystem that includes an outer vacuum bag positionable over the test specimen and sealable to the test bed and a vacuum pump for creating vacuum pressure in a space between the test surface of the test bed and the outer vacuum bag. The vacuum subsystem is configured to simulate the vacuum assisted resin infusion processes in the half moulds during manufacture of the wind turbine blade.

[0023] In yet another embodiment, the test system may include the test apparatus of the first aspect and a resin subsystem including a resin supply and a resin pump for directing resin from the resin supply to the test specimen on the test bed. The resin subsystem is configured to simulate the introduction of resin in the half mould during manufacture of the wind turbine blade.

[0024] In one embodiment, the test system may include the test apparatus of the first aspect and the test specimen that is configured to be received on the test bed of the test apparatus. In one embodiment, the test specimen has a material composition configured to simulate the one or more materials in the wind turbine blade mould during manufacture of a wind turbine blade. In one embodiment, the test specimen may include one or more of: i) a stack of fibre layers; ii) one or more core materials; and iii) spar cap materials (e.g., pultruded strips).

[0025] In another aspect of the invention, a method of simulating resin infusion in one or more materials in a wind turbine blade mould during manufacture of a wind turbine blade is disclosed. The method includes providing a test apparatus having a base frame and a test bed mounted to the base frame, providing a test specimen, positioning the test specimen on the test bed, arranging the test bed so as to simulate at least one of: i) a geometric condition; and ii) a thermal condition of the one or more materials in the wind turbine blade mould during manufacture of a wind turbine blade, and, subsequent to the arranging step, introducing resin into the test specimen.

[0026] In one embodiment, the arranging step may include arranging the test bed so as to simulate the geometrical condition of the one or more materials in the wind turbine blade mould during manufacture of a wind turbine blade, and the method may further include orienting the test bed so that the test specimen has a predetermined relationship relative to gravity. In one embodiment, orienting the test bed may include rotating the test bed relative to the base frame about a rotational axis so that the test specimen has the predetermined relationship relative to gravity.

[0027] In one embodiment, the arranging step may alternatively or additionally include arranging the test bed so as to simulate the thermal condition of the one or more materials in the wind turbine blade mould during manufacture of a wind turbine blade. In this embodiment, the method may include heating the test bed to a predetermined temperature. In one embodiment, for example, heating the test bed may include directing a heated heat transfer medium to a cavity formed in the test bed.

[0028] In one embodiment, the method may further include positioning an outer vacuum bag over the test specimen, sealing the outer vacuum bag to the test bed, and pulling a vacuum in the space between the outer vacuum bag and the test bed.

[0029] In one embodiment, the test bed may be oriented relative to gravity so as to define a lower end of the test specimen and an upper end of the test specimens, and the method may further include introducing the resin into the test specimen at a lower end thereof and locating vacuum taps at an upper end thereof for pulling the vacuum in the space between the outer vacuum bag and the test bed.

[0030] In one embodiment, the test bed may include at least one transparent test surface configured to receive the test specimen thereon, and the method may further include observing or videoing the infusion of resin into the test specimen from at least a perspective beneath the test bed.

[0031] Brief Description of the Drawings

[0032] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate one or more embodiments of the invention and, together with a general description of the invention given above, and the detailed description given below, serve to explain the invention.

[0033] Fig. 1 is a perspective view of a wind turbine having a plurality of wind turbine blades.

[0034] Fig. 2 is a perspective view of a wind turbine blade of the wind turbine of Fig. 1 .

[0035] Fig. 3 is a partial perspective view of a wind turbine half mould for forming a half shell of the wind turbine blade shown in Fig. 2.

[0036] Fig. 4 is an assembled perspective view of a test apparatus according to one embodiment of the present invention.

[0037] Fig. 5 is a disassembled perspective view of the test apparatus shown in Fig. 4.

[0038] Fig. 6 is schematic perspective view of a test system, including the test apparatus shown in Fig. 4, in accordance with an embodiment of the invention.

[0039] Fig. 7 is a cross-sectional view demonstrating the vacuum-assisted resin infusion process of the test specimen using the test system of Fig. 6.

[0040] Detailed Description

[0041] The exemplary embodiments described herein are provided for illustrative purposes and are not limiting. Other exemplary embodiments are possible, and modifications may be made to the exemplary embodiments within the scope of the present disclosure. Therefore, the description below is not meant to limit the scope of the present invention. In general, the description relates to a simulation or test apparatus and test system for investigating the infusion of resin within a fibrous test specimen placed on or in the test apparatus. The test apparatus and test system are configured to simulate various portions of a wind turbine blade mould in order to understand how the resin infuses within the blade materials at those portions of the blade mould. Thus, for example, and without limitation, the test apparatus may be configured to simulate the inclination of the fibrous mould material (i.e., verticality, gravitational effects, etc.) along certain portions of the blade mould. Additionally, the test apparatus and test system may be configured to simulate the thermal conditions within the wind turbine blade mould (e.g., half mould) during formation of the wind turbine blade (e.g., blade half shell). In this regard, the test apparatus may include a test bed on which a test specimen may be laid. The test specimen is formed of materials configured to simulate the blade material at portions of the wind turbine blade mould under test. The test specimen may be formed while the test bed is in a substantially horizontal position. Once formed, however, the test bed may be rotated so as to be in an inclined position, and possibly in a substantially vertical position, to simulate the inclination angle of the portion of the wind turbine blade mould under test. Resin may then be infused into the test specimen. The test bed may be heated to simulate the thermal conditions of the portion of the blade mould under test. Additionally, the test bed may be formed of transparent materials so that the resin infusion process may be visually observed. For example, the infusion process may be videoed with one or more cameras. The video may then be subject to various post-processing techniques to more clearly understand the resin infusion process and the development of dry spots within the material of the blade mould, as simulated by the test specimen on the test bed of the test apparatus.

