Multi-degree-of-freedom vibration test system

Abstract

The present invention belongs to the field of vibration test technology, and discloses a multi-degree-of-freedom vibration test system. The multi-degree-of-freedom vibration test system includes a test box, a work surface, an axial vibration generator and a ball joint device. The test box has a test cavity, and the environmental factors of the test cavity can be adjusted; the work surface is arranged in the test cavity, and the work surface is used to place the product; at least two groups of axial vibration generators are arranged outside the test box, and the two groups of axial vibration generators can generate two mutually perpendicular or two opposite and non-collinear excitation forces; the ball joint device is arranged between the vibration end of each axial vibration generator and the work surface. The multi-degree-of-freedom vibration test system of the present invention sets the work surface inside the test box, and simulates the real working environment of the product by adjusting the environmental factors of the cavity, thereby performing multi-degree-of-freedom vibration tests on the product in the real working environment, and finally meeting the vibration test requirements of various products in different environments.

Description

Technical Field

[0001] The present invention relates to the technical field of vibration testing, and in particular to a multi-degree-of-freedom vibration testing system. Background Art

[0002] Vibration testing is a method that simulates the vibration environments a product may encounter during transportation, installation, and use to assess its vibration resistance and reliability. Vibration testing can confirm product reliability in vibration environments, screen out defective products in advance, and conduct failure analysis. It can also verify that product design and functionality meet requirements.

[0003] Currently, equipment in the fields of vehicles, ships, weapons, aviation, and aerospace faces complex and harsh mechanical environments, often subject to the combined influence of temperature, humidity, air pressure, and vibration. Although current testing equipment can perform multi-degree-of-freedom composite vibration tests on products, the test environment differs significantly from the actual operating environment, making it difficult to fully evaluate the product's performance in complex environments. Summary of the Invention

[0004] The purpose of the present invention is to provide a multi-degree-of-freedom vibration test system that can simulate a product to perform a multi-degree-of-freedom composite vibration test in a real operating environment, so as to meet the vibration test requirements of various products in different environments and multiple degrees of freedom.

[0005] To achieve this object, the present invention adopts the following technical solutions:

[0006] Multi-degree-of-freedom vibration test system, including:

[0007] A test chamber having a test chamber, wherein environmental factors of the test chamber can be adjusted;

[0008] A work surface is provided in the test chamber and is used for placing products;

[0009] At least two groups of axial vibration generators, the two groups of axial vibration generators are capable of generating two mutually perpendicular or two opposite and non-collinear excitation forces, the axial vibration generators being disposed outside the test box; and

[0010] A ball joint device is arranged inside the test box, and the ball joint device is arranged between the vibration end of each axial vibration generator and the work table. The ball joint device can transmit the exciting force of the axial vibration generator to the work table.

[0011] Preferably, the ball joint device comprises:

[0012] A connecting seat, with ball grooves at both ends, wherein the inner cavity of the ball groove is arranged in a spherical crown shape;

[0013] A ball head is rotatably provided inside each ball groove, and each ball head is provided with an avoidance hole;

[0014] A limiting rod is passed through the connecting seat, and the avoidance holes are extended from both ends of the limiting rod, and the avoidance holes and the limiting rod are clearance-fitted; and

[0015] A limiting head is provided at each end of the limiting rod. The side of the limiting head opposite to the ball head abuts against the ball head, and the ball head can move relative to the limiting head.

[0016] Preferably, a limiting groove is provided on the side of the ball head facing away from the connecting seat, the side wall of the limiting groove is parallel to the outer wall of the ball head, the limiting head is placed inside the limiting groove, and the shape of the limiting head is adapted to the shape of the limiting groove.

[0017] Preferably, a through hole is provided on the limit head along the axial direction of the limit rod, both ends of the limit rod extend out of the through hole and are detachably connected with locking pieces, and the locking pieces abut against the limit head.

[0018] Preferably, an end cover is provided on the side of the ball head facing away from the connecting seat, and the end cover covers the opening of the limiting groove.

[0019] Preferably, the environmental factor is temperature, humidity or air pressure.

[0020] Preferably, a transition device is provided between the axial vibration generator and the test box, and the transition device is configured to transmit the exciting force of the axial vibration generator to the ball joint device.

[0021] Preferably, a connection hole is provided on the test box corresponding to the vibration end of the axial vibration generator, and a flexible sealing tube is provided between the test box and the axial vibration generator, and the sealing tube seals the connection hole.

