Half-sine impact test device with combined waveform generator

Abstract

The invention relates to the technical field of half-sine impact tests, in particular to a half-sine impact test device with a combined waveform generator, which comprises a base, an impacted seat, a primary waveform generator, a primary impact seat, a secondary waveform generator and a secondary impact seat, the collided seat is mounted on the top surface of the base; the primary waveform generator is mounted on the top surface of the collided seat; the primary impact seat is arranged above the top surface of the primary waveform generator in a manner of moving up and down; the secondary waveform generator is mounted on the top surface of the primary impact seat; and the secondary impact seat is arranged above the top surface of the secondary waveform generator in a manner of moving up and down. The primary impact seat moving downwards at a high speed impacts the primary waveform generator, a low-magnitude large-pulse-width half-sine impact waveform is generated on the primary impact seat, the primary impact seat moving upwards after bouncing collides with the secondary impact seat moving downwards, and the secondary waveform generator is used for generating a half-sine impact waveform on the secondary impact seat. And a high-magnitude small-pulse-width half-sine impact waveform is generated on the secondary impact seat.

Description

Technical Field

[0001] The invention relates to the technical field of half-sine impact test, and in particular to a half-sine impact test device with a combined waveform generator. Background Art

[0002] When the aircraft's mechanical structure and its electronic components are working, they are often exposed to dynamic environments such as turbulence, explosion, shock and vibration. Among them, shock refers to a high-level input force pulse acting on the equipment in a short period of time, including mechanical shock, explosion separation shock and ballistic shock. Half-sine shock is a common form of shock.

[0003] At present, the conventional half-sine impact test device can only generate a single half-sine waveform. Therefore, how to make the half-sine impact test device generate a high-level, small-pulse-width half-sine waveform while generating a low-level, large-pulse-width half-sine waveform has become a technical problem that needs to be solved urgently by those skilled in the art. Summary of the invention

[0004] The invention provides a semi-sine impact test device with a combined waveform generator, which is used to solve the problem of generating a semi-sine waveform with a high level and a small pulse width when generating a semi-sine waveform with a low level and a large pulse width.

[0005] The present invention provides a half-sine impact test device with a combined waveform generator, comprising:

[0006] Pedestal;

[0007] An impact seat is installed on the top surface of the base;

[0008] A primary waveform generator is installed on the top surface of the impact seat;

[0009] A primary impact seat is movably disposed above the top surface of the primary waveform generator;

[0010] The secondary waveform generator is installed on the top surface of the primary impact seat;

[0011] The secondary impact seat is arranged above the top surface of the secondary waveform generator in a manner that it can move up and down.

[0012] In some of the embodiments, the ratio of the weight of the primary impact seat to the weight of the secondary impact seat is equal to or greater than 10, and the bottom surface area is greater than the bottom surface area of ​​the secondary impact seat.

[0013] In some embodiments, there are multiple primary waveform generators, which are evenly installed on the top surface of the impact seat along the circumference of the impact seat;

[0014] The secondary waveform generator is one.

[0015] In some of the embodiments, each primary waveform generator is a first rubber spring;

[0016] The secondary waveform generator includes:

[0017] Second rubber spring;

[0018] The metal spring is embedded in the second rubber spring.

[0019] In some embodiments, the actual stiffness K of each primary waveform generator is m 'for:

[0020]

[0021] Among them, β 1 is the correction factor of the first rubber material, E a1 is the elastic modulus of the first rubber material, m is the number of primary waveform generators, H 1 is the axial height of each primary waveform generator, D is the outer diameter of each primary waveform generator, and d is the inner diameter of each primary waveform generator.

[0022] In some embodiments, the stiffness K of the secondary waveform generator 2 for:

[0023]

[0024] Among them, K j is the compressive stiffness of the metal spring, K x is the stiffness of the second rubber spring, E j is the elastic modulus of the metal material, I j is the section inertia moment of the metal material, X is, A j For 2 is the correction factor of the second rubber material, E a2 is the elastic modulus of the second rubber material, A x is the cross-sectional area of ​​the second rubber spring, H 2 is the axial height of the second rubber spring.