[0042] Turning now with reference to Fig. 1 , an exemplary wind turbine 10 is shown which includes a tower 12, a nacelle 14 disposed at the apex of the tower 12, and a rotor 16 operatively coupled to a generator (not shown) housed inside the nacelle 14, and a gearbox (not shown) housed inside the nacelle 14. In addition to the generator and gearbox, the nacelle 14 may house various components needed to convert wind energy into electrical energy and to operate and optimize the performance of the wind turbine 10. The tower 12 supports the load presented by the nacelle 14, rotor 16, and other wind turbine components housed inside or external to the nacelle 14. The tower 12 operates to elevate the nacelle 14 and the rotor 16 to a height above ground level or sea level, as may be the case, where air currents with lower turbulence and higher velocity are typically found.

[0043] The rotor 16 includes a central hub 18 and a plurality of wind turbine blades 20 (“blades”) attached to the central hub 18 at locations distributed about the circumference of the central hub 18. In the representative embodiment, the rotor 16 includes three blades 20, however the number of blades 20 may vary. The blades 20, which project radially outward from the central hub 18, are configured to interact with passing air currents to produce rotational forces that cause the central hub 18 to spin about its longitudinal axis 22. The design, construction, and operation of the blades 20 are familiar to a person having ordinary skill in the art of wind turbine design and may include additional functional aspects to optimize performance.

[0044] The rotor 16 may be coupled to the gearbox directly or indirectly by a drive shaft (not shown) to form a rotor assembly. Either way, the gearbox transfers the rotation of the rotor 16 through a coupling (not shown) to the generator. Wind exceeding a minimum speed may activate the rotor 16, causing the rotor 16 to rotate in a direction substantially perpendicular to the wind, and applying torque to the input shaft of the generator. The electrical power produced by the generator may be supplied to a power grid (not shown) or an energy storage system (not shown) for later release to the grid as understood by a person having ordinary skill in the art. In this way, the kinetic energy of the wind may be harnessed by the wind turbine 10 for power generation.

[0045] Fig. 2 is a perspective view of an exemplary one of the wind turbine blades 20 of the wind turbine 10. As shown, the blade 20 extends longitudinally in a spanwise direction S between a root end 24 and a tip end 26, and transversely in a chordwise C direction between a leading edge 28 and a trailing edge 30. In that regard, the blade 20 has a longitudinal length in the spanwise S direction extending from the root end 24 to the tip end 26. The length of blade may be 100 meters or greater, for example. The blade 20 includes an outer shell 32 that defines a generally hollow interior of the wind turbine blade 20 where at least one spar structure 34 may be located, as is typical for wind turbine blade designs. In one embodiment, the outer shell 32 may be formed from two half shells: an upper half shell 36 and a lower half shell 38. As discussed above, the upper half shell 36 and the lower half shell 38 are moulded bodies formed in a respective upper half shell mould and a lower half shell mould. Once formed, the upper half shell 36 and the lower half shell 38 are assembled together along the leading edge 28 and trailing edge 30 of the wind turbine blade 20 with the at least one spar structure 34 disposed therebetween.

[0046] Fig. 3 illustrates a half mould 44, which is representative of the upper half mould or the lower half mould for forming its respective upper half shell 36 or lower half shell 38. The half mould 44 includes a mould body 46 having mould cavity 48 defined by a mould surface 50. The mould surface 50 is shaped to correspond to the desired shape of the upper half shell 36 or the lower half shell 38 of the wind turbine blade 20. As discussed above, various materials (not shown), including release layers, fiber layers, core material, and optionally spar cap material, may be laid on the mould surface 50 of the half mould 44 to form the upper half shell 36 or the lower half shell 38 of the wind turbine blade 20. Resin, such as epoxy, is then introduced into the materials in the half mould 44 in accordance with, for example, resin infusion processes, and the material and resin cured to form the composite upper half shell 36 or lower half shell 38. In this regard, the half mould 44 may include a plurality of resin ports 52 in communication with a resin pump 54 and a resin supply 56 for introducing resin into the materials in the half mould 44. The half mould 44 may further include a plurality of heating elements 58 in communication with a heating unit 59 (e.g., having a controller) for heating the mould surface 50 to a desired temperature to facilitate resin infusion and curing. The elements for facilitating resin infusion into the half mould 44, including the resin ports 52, resin pump 54, and resin supply 56 are well known in the wind turbine industry and will not be discussed in further detail herein. Similarly, the heating elements 58 (and heating unit 59) for controlling the mould surface temperature are also known in the wind turbine industry and will not be discussed in further detail herein.

