Mechanical testing device and method for testing beam-shaped test specimens, in particular rotor blades of wind turbines

Description

[0001] The invention lies in the field of mechanics and mechanical engineering and can be used with particular advantage in the testing of rotors of wind turbines.

[0002] Specifically, the invention relates to a testing device and a method for testing beam-shaped test specimens, for example rotor blades or rotor blade sections of wind turbines.

[0003] Such rotor blades are exposed to severe and prolonged loads during operation. The goal is to achieve the longest possible service life for wind turbines, while preventing fracture due to material fatigue as reliably as possible.

[0004] In order to predict the service life of rotors or to optimize it through design measures, mechanical load tests are necessary that enable cyclic loading of rotor blades under reproducible and as precisely defined conditions as possible.

[0005] For this purpose, testing equipment is used that can be operated automatically over a longer period of time.

[0006] Such test equipment must allow for the storage, mounting, or clamping of rotor blades and also provide the possibility of cyclic mechanical load application in one or more directions using active load application devices. Passive load application devices may also be provided, which can be used, for example, to adjust system natural frequencies.

[0007] Various test cases require a force introduction in such a way that the test specimen retains certain degrees of freedom.

[0008] European patent application EP3433594 A1 discloses a testing device in which a test specimen is clamped in load frames, each of which can rotate / pivot about an axis. However, with the known system, even rotating the entire test specimen about its longitudinal axis, in order to be able to load it in both the flapping and pivoting directions of a rotor blade, is extremely complex and requires major modifications.

[0009] Furthermore, a mechanical testing device is known from US2019 / 094104 A1.

[0010] Against the background of the prior art, the object of the present invention is to provide a testing device and a testing method which allow the setting of different testing conditions to the greatest possible extent and in the simplest possible manner.

[0011] According to the invention, the object is achieved by a testing device with the features of patent claim 1. The subclaims dependent on claim 1 present possible implementations of testing devices.

[0012] The invention also relates to testing methods having the features of independent patent claims 9 and 10 and implementations of such methods.

[0013] The symmetry of the load frame makes it easy to rotate the test specimen around its longitudinal axis by 90 degrees at different angular values. This means that loads, in particular cyclic loads, can be applied to a test specimen from different directions using active load introduction devices. For example, with minimal modifications, a load test with a load in the pivot direction of a rotor blade is possible, followed by a load test with a load in the flapping direction, whereby the same active load introduction devices can be used. Rotations of the test specimen by angular values ​​other than 90 degrees are also possible in principle. This rotatability is essentially achieved by the fact that the frame section as a whole is rotatable and can be mounted in a supporting frame or support frame in various angular positions, in particular offset by 90 degrees from one another.

[0014] The invention also relates to a testing device in which the clamping device can be fastened in the frame part in several positions, in particular by means of a tensioning device, which are each rotated relative to one another about the longitudinal axis of the clamped test specimen, in particular rotated by 90 degrees.

[0015] Thus, alternatively or in addition to the ability to mount the load frame in multiple angular positions, the clamping device within the frame part of the load frame can also be rotated and fixed by 90 degrees around the longitudinal axis of the test specimen or, in the case of a circular frame part, by other angular amounts. To fix the clamping device in the frame part, a tensioning device is provided on the frame part, which enables the clamping device to be clamped in the frame part. The clamping device can in turn comprise several clamping blocks between which a test specimen can be clamped, in particular when the clamping device is clamped by the frame part. The tensioning device can be designed as a clamping clip or as a screw connection between the frame parts.

[0016] If the test specimen is tested again after a rotation of 90 degrees, the existing active and passive load introduction elements can be used at least partially for the new test, in particular if load introduction elements are provided for the load introduction in at least 2 mutually perpendicular directions.

[0017] Furthermore, the invention relates to a testing device in which the frame part has at least two frame-side pivot bearing parts or fastening devices for pivot bearing parts arranged offset by 90 degrees on its circumference, which are each designed to interact with support frame-side pivot bearing parts on a support frame or pivot bearing parts on a support frame.

