Design method of shock response spectrum simulation device for air cannon shock test

Abstract

The present invention provides a design method for an impact response spectrum simulation device for an air cannon impact test. According to the pyrotechnic impact test conditions and the parameter information of the test piece, a three-dimensional solid model of the simulation device is established and simulation calculation is performed to obtain a response spectrum curve; then the first parameter, the second parameter and the projectile incident speed of the simulation device are adjusted and iteratively optimized in turn until the simulation calculation result is close to the pyrotechnic impact test conditions; at the same time, based on the projectile incident speed and the third parameter of the simulation device, the corresponding air cannon air chamber pressure is calculated; the three-dimensional solid model is debugged and verified by simulation test to determine the design information of each parameter of the simulation device. In this way, the present invention can achieve high-precision control of the impact response spectrum shape in a wide range and high-efficiency design of the simulation device, greatly shorten the cycle of the air cannon impact test, and has high engineering application value.

Description

Technical Field

[0001] The invention relates to the technical field of aerospace product testing, and in particular to a design method for a shock response spectrum simulation device for an air cannon shock test and a shock response spectrum simulation device. Background Art

[0002] The pyrotechnic shock environment of a spacecraft is one of the most harsh dynamic environments experienced by precision equipment on board. The shock environment usually causes damage or failure to the precision equipment, reducing the service life and reliability of the equipment. Therefore, spacecraft products need to undergo ground shock tests before launch to assess the product's impact resistance.

[0003] The pyrotechnic shock environment of spacecraft is a complex shock environment with the following main features: (1) short duration, generally within 20ms; (2) high acceleration amplitude, generally in the range of 1000-10000g; (3) high frequency and wide range, generally in the range of 100Hz-4000Hz. With the increasing size of spacecraft structures and complexity of missions, the impact force of the pyrotechnic devices used to unlock is getting bigger and bigger, the magnitude of pyrotechnic shock tests of spacecraft products is constantly increasing, and the range of shock response spectrum characteristics (such as low-frequency slope, inflection point frequency, etc.) is also getting wider and wider. The shock response spectrum with large low-frequency slope (such as +12dB / Oct) and high inflection point frequency (such as 2000Hz) is increasingly used in actual engineering practice, which has exceeded the capability of traditional mechanical shock test equipment.

[0004] In view of the above-mentioned characteristics of the pyrotechnic shock environment, a pyrotechnic shock response spectrum simulation device based on air cannon excitation is required. Its basic principle is to use air cannon to excite the projectile to hit the resonant structure to produce a resonant response, and the fundamental frequency of the resonant structure matches the inflection point frequency of the shock response spectrum, thereby realizing the simulation of the shock environment. The design idea is to adjust the shock response spectrum by changing the parameters of the device, so as to simulate the complex oscillation shock generated by the explosion of spacecraft pyrotechnics more realistically, and meet the requirements in both frequency range and magnitude.

[0005] In specific engineering practice, customized design of test simulation devices is required to meet different requirements for shock response spectrum simulation. Since there are many designable parameters for air cannon shock test devices, and the effects of various parameters on the shock response spectrum are different, in order to design the test device efficiently and accurately, a design method for a pyrotechnic shock response spectrum simulation device for air cannon shock test is urgently needed. Summary of the invention

[0006] In view of the above-mentioned defects, the purpose of the present invention is to provide a design method for an impact response spectrum simulation device for air cannon impact test, which can achieve high-precision control of the impact response spectrum shape in a wide range and high-efficiency design of the simulation device, greatly shorten the cycle of the air cannon impact test, and has high engineering application value.

[0007] In order to achieve the above object, the present invention provides a design method for a shock response spectrum simulation device for an air cannon shock test, comprising the steps of:

[0008] According to the pyrotechnic impact test conditions and the parameter information of the test piece, a three-dimensional solid model of a simulation device including the test piece is established, and the three-dimensional solid model is simulated and calculated based on the display dynamics analysis software to obtain a response spectrum curve at a corresponding position of a response plate of the simulation device;

[0009] Through numerical simulation calculations, the inflection point frequency and low-frequency slope of the corresponding position of the response plate of the simulation device under multiple different first parameter conditions are obtained respectively; and based on the pyrotechnic impact test conditions and various simulation calculation results, the first target parameter of the simulation device is determined; wherein the first parameter is the thickness of the loading plate of the simulation device and the distribution of the positioning holes;

[0010] According to the difference between the simulation calculation result of the first target parameter and the pyrotechnic impact test condition, the second parameter of the simulation device is adjusted and the simulation calculation of the inflection point frequency and the low-frequency slope is performed until the second target parameter of the simulation device is determined; wherein the second parameter is the diameter and length of the connecting rod of the simulation device;

[0011] Calculating the projectile incident velocity corresponding to the simulation device based on the high-frequency amplitude preset in the pyrotechnic impact test condition;

[0012] The first target parameter, the second target parameter and the parameter combination of the projectile incidence velocity are simulated and calculated and iteratively processed until the differences between the inflection point frequency, the low-frequency slope and the high-frequency amplitude and the pyrotechnic impact test conditions respectively meet the test tolerance requirements, thereby obtaining a target parameter combination;

[0013] The corresponding air gun chamber pressure is calculated according to the projectile incident speed in the target parameter combination and the third parameter of the simulation device; wherein the third parameter includes the inner diameter area of ​​the gun barrel or the cross-sectional area of ​​the projectile, and the gun barrel length or the projectile incident length;

[0014] According to the target parameter combination and the air gun chamber pressure, the three-dimensional solid model is debugged and verified by simulation test to determine the design information of various parameters of the simulation device.