[0047] As discussed above, there may be one or more locations of the half mould 44 where it is desirable to understand fundamental aspects of resin infusion through the various materials on the mould surface 50 at the one or more locations. For example, Fig. 3 illustrates a first location Li corresponding to a location near the root end 24 of the blade shell 36, 38 where an understanding of resin infusion may be desired. The first location Li may be in a highly inclined area of the half mould 44 where gravitational and other effects may be significant. Fig. 3 also illustrates a second location L2 corresponding to a location away from the root end 24 and at a location of some inclination (e.g., perhaps not as severe as the first location) and some curvature (e.g., multi-dimensional curvature) in the mould surface 50. While two locations Li, L2 of the half mould 44 are mentioned and identified above, it should be appreciated that it may be desirable to understand resin infusion at other areas of the half mould 44 and aspects of the invention should not be limited to the two particular locations shown in Fig. 3.

[0048] Fig. 4 illustrates a test apparatus 60, referred to as simulation table 60 hereafter, for simulating the conditions within the half mould 44 at a specific location, such as at Li or l_2 of the half mould 44, and examining resin infusion behavior under the simulated conditions. As used herein, simulating the conditions within the half mould 44 include, but are not limited to, simulating at least one geometrical condition within the half mould 44, simulating at least one thermal condition within the half mould 44, and / or simulating at least one material condition within the half mould 44. To this end, the simulation table 60 includes a base frame 62 and a test bed 64 mounted to the base frame 62 for receiving a test specimen 66 thereon (shown in phantom). In an exemplary embodiment, the test bed 64 is movably mounted to the base frame 62 so that the test bed 64 is moveable relative to the base frame 62 to provide the test bed 64 in different orientations relative to a gravity vector g (referred to hereafter as just gravity g). As explained in more detail below, in one embodiment, the test bed 64 may be rotatable relative to the base frame 62 about a rotational axis 68 to position the test bed 64 in different orientations relative to gravity g.

[0049] Providing the ability to move the test bed 64 (and the test specimen 66 thereon) relative to the test frame 62 (and gravity g) allows the test apparatus 60 to more accurately simulate the geometric conditions of the materials that are in the half mould 44 during manufacture of the wind turbine blade 20. For example, the inclination of the materials in the half mould 44 (e.g., angle relative to gravity) may affect the ability of the resin to infuse within the materials-i.e., inclination effects resin infusion behavior of the materials in the half mould 44. Therefore, to more accurately simulate conditions within the half mould 44, the test apparatus 60 provides a means to affect the geometrical condition of the test specimen 66 under test on the test apparatus 60. Thus, the resin infusion behavior of the test specimen 66 will more accurately reflect the resin infusion behavior of the materials in the half mould 44.

[0050] In one embodiment, the base frame 62 includes a generally rectangular base 70 for supporting the simulation table 60 on the ground or support surface 72 of, for example, a test facility. The support surface 72 is configured such that when the simulation table 60 is positioned on the support surface 72, the base 70 is configured to be substantially horizontal. As used herein, substantially horizontal means within + / - 5° of horizontal. The rectangular base 68 includes a front strut 74 (e.g., beam or bar), a rear strut 76, and a pair of opposed side struts 78, 80 connected, for example, end-to-end in a rectangular configuration, such as by welding, various fasteners, or other means. The size of the base 70 must be adequate to support the test bed 64 and the test specimen 66 disposed thereon at different positions of the test bed 64 relative to the base 62. In one embodiment, the base 70 may have a width Wb of 4 m and a depth Db of 3 m (from a perspective from the front of the simulation table 60). However, the size of the base 70 may have different dimensions and remain within the scope of the present invention. Moreover, while the base 70 is described as having a rectangular shape, this is merely exemplary and the base 70 may have different shapes and remain within the scope of the present invention.

[0051] The base frame 62 may further include at least one and preferably a pair of bed support frames 82, 84 extending away from (e.g., upwardly from) respective side struts 78, 80 of the base 70. As discussed below, the bed support frames 82, 84 are configured to movably support, and more particularly rotatably support, the test bed 64 relative to the base frame 62. In one embodiment, each of the bed support frames 82, 84 may include a primary strut 86 and one or more secondary struts 88 that collectively support the test bed 64 on the base 70. In the illustrated embodiment, the primary struts 86 extend from their respective side struts 78, 80 at about the middle of the depth Db of the base 70 and substantially perpendicular thereto (e.g., in a substantially vertical direction). That is, when the simulation table 60 is positioned on the support surface 72, the primary struts 86 are configured to be substantially vertical. As used herein, substantially vertical means within + / - 5° of vertical (e.g., as defined by gravity g).

[0052] In one embodiment, as illustrated in Fig. 4, for example, each bed support frame 82, 84 may include two secondary struts 88. The two secondary struts 88 may be disposed on opposite sides of the primary strut 86 and extend from the base 70 to adjacent a top of the primary strut 86. For example, in one embodiment, each secondary strut 88 may extend from a corner between side strut 78, 80 and the front and rear struts 74, 76 and its respective primary strut 86. This gives each bed support frame 82, 84 a substantially triangular configuration when viewed from the side of the simulation table 60. Aspects of the invention are not limited to the bed support frames 82, 84 having a triangular configuration and it should be understood that the bed support frames 82, 84 may have a different shape or configuration and remain within the scope of the present invention. In addition, each bed support frame 82, 84 may include a plurality of first locking bores 90. As will be explained in more detail below, the plurality of first locking bores 90 may form part of a locking mechanism 92 for locking the relative position of the test bed 64 relative to the test frame 62, i.e. , preventing relative rotation between the test bed 64 and the base frame 62.