[0018] It can also be provided that two clamping blocks are provided within the clamping device, which leave a through opening between them for the test specimen, the width of which, measured perpendicular to the longitudinal axis of a clamped test specimen, is at least twice, in particular at least three or five times as large as its height, wherein in the case of a test specimen in the form of a rotor blade segment, the width of the through opening is measured in the pivoting direction and the height in the flapping direction.

[0019] The shape of the clamping blocks described in this way takes the shape of a wind turbine rotor blade into account. The extension of such a rotor blade in the pivot direction, which here corresponds to the width of the through-opening, is typically several times greater than the extension of a rotor blade in the flap direction at the same location relative to the longitudinal axis of the rotor blade. Nevertheless, according to the invention, the clamping blocks of the clamping device, assembled into a unit, can have a circular or square outer contour when viewed in the direction of the longitudinal axis of the clamped test specimen.

[0020] A further implementation can provide that the frame part is rotatably mounted in a first pivot bearing arrangement in a support frame about the first transverse axis, wherein the support frame has the same rotational symmetry as the frame part and the support frame is rotatably mounted in a second pivot bearing arrangement on a support frame about a second transverse axis of the test object clamped in the load frame, which second transverse axis runs perpendicular to the longitudinal axis and in particular inclined with respect to the first transverse axis, further in particular perpendicular to the first transverse axis of the test object.

[0021] Such an arrangement enables two-axis tests that require the test specimen to be able to rotate around several axes at a bearing point, in particular on a load frame.

[0022] It can also be provided that the support frame is pivotally mounted about a pivot axis perpendicular to the longitudinal axis of the test object and spaced therefrom.

[0023] The pivoting capability of the support frame, as described above, allows the test specimen to move along the longitudinal axis of the test specimen. This degree of freedom can be useful or necessary for both uniaxial and biaxial tests.

[0024] A further implementation may provide that the frame part in the first pivot bearing arrangement is mounted in a support frame so as to be rotatable about the first transverse axis and that the support frame is mounted so as to be pivotable about a pivot axis perpendicular to the longitudinal axis of the test object and spaced therefrom.

[0025] This allows the test specimen to move with the load frame in the direction of the longitudinal axis of the test specimen in the event that the load frame is mounted directly in a support frame, for example for uniaxial tests.

[0026] The invention can also relate to the fact that at least one active or passive load introduction means is provided within a test device, which has a load frame for connection to a test object or acts on such a load frame, wherein the load frame, as already described in detail above, has a frame part and a clamping device held in it, in which a beam-shaped test object, in particular a rotor blade or rotor blade segment, can be clamped so as to protrude through the load frame, and wherein the frame part has a four-fold rotational symmetry, in particular a square shape, or a circular ring shape.

[0027] This allows the load frames to be rotated around the longitudinal axis of the test object for each or all load frames used to couple the test object to active or passive load introduction devices.

[0028] In principle, it should be added to the above descriptions that the test device can in all cases have a device for one-sided storage or clamping of a test object, for example a rotor blade.

[0029] In addition to a testing device of the type mentioned above, the invention also relates to a method for carrying out a single-axis or two-axis test of a test specimen in the form of a rotor blade or rotor blade segment of a wind turbine using a testing device of the type described above, in which clamping blocks are first rotated into the desired position within the frame part of a load frame depending on the axis of the test specimen to be tested and are then clamped to the test specimen, and a load is then introduced into the test specimen according to a predetermined test scheme.

[0030] In this way, the test specimen can often be rotated around its longitudinal axis to the desired angular position for a desired test without rotating the frame part of the support frame. However, a combination of rotation of the clamping blocks within the support frame and the support frame itself around the longitudinal axis can also be provided.