[0015] Furthermore, before the step of performing simulation test debugging and verification on the three-dimensional solid model according to the target parameter combination and the air gun chamber pressure, the step further includes:

[0016] The high-frequency component of the response spectrum curve is adjusted by adjusting the fourth parameter of the simulation device; wherein the fourth parameter is the size specification of the incident rod and the material of the end of the incident rod.

[0017] Furthermore, the step of performing simulation calculation on the three-dimensional solid model based on display dynamics analysis software to obtain a response spectrum curve at a corresponding position of the simulation device response plate includes:

[0018] Meshing the three-dimensional solid model, setting boundary conditions and initial conditions;

[0019] The three-dimensional solid model is simulated and calculated using display dynamics analysis software to obtain a response spectrum curve at a corresponding position of a response plate of the simulation device.

[0020] Furthermore, the step of determining the first target parameter of the simulation device based on the pyrotechnic impact test conditions and various simulation calculation results includes:

[0021] respectively determining the difference between each of the simulation calculation results and the pyrotechnic impact test conditions;

[0022] The first parameter corresponding to the simulation calculation result with the smallest difference is determined as the first target parameter of the simulation device.

[0023] Furthermore, the relationship between the second parameter, the inflection point frequency and the low-frequency slope is as follows:

[0024] f=a1l 2 +a2l+a3;

[0025] k = b1expb2D;

[0026] Among them, f is the inflection point frequency, k is the low-frequency slope, l is the length of the connecting rod in the second parameter, D is the diameter of the connecting rod in the second parameter, and a1, a2, a3, b1, and b2 are all unknown coefficients obtained by fitting.

[0027] Furthermore, assuming that the projectile incident speed is v, and the high-frequency amplitude preset in the pyrotechnic impact test condition is g, the projectile incident speed is calculated based on the following formula:

[0028] g = c1v + c2;

[0029] Among them, c1 and c2 are the unknown coefficients obtained by fitting.

[0030] Further, let the inner diameter area of ​​the gun barrel or the cross-sectional area of ​​the projectile be S p The barrel length or projectile incident length is L p , the air cannon chamber pressure is p, then the air cannon chamber pressure is calculated based on the following formula:

[0031]

[0032] Where m is the mass of the projectile.

[0033] Based on the same invention structure, a shock response spectrum simulation device is also provided, which is designed based on any of the above-mentioned design methods; the shock response spectrum simulation device includes a specimen installation tool, a response plate, a connecting rod, a loading plate, an incident rod and an air cannon loading system;

[0034] The specimen installation tool is arranged at the center position of the response plate to install and fix the test product; the response plate is arranged on the side of the specimen installation tool away from the test product and is provided with a plurality of first positioning holes; the loading plate is arranged on the side of the response plate away from the specimen installation tool and is provided with second positioning holes corresponding to the first positioning holes one by one; at least one connecting rod is arranged between the response plate and the loading plate, and the two ends are detachably installed on the first positioning hole and the second positioning hole opposite to each other; the incident rod is arranged at the center position of the loading plate away from the connecting rod; the air cannon loading system includes a front barrel, a fixed barrel, an air cannon controller, an air cannon air chamber and an air source which are detachably connected in sequence, the front barrel has a projectile built in and the muzzle of the front barrel faces the incident rod, and the air cannon controller controls the air cannon air chamber to release air pressure to push the projectile to impact the incident rod.

[0035] The design method of the shock response spectrum simulation device for air cannon shock test described in the present invention establishes a three-dimensional solid model of the simulation device and performs simulation calculation according to the pyrotechnic shock test conditions and the parameter information of the test piece to obtain a response spectrum curve; then the first parameter, the second parameter and the projectile incident speed of the simulation device are adjusted and iteratively optimized in turn until the simulation calculation result is close to the pyrotechnic shock test conditions; at the same time, based on the projectile incident speed and the third parameter of the simulation device, the corresponding air cannon chamber pressure is calculated; then, according to the target parameter combination and the air cannon chamber pressure, the three-dimensional solid model is simulated and debugged and verified to determine the design information of each parameter of the simulation device. A shock response spectrum simulation device designed based on the design method is also provided. In this way, the present invention can achieve high-precision control of the shock response spectrum shape in a wide range and high-efficiency design of the simulation device, greatly shorten the cycle of the air cannon shock test, and has a high engineering application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 A flowchart of the steps of a design method of a shock response spectrum simulation device for an air cannon shock test provided by an embodiment of the present invention;