[0022] Preferably, the work surface is arranged horizontally, and four groups of axial vibration generators are arranged in sequence along the circumference of the work surface, and two adjacent groups of axial vibration generators are perpendicular to each other, and the excitation force direction of the axial vibration generators on the circumferential side of the work surface is horizontal.

[0023] Preferably, at least two groups of axial vibration generators are arranged at the bottom of the work surface along the horizontal direction, and the exciting force direction of the axial vibration generators at the bottom of the work surface is the vertical direction.

[0024] Beneficial effects of the present invention:

[0025] The multi-degree-of-freedom vibration test system of the present invention sets the work surface inside the test box, and adjusts the environmental factors of the cavity to simulate the real working environment of the product; when the product is subjected to the vibration test, the product is placed on the work surface, and at the same time, two sets of axial vibration generators apply two mutually perpendicular or two opposite and non-collinear excitation forces to the work surface through a ball joint device, thereby driving the work surface to perform multi-degree-of-freedom movement, so as to perform multi-degree-of-freedom composite vibration tests on the product in a real working environment, thereby meeting the vibration test requirements of various products in different environments. In addition, by setting the ball joint device between the axial vibration generator and the work surface, the installation eccentricity error can be eliminated through the spherical degree of freedom, ensuring that the excitation force is strictly transmitted along the axial direction, and avoiding additional bending moments due to machining deviations and / or assembly deviations; at the same time, the ball joint device can achieve a certain angle of deflection, and enable the work surface to translate and rotate, with more degrees of freedom. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a layout diagram of a first embodiment of a multi-degree-of-freedom vibration test system of the present invention;

[0027] Figure 2 yes Figure 1 Cross-sectional view along AA direction;

[0028] Figure 3 Schematic diagram of the force applied by the axial vibration generator when the work surface rotates around the Z axis in the first embodiment of the present invention;

[0029] Figure 4 is a cross-sectional view of the ball joint device along the axial direction of the connecting seat in the first embodiment of the present invention;

[0030] Figure 5 It is a structural diagram of the test box and the axial vibration generator in the second embodiment of the present invention.

[0031] In the picture:

[0032] 1. Test chamber; 11. Test cavity; 12. Connecting hole; 2. Work surface; 3. Axial vibration generator; 4. Ball joint device; 41. Connecting seat; 411. Ball groove; 412. First oil circuit; 42. Ball head; 421. Avoidance hole; 422. Limit groove; 43. Limit rod; 44. Limit head; 441. Through hole; 442. Second oil circuit; 45. Locking piece; 46. End cover; 47. Elastic gasket; 5. Transition device; 6. Base; 61. Mounting groove; 7. Sealing tube. DETAILED DESCRIPTION

[0033] The present invention will be further described in detail below with reference to the accompanying drawings and examples. It will be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention. It should also be noted that, for ease of description, the accompanying drawings only illustrate portions relevant to the present invention, not all structures.

[0034] In the description of the present invention, unless otherwise expressly specified or limited, the terms "connected," "connected," and "fixed" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention in specific circumstances.

[0035] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0036] In the description of this embodiment, the terms "upper," "lower," "right," and other orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely for ease of description and simplified operation. They do not indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used solely for descriptive purposes and have no special meanings.

[0037] Refer to the following Figures 1 to 5 The multi-degree-of-freedom vibration test system provided by the present invention is described. Example 1

[0038] Reference Figure 1 and Figure 2The multi-degree-of-freedom vibration test system includes a base 6, a test box 1, a work surface 2, an axial vibration generator 3 and a ball joint device 4. The test box 1 is arranged on the base 6. The test box 1 has a test cavity 11, and the environmental factors of the test cavity 11 can be adjusted. The work surface 2 is arranged inside the test box 1, and the work surface 2 is used to place products. There are at least two groups of axial vibration generators 3 outside the test box 1. The two groups of axial vibration generators 3 can generate two mutually perpendicular or two opposite and non-collinear excitation forces; the ball joint device 4 is connected between the vibration end of each axial vibration generator 3 and the work surface 2. The ball joint device 4 can transmit the excitation force of the axial vibration generator to the work surface.

