A combined high-g half-sine shock waveform generator and method

Abstract

The application discloses a combined high-g-value half-sine shock waveform generator and method, which comprises a gas storage tank, a launching cylinder, a combined waveform generator and a shock piston. A quick release device is arranged in the gas storage tank to instantaneously release compressed gas, and the compressed gas pushes the shock piston to move linearly along the launching cylinder at an acceleration. The shock piston collides with the combined waveform generator, an acceleration sensor on the shock piston records the acceleration signal of the shock process, and reflects the shock waveform experienced by the test piece. The combined waveform generator is composed of three material media of fiber non-woven fabric, polyurethane and asbestos. By changing the proportion of the three material media, the problem of strong nonlinearity of a single material medium can be corrected, and a high-g-value half-sine shock waveform complete in waveform and meeting a standard tolerance band can be obtained under high-speed impact. The application solves the problem of nonlinear mechanical behavior of a single material medium under high overload impact, and obtains a half-sine waveform meeting the standard tolerance band.

Description

Technical Field

[0001] This invention belongs to the field of mechanical environment and impact testing technology, specifically relating to a combined high-g half-sine impact waveform generator and method. Background Technology

[0002] In the military industry, represented by aerospace, aircraft structures, mechanical components, and electronic devices often face dynamic environmental conditions such as turbulence, explosions, impacts, and vibrations during operation. Incomplete statistics indicate that approximately 30% of weapon system malfunctions during use are related to impact environments; therefore, related products must undergo impact testing.

[0003] To meet the requirements of mechanical environment simulation in impact testing, a series of impact test standards have been proposed both domestically and internationally. For example, GJB150-18 "Environmental Test Methods for Military Equipment" specifies three waveforms for impact testing: half-sine wave, sawtooth wave with a back peak, and trapezoidal wave. Among these, the half-sine wave is most widely used to describe the impact effect of a system collision and rebound. Waveform generating devices, with waveform generators as their core structural components, have advantages such as low cost, convenient operation, and high repeatability, making them the most widely used impact testing devices. Currently, commonly used half-sine waveform generators are mostly made of rubber materials. In existing research, impact testing equipment, mainly drop-type impact test benches, has only generated waveforms with overload ranges between tens and hundreds of g. Research on overloads exceeding 1000 g is limited, which clearly cannot meet current impact testing requirements.

[0004] With the rapid development of aerospace vehicles and weaponry, high-g impact environment simulation testing is becoming increasingly important. Designing a high-g impact waveform generator that meets the aforementioned impact test standards has become an urgent problem to solve. Traditional waveform generators often use a single material medium as the waveform generator, which limits the design flexibility of the waveform generator. Furthermore, under high-overload and low-overload impact conditions, waveform generators using a single material medium exhibit significant nonlinear behavior in the waveform due to the different mechanical properties of the material, failing to meet the tolerance band requirements of the impact standards.

[0005] Therefore, there is a lack of a high-g half-sine impact waveform generator in the existing technology that is highly designable, low-cost, and meets the impact standard tolerance band. Summary of the Invention

[0006] To overcome the shortcomings of existing technologies, this invention provides a combined high-g-value half-sine impact waveform generator and method, including a gas storage tank, a launching cylinder, a combined waveform generator, and an impact piston. A quick-release device inside the gas storage tank instantly releases compressed gas, which propels the impact piston in an accelerated linear motion along the launching cylinder. The impact piston collides with the combined waveform generator, and an acceleration sensor on the impact piston records the acceleration signal during the impact process, reflecting the impact waveform experienced by the specimen. The combined waveform generator is constructed using three materials: nonwoven fiber, polyurethane, and asbestos. By changing the ratio of these three materials, the strong nonlinearity of a single material can be corrected, resulting in a high-g-value half-sine impact waveform with complete waveform and conforming to the standard tolerance band under high-speed impact. This invention solves the problem of nonlinear mechanical behavior of a single material under high overload impact conditions, obtaining a half-sine waveform conforming to the standard tolerance band.

[0007] The technical solution adopted by this invention to solve its technical problem is as follows:

[0008] A combined high-g half-sine impact waveform generator includes a base, a loading chamber, a gas tank, a launch tube, a combined waveform generator, a buffer tailstock, a guide rail, and an impact piston;

[0009] The ammunition loading compartment, launch tube, and guide rail are fixedly mounted on the base; the ammunition loading compartment is connected to the launch tube;

[0010] The buffer tailstock is mounted on a guide rail and can slide along the guide rail to adjust the relative position of the buffer tailstock and the launch tube.