[0037] Figure 2 A schematic structural diagram of the shock response spectrum simulation device provided by one embodiment of the present invention;

[0038] Figure 3 A schematic structural diagram of the loading plate design of the shock response spectrum simulation device provided in one embodiment of the present invention;

[0039] Figure 4 A schematic structural diagram of the incident rod design of the shock response spectrum simulation device provided by an embodiment of the present invention;

[0040] Figure 5 A comparison chart of response spectrum simulation results, test conditions and tolerance requirements obtained by the design method of the shock response spectrum simulation device for air cannon shock test provided by one embodiment of the present invention;

[0041] Among them: the attached drawings are marked with: 1. test piece installation tool; 2. response plate; 3. connecting rod; 4. loading plate; 5. mounting bracket; 6. incident rod; 7. front barrel; 8. projectile; 9. barrel connecting flange; 10. fixed barrel; 11. air cannon fixing bracket; 12. air cannon controller; 13. air cannon air chamber; 14. ground rail. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0043] It should be noted that references to "one embodiment", "embodiment", "example embodiment", etc. in this specification refer to the embodiment described, which may include specific features, structures or characteristics, but not every embodiment must include these specific features, structures or characteristics. In addition, such expressions do not refer to the same embodiment. Furthermore, when describing specific features, structures or characteristics in conjunction with an embodiment, whether or not there is an explicit description, it has been shown that it is within the knowledge of those skilled in the art to combine such features, structures or characteristics into other embodiments.

[0044] In addition, certain words are used in the specification and subsequent claims to refer to specific components or parts. Those with ordinary knowledge in the relevant field should understand that manufacturers can use different nouns or terms to refer to the same component or part. This specification and subsequent claims do not use differences in names as a way to distinguish components or parts, but use differences in the functions of components or parts as the criteria for distinction. "Including" and "including" mentioned throughout the specification and subsequent claims are open-ended terms and should be interpreted as "including but not limited to". In addition, the word "connected" here includes any direct and indirect electrical connection means. Indirect electrical connection means include connection through other devices.

[0045] Figure 1 A design method for a shock response spectrum simulation device for an air cannon shock test provided by an embodiment of the present invention is shown. The method is specifically used to design specification parameters of various components corresponding to the response spectrum simulation device according to the shock response spectrum simulation requirements, accurately and quickly simulate various shock response spectra of spacecraft products, and realize customized design of the response spectrum simulation device; the method includes the following steps:

[0046] S101: According to the pyrotechnic impact test conditions and the parameter information of the test piece, a three-dimensional solid model of a simulation device including the test piece is established, and the three-dimensional solid model is simulated and calculated based on the display dynamics analysis software to obtain the response spectrum curve at the corresponding position of the response plate of the simulation device. Among them, the pyrotechnic impact test conditions include information such as a preset low-frequency slope, a preset inflection point frequency, and a preset high-frequency amplitude required by the test; the test piece refers to a spacecraft product used for the test, and the parameter information of the test piece includes but is not limited to information such as the shape, size, and weight of the test piece; then, based on the above-mentioned pyrotechnic impact test conditions and the parameter information of the test piece, a three-dimensional solid model of a simulation device including the test piece is established; in specific implementation, the three-dimensional solid model of the simulation device is constructed with an initial general model of an impact response spectrum simulation device according to the pyrotechnic impact test conditions and the parameter information of the test piece; the specific features of the three-dimensional solid model of the simulation device of this embodiment can be referred to as follows Figure 2 The structure shown, i.e. the designed shock response spectrum simulation device, includes a specimen mounting fixture 1, a response plate 2, a connecting rod 3, a loading plate 4, an incident rod 6 and an air cannon loading system;

[0047] The specimen installation tool 1 is arranged at the center position of the response plate 2 for installing and fixing the test product (i.e., the test piece); the response plate 2 is arranged on the side of the specimen installation tool 1 away from the test product and is provided with a plurality of first positioning holes; the loading plate 4 is arranged on the side of the response plate 2 away from the specimen installation tool and is provided with second positioning holes corresponding to the first positioning holes one by one; at least one connecting rod 3 is arranged between the response plate 2 and the loading plate 4, and the two ends are detachably installed on the first positioning hole and the second positioning hole relative to each other; the incident rod 6 is arranged at the center position of the side of the loading plate 4 away from the connecting rod 3; the air cannon loading system includes a front barrel 7, a fixed barrel 10, an air cannon controller 12, an air cannon air chamber 13 and an air source which are detachably connected in sequence, the front barrel 7 is equipped with a projectile 8 and the muzzle of the front barrel 7 is facing the incident rod 6, and the air cannon controller 12 controls the air cannon air chamber 13 to release air pressure to push the projectile 8 to impact the incident rod 6. Furthermore, the specimen mounting tool 1, the response plate 2, the connecting rod 3, the loading plate 4 and the incident rod 6 are fixed on the mounting bracket 5, and the air cannon loading system also includes an air cannon fixing bracket 11 for supporting and a barrel connecting flange 9 for connecting the front barrel 7 and the fixed barrel 10, and the entire device is assembled on the ground rail 14.