[0053] Turning now to the test bed 64, in one embodiment, the test bed 64 includes a generally rectangular body 94 having a length W and a depth D. The test bed body 94 generally includes a test surface 96, a backing surface 98, and at least one side wall 100 extending between the test surface 96 and the backing surface 98. The test surface 96 is configured to receive the test specimen 66 thereon. In one embodiment, the test bed 64 is configured to be substantially the same size as the base 70 of the base frame 62 (e.g., a width Wt of 4 m and a depth Dt of 3 m). However, the size of the test bed 64 may have different dimensions and remain within the scope of the present invention. In one embodiment, the test surface 96 and the backing surface 98 of the test bed 64 may be formed from a transparent material. In this way, the resin infusion process through the test specimen 66 on the test surface 96 may be viewed at least from beneath the test bed 64. This may allow, for example, the resin infusion process of the test specimen 66 to be videoed by one or more cameras or other optical equipment positioned about the test specimen 66.

[0054] In an exemplary embodiment, the test bed 64 has a two-part construction including a first bed member 102 and a second bed member 104 which are coupled together to form the test bed 64. The first bed member 102 may include a generally rectangular frame 106 and a panel 108 disposed within the frame 106. The panel 108 defines the test surface 96 that receives the test specimen 66 thereon. As noted above, in a preferred embodiment, the panel 108 may be formed from a transparent material, such as glass, acrylics (polymethyl methacrylate (PMMA)), such as Perspex®, or polycarbonates. Other transparent materials may also be possible for panel 108. In a similar manner, the second bed member 104 may include a generally rectangular frame 110 and a panel 112 disposed within the frame 110. The panel 112 defines the backing surface 98 of the test bed 64. As noted above, in a preferred embodiment, the panel 112 may be formed from a transparent material, such as from materials provided above. Other transparent materials may also be possible for panel 112. In addition to the above, the first bed member 102 and the second bed member 104 may include one or more cross supports 114 to support the panels 108, 112 disposed within their respective frames 106, 110. For example, as illustrates in the figures, the second bed member 104 may include two cross supports 114 extending across the panel 112. This is merely exemplary and there may be more or less cross supports 114 across panels 108, 112 of one or each of the first and second bed members 102, 104.

[0055] In one embodiment, the frame 110 of the second bed member 104 may include a pair of hinge pins 116 extending outwardly from the frame 110 and on opposite sides of the frame 110. As will be discussed below in greater detail, the hinge pins 116 define the rotational axis 68 about which the test bed 64 is able to rotate relative to the base frame 62. In addition, in one embodiment, the frame 110 of the second bed member 104 may also include a second locking bore 118. As will be explained in more detail below, the second locking bore 118 forms part of the locking mechanism 92 for locking the relative position of the test bed 64 relative to the base frame 62, i.e. , preventing relative rotation between the test bed 64 and the base frame 62.

[0056] In an exemplary embodiment, when the first bed member 102 and the second bed member 104 are coupled together, a cavity 122 is defined between the test surface 96 (panel 108), the backing surface 98 (panel 112), and the at least one side wall 100 (frames 106, 110 of the first and second bed members 102, 104). The frames 106 and 110 of the first bed member 102 and the second bed member 104 are substantially the same size such that the first bed member 102 may be positioned atop the second bed member 104 and coupled together. For example, the first bed member 102 and the second bed member 104 may be coupled together with a plurality of fasteners (e.g., screws, bolts, etc.) located along the periphery of the frames 106, 110. As will be explained in more detail below, the cavity 122 in the test bed 64 is to provide for heating the test specimen 66 located on the test surface 96 of the test bed 64.

[0057] Providing the ability to heat the test bed 64 allows the test apparatus 60 to more accurately simulate the thermal condition of the materials that are in the half mould 44 during manufacturing of the wind turbine blade 20. For example, the viscosity of the resin is temperature dependent, thus the thermal conditions in the half mould 44 affect the ability of the resin to infuse within the materials-i.e., the temperature effects the resin infusion behavior of the materials in the half mould 44. Therefore, to more accurately simulate conditions within the half mould 44, the test apparatus 60 provides a means to affect the thermal condition of the test specimen 66 under test on the test apparatus 60. Thus, the resin infusion behavior of the test specimen 66 will more accurately reflect the resin infusion behavior of the materials in the half mould 44.

[0058] In one embodiment according to the invention, the simulation table 60 forms part of a test system 130 that includes ancillary subsystems that facilitate use of the simulation table 60 to examine the resin infusion behavior of blade materials in the half mould 44 during manufacture of the wind turbine blade 20 (e.g., upper and / or lower half shells 32, 34). By way of example, and without limitation, the test system 130 may include a resin subsystem 132 having a resin supply 134 and a resin pump 136 in fluid communication with the resin supply 134. The resin supply 134 may include a container, bag, tank, etc. for holding an amount resin. The resin pump 136 is configured to move the resin from the resin supply 134 to the resin tap points adjacent the test specimen 66 on the test bed 64 of the simulation table 60 via, for example, one or more conduits (e.g., hoses, tubes, etc.).