[0031] The invention also relates to a method for carrying out a biaxial test of a test specimen in the form of a rotor blade or rotor blade segment of a wind turbine with a test device according to the type described above, in which two loading directions are first determined by rotating clamping blocks within a load frame and / or by rotating the load frame in a support frame and then, by adjusting one or more passive load introduction elements, at least one of which acts only in one or parallel to one of the loading directions, the suitable loading frequencies in the two loading directions are set in a desired relationship to one another such that one of the two suitable loading frequencies is an integer multiple of the other suitable loading frequency,where the suitable loading frequencies are in particular the system natural frequencies of the test specimen for a vibration in the respective loading direction.

[0032] The test specimen's ability to rotate around its longitudinal axis allows for freely adjusting the loading directions and the effective directions of the passive load application devices. For example, a rotor blade can be easily tested not only in the flapping and tilting directions, but also in directions in between.

[0033] In the following, the invention is shown and subsequently described using embodiments and examples in figures of a drawing.

[0034] It shows: Figure 1 and Figure 2 each a test device in a side view with a test specimen mounted on one side, Figure 3a load frame rotatably mounted on a support frame, which does not fall within the scope of the claims, Figure 4 a load frame with fourfold symmetry, according to the claimed invention Figure 5 a circular, ring-shaped load frame which does not fall within the scope of the claims, Figure 6 a load frame rotatably mounted in a support frame, the support frame being rotatably mounted in a support frame which does not fall within the scope of the claims, Figure 7 a load frame and a support frame as in Figure 6 shown in enlarged form, which does not fall within the scope of the claims, Figure 8 a circular load frame mounted in a likewise circular support frame, which does not fall within the scope of the claims, Figure 9 as well as Figure 10a load frame rotatable about an axis at a rotatably mounted end of a test specimen, which does not fall within the scope of the claims, Figure 11, 12 a load frame rotatable about two axes, in which a test specimen is mounted at one of its ends, which does not fall within the scope of the claims, and Figure 13 schematic side view of a test device in which a test specimen is firmly clamped on one side in a holding device.

[0035] Figure 1 shows a side view of a test specimen 1 in the form of a rotor blade of a wind turbine, which is pivotally mounted on one side on a holding device 2 in a bearing device 2b. Within the bearing device 2b, the test specimen can be clamped into a load frame according to the invention.

[0036] The test specimen 1 is mounted on a support frame 15 by means of a load frame 4a, rotatable about a transverse axis 9. The support frame, in turn, is mounted on the foundation side, rotatable about a pivot axis 17. The axes 9, 17 are perpendicular to the plane of the drawing.

[0037] The test specimen is supported against the foundation 3 by means of the support frame 15.

[0038] The test specimen 1 is clamped in a further load frame 4b, and an active load introduction device 18b engages the load frame 4b. By means of the active load introduction device 18b, which can be configured, for example, as an electromagnetically, hydraulically, or pneumatically driven actuator, a load can be applied to the test specimen in the direction of arrow 20. During a load test, this load can be changed cyclically, so that it acts periodically, for example, in the form of a sinusoidal, sawtooth, or rectangular load.

[0039] Additionally, a load frame 4c is arranged on the test specimen 1, by means of which a passive load introduction device 19a in the form of a mass attached to the test specimen is coupled. The size of the mass and its position along the longitudinal axis 8 of the test specimen allow the system natural frequency of the test specimen to be adjusted appropriately for vibrations in the direction of arrow 20.

[0040] The load frames 4a, 4b, 4c and the load frames used on the frame of the bearing 2b can each be used individually or in groups or all of them can be designed as load frames according to the invention with a fourfold symmetry, which are designed as square load frames.

[0041] This allows the test specimen 1 to be easily rotated 90 degrees around its longitudinal axis 8, for example, and then tested using the same load application means 18b. In this way, at least several independent uniaxial tests can be performed with minimal effort.

[0042] In the Figure 2 is a test facility similar to that in the Figure 1 The test device shown is shown, however, the active load introduction means 18a, 18b being designed such that each of them acts in a different loading direction. A first active load introduction means 18a is provided, by means of which a variable load can be generated on the test specimen 1 in a direction perpendicular to the plane of the drawing. In addition, a second active load introduction means 18b is shown, by means of which a load can be applied to the test specimen in the direction of arrow 20, i.e., in the plane of the drawing.