[0025] In some of these embodiments, the sum of stiffnesses of the plurality of primary waveform generators is less than the stiffness of the secondary waveform generator.

[0026] In some embodiments, it also includes:

[0027] A first guide rod, the axis of which is vertically arranged, and the bottom end of which is mounted on the top surface of the impact seat;

[0028] A first guide hole for the first guide rod to pass through is formed on the primary impact seat.

[0029] In some embodiments, it also includes:

[0030] A second guide rod, the axis of which is vertically arranged, and the bottom end of which is mounted on the top surface of the primary impact seat;

[0031] A second guide hole for the second guide rod to pass through is formed on the secondary impact seat.

[0032] In some embodiments, it also includes:

[0033] A first acceleration sensor is mounted on the primary impact seat;

[0034] The second acceleration sensor is installed on the secondary impact seat.

[0035] The beneficial effects of the present invention are as follows: the semi-sine impact test device with a combined waveform generator of the present invention is provided with a primary waveform generator, a primary impact seat, a secondary waveform generator and a secondary impact seat, and the primary impact seat moving downward at high speed hits the primary waveform generator, and in the process of the primary waveform generator recovering its deformation, a low-level large-pulse-width semi-sine impact waveform is generated on the primary impact seat, and the primary impact seat moving upward after rebound collides with the secondary impact seat moving downward, and with the help of the secondary waveform generator, a high-level small-pulse-width semi-sine impact waveform is generated on the secondary impact seat. In this way, when a low-level large-pulse-width semi-sine waveform is generated, a high-level small-pulse-width semi-sine wave can also be generated to meet the needs of a composite semi-sine impact test. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a structural schematic diagram of some specific embodiments of a half-sine impact test device with a combined waveform generator of the present invention;

[0037] Figure 2 yes Figure 1 The cross-sectional schematic diagrams of some specific embodiments of the primary waveform generator in the half-sine impact test device with a combined waveform generator are shown;

[0038] Figure 3 yes Figure 1 The cross-sectional schematic diagrams of other specific embodiments of the primary waveform generator in the half-sine impact test device with a combined waveform generator are shown;

[0039] Figure 4 yes Figure 1 The cross-sectional schematic diagrams of some specific embodiments of the secondary waveform generator in the half-sine impact test device with a combined waveform generator are shown;

[0040] Figure 5 It is a semi-sine impact waveform generated when the impact seat works;

[0041] Figure 6 It is a semi-sine impact waveform generated when the secondary impact seat is working.

[0042] In the accompanying drawings, 110 is a base; 120 is a collision seat; 130 is a primary waveform generator; 140 is a primary impact seat; 150 is a secondary waveform generator; 151 is a second rubber spring; 152 is a metal spring; 160 is a secondary impact seat; 170 is a first guide rod; and 180 is a second guide rod. DETAILED DESCRIPTION

[0043] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than 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.

[0044] As described in the background technology, the traditional half-sine impact test device can only generate a single half-sine waveform. Therefore, how to make the half-sine impact test device generate a high-level, small-pulse-width half-sine waveform while generating a low-level, large-pulse-width half-sine waveform has become a technical problem that needs to be solved urgently by those skilled in the art.

