A free vibration test platform

Abstract

The present application discloses a free vibration test platform, which relates to the technical field of vibration testers and is used to realize the drawing of stress-strain curves of SMA. The free vibration test platform includes a table assembly, a distance measuring assembly and a test assembly; the test assembly is arranged on the table assembly and freely vibrates on the table assembly; the distance measuring assembly is arranged on the side of the table assembly and directly faces the test assembly, and can measure and record the distance change of the test assembly during the free vibration process. The embodiment of the present invention uses the test assembly to vibrate freely on the table assembly, and the distance measuring assembly measures and records the movement distance of the repeatedly vibrating test assembly, thereby realizing the drawing of the free vibration curve of the test piece, i.e., SMA, and analyzing the factors affecting the damping capacity of SMA.

Description

Technical Field

[0001] The present application relates to the technical field of vibration testers, and in particular to a free vibration test platform. Background Art

[0002] Shape memory alloys (SMA) are materials composed of two or more metal elements that have shape memory effect (SME) through thermoelasticity and martensitic phase transformation and its inversion. Shape memory alloys are the best shape memory materials. So far, more than 50 alloys with shape memory effect have been found. There are many successful examples of their application in the aerospace field. The huge antennas on artificial satellites can be made of shape memory alloys.

[0003] An important property of shape memory alloys is pseudoelasticity (also known as superelasticity), which means that under external forces, shape memory alloys have a much greater ability to recover from deformation than ordinary metals, that is, the large strain generated during loading will recover with unloading. This property has been widely used in medicine, building shock absorption and daily life.

[0004] The three most important factors that affect the free vibration of SMA are: mass block weight, initial displacement of mass block and SMA pre-strain. Therefore, it is necessary to control variables to draw the free vibration curve of SMA. Summary of the invention

[0005] The embodiment of the present application provides a free vibration test platform to achieve the drawing of the free vibration curve of the SMA.

[0006] An embodiment of the present invention provides a free vibration test platform, comprising a table top component, a distance measuring component and a test component; the test component is arranged on the table top component and freely vibrates on the table top component; the distance measuring component is arranged on the side of the table top component and faces the test component, and can measure and record the distance change of the test component during the free vibration process.

[0007] In one possible implementation, the table top assembly includes a platform base plate, support legs and limit holes; the multiple support legs are respectively connected to the four corners of the lower surface of the platform base plate; the multiple groups of limit holes are arranged at equal intervals along the longitudinal symmetry axis of the platform base plate, and are symmetrical relative to the transverse symmetry axis of the platform base plate.

[0008] In a possible implementation, the test assembly includes a mass block, a test piece and a wire pressing block; the test piece passes through the mass block, and two ends of the test piece are respectively connected to a wire pressing block; the mass block is arranged at the symmetry center of the test piece; the two wire pressing blocks are respectively connected to the limit holes symmetrical with respect to the transverse symmetry axis of the platform bottom plate.

[0009] In a possible implementation, the mass block is cylindrical, and a side surface of the mass block is disposed on an upper surface of the platform bottom plate.

[0010] In a possible implementation, a steel plate is laid on the platform bottom plate below the mass block; the height of the hole of the mass block for the test piece to pass through from the upper surface of the platform bottom plate is the same as the height of the position where the test piece is connected to the wire pressing block from the upper surface of the platform bottom plate.

[0011] In a possible implementation, the distance measuring assembly includes a distance measuring device bracket and a laser distance measuring device; the distance measuring device bracket is connected to the longitudinal side of the platform bottom plate; the laser distance measuring device is arranged on the distance measuring device bracket and faces the mass block.

[0012] In one possible implementation, a free vibration test platform also includes an electromagnetic component; the electromagnetic component includes a bracket and an electromagnet; the bracket is connected to the side of the platform base plate and extends above the platform base plate; the electromagnet is connected to the bracket and faces above the mass block.