[0039] As described above, when the product is subjected to vibration test, the product is placed on the work surface 2, and the environmental factors of the cavity are adjusted to simulate the real working environment of the product. At the same time, two sets of axial vibration generators 3 can apply two mutually perpendicular or two opposite and non-collinear excitation forces to the work surface, thereby driving the work surface 2 to move with two degrees of freedom. More sets of axial vibration generators 3 can drive the work surface 2 to move with more degrees of freedom through the ball joint device 4, so as to perform multi-degree-of-freedom vibration tests on the product in a real working environment, so as to meet the vibration test needs of various products in different environments and multiple degrees of freedom.

[0040] It should be noted that environmental factors refer to factors that affect the environmental conditions of the test chamber 11, such as temperature, humidity, air pressure, and light. Temperature deviations and fluctuations can affect material performance. Humidity affects the hygroscopicity and corrosiveness of materials. Materials in high humidity environments are more susceptible to moisture absorption and expansion, affecting their performance. Air pressure changes can cause variations in the concentrations of oxygen and carbon dioxide in the atmosphere, in turn affecting the material's oxidation reaction and corrosion rate. Light primarily affects the material's photoaging test. Different light sources (such as carbon arc lamps, xenon lamps, and fluorescent lamps) have different radiation characteristics, which can affect photochemical reactions such as discoloration and aging. By adjusting these environmental factors, the chamber environment can be made as close as possible to the product's actual operating environment, thereby improving the accuracy of test results.

[0041] Optionally, the specific structure of the test box 1 in this embodiment is set with reference to the environmental test box. The adjustable environmental factors include temperature, humidity and air pressure. The specific structure of the test box 1 is existing technology and will not be repeated here.

[0042] Exemplarily, the base 6 is horizontally arranged and has a mounting slot 61 on the top, the test box 1 is located directly above the mounting slot 61, and the work surface 2 is a square plate and is horizontally arranged inside the test box 1. In other embodiments, the base 6 can also be tilted to a certain extent.

[0043] Optionally, four groups of axial vibration generators 3 are sequentially arranged along the circumference of the work surface 2, and two adjacent groups of axial vibration generators 3 are perpendicular to each other, and the excitation force direction of the axial vibration generators 3 on the circumferential side of the work surface 2 is horizontal. Each group of axial vibration generators 3 includes two parallel axial vibration generators 3, that is, two axial vibration generators 3 are horizontally arranged corresponding to each side of the work surface 2. In some other embodiments, each group of axial vibration generators 3 may also include only one axial vibration generator 3. One end of each axial vibration generator 3 is fixedly connected to the base 6, and the other end is fixedly connected to the ball joint device 4.

[0044] It can be understood that a three-dimensional coordinate system is established with the center of gravity of the work table 2 as the coordinate origin, the X-axis and Y-axis of the three-dimensional coordinate system are two axes perpendicular to each other in the horizontal plane, and the Z-axis of the three-dimensional coordinate system is set along the vertical direction, that is, the four axial vibration generators 3 are set along the X-axis, and the four axial vibration generators 3 are set along the Y-axis.

[0045] When all the axial vibration generators 3 arranged along the X-axis work at the same time and the directions of the exciting forces are the same, the work table 2 can be driven to move unidirectionally along the X-axis; when all the axial vibration generators 3 arranged along the Y-axis work at the same time and the directions of the exciting forces are the same, the work table 2 can be driven to move unidirectionally along the Y-axis; and when all the above-mentioned axial vibration generators 3 work at the same time in the above-mentioned state, the work table 2 can be driven along the X-axis and the Y-axis; in this way, the work table 2 can be moved along the X-axis and / or the Y-axis.

[0046] Reference Figure 3 In addition, when the excitation forces of two coaxial axial vibration generators 3 among the four axial vibration generators 3 arranged along the X-axis are in opposite directions to those of the other two coaxial axial vibration generators 3, the work table 2 is driven to rotate about the Z-axis. Of course, when the excitation forces of two coaxial axial vibration generators 3 among the four axial vibration generators 3 arranged along the Y-axis are in opposite directions to those of the other two coaxial axial vibration generators 3, the work table 2 can also be driven to rotate about the Z-axis. Specifically in this embodiment, all horizontally arranged axial vibration generators 3 operate simultaneously as described above, thereby driving the work table 2 to rotate about the Z-axis, which can make the force on the work table 2 more uniform.