[0059] The test system 130 may further include a heating subsystem 140 for heating the test surface 96 of the test bed 64, and thereby heating the test specimen 66 located thereon. In one embodiment, the heating subsystem 140 may include a plurality of heating elements (e.g., electric heating elements; not shown) on, for example, an underside of the panel 108 of the first bed member 102. In another embodiment, however, the heating subsystem 140 may include an external heater 142 for moving a heated heat transfer medium into the cavity 122 in the test bed 64 of the simulation table 60. In one embodiment, the heat transfer medium may be a gas, such as air. In another embodiment, the heat transfer medium may be a liquid, such as water. In this regard, the cavity 122 may include at least one fluid inlet 144 (one shown) for introducing the heat transfer medium into the cavity 122 and at least one fluid outlet 146 (one shown) for evacuating the heat transfer medium out of the cavity 122. In one embodiment, the at least one fluid inlet 144 and the at least one fluid outlet 146 may be in opposed comers of the cavity 122. It should be recognized, however, that the number of fluid inlets 144, number of fluid outlets 146, and their arrangement in the cavity 122 may differ from that shown but remain within the scope of the present invention.

[0060] In one embodiment, the heating subsystem 140 may be a closed-loop system. In this regard, the heating subsystem 140 may include at least one hot fluid conduit 148 extending from the “hot side” of the heater 142 that is connected to the at least one fluid inlet 144 to the cavity 122. In a similar manner, the heating subsystem 140 may include at least one cold fluid conduit 150 extending from the “cold side” of the heater 142 that is connected to the at least one fluid outlet 146. Heaters for such closed-loop systems are known in the wind turbine industry and a further description of the heater 142 will not be provided herein for sake of brevity. A closed-loop system is exemplary, however, and the heating subsystem 140 may be configured as an open-type system in alternative embodiments.

[0061] As noted above, in one aspect of the invention, the simulation table 60 includes the ability to move, e.g., rotate, the test bed 64 relative to the base frame 62 to simulate a geometrical condition of the materials in the half mould 44, e.g., inclination of the materials in the half mould 44 to gravity g. In this regard, the simulation table 60 or the testing system 130 may include a drive subsystem 160 having a drive mechanism 162 for moving the test bed 64 relative to the base frame 62. In one embodiment, for example, the drive mechanism 162 may include a hand crank (not shown) for manually rotating the test bed 64 relative to the base frame 62. In another embodiment, the drive mechanism 162 may include a drive motor (not shown) for rotating the test bed 64 relative to the base frame 62. For example, the drive motor may include a pulley that is coupled to a pulley on one of the hinge pins 116 of the test bed 64 via a belt or chain such that activation of the drive motor turns the pulley and rotates the test bed 64. These two drive mechanisms 162 are merely exemplary and a wide range of drive mechanisms may be used to rotate the test bed 64 relative to the base frame 62 and aspects of the invention should not be limited to that described above.

[0062] As also noted above, certain aspects of the simulation table 60, such as the test surface 96 and the backing surface 98 of the test bed 64, may be made from transparent materials so that the infusion of resin in the test specimen 66 may be visualized. This visualization may be by human observation or by visualization equipment to capture the resin infusion process of the test specimen 66 for later review and analysis. In this regard, the test system 130 may include a visualization subsystem 170 having one or more cameras 172, for example, for capturing the resin infusion of the test specimen 66. The cameras 172 may be configured to provide visual images and / or thermal images of the resin infusion process. In one embodiment, the visualization subsystem 170 may include a data storage device (e.g., memory of a controller, computer, etc.) for storing the data from the cameras 172. The data from the one or more cameras 172 may be processed to garner valuable information about the resin infusion process, including resin infusion front locations, speeds, temperatures, “A” surface behavior and “B” surface behavior, differentials between A and B surface behaviors, dry spot formation, and other information.

[0063] Furthermore, in one embodiment, the testing system 130 may include a vacuum subsystem 180 having one or more vacuum pumps 182 for pulling a vacuum on the test specimen 66 during testing. As discussed above, during the manufacture of the upper and lower half shells 32, 34 of the wind turbine blade 20, vacuum-assisted resin infusion processes are used. To emulate this during the simulation using the test system 130, vacuum-assisted techniques are also used to assist the resin infusion in the test specimen 66. In this regard, the one or more vacuum pumps 182 may be operatively connected to the space between the test surface 98 of the test bed 96 and an outer vacuum cover or bag 184 positioned over the test specimen 66 and sealed to the test bed 96 via one or more vacuum taps 186 that are connected to the one or more vacuum pump 182 via suitable conduits 188 (e.g., hoses or tubes). Additional details of the vacuum subsystem 180 are discussed below. A method of using the simulation table 60, and more particularly, the testing system 130 will now be described. The test bed 64 of the simulation table 60 may initially be positioned in a substantially horizontal configuration with the test surface 98 of the test bed 84 facing upwardly. If the test bed 64 is not already in this position, the drive mechanism 162 of the drive subsystem 160 may be used to position the test bed 64 in the substantially horizontal position. Once in the substantially horizontal position, the test bed 64 may be locked relative to the base frame 62 using the locking mechanism 92. In this regard, a locking pin may be inserted into one of the plurality of first locking bores 90 and the second locking bore 118 that is aligned with the one of the plurality of first locking bores 90 when the test bed 64 is in the substantially horizontal position.