[0048] After constructing a three-dimensional solid model of the simulation device, the model is simulated and calculated using display dynamics analysis software to obtain a response spectrum curve at the corresponding position of the response plate of the simulation device in the model.

[0049] In this embodiment, step S101 specifically includes: meshing the three-dimensional solid model, setting boundary conditions and initial conditions; and simulating the three-dimensional solid model using display dynamics analysis software to obtain a response spectrum curve at a corresponding position of a response plate of the simulation device.

[0050] For example, in one embodiment, the pyrotechnic impact test conditions are a low-frequency slope k = +12dB / Oct, an inflection point frequency f = 2000Hz and a high-frequency amplitude g = 4000g, the shape and size of the test piece are 298mm×318mm×217mm, and the weight is 5.47kg; based on the above information, a three-dimensional solid model of a simulation device including the test piece is established, meshing is performed, boundary conditions and initial conditions are set, and simulation calculations are performed using display dynamics analysis software to obtain a response spectrum curve at the corresponding position of the response plate 2 of the simulation device.

[0051] S102: By numerical simulation calculation, the inflection point frequency and low-frequency slope of the corresponding position of the response plate of the simulation device under multiple different first parameter conditions are obtained respectively; and based on the pyrotechnic impact test conditions and each simulation calculation result, the first target parameter of the simulation device is determined; wherein the first parameter is the thickness and the positioning hole distribution of the loading plate of the simulation device; the structural features of the loading plate of this embodiment are as follows Figure 3 shown.

[0052] In this step S102, numerical simulation is used to obtain the simulation device at different loading plate thicknesses d1, d2, ..., d n and different positioning holes h1~h 13 Under the condition of , the inflection point frequency f and the low-frequency slope k of the corresponding position of the response plate are determined, and then based on the pyrotechnic impact test conditions and various simulation calculation results, the first target parameters of the simulation device are determined.

[0053] Furthermore, the step of determining the first target parameter of the simulation device based on the pyrotechnic impact test conditions and each simulation calculation result includes: respectively determining the difference between each simulation calculation result and the pyrotechnic impact test condition; and determining the first parameter corresponding to the simulation calculation result with the smallest difference as the first target parameter of the simulation device. n and different positioning holes h1~h 13 After obtaining the simulation results corresponding to each condition under the conditions, the loading plate thickness d closest to the pyrotechnic impact test condition is selected from these simulation results. i and positioning hole h i combination.

[0054] See also Figure 3In one embodiment, numerical simulation is used to calculate the thicknesses d1, d2, ..., d n and different positioning holes h1~h 13 Under the condition of , the inflection point frequency f and the low-frequency slope k of the corresponding position of the response plate 2; for example, the following Table 1 shows the numerical simulation data of different thicknesses and positioning hole combinations of the partial loading plate 4.

[0055] Table 1:

[0056]

[0057]

[0058] According to the simulation calculation results corresponding to different thicknesses and positioning hole combinations of the loading plate 4 in the above table, the thickness and positioning hole combination of the loading plate 4 closest to the test conditions is selected as (thickness d i =20mm, positioning hole h4).

[0059] S103: According to the difference between the simulation calculation result of the first target parameter and the pyrotechnic impact test condition, the second parameter of the simulation device is adjusted and the inflection point frequency and low-frequency slope are simulated and calculated until the second target parameter of the simulation device is determined; wherein the second parameter is the diameter and length of the connecting rod of the simulation device. In specific implementation, according to the difference between the inflection point frequency f and low-frequency slope k obtained by the simulation calculation of the first target parameter selected in step S102 and the pyrotechnic impact test condition, different diameters D1, D2, ..., D n and different lengths l1, l2, ..., l n until the corresponding simulation calculation result is close to the pyrotechnic impact test condition, the diameter and length of the corresponding connecting rod are determined as the second target parameters;

[0060] Specifically, the relationship between the second parameter, the inflection point frequency and the low-frequency slope is as follows:

[0061] The relationship between the connecting rod length l and the inflection point frequency f is obtained by fitting a quadratic polynomial:

[0062] f=a1l 2 +a2l+a3;

[0063] The relationship between the connecting rod diameter D and the low-frequency slope k is obtained by exponential function fitting:

[0064] k = b1expb2D;

[0065] Among them, f is the inflection point frequency, k is the low-frequency slope, l is the length of the connecting rod in the second parameter, D is the diameter of the connecting rod in the second parameter, and a1, a2, a3, b1, and b2 are all unknown coefficients obtained by fitting.

[0066] In step S103 of this embodiment, the combination of the connecting rod diameter D and length l that is closest to the test conditions is calculated from the above formula, such as Figure 4 shown.