[0047] Furthermore, at least two groups of axial vibration generators 3 are provided horizontally at the bottom of the work surface 2, and the excitation force direction of the axial vibration generators 3 at the bottom of the work surface 2 is vertical. In this embodiment, two groups of axial vibration generators 3 are provided horizontally at the bottom of the work surface 2, each group having two axial vibration generators 3, and four axial vibration generators 3 are provided along the Z axis, and the four axial vibration generators 3 are evenly distributed around the Z axis.

[0048] When the axial vibration generators 3 arranged along the Z axis are simultaneously driven, they can drive the work surface 2 to move along the Z axis. If the excitation forces of the axial vibration generators 3 on both sides of the X axis are in opposite directions, the work surface 2 can be driven to rotate around the X axis. If the excitation forces of the axial vibration generators 3 on both sides of the Y axis are in opposite directions, the work surface 2 can be driven to rotate around the Y axis. In this way, the work surface 2 can move along the Z axis, rotate around the X axis, and / or rotate around the Y axis. In addition to the rotation of the work surface 2 around the Z axis, movement along the X axis, and / or movement along the Y axis, the work surface 2 ultimately has six degrees of freedom: movement along the X, Y, and Z axes, and rotation around the X, Y, and Z axes.

[0049] From the above content, it can be seen that when two groups of axial vibration generators 3 with mutually perpendicular excitation force directions are set, the work table 2 can have two degrees of freedom of motion along a straight line. When two groups of axial vibration generators 3 with opposite and non-collinear excitation force directions are set, the work table 2 can have one degree of freedom of motion along a straight line and one degree of freedom of rotation about a straight line. That is, setting two groups of axial vibration generators 3 can give the work table 2 multiple degrees of freedom, and the specific number and arrangement positions of the axial vibration generators 3 can be selected according to the needs of the test.

[0050] Furthermore, a transition device 5 is provided between the axial vibration generator 3 and the test box 1. The transition device 5 is configured to transmit the exciting force of the axial vibration generator 3 to the ball joint device 4. The transition device 5 in this embodiment is a vibration transmission device in the prior art. The transmission of the exciting force is achieved through the vibration transmission device, and the test box 1 is sealed.

[0051] Reference Figure 4 Exemplarily, the ball joint device 4 includes a connecting seat 41, a ball head 42, a limiting rod 43 and a limiting head 44. The connecting seat 41 is cylindrical and is coaxially arranged with the axial vibration generator 3. Ball grooves 411 are provided at both ends of the connecting seat 41. The inner cavity of the ball groove 411 is in the shape of a spherical crown (the part formed by the spherical surface being cut off by a plane, and its height is less than the radius of the sphere, that is, it does not reach the height of a hemisphere). A ball head 42 is rotatably provided inside each ball groove 411, and an avoidance hole 421 is provided on each ball head 42. The two ball heads 42 are respectively connected to the work table 2 and the transition device 5. The limiting rod 43 is coaxially arranged with the connecting seat 41, and the limiting rod 43 passes through the connecting seat 41. Avoidance holes 421 are extended from both ends of the limiting rod 43, and the avoidance holes 421 and the limiting rod 43 are clearance-fitted. A limiting head 44 is provided at each end of the limiting rod 43 . The side of the limiting head 44 opposite to the ball head 42 abuts against the ball head 42 , and the ball head 42 can move relative to the limiting head 44 .

[0052] Through the above-mentioned arrangement, first, the ball joint device 4 transmits the exciting force transmitted from the axial vibration generator 3 to the transition device 5 to the work surface 2, and the ball joint device 4 can realize a certain angle of deflection, and enable the work surface 2 to perform a certain translation and rotation relative to the transition device 5, so that the work surface 2 has six degrees of freedom.

[0053] Secondly, in this embodiment, the movement range of the ball head 42 is limited by the gap between the avoidance hole 421 and the limit rod 43, that is, the rotation of the ball head 42 is limited to a certain extent by the limit rod 43 to prevent the ball head 42 from excessive rotation. In this way, the movement range of the work table 2 can be controlled within a normal range to prevent the ball head 42 from getting stuck due to excessive movement range; at the same time, it can avoid the surface of the ball head 42 from being excessively exposed to a high temperature and high pressure environment, prevent the smooth surface of the ball head 42 from being corroded, and extend the service life of the ball joint device 4.