[0011] The combined waveform generator is installed in a clamp on the buffer tailstock near the end of the launch tube; the combined waveform generator is composed of two layers of non-woven fiber fabric, one layer of polyurethane, and two layers of asbestos.

[0012] The impact piston is internally fixed to the test piece and the acceleration sensor, and the impact piston is initially placed in the loading compartment.

[0013] The loading compartment is connected to the gas storage tank; the gas storage tank stores compressed air, and a quick-release device is installed in the gas storage tank to release the compressed gas instantly. The compressed gas pushes the impact piston to move in an accelerated linear motion along the launch tube; the impact piston and the combined waveform generator collide to complete one test; the acceleration sensor on the impact piston records the acceleration signal of the entire impact process, reflecting the impact waveform experienced by the test piece.

[0014] Preferably, the gas storage tank is equipped with a pressure sensor to detect air pressure in real time.

[0015] Preferably, the nonwoven fiber fabric is industrial wool felt.

[0016] Preferably, the thickness of the nonwoven fiber, polyurethane, and asbestos is 5 mm.

[0017] Preferably, the impact piston has a mass of 11.37 kg.

[0018] A combined method for generating high-g half-sine impulse waveforms includes the following steps:

[0019] Step 1: Install the specimen and acceleration sensor. Fix the specimen inside the impact piston with a clamp and fix the acceleration sensor to the tail of the impact piston.

[0020] Step 2: Insert the impact piston containing the test specimen into the loading chamber, lock the loading chamber door, and the clamping is complete;

[0021] Step 3: Install the combined waveform generator and fix it on the clamp at the end of the buffer tailstock near the launch tube.

[0022] Step 4: Move the buffer tailstock along the guide rail to the specified position at the distance from the launch tube port;

[0023] Step 5: Inflate the air tank. Observe the air pressure through the pressure sensor inside the air tank. Once the air pressure reaches the set pressure, use the quick-release mechanism to release the air from the air tank instantly.

[0024] Step 6: Driven by compressed air, the impact piston moves in an accelerated linear motion along the launch tube, impacting the combined waveform generator to complete one impact; the acceleration sensor on the impact piston records the acceleration signal of the entire impact process, reflecting the impact waveform experienced by the specimen.

[0025] Step 7: After the impact ends, allow the buffer tailstock to reset along the guide rail;

[0026] Step 8: Replace the test piece, push the impact piston from the launch tube port to the loading chamber, replace the combined waveform generator, and conduct the next test.

[0027] The beneficial effects of this invention are as follows:

[0028] 1) This invention innovatively adopts a combined waveform generator. Under different impact velocities, the nonlinear mechanical behavior of a single material medium under high overload impact conditions can be solved by adjusting the ratio of the material medium in the combined waveform generator, and a half-sine waveform that conforms to the standard tolerance band can be obtained.

[0029] 2) This invention breaks through the design limitations of traditional single-medium material waveform generators and greatly expands the design space of high-g waveform generators. Experiments have proven that this invention can effectively generate half-sine impact waveforms with overloads of 5000g to 10000g.

[0030] 3) This invention will enable the development of high-overhead carrier wave generator equipment that ranks among the world's best, filling the gap in my country's research and development in this field, and providing a reliable ground mechanical model experimental environment for the development of my country's advanced weapons and aerospace vehicles.

[0031] 4) This invention is simple to manufacture, uses reliable materials, and is inexpensive. Combined with the corresponding impact test bench, it can bring positive social and economic benefits. Attached Figure Description

[0032] Figure 1 This is a front view of the present invention.

[0033] Figure 2 This is a three-axis isometric view of the present invention.

[0034] Figure 3 The images show a side view and a three-axis isometric view of the combined waveform generator of the present invention: (a) side view, (b) three-axis isometric view.

[0035] Figure 4 The images show the front view and three-axis isometric views of the impact piston of the present invention: (a) front view, (b) three-axis isometric view.

[0036] Figure 5 This is a schematic diagram of the impact results in an embodiment of the present invention.

[0037] In the diagram: 1-base, 2-loading compartment, 3-gas tank, 4-launch tube, 5-combined waveform generator, 6-buffer tailstock, 7-guide rail, 8-impact piston, 501 and 502-fiber nonwoven fabric, 503-polyurethane, 504 and 505-asbestos. Detailed Implementation

[0038] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0039] The problem to be solved by the present invention is to design a high g-value impulse waveform generator with a g-value greater than 8000, which addresses the shortcomings of the existing technology.