[0045] To solve the above problems, refer to Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 6The present invention provides a half-sine impact test device with a combined waveform generator, including a base 110, a hit seat 120, a primary waveform generator 130, a primary impact seat 140, a secondary waveform generator 150 and a secondary impact seat 160. The hit seat 120 is installed on the top surface of the base 110, and the hit seat 120 is supported by the base 110. The primary waveform generator 130 is detachably installed on the top surface of the hit seat 120 by bolts. The primary impact seat 140 is movably arranged above the top surface of the primary waveform generator 130. The secondary waveform generator 150 is detachably installed on the top surface of the primary impact seat 140 by bolts. The secondary impact seat 160 is movably arranged above the top surface of the secondary waveform generator 150. It should be noted that the energy of the downward impact of the primary impact seat 140 and the secondary impact seat 160 can be obtained by means of an impact cylinder or a free fall. Before the primary impact seat 140 and the secondary impact seat 160 move downward, the bottom surface of the primary impact seat 140 should be higher than the top surface of the primary waveform generator 130, and the top surface of the secondary impact seat 160 should be higher than the top surface of the secondary waveform generator 150. Corresponding test pieces can be installed on the primary impact seat 140 and the secondary impact seat 160 respectively. The primary impact seat 140 moving downward at high speed hits the primary waveform generator 130 and moves to the lowest position. In the process of the primary waveform generator 130 recovering its deformation, a low-level large-pulse-width half-sine impact waveform is generated on the primary impact seat 140, and the primary impact seat 140 moving upward after rebound collides with the secondary impact seat 160 moving downward, and with the help of the secondary waveform generator 150, a high-level small-pulse-width half-sine impact waveform is generated on the secondary impact seat 160. In this way, when a low-level large-pulse-width half-sine waveform is generated, a high-level small-pulse-width half-sine wave can also be generated to meet the requirements of the composite half-sine impact test.

[0046] Assume that the mass of the impact seat 140 is m 1 , the mass of the secondary impact seat 160 is m 2 The sum of the stiffness of the multiple primary waveform generators 130 is K 1 , the stiffness of the secondary waveform generator 150 is K 2 The duration of the pulse width of the impact seat 140 is Δt 1 The duration of the pulse width of the secondary impact seat 160 is Δt 2 , from the collision theory we know:

[0047]

[0048]

[0049] Assume that the impact magnitude required to be generated on the impact seat 140 is G 1 The impact magnitude required to be generated on the secondary impact seat 160 is G2 , the impact magnitude magnification is n, then

[0050]

[0051] Among them, μ is the amplification factor, which is related to the recovery of the waveform generator during collision. The actual measured μ is about 0.4.

[0052] In order to be more conducive to generating a low-level large-pulse-width half-sine impact waveform on the primary impact seat 140, and generating a high-level small-pulse-width half-sine impact waveform on the secondary impact seat 160, the ratio of the weight of the primary impact seat 140 to the weight of the secondary impact seat 160 should be equal to or greater than 10, and the bottom surface area should be greater than the bottom surface area of ​​the secondary impact seat 160. There are multiple primary waveform generators 130, which are evenly installed on the top surface of the impact seat 120 along the circumference of the impact seat 120. There is one secondary waveform generator 150, which is adapted to the secondary impact seat 160 with a smaller bottom surface area. The sum of the stiffness of the multiple primary waveform generators 130 should be less than the stiffness of the secondary waveform generator 150.

[0053] In some embodiments, such as Figure 2 As shown, each primary waveform generator 130 is a first rubber spring of a cylindrical structure. The material of the first rubber spring is a first rubber material. Assume that the stiffness of each primary waveform generator 130 is K m , the elastic modulus of the first rubber material is E a1 The number of the primary waveform generators 130 is m, and the axial height of each primary waveform generator 130 is H 1 , the outer diameter of each primary waveform generator 130 is D, and the inner diameter of each primary waveform generator 130 is d, then

[0054]

[0055] In fact, according to the selected rubber type, when calculating the actual stiffness of each primary waveform generator 130, a correction coefficient of the rubber material needs to be introduced. Assume that the correction coefficient of the first rubber material is β 1 , the actual stiffness of each primary waveform generator 130 is K m ',but

[0056]

[0057] In other embodiments, such as Figure 3 As shown, each primary waveform generator 130 is a first rubber spring of a cylindrical structure. At this time, d=0.

[0058] According to the elastic modulus and correction coefficient of the selected rubber material, the sum of the stiffness K of the multiple primary waveform generators 130 can be adjusted in combination with the number of primary waveform generators 130 and the size of each waveform generator. 1 .

