Test device and method for bending fatigue life of test piece based on reciprocating motion of vibration table

Abstract

The present application relates to the field of test piece life test, in particular to a test piece bending fatigue life test device and method based on the reciprocating motion of a vibration table, which mainly solves the technical problem that the existing test device cannot meet the actual test needs. The device comprises a vibration table, three connecting pieces, two rotating pieces, two fixed seats, a mounting base, a translation assembly and a sliding assembly; the first connecting piece, the first rotating piece and the second connecting piece are rotationally connected in sequence; the third connecting piece is rotationally connected with the second rotating piece; the second connecting piece and the third connecting piece are rotationally connected on the translation assembly; the first connecting piece is rotationally connected with the mounting base, which is mounted on the table surface of the vibration table; the hinge point on the second rotating piece and the sliding end of the sliding assembly are respectively connected with the test piece; the first fixed seat and the rotating piece are rotationally connected on the first rotating piece and the second rotating piece; the translation assembly, the sliding assembly, the first fixed seat and the second fixed seat are respectively mounted on the stationary mounting frame of the vibration table.

Description

Technical Field

[0001] This invention relates to a test specimen life testing device and method, specifically to a test specimen bending fatigue life testing device and method based on the reciprocating motion of a vibration table. Background Technology

[0002] When the accuracy requirements for specimen life testing are not high, engineering practice typically involves directly conducting sinusoidal fixed-frequency tests on a series of specimens using a vibration table and monitoring the strain at the easily fractured locations to obtain the strain-life curve. However, this method has the following significant drawbacks: 1) The strain at the easily fractured locations of the specimen is undesignable and requires actual testing to obtain accurately; 2) For a given type of specimen, sinusoidal vibration tests can only be conducted at one of its natural frequencies, and the strain response of the specimen is unstable; 3) During the test, the natural frequency of the specimen is prone to change, leading to repeated adjustments and checks, making it difficult to guarantee the progress. Therefore, how to utilize the existing functions of a vibration table to achieve a more designable and stable bending fatigue life test for specimens has practical engineering significance. Summary of the Invention

[0003] To address the technical problem that existing test devices and methods for testing the life of test specimens are insufficient to meet actual testing needs, this invention provides a test device and method for testing the bending fatigue life of test specimens based on the reciprocating motion of a vibration table.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: A test device for testing the bending fatigue life of a test specimen based on the reciprocating motion of a vibration table, comprising a vibration table; its special feature is that: It also includes a first connector, a first rotating component, a second connector, a third connector, a second rotating component, a mounting base, a translational assembly, a sliding assembly, a first fixed base, and a second fixed base; The first connecting member, the first rotating member, the second connecting member, and the third connecting member are all long straight rod structures, and the second rotating member is an L-shaped structure; The first connecting member, the first rotating member, and the second connecting member are rotatably connected in sequence. One end of the third connector is rotatably connected to one end of the second rotating member; The other ends of the second and third connectors are respectively rotatably connected to the two translational ends of the translational assembly; The other end of the first connector is rotatably connected to one end of the mounting base, which is mounted on the table surface of the vibration table; The other end of the second rotating component is provided with a hinge point, and the hinge point and the sliding end of the sliding component are respectively used to connect the two ends of the test piece to be tested; the sliding direction of the sliding end is parallel to the translation direction of the translation component. The first fixed base is rotatably connected to the side wall of the first rotating member near the end of the first connecting member, and the second fixed base is rotatably connected to the corner of the L-shaped structure of the second rotating member; The translational component, sliding component, first fixed seat and second fixed seat are respectively mounted on the static mounting frame of the vibration table; Define the direction of motion of the vibration table as the X-axis, and the direction perpendicular to the vibration table surface as the Y-axis; In the initial state: the length direction of the first connector, the second connector, the third connector, the long arm section of the second rotating member, the mounting base and the test piece, as well as the translation direction of the translation component and the sliding direction of the sliding component are all set along the X direction; the short arm sections of the first rotating member and the second rotating member are both set along the Y direction.