[0043] The test subject 1 is as in the Figure 1In the variant shown, the test specimen is pivotally mounted on a holding device 2 by means of a bearing device 2b and held in a support frame 15 by means of a load frame 4a'. Similar applications are also conceivable in which the test specimen is clamped at one end in the holding device.

[0044] The active load introduction means 18a, 18b can also act on the test specimen via a load frame 4b'. The load frames 4a', 4b' are each mounted rotatably about a first transverse axis in a support frame, which in turn is mounted rotatably about a second transverse axis. Each of the load frames 4a', 4b' is square in design with fourfold rotational symmetry. In this way, the test specimen 1 can be rotated about several axes when transverse forces are applied, so that even biaxial tests can be carried out without difficulty. The test specimen can be secured in the respective load frame by means of a clamping device with at least two clamping blocks, whereby the clamping device is also rotatable in the load frame, so that the test specimen can be rotated about its longitudinal axis even without rotating the frame parts in order to set suitable test conditions.

[0045] The Figure 3shows, in a direction of view along the longitudinal axis 8 of a test specimen, the test specimen 1 in cross section as well as a view of a support frame 15 which is pivotably attached to a foundation 3 about a pivot axis 17.

[0046] The support frame 15 has two longitudinal beams 15a, 15b and transverse beams 15c, 15d, as well as pivot bearing elements on the support frame side, which complement pivot bearing elements 11a, 11b on the frame part side to form pivot bearings. This allows a load frame 4d to rotate relative to the support frame 15 about the first transverse axis 9.

[0047] The load frame 4d is rectangular and has a rectangular frame part 5 with the frame part elements 5a, 5b, 5c, 5d. Two clamping blocks 6a, 6b of a clamping device are clamped in the frame part 5. These have a through opening 6c between them for the test specimen 1. The elements 5a, 5b, 5c, 5d of the frame part 5 can be clamped together using fastening means such as screws or clamps in order to clamp the clamping blocks 6a, 6b and the test specimen 1 between them.

[0048] In the Figure 4In a view along the longitudinal axis 8 of the test specimen, a load frame 4e is shown, which exhibits fourfold symmetry around the longitudinal axis 8 of the test specimen 1. The load frame 4e has a square contour. The long sides of the frame part 5 are, in this case, of equal length. The clamping blocks 6a' and 6b' thus form a clamping device, which also has a square outer contour and can be rotated in 90° increments relative to the frame part 5. Thus, the test specimen 1 can also be fastened in the frame part 5 in positions rotated by 90° relative to one another.

[0049] In the Figure 4 The load frame can be rotated about a first transverse axis 9 relative to a support frame 15 by means of pivot bearing parts 11a, 11b.

[0050] In addition to the pivot bearing parts 11a, 11b symbolically shown as pins, the frame part 5' also has pivot bearing parts 11c, 11d, each offset by 90°, so that the load frame can also be rotated and supported by 90° relative to the support frame.

[0051] In the Figure 5 a test specimen 1 is shown which is clamped between two clamping blocks 6a", 6b", which together form a circular contour. The clamping device 6a", 6b" is clamped in its entirety in a circular ring-shaped frame part 5". For this purpose, the frame part 5" is divided into two semicircular ring parts which can be clamped together by means of clamps or screws in order to clamp the circular clamping device between them. The frame part 5" is mounted in a support device 15 so as to be rotatable about a first transverse axis 9. Further pivot bearing parts are symbolically shown on the circumference of the frame part 5".

[0052] Alternatively, a circular frame can be designed as a large bearing, particularly a ball or cone bearing. The clamping device can be easily rotated within this frame together with the test specimen when clamped. This also allows the test specimen to be supported in a torsion-free manner. If both frames 2b and 4a are designed as large bearings, the large bearing can be locked to one of the frames so that the torsion can be absorbed at least in one frame.