[0067] For example, in one embodiment, the difference between the inflection point frequency f and the low-frequency slope k obtained by the simulation calculation of the first target parameter in step S102 and the pyrotechnic impact test conditions is referred to as Figure 4 Choose different diameters D1, D2, ..., D n and different lengths l1, l2, ..., l n The connection rod 3 is simulated and calculated; the relationship between the length l of the connection rod 3 and the inflection point frequency f is obtained by fitting a univariate quadratic polynomial:

[0068] f=-0.0419l 2 +21.67l-3.4;

[0069] The relationship between the diameter D of the connecting rod 3 and the low-frequency slope k is obtained by exponential function fitting:

[0070] k = 14.235exp(-0,002D);

[0071] The diameter D=85 mm and the length l=120 mm of the connecting rod 3 which are closest to the pyrotechnic impact test conditions are calculated.

[0072] S104: Based on the high-frequency amplitude preset in the pyrotechnic impact test conditions, the projectile incidence velocity corresponding to the simulation device is calculated. In this step, the high-frequency amplitude is further preliminarily adjusted, and the high-frequency amplitude g preset in the required pyrotechnic impact test conditions is used as the target, and the high-frequency amplitude simulation calculation is performed on the selected loading plate, positioning hole, and connecting rod combination to calculate the projectile incidence velocity corresponding to the simulation device.

[0073] In a specific implementation, assuming that the projectile incident speed is v, and the high-frequency amplitude preset in the pyrotechnic impact test condition is g, the projectile incident speed is calculated based on the following formula:

[0074] g = c1v + c2;

[0075] Wherein, c1 and c2 are the coefficients to be determined obtained by fitting. In this embodiment, the linear relationship is specifically used to fit the expression of the high-frequency amplitude g and the projectile incident velocity v; thereby, the projectile incident velocity v closest to the pyrotechnic impact test condition is calculated.

[0076] For example, in one embodiment, taking the preset high-frequency amplitude g of the required pyrotechnic impact test conditions as the target, a high-frequency amplitude simulation calculation is performed on the selected combination of the loading plate 4, the positioning hole, and the connecting rod 3, and a linear relationship is used to fit the expression of the high-frequency amplitude g and the incident velocity v of the projectile 8:

[0077] g = 766.78v-12.52;

[0078] The high-frequency amplitude g of the pyrotechnic impact test condition is substituted into the formula, thereby calculating the projectile 8 incident velocity v=5.23 m / s which is closest to the test condition.

[0079] S105: Simulate and iterate the parameter combination of the first target parameter, the second target parameter and the projectile impact velocity until the differences between the inflection point frequency, the low-frequency slope and the high-frequency amplitude and the pyrotechnic impact test conditions respectively meet the test tolerance requirements, thereby obtaining the target parameter combination.

[0080] After the high-frequency amplitude g is adjusted in the above step S104, the inflection point frequency f and the low-frequency slope k may change accordingly; in response to this situation, the present embodiment further simulates and calculates the first target parameter, the second target parameter and the parameter combination of the projectile incidence velocity obtained in the above steps in step S105, and performs iterative correction to allow the design to continue.

[0081] In specific implementation, the thickness d of the loading plate obtained by the above steps is i 、Positioning hole h i , connecting rod diameter D, connecting rod length l and projectile incident speed v are simulated and calculated; after obtaining the corresponding simulation calculation results (i.e., the corresponding inflection point frequency, low-frequency slope and high-frequency amplitude and other information are obtained by simulation), they are compared with the inflection point frequency, low-frequency slope and high-frequency amplitude and other related information preset in the pyrotechnic impact test conditions to confirm the difference between the response spectrum simulation calculation results and the pyrotechnic impact test conditions. Based on this difference, the aforementioned steps S103 to S104 are repeatedly executed until the differences between the low-frequency slope, inflection point frequency and high-frequency amplitude of the response spectrum simulation calculation results and the pyrotechnic impact test conditions meet the test tolerance requirements, thereby obtaining the loading plate thickness d i 、Positioning hole h i , connecting rod diameter D, connecting rod length l and projectile incidence speed v are the final target parameter combinations; the target parameter combination can be applied to subsequent designs.

[0082] For example, in one embodiment, the parameters obtained by combining steps S101 to S104 are: the thickness d of the loading plate 4 i=20mm, positioning hole h4, connecting rod 3 diameter D=85mm, connecting rod length l=120mm and projectile incident speed v=5.23m / s combination for simulation calculation; according to the difference between the response spectrum simulation calculation result and the test conditions, steps S103 to S104 are repeated until the difference between the low-frequency slope k, inflection point frequency f and high-frequency amplitude g of the response spectrum simulation calculation result and the pyrotechnic impact test conditions meet the test tolerance requirements, thereby obtaining the loading plate 4 thickness d corresponding to the response spectrum simulation calculation result i =20mm, positioning hole h4, connecting rod 3 diameter D=80mm, connecting rod 3 length l=110mm and projectile 8 incident speed v=5.5m / s final target parameter combination.