[0005] Furthermore, the translational assembly includes a slider bracket and a translational slider; The slider bracket is installed on the static mounting frame of the vibration table, and its interior is provided with a slide rail for the translational slider to slide. The translational slider is mounted on the slide rail of the slider bracket. The two ends of the translational slider along its sliding direction are the two translational ends of the translational assembly, and are rotatably connected to the other ends of the second and third connecting members, respectively.

[0006] Furthermore, the sliding assembly includes a mounting bracket and a slider body; The mounting bracket is installed on the static mounting frame of the vibration table, and its interior is provided with a slide rail for the slider body to slide. The slider body is mounted on the slide rail of the sliding assembly, and its end near the hinge point is the sliding end of the sliding assembly, which is used to connect one end of the test piece to be tested.

[0007] Furthermore, the connection point between the first rotating member and the first fixed seat is defined as the origin, the part from the origin toward the first connecting member is the short arm segment, and the direction toward the second connecting member is the long arm segment; The length ratio of the long arm segment to the short arm segment of the first rotating component and the length ratio of the long arm segment to the short arm segment of the second rotating component are both 4-6.

[0008] Furthermore, the length ratio of the long arm segment to the short arm segment of the first rotating member, and the length ratio of the long arm segment to the short arm segment of the second rotating member, are both 5.

[0009] Furthermore, the translational component, the sliding component, the first fixed seat, and the second fixed seat are respectively mounted on the static mounting frame of the vibration table by bolts, and the mounting base is fixed to the table surface of the vibration table by bolts.

[0010] Furthermore, the rotatable connection is a connection via a rotating shaft.

[0011] Meanwhile, the present invention also provides a method for testing the bending fatigue life of a test specimen based on the reciprocating motion of a vibration table, using the aforementioned test device for testing the bending fatigue life of a test specimen based on the reciprocating motion of a vibration table, characterized by comprising the following steps: Step 1: Adjust the installation position of the sliding component according to the length of the test piece to be tested, so that the distance between the sliding component and the hinge point is compatible with the length of the test piece to be tested. Step 2: Connect both ends of the test piece to the hinge point and the sliding end of the sliding assembly, respectively; Step 3: Start the vibration table. The table surface moves along the X direction, driving the first connecting member to follow the movement. Then, the second connecting member rotates through the first rotating member, the second connecting member, the translational component, and the third connecting member, thereby applying a bending moment to the test piece. Step 4: During the application of bending moment, continuously count the number of swings of the test piece and monitor the strain at the easily fractured location of the test piece. Determine whether the test piece has experienced fatigue failure based on the strain data and the appearance characteristics of the test piece. The number of swings when fatigue failure occurs is taken as the bending fatigue life of the test piece, and the test is completed.

[0012] The beneficial effects of this invention are: This invention uses connecting parts of different arm lengths and rotating parts to convert small-amplitude motion into large-amplitude motion that meets the test requirements, and uses a combination of connecting rods and translational pairs to realize the conversion between linear motion and curvilinear motion. Finally, it avoids non-bending stress generated during the bending deformation of the test piece through sliding components, hinges and other measures. Combined with a vibration table, the test piece life test device can meet the actual test needs. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of an embodiment of the test piece bending fatigue life testing device based on the reciprocating motion of a vibration table (the vibration table is not shown). Figure 2 This is a schematic diagram of the translational component in an embodiment of the present invention; Figure 3 This is a schematic diagram of the sliding component in an embodiment of the present invention.