[0064] Moreover, because the test bed 64 may be in the substantially horizontal position for an extended period of time, and because the weight on the test bed 64 may be substantial (i.e. , the weight of the test specimen 66), the simulation table 60 may include addition supports for the test bed 64 in the form of a plurality of support stanchions 200. In one embodiment, the plurality of support stanchions 200 may be coupled to the base frame 62 and extend so as to engage the underside of the test bed 64, i.e., the underside of the frame 110 of the second bed member 104. For example, in one embodiment, two support stanchions 200 may be connected to the front strut 74 of the base frame 62 and two support stanchions 200 may be connected to the rear strut 76 of the base frame 62. Other numbers and arrangements of the plurality of support stanchions 200 are also possible. For example, in another embodiment, the plurality of support stanchions 200 may be coupled to the support surface 72 in spaced relation to the base frame 62 of the simulation table 60.

[0065] Furthermore, at least one of the plurality of support stanchions 200 may be moveable or removable so as to allow the test bed 64 to move relative to the base frame 62 away from the substantially horizontal position. By way of example, and without limitation, at least one of the plurality of support stanchions 200 may be pivotable so as to move out of the way of the test bed 64 during its movement away from the substantially horizontal position. In one embodiment, a plurality of the support stanchions 200, including each of the support stanchions 200, may be pivotable. For example, the two support stanchions 200 extending from the front strut 72 may be pivoted so as to move out of the way of the test bed 64 as it is rotated away from the substantially horizontal position. It should be recognized, however, that the movement / removability of the at least one of the plurality of support stanchions 200 may be achieved in other ways that remain within the scope of the present invention. Once in the substantially horizontal position, the test specimen 66 may be formed on the test surface 96 of the test bed 64.

[0066] Fig. 7 illustrates an exemplary test specimen 66 on the test surface 96 of the test bed 64 in accordance with an exemplary embodiment. The molding method may include placing a release agent 202 such as a liquid release coating, a wax, or a solid barrier (e.g., Teflon® tape) over the test surface 96 of the test bed 64. An optional layer (not shown) of release material (e.g., film) may then be applied over the release agent 202. In addition, a first optional layer of peel ply 204 may be applied over the release material layer, if present, or directly over the release agent 202. Next, several layers 206 of the fiber fabric may be placed over one another (e.g., stacked) to define a first assembly of layers, until a desired, predetermined thickness is reached in accordance with the design. The fiber fabric may include glass fiber, carbon fiber or other material or combination of materials known to those of ordinary skill in the art. The fibers of the fabric may be unidirectional or bidirectional (e.g., biax fabric). The fibers of the fabric may be selected to generally correspond to the fibers in the area of the half mould 44 being tested. Thus, if the area of the half mould 44 being tested includes unidirectional fibers, then the layers 206 should be unidirectional fibers. Similarly, if the area of the half mould 44 being tested includes bidirectional fibers, then the layers 206 should be bidirectional fibers. The goal is to use fabric layers 206 that simulate the fibers in the area of the half mould 44 under test. The fiber fabric may be dry.

[0067] If the area of the half mould 44 under test includes core material or spar cap material, then those materials should also be included in the test specimen 66 being formed on the test surface 96 of the test bed 64. For example, as illustrated in Fig. 7, one or more layers of core material 208 may be placed over the first assembly of layers 206. Next, several layers 210 of the fiber fabric may be placed over one another (e.g., stacked) to define a second assembly of layers and a third assembly of layers on both sides of the core material 208, until a desired, predetermined thickness is reached in accordance with the design. Similar to above, the fiber fabric may include glass fiber, carbon fiber or other material or combination of materials known to those of ordinary skill in the art. The fiber fabric may be dry. After locating the core material 208 and fabric layers 210 on the test surface 96, additional layers 212 of the fiber fabric may be placed over one another to define a fourth assembly of layers 212, until a desired, predetermined thickness is reached in accordance with the design. Similar to above, the fiber fabric may include glass fiber, carbon fiber or other material or combination of materials known to those of ordinary skill in the art. The fiber fabric may be dry.

[0068] Once this assembly is reached, a second optional peel ply 214 made, for example, of nylon or some other tightly woven fabric impregnated with a release agent, may be applied over the formed assembly. Once the second optional peel ply 214 is in place, a layer 216 of release film may be applied thereover. In this embodiment, a transport mesh 218 may then be applied over the second optional peel ply 214, which is configured for resin transport and gas evacuation during formation of the composite laminate. With continued reference to Fig. 7, an outer vacuum bag 184 may be placed over the above-mentioned layers and secured in place against the test bed 64 of the simulation table 60 via a securing element 220, such as a bag sealant tape. The vacuum subsystem 180, and more particularly the vacuum pump 182 is in fluid communication with the space between the outer vacuum bag 184 and the test surface 96 of the test bed 64 via the one or more vacuum taps 186 and conduits 188 between the vacuum pump 182 and the vacuum taps 186.