[0040] Traditional half-sine waveform generators mostly use rubber materials. Under low overload impact conditions, rubber-based waveform generators can obtain half-sine impact waveforms that meet the standard tolerance band. However, as the impact velocity increases, rubber materials exhibit significant nonlinear elastic behavior under high overload impact, resulting in a waveform with a "sharp peak and thin waist" nonlinear characteristic, which fails to meet the requirements of the standard tolerance band.

[0041] This invention uses a combination waveform generator composed of three materials: nonwoven fiber, polyurethane, and asbestos. By changing the ratio of the three materials, the problem of strong nonlinearity of a single material can be corrected, and a high-g half-sine impact waveform with complete waveform and conforming to the standard tolerance band can be obtained under high-speed impact.

[0042] The combined waveform generator used in this invention is low in cost and easy to operate. The impact waveform has reliable repeatability. With the matching impact testing device, a high overload half-sine impact waveform of over 8000g can be obtained.

[0043] The technical solution adopted in this invention is a waveform generator based on a horizontal air cannon impact platform. The horizontal air cannon impact platform is a means of simulating high overload impacts, mainly used for dynamic structural integrity and adaptability tests on fuses, aircraft components, etc., to assess the reliability of the test specimen's function and structural integrity under high overload impact environments. Its main features include a base, loading compartment, air tank, launch tube, impact piston, acceleration sensor, waveform generator, buffer tailstock, and guide rail. The test specimen, mounted on the clamp of the impact piston, can be considered as an entire impact structure. An acceleration sensor is fixedly installed on the impact piston to identify the acceleration of the impact structure. At the instant of impact, a half-sine wave will be generated in the impact structure, causing it to decelerate, i.e., generating a certain acceleration response. When the velocity of the impact structure drops to zero, i.e., the impact structure reaches force equilibrium and the acceleration drops to zero, completing one half-sine impact waveform simulation.

[0044] This invention improves the nonlinear mechanical properties of the waveform generator under high overload impact by changing the combination of materials and media in the waveform generator and matching the impact velocity, thereby obtaining a high-g half-sine impact waveform that conforms to the standard tolerance band. Through repeated experimental verification, the fiber nonwoven fabric, polyurethane, and asbestos combined waveform generator used in this invention can generate a half-sine impact wave with a peak value of 8000g and a pulse width of 0.5ms under high-speed impact. Polyurethane serves as the main material medium for generating the half-sine waveform, the fiber nonwoven fabric filters out noise to maintain waveform stability during high overload impact, and asbestos provides stiffness support for the waveform generator to meet the peak value waveform requirements.

[0045] The air tank provides compressed air for driving the impact piston, which is driven by air pressure. The initial impact velocity can be controlled by adjusting the air pressure.

[0046] The impact piston is inserted from the rear of the loading compartment, where a test piece and an acceleration sensor are fixed. Compressed air pushes the impact piston forward to accelerate and impact the combined waveform generator, generating the required overload and pulse width.

[0047] The accelerometer is installed at the center of the tail of the impact piston. When the impact piston collides with the combined waveform, it begins to collect the impact response signal of the impact piston and record the half-sine impact waveform signal.

[0048] The tail of the launch tube is equipped with a pressure sensor that can measure the air pressure in real time. When the air pressure reaches a predetermined value, the locking mechanism is opened, and the impact piston will move along the launch tube in a translational acceleration motion to ensure that the impact surface of the impact piston collides head-on with the combined waveform generator.

[0049] The buffer tailstock provides a fixed support constraint for the combined waveform generator. After the impact piston completes one collision, the buffer tailstock will absorb the excess kinetic energy.

[0050] A combined high-g half-sine impact waveform generator includes a base 1, a loading chamber 2, an air tank 3, a launch tube 4, a combined waveform generator 5, a buffer tailstock 6, a guide rail 7, and an impact piston 8.

[0051] The ammunition loading compartment 2, the launch tube 4, and the guide rail 7 are fixedly mounted on the base 1; the ammunition loading compartment 2 is connected to the launch tube 4;

[0052] The buffer tailstock 6 is mounted on the guide rail 7 and can slide along the guide rail 7 to adjust the relative position of the buffer tailstock 6 and the launch tube 4.

[0053] The combined waveform generator 5 is installed in a clamp on the buffer tailstock 6 near one end of the launching tube 4; the combined waveform generator 5 is composed of two layers of non-woven fiber fabric, one layer of polyurethane, and two layers of asbestos.