[0014] The attached figures are labeled as follows: 01-Test specimen; 1-First connecting member, 2-First rotating member, 3-Second connecting member, 4-Third connecting member, 5-Second rotating member, 6-Mounting base, 7-Translation assembly, 71-Slider bracket, 72-Translation slider; 8-Sliding assembly, 81-Mounting bracket, 82-Slider body; 9-First fixed seat, 10-Second fixed seat, 11-Hinge point. Detailed Implementation

[0015] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings and embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0016] like Figure 1 As shown in the figure, the present invention provides a test device and method for testing the bending fatigue life of a test piece based on the reciprocating motion of a vibration table, which mainly includes a vibration table, a first connecting member 1, a first rotating member 2, a second connecting member 3, a third connecting member 4, a second rotating member 5, a mounting base 6, a translational component 7, a sliding component 8, a first fixed seat 9, and a second fixed seat 10.

[0017] Among them, the first connecting member 1, the first rotating member 2, the second connecting member 3 and the third connecting member 4 are all long straight structures, and the second rotating member 5 is an L-shaped structure; The mounting base 6 is fixed to the table surface of the vibration table with bolts, and the length of the mounting base is set along the movement direction of the vibration table surface. The movement direction of the vibration table surface is the X direction, and the vertical direction is the Y direction.

[0018] In its initial state, the first connecting member 1 is positioned along the X direction, with its two ends connected to the mounting base 6 and one end of the first rotating member 2 respectively via rotating shafts, thereby converting the linear motion of the platform into the curved motion of one end of the first rotating member 2.

[0019] The first rotating component 2 is initially positioned along the Y-axis to ensure the most efficient transmission of motion amplitude. The first mounting base is mounted on the side wall of the first rotating component 2 via a rotating shaft. The first mounting base is located near one end of the first rotating component 2, dividing it into a short arm segment and a long arm segment, with a ratio of 4-6. This ensures relatively low stress levels during the movement of both the long and short arms, providing sufficient structural fatigue safety margin, while also providing sufficient motion amplification to meet the expected design requirements. The larger the ratio of the long arm segment to the short arm segment, the more significant the conversion of small-amplitude vibration table movements into large-amplitude movements. In this embodiment, a ratio of 5 is recommended to achieve the conversion of the first rotating component 2 from small-amplitude curvilinear motion of the short arm segment to amplified curvilinear motion of the long arm segment. Simultaneously, the first mounting base is fixed to the stationary mounting frame of the vibration table with bolts.

[0020] The second connecting member 3 is set along the X direction in the initial state, and its two ends are respectively connected to one of the translational ends of the long arm segment of the first rotating member 2 and the translational component 7 through a rotating shaft, so as to realize the curvilinear motion of the long arm segment of the first rotating member 2 into the linear motion of the translational component 7.

[0021] The two translational ends of the translational component 7 can slide freely in the X direction.

[0022] Specifically, the translation component 7 includes a slider bracket 71 and a translation slider 72; the slider bracket 71 is mounted on the static mounting frame of the vibration table, and a slide rail for the translation slider 72 to slide is provided inside it; the translation slider 72 is mounted on the slide rail of the slider bracket 71, and the two ends of the translation slider 72 along its sliding direction are the two translation ends of the translation component 7.

[0023] The third connecting member 4 is set along the X direction in the initial state. Its two ends are connected to the other translational end of the translational component 7 and the short arm end of the second rotating member 5 through a rotating shaft, so as to realize the linear motion of the translational slider 72 into the curvilinear motion of the short arm segment of the second rotating member 5.

[0024] The greater the ratio of the length of the long arm to the length of the short arm of the second rotating component 5, the more significant the motion amplification effect. It is recommended to set the ratio to 5 here, so as to realize the transformation of the small-amplitude curved motion of the short arm segment to the amplified curved motion of the long arm segment of the second rotating component 5.

[0025] The second fixed seat 10 is connected to the bend of the second rotating member 5 by rotation and is fixed to the static mounting frame of the vibration table by bolts.

[0026] The other end of the second rotating member 5 is provided with a hinge point 11, which is used to connect the end of the test piece 01 to be tested, so that the large-scale movement of the long arm section of the second rotating member 5 can act on the end of the test piece 01 and release the corresponding bending moment, ensuring that the root of the fixed end of the test piece 01 can generate the expected bending stress.