[0069] While the test bed 64 remains in the substantially horizontal position, the resin subsystem 132, and more particularly the resin supply 134 may be put in fluid communication with the space between the outer vacuum bag 184 and the test surface 96 of the test bed 64 via one or more resin taps and conduits between the resin pump 136 and the resin taps. Additionally, the vacuum pump 182 of the vacuum subsystem 180 may be activated to essentially pull the outer vacuum bag 184 toward the test surface 96 and thereby secure the test specimen 66 to the tst bed 64. At this point, the test bed 64 of the simulation table 60 may be rotated about its rotational axis 68 between its substantially horizontal position and an inclined position relative to gravity g. In this regard, the locking pin may be removed from the one of the plurality of first locking bores 90 and second locking bore 118 so that the test bed 64 is free to rotate away from the substantially horizontal position. For example, the drive mechanism 162 of the drive subsystem 160 may be activated to rotate the test bed 64 relative to the base frame 62 to a desired inclined position. In one embodiment, the inclined position may be the substantially vertical position, as shown in Figs. 6 and 7, for example. However, the inclined position may be any angle between being substantially horizontal and substantially vertical. For example, the test bed 64 may be configured to be angled at 5-15 predetermined angles between the horizontal and vertical positions (e.g., 10 predetermined angles). There may be more or less than this number.

[0070] Once the desired angle of the test bed 64 has been reached, the resin pump 136 may be activated to supply resin from the resin supply 134 to the resin tap points in communication with the test specimen 66 on the test surface 96 and underneath the outer vacuum bag 184. The vacuum pump 182 is effective to pull air out of the space between the outer vacuum bag 184 and the test surface 96. The vacuum pump 182 is also effective to pull resin from the resin tap points toward the vacuum tap points 186 and through the test specimen 66. Also, during this time, the one or more cameras 172 from the visualization subsystem 170 may be activated to capture the infusion of resin through the test specimen 66. In one embodiment, when the test bed 64 is inclined, the resin tap points may be configured to be at the lower end of the test specimen 66 and the vacuum tap points 186 may be configured to be at the upper end of the test specimen, as illustrated in Fig. 7. Other arrangements are possible, however.

[0071] In one embodiment, the heating subsystem 140 may remain off so that only the effects of the geometrical conditions within the half mould 44 on the behavior of resin infusion in the test specimen 66 may be examined. In another embodiment, however, the effects of both the geometrical conditions and the thermal conditions within the half mould 44 on the behavior of resin infusion in the test specimen 66 may be examined. More particularly, the heater 142 of the heating subsystem 140 may be activated to circulate the heat transfer fluid to / from the cavity 122 in the test bed 64. For example, the heater 142 may be controlled such that the temperature of the test surface 96 of the test bed 54 may be at a predetermined temperature. For example, the heating subsystem 140 may be configured to deliver the heat transfer medium to the cavity 122 at between about 90°C and about 120°C. Other temperatures are, however, possible.

[0072] In addition to the above, once the resin has been infused into the test specimen 66 on the test table 64, a curing blanket or cover (not shown) may be positioned over the outer vacuum bag 184 of the vacuum subsystem 180 and activated to aid in curing the test specimen 66. Once the test specimen 66 is fully cured, the test specimen 66 may be removed from the test bed 64 of the simulation table 60. To remove the test specimen 66 from the test bed 64, the test bed 64 may be rotated back to the substantially horizontal position. Once removed, the test specimen 66 may then be subjected to various testing, such as ultrasonic testing and destructive testing procedures, such as section testing, to examine the resin infusion process and dry patch formation on a smaller and less-costly scale.

[0073] While the invention has been illustrated by a description of various embodiments, and while these embodiments have been described in considerable detail, it is not the intention of the Applicant to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. The invention in its broader aspects is therefore not limited to the specific details, representative apparatus and method, and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of the Applicant’s general inventive concept.

Claims

CLAIMS1 . A test apparatus (60) for resin infusion of a test specimen (66) that simulates resin infusion in one or more materials in a wind turbine blade mould (44) during manufacture of a wind turbine blade (20), the test apparatus (60) comprising: a base frame (62); and a test bed (64) mounted to the base frame (62), the test bed (64) configured to receive the test specimen (66) during resin infusion testing, wherein the test apparatus (60) is configured to simulate at least one of: i) a geometric condition; and ii) a thermal condition of the one or more materials in the wind turbine blade mould (44) during manufacture of a wind turbine blade (20).

2. The test apparatus (60) of claim 1 , wherein the test apparatus (60) is configured to simulate the geometric condition of the one or more materials in the wind turbine blade mould (44) during manufacture of a wind turbine blade (20), and wherein the test bed (64) is movably mounted to the base frame (62) to change the orientation of the test specimen (66) positioned on the test bed (64) relative to gravity (g).

3. The test apparatus (60) of claim 2, wherein the test bed (64) is rotatably mounted to the base frame (62) so as to be rotatable relative to the base frame (62) about a rotational axis (68).

4. The test apparatus (60) of claim 2 or 3 further comprising, a drive mechanism (162) for moving the test bed (64) relative to the base frame (62).

5. The test apparatus (60) of claim 4, wherein the drive mechanism (162) includes a hand crank or a motor arranged to move the test bed (64) relative to the base frame (62).

6. The test apparatus (60) of any of claims 2-5, further comprising a lock mechanism (92) for locking the position of the test bed (64) relative to the base frame (62).