[0053] The same applies to the frames of the two-axis test in Fig. 8 ; in this case, either the support frame or preferably the load frame is designed as a large bearing and can optionally be locked.

[0054] The Figure 6shows a load frame 4g which is rectangular in shape and has a rectangular clamping device. The rectangular frame part of the load frame 4g is mounted rotatably about a first transverse axis 9 relative to a support frame 14. The support frame 14 has a correspondingly rectangular shape and is in turn mounted rotatably about a second transverse axis 10 on a support frame 15. Overall, a cardanic suspension of the load frame 4g in the support frame 15 can thus be achieved. The support frame 15 is also mounted pivotably about a pivot axis 17 on the foundation 3. Furthermore, the support frame 15 is, in comparison to Fig. 3angled so that transverse forces parallel to the pivot axis 17 can also be absorbed at the supports 21. The supports 22 of the axis 10 as well as the supports 21 are designed, for example, as ball joints. The transverse axes 9, 10 are perpendicular to each other in the example shown. Such a vertical arrangement of the pivot axes is not absolutely necessary, for example, in the case of circular frame parts or load frames, as will be shown below with reference to the Figure 8 is shown.

[0055] In the Figure 7 the configuration with a rectangular load frame 4g, which is rotatably mounted in a likewise rectangular support frame 14, is shown again in detail in an enlarged form.

[0056] According to the claimed invention, the load frame 4g is square in shape and thus has a fourfold symmetry of the support frame 14, so that the load frame 4g can be rotated within the support frame 14 in 90° increments. Corresponding frame-side pivot bearing parts and support frame-side pivot bearing parts can be provided on the load frame 4g and / or on the support frame 14, so that pivot bearings are formed in each of the positions rotated by 90° relative to each other around the longitudinal axis of the test specimen.

[0057] The carrier frame can also be rotatable relative to the support frame around the longitudinal axis of the test object, in the case of a square carrier frame in 90° steps.

[0058] In the Figure 8a circular ring-shaped load frame 4h is shown, which has a frame part made of two semicircular ring segments that are braced against each other and clamp a circular clamping device 6a", 6b". The clamping device 6a", 6b" can, on the one hand, be continuously rotated and clamped relative to the frame part of the load frame 4h about the longitudinal axis of the test specimen 1. On the other hand, the circular ring-shaped frame part can also be rotatably mounted or mountable in various rotational positions relative to the support frame 14'. For this purpose, pivot bearing parts on the frame part side can be arranged in various positions on the frame part, which pivot bearing parts can each interact with pivot bearing parts on the support frame side and form pivot bearings.On the other hand, it is also possible to provide simple fastening devices for pivot bearing parts on the circumference of the frame part of the load frame 4h, for example in the form of bores into which pivot bearing parts can be inserted in order to position the load frame 4h in different rotational positions relative to the support frame 14' and to mount it in a pivot bearing in each case.

[0059] The support frame 14' is mounted by means of pivot bearings around the second transverse axis 10 relative to a support frame 15. In the Figure 8 It can be seen that the first transverse axis 9, about which the load frame 4h is rotatable, is inclined at an angle other than 90° relative to the second transverse axis 10, about which the support frame 14' is rotatably mounted. However, an angle of 90° can also be provided between the two transverse axes 9, 10.

[0060] The support frame 14' can also have a plurality of pivot bearing parts in order to be rotatably mounted on the support frame in several angular positions, which are rotated relative to one another about the longitudinal axis of the test piece 1.

[0061] The Figure 9 shows a view of the holding device 2 in the longitudinal direction 8 of the test specimen, a load frame 4i in which a test specimen is clamped, wherein the load frame 4i is mounted rotatably about a horizontally arranged first transverse axis 9. The mounting of the load frame 4i provides pivot bearings, which are arranged on holder arms 2c, 2d of the bearing device 2b. The position of the pivot bearings is shown in the plan view of the Figure 10can be seen. If a square load frame according to the invention is selected instead of the rectangular load frame 4i, both the clamping device within the frame part and the frame part itself can be easily rotated by 90° about the longitudinal axis and stored in the bearing device 2b, 2c, 2d.