[0027] Preferably, the dimensions of the first rotating component 2 and the second rotating component 5 are designed to ensure that the stress levels of the long and short arms are sufficiently low during operation, thereby providing a sufficient structural fatigue safety margin. They also need to have sufficient rigidity to ensure that no significant elastic vibration occurs during operation, thus preventing a reduction in their performance.

[0028] The sliding section of the sliding assembly 8 can slide freely in the X direction, avoiding the generation of non-bending stress. Specifically, the sliding assembly 8 includes a mounting bracket 81 and a slider body 82; the mounting bracket 81 is mounted on the static mounting frame of the vibration table, and its interior is provided with a slide rail for the slider body 82 to slide; the slider body 82 is mounted on the slide rail of the sliding assembly 8, and its end near the hinge point 11 is the sliding end of the sliding assembly 8, which is used to connect to the root of the fixed end of the test piece 01 to be tested, and during connection, the test piece 01 can be tightened and reliably fixed by screws.

[0029] During testing, the specific steps are as follows: Step 1: Adjust the installation position of the sliding component 8 according to the length of the test piece 01 to be tested, so that the distance between the sliding component 8 and the hinge point 11 is adapted to the length of the test piece 01 to be tested. Step 2: Connect both ends of the test piece 01 to the hinge point 11 and the sliding end of the sliding assembly 8, respectively; Step 3: Start the vibration table. The table surface moves along the X direction, driving the first connecting piece 1 to follow the movement. Then, the other end of the second rotating piece 5 is driven to rotate through the first rotating piece 2, the second connecting piece 3, the translational component 7, and the third connecting piece 4 in sequence, thereby applying a bending moment to the test piece 01. Step 4: During the application of bending moment, continuously count the number of swings of test piece 01 and monitor the strain at the fracture location of test piece 01. Determine whether test piece 01 has experienced fatigue failure based on the strain data and appearance characteristics of test piece 01. The number of swings when fatigue failure occurs is taken as the bending fatigue life corresponding to test piece 01, and the test is completed.

[0030] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions within the technical scope disclosed in the present invention should be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A test device for testing the bending fatigue life of a test specimen based on the reciprocating motion of a vibration table, comprising a vibration table; Its features are: It also includes a first connector (1), a first rotating component (2), a second connector (3), a third connector (4), a second rotating component (5), a mounting base (6), a translational assembly (7), a sliding assembly (8), a first fixed seat (9), and a second fixed seat (10); The first connecting member (1), the first rotating member (2), the second connecting member (3) and the third connecting member (4) are all long straight rod structures, and the second rotating member (5) is an L-shaped structure; The first connecting member (1), the first rotating member (2), and the second connecting member (3) are rotatably connected in sequence; One end of the third connector (4) is rotatably connected to one end of the second rotating member (5); The other ends of the second connector (3) and the third connector (4) are respectively rotatably connected to the two translational ends of the translational assembly (7); The other end of the first connector (1) is rotatably connected to one end of the mounting base (6), which is mounted on the table surface of the vibration table; The other end of the second rotating member (5) is provided with a hinge point (11), and the hinge point (11) and the sliding end of the sliding component (8) are respectively used to connect the two ends of the test piece (01) to be tested; the sliding direction of the sliding end is parallel to the translation direction of the translation component (7). The first fixed seat (9) is rotatably connected to the side wall of the first rotating member (2) near the end of the first connecting member (1), and the second fixed seat (10) is rotatably connected to the corner of the L-shaped structure of the second rotating member (5). The translation component (7), sliding component (8), first fixed seat (9) and second fixed seat (10) are respectively installed on the static mounting frame of the vibration table; Define the direction of motion of the vibration table as the X-axis, and the direction perpendicular to the vibration table surface as the Y-axis; In the initial state: the long arm sections of the first connector (1), the second connector (3), the third connector (4), the second rotating member (5), the mounting base (6), and the test piece (01) are all set along the X direction, as are the translational direction of the translational component (7) and the sliding direction of the sliding component (8); the short arm sections of the first rotating member (2) and the second rotating member (5) are all set along the Y direction.