7. The test apparatus (60) of any of claims 2-6, further comprising at least one support stanchion (200) for supporting the test bed (64) in at least one position relative to the base frame (62).

8. The test apparatus (60) any of the preceding claims, wherein the test apparatus (60) is configured to simulate the thermal condition of the one or more materials in the wind turbine blade mould (44) during manufacture of a wind turbine blade (20), and wherein the test bed (64) comprises: a test surface (96) configured to receive the test specimen (66) thereon; a backing surface (98) opposite the test surface; and at least one side surface (100) extending between the test surface (96) and the backing surface (98) to define a cavity (122) within the test bed (64).

9. The test apparatus (60) of claim 8, wherein at least the test surface (96) and the backing surface (98) of the test bed (64) are each made from a transparent material.

10. A testing system (130), comprising: the test apparatus (60) of claim 9; and a visualization subsystem (170) including at least one camera (172) for videoing the infusion of resin in the test specimen (66).

11. A testing system (130), comprising: the test apparatus (60) of claim 8 or 9; and a heating subsystem (140) configured to control a temperature of the test surface (96) of the test bed (64).

12. The testing system (130) of claim 11 , wherein the heating subsystem (140) comprises: a heater (142) operatively coupled to the cavity (122) of the test bed (64), the heater (142) configured to heat a heat transfer medium for delivery to the cavity (122) of the test bed (64), wherein the cavity (122) includes at least one fluid inlet (144) and at least one fluid outlet (146) for respectively introducing the heat transfer medium into the cavity (122) and removing the heat transfer medium from the cavity (122).

13. The testing system (130) of claim 12, wherein the heat transfer medium includes a gas, preferably air.

14. The testing system of any of claims 11-13, wherein the heating subsystem (140) is a closed-loop heating unit.

15. The testing system of any of claims 10-14, further comprising a vacuum subsystem (180), the vacuum subsystem comprising: an outer vacuum bag (184) positionable over the test specimen (66) and sealable to the test bed (64); and a vacuum pump (182) for creating vacuum pressure in a space between the test surface (96) of the test bed (64) and the outer vacuum bag (184).

16. The testing system (130) of any of claims 10-15, further comprising a resin subsystem (132), the resin subsystem comprising: a resin supply (134); and a resin pump (136) for directing resin from the resin supply (134) to the test specimen (66) on the test bed (64).

17. The testing system (130) of any of claims 10-16, further comprising the test specimen (66) that is configured to be received on the test bed (64) of the test apparatus (60).

18. The testing system (130) of claim 17, wherein test specimen (66) has a material composition configured to simulate the one or more materials in the wind turbine blade mould (44) during manufacture of a wind turbine blade (20).

19. The testing system (130) of claim 18, wherein the test specimen (66) includes one or more of: i) a stack of fibre layers; ii) core materials; and iii) spar cap materials.

20. A method of simulating resin infusion in one or more materials in a wind turbine blade mould (44) during manufacture of a wind turbine blade (20), comprising: providing a test apparatus (60) having a base frame (62) and a test bed (64) mounted to the base frame (62); providing a test specimen (66); positioning the test specimen (66) on the test bed (64); arranging the test bed (64) so as to simulate at least one of: i) a geometric condition; and ii) a thermal condition of the one or more materials in the wind turbine blade mould (44) during manufacture of a wind turbine blade (20); and subsequent to the arranging step, introducing resin into the test specimen (66).21 . The method of claim 20, wherein the arranging step includes arranging the test bed (64) so as to simulate the geometrical condition of the one or more materials in the wind turbine blade mould (44) during manufacture of a wind turbine blade (20), and wherein the method further comprises: orienting the test bed (64) so that the test specimen (66) has a predetermined relationship relative to gravity (g).

22. The method of claim 21 , wherein orienting the test bed (64) comprises rotating the test bed (64) relative to the base frame (62) about a rotational axis (68) so that the test specimen (66) has the predetermined relationship relative to gravity (g).

23. The method of any of claims 20-22, wherein the arranging step includes arranging the test bed (64) so as to simulate the thermal condition of the one or more materials in the wind turbine blade mould (44) during manufacture of a wind turbine blade (20), and wherein the method further comprises: heating the test bed (64) to a predetermined temperature.

24. The method of claim 23, wherein heating the test bed (64) comprises directing a heated heat transfer medium to a cavity (122) formed in the test bed (64).

25. The method of any of claims 20-24, further comprising: positioning an outer vacuum bag (184) over the test specimen (66); sealing the outer vacuum bag (184) to the test bed (64); and pulling a vacuum in the space between the outer vacuum bag (184) and the test bed (64).

26. The method of claim 25, wherein the test bed (64) is oriented relative to the gravity (g) so as to define a lower end of the test specimen (66) and an upper end of the test specimen (66), and wherein the method further comprises: introducing the resin into the test specimen (66) at a lower end thereof; and locating vacuum taps (186) at an upper end thereof for pulling the vacuum in the space between the outer vacuum bag (184) and the test bed (64).

27. The method of any of claims 20-26, wherein the test bed (64) includes at least one transparent test surface (96) configured to receive the test specimen (66) thereon, and wherein the method further comprises: observing or videoing the infusion of resin into the test specimen (66) from at least a perspective beneath the test bed (64).

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