[0083] S106: According to the projectile incident speed in the target parameter combination and the third parameter of the simulation device, the corresponding air gun chamber pressure is calculated; wherein the third parameter includes the inner diameter area of ​​the barrel or the cross-sectional area of ​​the projectile, and the barrel length or the projectile incident length. After the projectile incident speed is calculated in the above step S105, the air gun chamber pressure can be further calculated based on the law of conservation of energy and the third parameter of the simulation device.

[0084] In specific implementation, assume that the inner diameter area of ​​the gun barrel or the cross-sectional area of ​​the projectile is S p The barrel length or projectile incident length is L p , the air cannon chamber pressure is p, then the air cannon chamber pressure is calculated based on the following formula:

[0085]

[0086] Where m is the mass of the projectile.

[0087] For example, in one embodiment, assuming that the required projectile 8 incident speed v = 5.5 m / s, according to the length of the front barrel 7 or the incident length L of the projectile 8 p =0.4m, mass of projectile 8 m = 5kg, radius r = 50mm, cross section S P =0.007854m2, then according to the law of conservation of energy, the relationship is:

[0088]

[0089] That is, the pressure p of the air gun chamber 13 corresponding to the required projectile 8 incident speed v is calculated to be 0.024 MPa.

[0090] S107: According to the target parameter combination and the air chamber pressure of the air gun, the three-dimensional solid model is simulated and tested to determine the design information of each parameter of the simulation device. That is, the pyrotechnic shock response spectrum simulation test is carried out to debug and verify the counterweight to be simulated; finally, the thickness d of the loading plate 4 is determined. i 、Positioning hole h i , the diameter D of the connecting rod 3, the length l of the connecting rod 3 and the pressure p of the air gun chamber 13 are used to determine the final design scheme of the simulation device; in this way, the present embodiment obtains the design parameters of the shock response spectrum simulation device, which can make the response spectrum simulation results of the simulation device meet the test conditions and tolerance requirements, and the shock response spectrum simulation results are accurate.

[0091] Optionally, before step S107, it also includes: adjusting the high-frequency component of the response spectrum curve by adjusting the fourth parameter of the simulation device; wherein the fourth parameter is the size specification of the incident rod and the material of the end of the incident rod. This step can be used to fine-tune the high-frequency amplitude g, that is, the impact response spectrum generated by the simulation device on the response plate 2 appears "upward" or "downward" in the high-frequency part. In order to further fine-tune the high-frequency component, the size specification of the incident rod 6 in the simulation model is changed, and felt is added to the end of the incident rod 6 for fine-tuning until the high-frequency amplitude of the simulation calculation result becomes "flat" so that the result better meets the test requirements. In this way, the final design specifications of the incident rod 6 and the design scheme of the felt at the end of the incident rod 6 can be further determined in step S107.

[0092] Figure 5 It is shown that the design method of the shock response spectrum simulation device for air cannon shock test described in this embodiment can make the curve of the shock response spectrum simulation result close to the curve of the pyrotechnic shock test condition, and the curve of the shock response spectrum simulation result is within the tolerance range.

[0093] The design method of the present invention greatly improves the test design efficiency and design accuracy by proposing a reasonable setting of design steps and a quantitative solution method of key parameters, so that the designed simulation device can meet the test requirements, avoid the inability to conduct the test due to incorrect selection of device parameters, and reduce repetitive design; at the same time, a scientific and reasonable step setting is also carried out, and initial setting, fine solution, and iterative optimization are carried out in sequence according to different test conditions. On the basis of ensuring the test control accuracy, the design and early preparation time cost of the test are greatly reduced; a device design method for correcting-iterating-optimizing design parameters using numerical simulation is provided, which greatly improves the design accuracy, effectively avoids the risk of insufficient design margin due to excessive deviation of the actual device state from the design state due to insufficient early design accuracy in the subsequent actual test debugging process, and improves the stability of the simulation device and the safety of the test.

[0094] See also Figure 2 Based on the same invention structure, a shock response spectrum simulation device is also provided, and the shock response spectrum simulation device is designed based on the design method described in the above embodiment; the shock response spectrum simulation device includes a specimen installation tool 1, a response plate 2, a connecting rod 3, a loading plate 4, an incident rod 6 and an air cannon loading system;

[0095] The specimen installation tool 1 is arranged at the center position of the response plate 2 for installing and fixing the test product; the response plate 2 is arranged on the side of the specimen installation tool 1 away from the test product and is provided with a plurality of first positioning holes; the loading plate 4 is arranged on the side of the response plate 2 away from the specimen installation tool 1 and is provided with second positioning holes corresponding to the first positioning holes one by one; at least one connecting rod 3 is arranged between the response plate 2 and the loading plate 4, and the two ends are detachably installed on the first positioning hole and the second positioning hole relative to each other; the incident rod 6 is arranged at the center position of the side of the loading plate 4 away from the connecting rod 3; the air cannon loading system includes a front barrel 7, a fixed barrel 10, an air cannon controller 12, an air cannon air chamber 13 and an air source which are detachably connected in sequence, the front barrel 7 has a projectile 8 built in and the muzzle of the front barrel 7 is facing the incident rod 6, and the air cannon controller 12 controls the air cannon air chamber 13 to release air pressure to push the projectile 8 to impact the incident rod 6. Furthermore, the specimen mounting tool 1, the response plate 2, the connecting rod 3, the loading plate 4 and the incident rod 6 are fixed on the mounting bracket 5, and the air cannon loading system also includes an air cannon fixing bracket 11 for supporting and a barrel connecting flange 9 for connecting the front barrel 7 and the fixed barrel 10, and the entire device is assembled on the ground rail 14.