[0062] The Figure 11 shows a top view analogous to the Figure 9 in a plan view, a load frame 4j, which is rectangular in shape and into which a test specimen 1 is clamped. The load frame 4j has a rectangular frame part 5j, which is rotatably mounted about a vertical first transverse axis 9 in pivot bearings within a support frame 14. The support frame 14 is also rectangular in shape and is rotatably mounted about a horizontal second transverse axis 10 on angled arms 2c, 2d of the support device 2b by means of pivot bearings, as can be seen from the Figure 12as seen in a top view. The supports are mounted on ball bearings and can therefore also absorb transverse forces.

[0063] This results in a cardanic suspension / support of the test specimen 1 on the holding device 2, which gives the test specimen the degrees of freedom necessary, for example, for a biaxial test. If the load frame 4j and the support frame 14 are designed square or circular, as shown in the Figure 4 and 8 As shown, the load frame 4j can also be rotated within the support frame 14 by 90° or, in the case of a circular ring-shaped design, in any angular steps around the longitudinal axis of the test specimen.

[0064] Additionally, it is possible to adjust the clamping blocks within the load frame 4j in 90° increments in the case of the square design according to the invention, and in arbitrary or preset discrete angular increments in the case of a circular design of the load frame. This simplifies the options for rotating the test specimen 1 around its longitudinal axis in order to adjust the loading directions during the test as desired.

[0065] In the Figure 13A test specimen 1 is shown in a test facility in which the test specimen, in the form of a rotor blade, is firmly clamped on one side to a holding device 2 in a clamping device 2a, such that it has no degrees of freedom at this end. Examples of passive load introduction means 19b, 19c and an active load introduction means 18 are shown, each of which acts on load frames 4k, 4l, 4m. These load frames can, as shown in the above examples, be designed according to the invention with a fourfold symmetry or also in a circular ring shape. Each of the load frames 4k, 4l, 4m can have such a design.

[0066] This means that the different types of one-sided mounting / clamping of rotor blades shown provide all possible combinations with rotating load frames.

[0067] The passive load introduction devices 19a, 19b, 19c are used to set suitable system natural frequencies of the test object during the test. These devices can be designed either as spring elements for connecting a load frame to a stationary point or as a decoupled or directly coupled mass. Individual, several, or all of the passive load introduction devices can also be designed to act on the test object only in one of the loading directions, so that the system natural frequencies of the test object can be individually adjusted in the intended loading directions. The active load introduction devices 18a, 18b can also be adjusted separately from one another with regard to the periodicity of the load introduction, so that cyclic excitation in the desired loading directions can be selected at the system natural frequencies or in the immediate vicinity of the system natural frequencies of the test object.According to the invention, the test conditions can be easily and conveniently adjusted by means of the various options for the rotation of the test specimen, and when carrying out the test, it can be provided that the loading frequency in one of the desired loading directions is an integer multiple of the loading frequency in the second desired loading direction.

Claims

1. A mechanical test device with at least one load frame (4a, 4a', 4b, 4b', 4c, 4e, 4k, 4l, 4m) which has a frame part (5') and a clamping device (6a) held therein, in which a beam-shaped test specimen (1), in particular a rotor blade or rotor blade segment, can be clamped projecting through the load frame, wherein the load frame is mounted in a first pivot bearing arrangement on a carrier frame (14, 14') or a support frame (15) so as to be rotatable about a first transverse axis (9) of the test specimen, which extends perpendicularly to its longitudinal axis (8) projecting through the clamping device, characterized in that the load frame has a square shape with a four-fold rotational symmetry.

2. The test device according to claim 1, characterized in that the clamping device (6a) is fastenable in the frame part (5') in multiple positions, in particular by means of a tensioning device, each of said positions being rotated by 90 degrees relative to one another about the longitudinal axis (8) of the clamped test specimen (1).