[0013] In one possible implementation, a free vibration test platform also includes an electromagnetic component; the electromagnetic component includes a support and an electromagnet; the support is connected to the upper surface of the platform base plate and is arranged close to the side of the platform base plate; the electromagnet is connected to the support and faces the side of the mass block.

[0014] One or more technical solutions provided in the embodiments of the present invention have at least the following technical effects or advantages:

[0015] The embodiment of the present invention allows the test component to vibrate freely on the table component, and the distance measuring component measures and records the movement distance of the repeatedly vibrating test component, thereby achieving the drawing of the free vibration curve of the test piece, i.e., SMA, and analyzing the factors affecting the damping capacity of the SMA. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments of the present invention or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 A structural schematic diagram of a free vibration test platform provided in an embodiment of the present application;

[0018] Figure 2 Another structural schematic diagram of a free vibration test platform provided in an embodiment of the present application.

[0019] Figure numerals: 11 - platform bottom plate; 12 - support foot; 21 - bracket; 22 - electromagnet; 23 - support; 13 - limit hole; 31 - rangefinder bracket; 32 - laser rangefinder; 41 - mass block; 42 - piece to be tested; 43 - wire pressing block. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] In the description of the embodiments of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, rather than indicating or implying that the devices or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limitations on the present invention. The terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance. In addition, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present invention can be understood according to the specific circumstances.

[0022] This embodiment provides a free vibration test platform. Please refer to the accompanying drawings in the specification. Figure 1 and Figure 2 .

[0023] Reference Figure 1 As shown, a free vibration test platform includes a table assembly, a distance measuring assembly and a test assembly; the test assembly is arranged on the table assembly and freely vibrates on the table assembly; the distance measuring assembly is arranged on the side of the table assembly and faces the test assembly, and can measure and record the distance change of the test assembly during the free vibration process.

[0024] The embodiment of the present invention allows the test component to vibrate freely on the table component, and the distance measuring component measures and records the movement distance of the repeatedly vibrating test component, thereby achieving the drawing of the free vibration curve of the test piece, i.e., SMA, and analyzing the factors affecting the damping capacity of the SMA.

[0025] Specifically, the table top assembly includes a platform base plate 11, support legs 12 and limiting holes 13; multiple support legs 12 are respectively connected to the four corners of the lower surface of the platform base plate 11; multiple groups of limiting holes 13 are arranged at equal intervals along the longitudinal symmetry axis of the platform base plate 11, and are symmetrical relative to the transverse symmetry axis of the platform base plate 11.

[0026] The support legs 12 are used to support the platform bottom plate 11, and the support legs 12 can be adjusted to ensure that the platform bottom plate 11 is level. Each group of limit holes 13 includes two, which are arranged along the longitudinal symmetry axis of the platform bottom plate 11 and are symmetrical with respect to the transverse symmetry axis of the platform bottom plate 11. The distances between each group of limit holes 13 on the same side are equal, and they are used to fix the test assembly and adjust the prestrain of the test assembly.

[0027] Specifically, the test assembly includes a mass block 41, a test piece 42 and a wire pressing block 43; the test piece 42 passes through the mass block 41, and the two ends of the test piece 42 are respectively connected to a wire pressing block 43; the mass block 41 is set at the symmetry center of the test piece 42; the two wire pressing blocks 43 are respectively connected to the limit holes 13 symmetrical with respect to the transverse symmetry axis of the platform bottom plate 11.

[0028] The mass block 41 is arranged at the symmetric center of the test piece 42 and can pull the test piece 42 to deform. The two ends of the test piece 42 are respectively connected to a wire pressing block 43, and the two wire pressing blocks 43 are respectively fixed in the symmetrical limiting holes 13 on both sides of the platform bottom plate 11.

[0029] The mass block 41 is stretched perpendicularly to the test piece 42 to deform the test piece 42, and the test piece 42 is released, and the test piece 42 is repeatedly loaded and unloaded. Since SMA has good damping characteristics, its stress-strain curve will form a hysteresis loop to dissipate the energy of mechanical loading.