[0096] The air cannon loading system is used to launch a projectile 8 to strongly collide with the incident rod 6 and generate a shock wave. It is arranged on the side of the incident rod 6 away from the loading plate 4, and includes a projectile 8, an air cannon gas chamber 13, an air source, a gun barrel and an air cannon controller 12; the air cannon gas chamber 13 is connected to the air cannon through a gas pipeline to provide compressed air; the air cannon controller 12 is connected to the air cannon gas chamber 13 through a solenoid valve to control the compression in the air cannon gas chamber 13 and its instantaneous release. The air cannon gas chamber 13 is connected to the gas source, the air cannon controller 12 and the gun barrel, and is used to store compressed gas of a fixed pressure and release the gas under the action of the air cannon controller 12. One end of the gun barrel is connected to the gas chamber, and the other end is aligned with the incident rod 6 at a distance not exceeding the length of the projectile 8, so as to provide a movement path of compressed gas and the projectile 8. The projectile 8 is placed at a specific distance in the gun barrel, and can move horizontally along the gun barrel to collide with the incident rod 6 under the release drive of the compressed gas, and rebound along the gun barrel after the collision.

[0097] Specifically, according to the shock response spectrum requirements to be achieved, the specification parameters of multiple components in the shock response spectrum device described in this embodiment are designed based on the design method described in the above embodiment.

[0098] In summary, the design method of the shock response spectrum simulation device for air cannon impact test described in the present invention establishes a three-dimensional solid model of the simulation device and performs simulation calculations based on the pyrotechnic impact test conditions and the parameter information of the test piece to obtain a response spectrum curve; then the first parameter, the second parameter and the projectile incident speed of the simulation device are adjusted and iteratively optimized in turn until the simulation calculation result is close to the pyrotechnic impact test conditions; at the same time, based on the projectile incident speed and the third parameter of the simulation device, the corresponding air cannon chamber pressure is calculated; then, according to the target parameter combination and the air cannon chamber pressure, the three-dimensional solid model is simulated and debugged and verified to determine the design information of each parameter of the simulation device. A shock response spectrum simulation device designed based on the design method is also provided. In this way, the present invention can achieve high-precision control of the shock response spectrum shape in a wide range and high-efficiency design of the simulation device, greatly shorten the cycle of the air cannon impact test, and has a high engineering application value.

[0099] Of course, the present invention may have many other embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art may make various corresponding changes and modifications based on the present invention, but these corresponding changes and modifications should all fall within the scope of protection of the claims attached to the present invention.

Claims

1. A design method for a shock response spectrum simulation device for air cannon shock test, characterized in that: Includes steps: According to the pyrotechnic impact test conditions and the parameter information of the test piece, a three-dimensional solid model of a simulation device including the test piece is established, and the three-dimensional solid model is simulated and calculated based on the display dynamics analysis software to obtain a response spectrum curve at a corresponding position of a response plate of the simulation device; Through numerical simulation calculations, the inflection point frequency and low-frequency slope of the corresponding position of the response plate of the simulation device under multiple different first parameter conditions are obtained respectively; and based on the pyrotechnic impact test conditions and various simulation calculation results, the first target parameter of the simulation device is determined; wherein the first parameter is the thickness of the loading plate of the simulation device and the distribution of the positioning holes; According to the difference between the simulation calculation result of the first target parameter and the pyrotechnic impact test condition, the second parameter of the simulation device is adjusted and the simulation calculation of the inflection point frequency and the low-frequency slope is performed until the second target parameter of the simulation device is determined; wherein the second parameter is the diameter and length of the connecting rod of the simulation device; the second target parameter is the diameter and length of the connecting rod; Calculating the projectile incident velocity corresponding to the simulation device based on the high-frequency amplitude preset in the pyrotechnic impact test condition; The first target parameter, the second target parameter and the parameter combination of the projectile incidence velocity are simulated and calculated and iteratively processed until the differences between the inflection point frequency, the low-frequency slope and the high-frequency amplitude and the pyrotechnic impact test conditions respectively meet the test tolerance requirements, thereby obtaining a target parameter combination; The corresponding air gun chamber pressure is calculated according to the projectile incident speed in the target parameter combination and the third parameter of the simulation device; wherein the third parameter includes the inner diameter area of ​​the gun barrel or the cross-sectional area of ​​the projectile, and the gun barrel length or the projectile incident length; According to the target parameter combination and the air chamber pressure of the air cannon, the three-dimensional solid model is debugged and verified by simulation test to determine the design information of each parameter of the simulation device; The step of determining the first target parameter of the simulation device based on the pyrotechnic impact test conditions and various simulation calculation results comprises: respectively determining the difference between each of the simulation calculation results and the pyrotechnic impact test conditions; Determine the first parameter corresponding to the simulation calculation result with the smallest difference as the first target parameter of the simulation device; Wherein, the shock response spectrum simulation device includes a specimen installation tool, the response plate, the connecting rod, a loading plate, an incident rod and an air cannon loading system; The specimen installation tool is arranged at the center position of the response plate to install and fix the test product; the response plate is arranged on the side of the specimen installation tool away from the test product and is provided with a plurality of first positioning holes; the loading plate is arranged on the side of the response plate away from the specimen installation tool and is provided with second positioning holes corresponding to the first positioning holes one by one; at least one connecting rod is arranged between the response plate and the loading plate, and the two ends are detachably installed on the first positioning hole and the second positioning hole opposite to each other; the incident rod is arranged at the center position of the loading plate away from the connecting rod; the air cannon loading system includes a front barrel, a fixed barrel, an air cannon controller, an air cannon air chamber and an air source which are detachably connected in sequence, the front barrel has a projectile built in and the muzzle of the front barrel faces the incident rod, and the air cannon controller controls the air cannon air chamber to release air pressure to push the projectile to impact the incident rod.