[0054] In addition, the inner cavity of the ball groove 411 is configured as a spherical crown, and there is no need to separate the connecting seat 41 into two parts for processing, which facilitates processing thereof and installation of the ball head 42 .

[0055] It is worth noting that the middle section of the limiting rod 43 corresponds to the position of the avoidance hole 421 and is arranged parallel to the side walls of the avoidance hole 421, so that when the ball head 42 rotates to the extreme position, the two parallel side walls abut against each other, preventing the edge of the avoidance hole 421 from colliding with the limiting rod 43 and causing damage to the ball head 42, thereby protecting the ball head 42.

[0056] Furthermore, a limiting groove 422 is provided on the side of the ball head 42 facing away from the connecting seat 41. The sidewall of the limiting groove 422 is parallel to the outer wall of the ball head 42, that is, the inner cavity of the limiting groove 422 is also configured in a spherical cap shape. The limiting head 44 is placed inside the limiting groove 422. The side of the limiting head 44 close to the limiting groove 422 is adapted to the sidewall of the limiting groove 422, that is, the limiting head 44 is configured in a spherical cap shape. Thus, the limiting head 44 abuts the ball head 42 against the surface of the ball groove 411. The contact area between the limiting head 44 and the ball head 42 is large, which can firmly limit the ball head 42, prevent the formation of a gap between the ball head 42 and the ball groove 411, and prevent air inside the test chamber 1 from entering between the ball head 42 and the ball groove 411. At the same time, it also prevents the ball head 42 from separating from the limiting rod 43. Optionally, in some other embodiments, the limiting head 44 may also be tubular, with an edge at one end thereof abutting against the side wall of the limiting groove 422 .

[0057] To facilitate installation and maintenance of the ball hinge assembly 4, each stopper 44 is provided with a through hole 441 along the axial direction of the stopper rod 43. Both ends of the stopper rod 43 extend through holes 441 and are detachably connected to locking members 45, which abut against the stopper 44. In this embodiment, the locking member 45 is a nut, which is threadedly connected to the end of the stopper rod 43. Thus, tightening the nut secures the stopper 44. When installing the ball hinge assembly 4, it is sufficient to install the ball head 42 and the stopper 44 in sequence, then tighten the nut. After loosening the nut, the ball head 42 and the stopper 44 can be inspected and replaced. Alternatively, in other embodiments, the locking member 45 is a nut or a locating pin.

[0058] It is worth noting that, in order to prevent the nut from loosening, an elastic gasket 47 is provided between the nut and the limiting head 44 , so that elastic force is applied to the nut by the elastic gasket 47 to prevent the nut from loosening.

[0059] Furthermore, an end cover 46 is connected to the side of each ball head 42 facing away from the connecting seat 41, and the end cover 46 covers the opening of the limiting groove 422. The end cover 46 can facilitate the connection between the ball head 42 and other components, and at the same time seal the limiting groove 422, thereby protecting the limiting head 44.

[0060] To ensure smoother rotation of the ball joint 42, a first oil passage 412 is defined within the connecting seat 41, and a second oil passage 442 is defined within the limiting head 44. The first oil passage 412 communicates with the ball groove 411, allowing lubricating oil to flow between the ball joint 42 and the ball groove 411, forming an oil film between the two. The second oil passage 442 communicates with the limiting groove 422, allowing lubricating oil to flow between the limiting head 44 and the limiting groove 422, forming an oil film between the two. This oil film lubricates the ball joint 42, giving the ball joint assembly 4 advantages such as high rigidity, good uniformity, good universality, and excellent dynamic performance. The oil film also provides excellent sealing properties, preventing gas within the test chamber 1 from entering the space between the ball joint 42 and the ball groove 411. Furthermore, the oil passage is airtight and unaffected by the air pressure and humidity within the test chamber 1. Example 2

[0061] Reference Figure 5 The difference between this embodiment and the first embodiment is that: in this embodiment, the transition device 5 is cancelled, and the axial vibration generator 3 is directly connected to the ball joint device 4. Specifically, a connecting hole 12 is opened on the test box 1 corresponding to the vibration end of each axial vibration generator 3, and the vibration end of the axial vibration generator 3 is connected to the ball joint device 4 through the connecting hole 12.