[0030] By replacing the mass block 41, the weight of the mass block 41 can be changed; by adjusting the initial position of the mass block 41, the initial offset of the mass block 41 can be changed; by adjusting the positions of the two pressing blocks 43 in the limiting holes 13, the SMA prestrain can be changed.

[0031] Under the premise that other variables remain unchanged, a single variable is changed, and the distance measuring component can measure the distance change during the repeated movement of the mass block 41 and draw the stress-strain curve of the SMA.

[0032] Reference Figure 1 As shown, the mass block 41 is cylindrical, and the side surface of the mass block 41 is arranged on the upper surface of the platform bottom plate 11 .

[0033] The mass block 41 rolls on the platform bottom plate 11 , reducing or even eliminating the influence of gravity on the mass block 41 .

[0034] A steel plate is laid on the platform bottom plate 11 below the mass block 41; the height of the hole of the mass block 41 for the test piece 42 to pass through from the upper surface of the platform bottom plate 11 is the same as the height of the position where the test piece 42 is connected to the wire pressing block 43 from the upper surface of the platform bottom plate 11.

[0035] The platform bottom plate 11 below the mass block 41 is paved with a steel plate to ensure that the platform bottom plate 11 in the moving area of ​​the mass block 41 is smooth and reduce the friction between the mass block 41 and the platform bottom plate 11. The platform bottom plate 11 in the non-moving area of ​​the mass block 41 may not be provided with a steel plate to reduce the cost and save costs.

[0036] The steel plate can be embedded in the platform bottom plate 11 or arranged on the upper surface of the platform bottom plate 11. The test piece 42 passes through the center of the mass block 41, and both ends are fixed on the wire pressing block 43 to ensure that the test piece 42 is kept at the same height without bending.

[0037] Continue to refer to Figure 1 As shown, the distance measuring assembly includes a distance measuring device bracket 31 and a laser distance measuring device 32; the distance measuring device bracket 31 is connected to the longitudinal side of the platform bottom plate 11; the laser distance measuring device 32 is arranged on the distance measuring device bracket 31 and faces the mass block 41. The distance measuring device bracket 31 is connected to the side of the platform bottom plate 11, and is used to fix and support the laser distance measuring device 32. The laser distance measuring device 32 faces the movement direction of the mass block 41. When the mass block 41 moves repeatedly, the laser distance measuring device 32 measures the change in the distance between the mass block 41 and the laser distance measuring device 32. The free vibration curve of the SMA is drawn according to the movement trajectory of the mass block 41, and the factors affecting the damping capacity of the SMA are analyzed.

[0038] Reference Figure 2As shown, a free vibration test platform also includes an electromagnetic component; the electromagnetic component includes a bracket 21 and an electromagnet 22; the bracket 21 is connected to the side of the platform base plate 11 and extends above the platform base plate 11; the electromagnet 22 is connected to the bracket 21 and faces above the mass block 41.

[0039] The bracket 21 is connected to the side of the platform base plate 11 opposite to the ranging component. The bracket 21 extends above the platform base plate 11. The electromagnet 22 is suspended above the mass block 41 through the bracket 21. The magnetic attraction of the electromagnet 22 is adjusted to balance the gravity of the mass block 41 and reduce the friction effect between the mass block 41 and the platform base plate 11 caused by the gravity.

[0040] Reference Figure 1 As shown, a free vibration test platform also includes an electromagnetic component; the electromagnetic component includes a support 23 and an electromagnet 22; the support 23 is connected to the upper surface of the platform base plate 11 and is arranged close to the side of the platform base plate 11; the electromagnet 22 is connected to the support 23 and faces the side of the mass block 41.