[0059] In some embodiments, such as Figure 4 As shown, the secondary waveform generator 150 includes a second rubber spring 151 of a cylindrical structure and a metal spring 152. The metal spring 152 is embedded in the second rubber spring 151, and its cross section is a grid structure, and is integrally formed with the second rubber spring 151. In this way, the stiffness and strength of the secondary waveform generator 150 meet the requirements of high impact level and small pulse width. Assume that the stiffness of the secondary waveform generator 150 formed by the second rubber spring 151 and the metal spring 152 connected in parallel is K 2 , the compressive stiffness of the metal spring 152 is K j , the stiffness of the second rubber spring 151 is K x , the elastic modulus of metal material is E j , the cross-sectional inertia moment of the metal material is I j , X 2 dA j is the integral of the product of the area of ​​each microelement of the metal material and the square of the distance from each microelement to a specified axis on the cross section. The material of the second rubber spring 151 is the second rubber material, and the elastic modulus of the second rubber material is E a2 , the cross-sectional area of ​​the second rubber spring 151 is A x , the axial height of the second rubber spring 151 is H 2 , the correction factor of the second rubber material is β 2 ,but

[0060]

[0061] Specifically, in the exemplary embodiment, the half-sine impact test device with a combined waveform generator further includes a first guide rod 170, two second guide rods 180, a first acceleration sensor and a second acceleration sensor. The axis of the first guide rod 170 is vertically arranged, and the bottom end is detachably mounted on the top surface of the impact seat 120 by bolts. A first guide hole for the first guide rod 170 to pass through is formed on the primary impact seat 140. The first guide hole is a blind hole, and the hole depth is greater than the axial length of the first guide rod 170, which can prevent the first guide rod 170 from interfering with the movement of the secondary impact seat 160. With the help of the first guide hole and the first guide rod 170, the high-speed primary impact seat 140 can move up and down in the vertical direction, which is conducive to forming a half-sine waveform. The axes of the two second guide rods 180 are both vertically arranged, and the bottom ends are detachably mounted on the opposite sides of the top surface of the primary impact seat 140 by bolts. Second guide holes for the second guide rod 180 to pass through are respectively formed on the opposite sides of the secondary impact seat 160. The two second guide holes are through holes. With the help of the second guide holes and the second guide rod 180, the high-speed secondary impact seat 160 can move up and down in the vertical direction, which is conducive to forming a semi-sine waveform. Moreover, compared with the form of a single second guide hole, it better constrains the secondary impact seat 160 to move up and down, and prevents the secondary impact seat 160 from rotating. The first acceleration sensor is detachably mounted on the primary impact seat 140 to measure the acceleration of the primary impact seat 140. The second acceleration sensor is detachably mounted on the secondary impact seat 160 to measure the acceleration of the secondary impact seat 160.

[0062] Preferably, the first rubber material and the second rubber material are polyurethane, natural rubber or polyisoprene, etc. The metal material is copper or beryllium copper alloy, etc. The primary impact seat 140 and the secondary impact seat 160 are made of aluminum alloy. The first guide rod 170 and each second guide rod 180 are made of stainless steel, which has high strength and rigidity.

[0063] Preferably, the primary impact seat 140 is an inverted polygonal pyramid structure, and the secondary impact seat 160 is an inverted polygonal pyramid structure.

[0064] In some practical applications, the impact magnitude of the semi-sine waveform generated by the primary impact seat 140 is required to be 650g (g is the acceleration of gravity), the pulse width duration is 5ms, and the impact magnitude of the semi-sine waveform generated by the secondary impact seat 160 is required to be 3000g (g is the acceleration of gravity), and the pulse width duration is 0.12ms. The mass m of the selected primary impact seat 140 is 1 The mass of the secondary impact seat is 125kg and the mass of the secondary impact seat is 160m 2 is 12.5kg. After calculation, we can get K 1 5.4×10 7 Nm, K2 7.79×10 9 Nm. When four primary waveform generators 130 are used in the half-sine impact test, the actual stiffness of each primary waveform generator 130 should be K m ' is 1.36×10 7 Nm. Through calculation, the required actual stiffness can be obtained through the following combinations, as shown in Table 1:

[0065]