2. The design method of the shock response spectrum simulation device for air cannon shock test according to claim 1 is characterized in that: Before the step of performing simulation test debugging and verification on the three-dimensional solid model according to the target parameter combination and the air gun chamber pressure, the step further includes: The high-frequency component of the response spectrum curve is adjusted by adjusting the fourth parameter of the simulation device; wherein the fourth parameter is the size specification of the incident rod and the material of the end of the incident rod.

3. The design method of the shock response spectrum simulation device for air cannon shock test according to claim 1 is characterized in that: The step of performing simulation calculation on the three-dimensional solid model based on the display dynamics analysis software to obtain the response spectrum curve at the corresponding position of the simulation device response plate comprises: Meshing the three-dimensional solid model, setting boundary conditions and initial conditions; The three-dimensional solid model is simulated and calculated using display dynamics analysis software to obtain a response spectrum curve at a corresponding position of a response plate of the simulation device.

4. The design method of the shock response spectrum simulation device for air cannon shock test according to claim 1 is characterized in that: The relationship between the second parameter, the inflection point frequency and the low-frequency slope is as follows: <h2 style=";text-align:left;direction:ltr">f=a1l<h2 style=";text-align:left;direction:ltr"> 2 <h2 style=";text-align:left;direction:ltr"> +a2l+a3; k = b1expb2D; Among them, f is the inflection point frequency, k is the low-frequency slope, l is the length of the connecting rod in the second parameter, D is the diameter of the connecting rod in the second parameter, and a1, a2, a3, b1, and b2 are all unknown coefficients obtained by fitting.

5. The design method of the shock response spectrum simulation device for air cannon shock test according to claim 1, characterized in that: Assuming that the projectile incident speed is v, and the high-frequency amplitude preset in the pyrotechnic impact test condition is g, the projectile incident speed is calculated based on the following formula: g=c1v+c2; Among them, c1 and c2 are the unknown coefficients obtained by fitting.

6. The design method of the shock response spectrum simulation device for air cannon shock test according to claim 5 is characterized in that The inner diameter area of ​​the gun barrel or the cross-sectional area of ​​the projectile is S p The barrel length or projectile incident length is L p , the air cannon chamber pressure is p, then the air cannon chamber pressure is calculated based on the following formula: Where m is the mass of the projectile.

7. A shock response spectrum simulation device, characterized in that: The shock response spectrum simulation device is designed based on the design method according to any one of claims 1 to 6; the shock response spectrum simulation device comprises a specimen installation tool, a response plate, a connecting rod, a loading plate, an incident rod and an air cannon loading system; The specimen installation tool is arranged at the center position of the response plate to install and fix the test product; the response plate is arranged on the side of the specimen installation tool away from the test product and is provided with a plurality of first positioning holes; the loading plate is arranged on the side of the response plate away from the specimen installation tool and is provided with second positioning holes corresponding to the first positioning holes one by one; at least one connecting rod is arranged between the response plate and the loading plate, and the two ends are detachably installed on the first positioning hole and the second positioning hole opposite to each other; the incident rod is arranged at the center position of the loading plate away from the connecting rod; the air cannon loading system includes a front barrel, a fixed barrel, an air cannon controller, an air cannon air chamber and an air source which are detachably connected in sequence, the front barrel has a projectile built in and the muzzle of the front barrel faces the incident rod, and the air cannon controller controls the air cannon air chamber to release air pressure to push the projectile to impact the incident rod.

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