[0041] The support 23 is arranged on the upper surface of the platform bottom plate 11, and the electromagnet 22 is installed on the side of the support 23 close to the mass block 41 for adsorbing the electromagnet 22. At the beginning of the experiment, the mass block 41 is moved to the electromagnet 22, the electromagnet 22 is powered on, the mass block 41 is fixed, the laser rangefinder 32 is turned on, the electromagnet 22 is powered off, and the mass block 41 is allowed to vibrate freely.

[0042] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other. Each embodiment focuses on the differences from other embodiments.

[0043] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit the present application. Although the present application has been described in detail with reference to the aforementioned embodiments, a person of ordinary skill in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some or all of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the present application.

Claims

1. A free vibration test platform, characterized in that: Including table assembly, distance measuring assembly and testing assembly; The test assembly is arranged on the table assembly and vibrates freely on the table assembly; The distance measuring component is arranged at the side of the table component and directly facing the test component, and can measure and record the distance change of the test component during the free vibration process, thereby realizing the drawing of the free vibration curve of the test piece, i.e., SMA, and analyzing the factors affecting the damping capacity of SMA; The table top assembly comprises a platform bottom plate (11), supporting feet (12) and limiting holes (13); The plurality of support legs (12) are respectively connected to the four corners of the lower surface of the platform bottom plate (11); The plurality of groups of limiting holes (13) are arranged at equal intervals along the longitudinal axis of symmetry of the platform bottom plate (11), and are symmetrical with respect to the transverse axis of symmetry of the platform bottom plate (11); The test assembly comprises a mass block (41), a test piece (42) and a wire pressing block (43); The test piece (42) passes through the mass block (41), and two ends of the test piece (42) are respectively connected to one of the wire pressing blocks (43); The mass block (41) is arranged at the symmetry center of the object to be tested (42); The two wire pressing blocks (43) are respectively connected to the limiting holes (13) symmetrical with respect to the transverse symmetry axis of the platform bottom plate (11); The mass block (41) is stretched perpendicularly to the test piece (42) to deform the test piece (42), and the test piece (42) is loosened, so that the test piece (42) undergoes repeated loading and unloading processes; By replacing the mass block (41), the weight of the mass block (41) can be changed; by adjusting the initial position of the mass block (41) for stretching, the initial offset of the mass block (41) can be changed; and by adjusting the positions of the two pressing blocks (43) in the limiting holes (13), the pre-strain of the SMA can be changed.

2. The free vibration test platform according to claim 1, characterized in that: The mass block (41) is cylindrical, and the side surface of the mass block (41) is arranged on the upper surface of the platform bottom plate (11).

3. The free vibration test platform according to claim 1, characterized in that: A steel plate is laid on the platform bottom plate (11) below the mass block (41); The height of the hole of the mass block (41) through which the test piece (42) passes from the upper surface of the platform bottom plate (11) is the same as the height of the position where the test piece (42) is connected to the wire pressing block (43) from the upper surface of the platform bottom plate (11).

4. The free vibration test platform according to claim 1, characterized in that: The distance measuring assembly comprises a distance measuring device support (31) and a laser distance measuring device (32); The rangefinder bracket (31) is connected to the longitudinal side of the platform bottom plate (11); The laser rangefinder (32) is arranged on the rangefinder bracket (31) and faces the mass block (41).

5. The free vibration test platform according to claim 1, characterized in that: Also included are electromagnetic components; The electromagnetic assembly comprises a bracket (21) and an electromagnet (22); The bracket (21) is connected to the side of the platform bottom plate (11) and extends above the platform bottom plate (11); The electromagnet (22) is connected to the bracket (21) and faces upward of the mass block (41).

6. The free vibration test platform according to claim 1, characterized in that: Also included are electromagnetic components; The electromagnetic assembly comprises a support (23) and an electromagnet (22); The support (23) is connected to the upper surface of the platform bottom plate (11) and is arranged close to the side edge of the platform bottom plate (11); The electromagnet (22) is connected to the support (23) and faces the side of the mass block (41).

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