[0066] Table 1

[0067] When performing the half-sine impact test, the hardness of the first rubber material used is 85Hs, the diameter of each primary waveform generator 130 is 200mm, and the axial height of each primary waveform generator 130 is 46.8mm. The diameter of the secondary waveform generator 150 used is 165mm, and the axial height is 2.5mm. The material of the second rubber spring 151 of the secondary waveform generator 150 is polyurethane with a hardness of 75Hs, and the metal spring 152 is made of copper wire with a diameter of 1mm. The stiffness of the secondary waveform generator 150 is calculated to be 7.8×10 9 When conducting a half-sine impact test, a half-sine impact waveform with an impact magnitude of less than 825g and a pulse width duration of 5ms is generated on the impact seat 140. Figure 5 A semi-sine impact waveform with an impact magnitude greater than 3000g and a pulse width duration of 0.12ms is generated on the secondary impact seat 160, as shown in FIG. Figure 6 shown.

[0068] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0069] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0070] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0071] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0072] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A half-sine impact test device with a combined waveform generator, characterized in that: include: Pedestal; An impact seat is installed on the top surface of the base; A primary waveform generator is mounted on the top surface of the impact seat; A primary impact seat is movably disposed above the top surface of the primary waveform generator; A secondary waveform generator is mounted on the top surface of the primary impact seat; The secondary impact seat is movably arranged above the top surface of the secondary waveform generator.

2. The half-sine impact test device with a combined waveform generator according to claim 1, characterized in that: The ratio of the weight of the primary impact seat to the weight of the secondary impact seat is equal to or greater than 10, and the bottom surface area is greater than the bottom surface area of ​​the secondary impact seat.

3. The half-sine impact test device with a combined waveform generator according to claim 1, characterized in that: The primary waveform generator is multiple and evenly installed on the top surface of the impact seat along the circumference of the impact seat; There is one secondary waveform generator.

4. The half-sine impact test device with a combined waveform generator according to claim 3, characterized in that: Each of the primary waveform generators is a first rubber spring; The secondary waveform generator comprises: Second rubber spring; The metal spring is embedded in the second rubber spring.

5. The half-sine impact test device with a combined waveform generator according to claim 4, characterized in that: The actual stiffness K of each of the primary waveform generators m 'for: Where β1 is the correction coefficient of the first rubber material, E a1 is the elastic modulus of the first rubber material, m is the number of the primary waveform generators, H1 is the axial height of each of the primary waveform generators, D is the outer diameter of each of the primary waveform generators, and d is the inner diameter of each of the primary waveform generators.

6. The half-sine impact test device with a combined waveform generator according to claim 4, characterized in that: The stiffness K2 of the secondary waveform generator is: Among them, K j is the compressive stiffness of the metal spring, K x is the stiffness of the second rubber spring, E j is the elastic modulus of the metal material, I j is the section inertia moment of the metal material, X is, A j is, β2 is the correction coefficient of the second rubber material, E a2 is the elastic modulus of the second rubber material, A x is the cross-sectional area of ​​the second rubber spring, and H2 is the axial height of the second rubber spring.

7. The half-sine impact test device with a combined waveform generator according to claim 4, characterized in that: The sum of stiffnesses of the plurality of primary waveform generators is smaller than the stiffness of the secondary waveform generator.

8. The half-sine impact test device with a combined waveform generator according to any one of claims 1 to 7, characterized in that: Also includes: A first guide rod, the axis of which is vertically arranged, and the bottom end of which is mounted on the top surface of the impact seat; The primary impact seat is formed with a first guide hole for the first guide rod to pass through.

9. The half-sine impact test device with a combined waveform generator according to any one of claims 1 to 7, characterized in that: Also includes: A second guide rod, the axis of which is vertically arranged, and the bottom end of which is mounted on the top surface of the primary impact seat; The secondary impact seat is formed with a second guide hole for the second guide rod to pass through.

10. The half-sine impact test device with a combined waveform generator according to any one of claims 1 to 7, characterized in that: Also includes: A first acceleration sensor is mounted on the primary impact seat; The second acceleration sensor is installed on the secondary impact seat.

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