3. The test device according to claim 1 or 2, characterized in that the frame part (5') has, arranged offset by 90 degrees on its periphery, at least two frame-part-side pivot bearing parts or fastening devices for pivot bearing parts, which are each configured to cooperate with carrier-frame-side pivot bearing parts on a carrier frame (14, 14') or pivot bearing parts on a support frame (15).

4. The test device according to claim 1, 2 or 3, characterized in that two clamping blocks are provided within the clamping device (6a) and leave free between them a through-opening (6c) for the test specimen (1), the width (6d) of said through-opening, measured perpendicular to the longitudinal axis (8) of a clamped test specimen, being at least twice, in particular at least three or five times, as great as its height (6e), wherein, in the case of a test specimen in the form of a rotor blade segment, the width of the through-opening is measured in the edgewise direction and the height is measured in the flapwise direction.

5. The test device according to any one of claims 1 to 4, in which in a first pivot bearing arrangement (20a, 20b) the frame part (5') is rotatably mounted in a carrier frame about the first transverse axis (9), characterized in that the carrier frame (14, 14') has the same rotational symmetry as the frame part and the carrier frame is rotatably mounted in a second pivot bearing arrangement on a support frame (15) about a second transverse axis (10) of the test specimen clamped in the load frame (4a, 4a', 4b, 4b', 4c, 4e, 4k, 4l, 4m), which axis extends perpendicularly to the longitudinal axis and in particular inclined with respect to the first transverse axis (9), more particularly perpendicularly to the first transverse axis of the test specimen.

6. The test device according to claim 5, characterized in that the support frame (15) is mounted pivotably about a pivot axis (17) perpendicular to the longitudinal axis (8) of the test specimen (1) and spaced apart therefrom.

7. The test device with a load frame according to any one of claims 1 to 4, characterized in that the frame part (5') in the first pivot bearing arrangement (11a, 11b) is mounted in a support frame (15) so as to be rotatable about the first transverse axis (9) and the support frame is mounted pivotably about a pivot axis (17) perpendicular to the longitudinal axis of the test specimen and spaced apart therefrom.

8. The test device according to any one of claims 1 to 7, characterized in that at least one active or passive load introduction means (19a, 19b, 19c) is provided, which has a load frame (4a, 4a', 4b, 4b', 4c, 4e, 4k, 4l, 4m) for connection to a test specimen (1), wherein the load frame has a frame part (5') and a clamping device held therein, in which a beam-shaped test specimen, in particular a rotor blade or rotor blade segment can be clamped projecting through the load frame, and wherein the frame part has a four-fold rotational symmetry, in particular a square shape, or a circular ring shape.

9. A method for carrying out a uniaxial or biaxial testing of a test specimen in the form of a rotor blade or rotor blade segment (1) of a wind turbine with a test device according to any one of the preceding claims, characterized in that firstly clamping blocks are rotated to the desired position within the frame part in dependence on the axis of the test specimen (1) to be tested within the frame part (5') of the load frame (4a, 4a', 4b, 4b', 4c, 4e, 4k, 4l, 4m), and are then clamped to the test specimen, and in that thereafter a load is introduced into the test specimen according to a predetermined test scheme.

10. A method for carrying out a biaxial testing of a test specimen in the form of a rotor blade or rotor blade segment (1) of a wind turbine with a test device according to any one of the preceding claims, characterized in that two loading directions (20) are firstly defined by rotating clamping blocks within the load frame (4a, 4a', 4b, 4b', 4c, 4e, 4k, 4l, 4m) and / or by rotating the load frame in a carrier frame (14, 14'), and then, by adjusting one or more passive load-introducing elements (19a, 19b, 19c), of which at least one acts only in one or parallel to one of the loading directions, the suitable loading frequencies in the two loading directions are set in a desired ratio to one another in such a way that one of the two suitable loading frequencies is identical to or an integer multiple of the other suitable loading frequency, wherein the suitable loading frequencies are in particular in each case system natural frequencies of the test specimen for an oscillation in the respective loading direction.