2. The test device for testing the bending fatigue life of a test piece based on the reciprocating motion of a vibration table according to claim 1, characterized in that: The translational assembly (7) includes a slider bracket (71) and a translational slider (72); The slider bracket (71) is installed on the static mounting frame of the vibration table, and a slide rail is provided inside for the translational slider (72) to slide. The translational slider (72) is mounted on the slide rail of the slider bracket (71). The two ends of the translational slider (72) along its sliding direction are the two translational ends of the translational assembly (7), and are rotatably connected to the other ends of the second connector (3) and the third connector (4), respectively.

3. The test device for testing the bending fatigue life of a test piece based on the reciprocating motion of a vibration table according to claim 2, characterized in that: The sliding assembly (8) includes a mounting bracket (81) and a slider body (82); The mounting bracket (81) is mounted on the static mounting frame of the vibration table, and a slide rail is provided inside for the slider body (82) to slide. The slider body (82) is mounted on the slide rail of the sliding assembly (8), and its end near the hinge point (11) is the sliding end of the sliding assembly (8), which is used to connect one end of the test piece (01) to be tested.

4. The test device for testing the bending fatigue life of a test specimen based on the reciprocating motion of a vibration table according to any one of claims 1-3, characterized in that: The connection point between the first rotating member (2) and the first fixed seat (9) is defined as the origin. The part from the origin toward the first connecting member (1) is the short arm segment, and the part toward the second connecting member (3) is the long arm segment. The length ratio of the long arm segment to the short arm segment of the first rotating member (2) and the length ratio of the long arm segment to the short arm segment of the second rotating member (5) are both 4-6.

5. The test device for testing the bending fatigue life of a test piece based on the reciprocating motion of a vibration table according to claim 4, characterized in that: The length ratio of the long arm segment to the short arm segment of the first rotating member (2) and the length ratio of the long arm segment to the short arm segment of the second rotating member (5) are both 5.

6. The test device for testing the bending fatigue life of a test specimen based on the reciprocating motion of a vibration table according to claim 4, characterized in that: The translation component (7), sliding component (8), first fixed seat (9) and second fixed seat (10) are respectively installed on the static mounting frame of the vibration table by bolts, and the mounting base (6) is fixed to the table surface of the vibration table by bolts.

7. The test device for testing the bending fatigue life of a test piece based on the reciprocating motion of a vibration table according to claim 1, characterized in that: The rotatable connection is a connection via a rotating shaft.

8. A method for testing the bending fatigue life of a test specimen based on the reciprocating motion of a vibration table, using the testing device for testing the bending fatigue life of a test specimen based on the reciprocating motion of a vibration table as described in any one of claims 1-7, characterized in that, Includes the following steps: Step 1: Adjust the installation position of the sliding component (8) according to the length of the test piece (01) to be tested, so that the distance between the sliding component (8) and the hinge point (11) is compatible with the length of the test piece (01) to be tested. Step 2: Connect the two ends of the test piece (01) to the hinge point (11) and the sliding end of the sliding assembly (8) respectively; Step 3: Start the vibration table. The table surface moves along the X direction, driving the first connecting piece (1) to follow the movement. Then, the other end of the second rotating piece (5) is driven to rotate through the first rotating piece (2), the second connecting piece (3), the translational component (7), and the third connecting piece (4) in sequence, thereby applying a bending moment to the test piece (01). Step 4: During the application of bending moment, continuously count the number of swings of the test piece (01) and monitor the strain at the easily fractured position of the test piece (01). Determine whether the test piece (01) has fatigue failure based on the strain data and the appearance characteristics of the test piece (01). The number of swings when fatigue failure occurs is taken as the bending fatigue life of the test piece (01) to complete the test.

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