[0062] In addition, a flexible sealing tube 7 is connected between the test box 1 and the axial vibration generator 3. The sealing tube 7 is mounted on the outside of the vibration end of the axial vibration generator 3. The sealing tube 7 seals the gap between the test box 1 and the axial vibration generator 3, thereby achieving a seal inside the test box 1 to stabilize the air pressure inside the test box 1. The sealing tube 7 in this embodiment is a corrugated tube that can expand and contract to a certain extent; optionally, in other embodiments, the sealing tube 7 can also be a corrugated tube or a hose.

[0063] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention and are not intended to limit the embodiments of the present invention. A person skilled in the art would be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. Multi-degree-of-freedom vibration test system, characterized by: include: A test box (1) has a test chamber (11), wherein the environmental factors of the test chamber (11) can be adjusted; A work surface (2) is provided in the test chamber (11), and the work surface (2) is used for placing products; At least two groups of axial vibration generators (3), the two groups of axial vibration generators (3) are capable of generating two mutually perpendicular or two mutually opposite and non-collinear excitation forces, the axial vibration generators (3) being arranged outside the test box (1); and A ball joint device (4) is arranged inside the test box (1), the ball joint device (4) is arranged between the vibration end of each axial vibration generator (3) and the work surface (2), and the ball joint device (4) is capable of transmitting the exciting force of the axial vibration generator (3) to the work surface (2); The ball joint device (4) comprises: A connecting seat (41) having ball grooves (411) at both ends; A ball head (42) is rotatably provided inside each ball groove (411), and a avoidance hole (421) is provided on each ball head (42); A limiting rod (43) is provided through the connecting seat (41), and both ends of the limiting rod (43) extend out of the avoidance hole (421), and a clearance fit is formed between the avoidance hole (421) and the limiting rod (43); and A limiting head (44) is provided at each end of the limiting rod (43), and the side of the limiting head (44) opposite to the ball head (42) abuts against the ball head (42), and the ball head (42) can move relative to the limiting head (44).

2. The multi-degree-of-freedom vibration test system according to claim 1, characterized in that: The inner cavity of the ball groove (411) is arranged in the shape of a spherical crown.

3. The multi-degree-of-freedom vibration test system according to claim 2, characterized in that: A limiting groove (422) is provided on a side of the ball head (42) facing away from the connecting seat (41), the side wall of the limiting groove (422) is parallel to the outer wall of the ball head (42), and the limiting head (44) is placed inside the limiting groove (422), and the shape of the limiting head (44) is adapted to the shape of the limiting groove (422).

4. The multi-degree-of-freedom vibration test system according to claim 3, characterized in that: A through hole (441) is provided on the limiting head (44) along the axial direction of the limiting rod (43). Both ends of the limiting rod (43) extend out of the through hole (441) and are detachably connected to a locking member (45). The locking member (45) abuts against the limiting head (44).

5. The multi-degree-of-freedom vibration test system according to claim 3, characterized in that: An end cover (46) is provided on the side of the ball head (42) facing away from the connecting seat (41), and the end cover (46) covers the opening of the limiting groove (422).

6. The multi-degree-of-freedom vibration test system according to any one of claims 1 to 5, characterized in that: The environmental factors include temperature, humidity or air pressure.

7. The multi-degree-of-freedom vibration test system according to any one of claims 1 to 5, characterized in that: A transition device (5) is provided between the axial vibration generator (3) and the test box (1), and the transition device (5) is configured to transmit the exciting force of the axial vibration generator (3) to the ball joint device (4).

8. The multi-degree-of-freedom vibration test system according to any one of claims 1 to 5, characterized in that: A connection hole (12) is provided on the test box (1) at a vibration end corresponding to the axial vibration generator (3), and a flexible sealing tube (7) is provided between the test box (1) and the axial vibration generator (3), wherein the sealing tube (7) seals the connection hole (12).

9. The multi-degree-of-freedom vibration test system according to any one of claims 1 to 5, characterized in that: The work surface (2) is arranged horizontally, and four groups of axial vibration generators (3) are sequentially arranged along the circumference of the work surface (2), and two adjacent groups of axial vibration generators (3) are perpendicular to each other, and the excitation force direction of the axial vibration generators (3) on the circumferential side of the work surface (2) is horizontal.

10. The multi-degree-of-freedom vibration testing system according to claim 9, characterized in that: At least two groups of axial vibration generators (3) are arranged at the bottom of the work surface (2) along the horizontal direction, and the exciting force direction of the axial vibration generators (3) at the bottom of the work surface (2) is the vertical direction.

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