[0054] The impact piston 8 is internally fixedly installed with the test piece and the acceleration sensor. The impact piston 8 is initially placed in the loading compartment 2.

[0055] The loading compartment 2 is connected to the gas storage tank 3; the gas storage tank 3 stores compressed air, and a quick-release device is installed in the gas storage tank 3 to release the compressed gas instantly. The compressed gas pushes the impact piston 8 to move in an accelerated linear motion along the launch tube 4; the impact piston 8 and the combined waveform generator 5 collide to complete one test; the acceleration sensor on the impact piston 8 records the acceleration signal of the entire impact process, reflecting the impact waveform experienced by the test piece.

[0056] Preferably, the gas storage tank 3 is equipped with a pressure sensor to detect air pressure in real time.

[0057] Preferably, the nonwoven fiber fabric is industrial wool felt.

[0058] Preferably, the thickness of the nonwoven fiber, polyurethane, and asbestos is 5 mm.

[0059] Preferably, the impact piston 8 has a mass of 11.37 kg.

[0060] A combined method for generating high-g half-sine impulse waveforms includes the following steps:

[0061] Step 1: Install the test specimen and the acceleration sensor. Fix the test specimen inside the impact piston 8 with a clamp and fix the acceleration sensor at the tail of the impact piston 8.

[0062] Step 2: Insert the impact piston 8 containing the test piece into the loading compartment 2, lock the loading compartment 2 door, and the clamping is complete;

[0063] Step 3: Install the combined waveform generator 5 and fix the combined waveform generator 5 on the clamp at the end of the buffer tailstock 6 near the launching tube 4.

[0064] Step 4: Move the buffer tailstock 6 along the guide rail 7 to the specified position at the port of the launch tube 4;

[0065] Step 5: Inflate the air tank 3. Observe the air pressure through the pressure sensor inside the air tank 3. After the air pressure reaches the set pressure, use the quick release mechanism to release the air from the air tank 3 instantly.

[0066] Step 6: The impact piston 8, driven by compressed air, moves in an accelerated linear motion along the launching cylinder 4, impacting the combined waveform generator 5 to complete one impact; the acceleration sensor on the impact piston 8 records the acceleration signal of the entire impact process, reflecting the impact waveform experienced by the specimen.

[0067] Step 7: After the impact ends, the buffer tailstock 6 is reset along the guide rail 7;

[0068] Step 8: Replace the test piece, push the impact piston 8 from the launch tube 4 port to the loading chamber 2, replace the combined waveform generator 5, and conduct the next test. Specific implementation examples:

[0070] Reference Figure 1-4This invention develops a combined high-g half-sine impact waveform generator. The invention mainly includes: a base 1, a loading chamber 2, an air tank 3, a launch tube 4, a combined waveform generator 5, a buffer tailstock 6, a guide rail 7, and an impact piston 8. The buffer tailstock 6 is connected to the guide rail 7, allowing adjustment of the relative position between the buffer tailstock 6 and the launch tube 4. The combined waveform generator 5 is composed of three different material media: 501 and 502 (fiber nonwoven fabric), 503 (polyurethane), and 504 and 505 (asbestos). The air tank 3 stores compressed air and is equipped with a pressure sensor to monitor the air pressure in real time. The impact piston 8 has a test specimen and an acceleration sensor fixedly installed inside. Before the experiment, the impact piston 8 is placed in the loading chamber 2. The loading chamber 2 is connected to the air tank 3, which has a quick-release device that can instantly release compressed gas. The compressed gas pushes the impact piston 8 in an accelerated linear motion along the launch tube 4. The combined waveform generator 5 is installed in a fixture on the buffer tailstock 6. The impact piston 8 impacts the combined waveform generator 5 to complete one test. The acceleration sensor on the impact piston 8 records the acceleration signal throughout the impact process, reflecting the impact waveform experienced by the specimen.

[0071] Example 1:

[0072] Industrial wool felt, polyurethane, and asbestos are selected as the material media for the combined waveform generator 5, such as... Figure 3 In the structure shown, 501 and 502 are industrial felt, 503 is polyurethane, and 504 and 505 are asbestos. The thickness of each material is 5 mm. The impact piston 8 has a mass of 11.37 kg and impacts the combined waveform generator 5 under a pressure of 0.14 MPa.

[0073] Impact results as Figure 5 As shown, after the impact piston 8 impacts the combined waveform generator 5, the acceleration sensor records the entire impact waveform. The results show that the peak acceleration of the half-sine impact waveform in this implementation case is 8103.753g, and the pulse width is 0.415ms. Using the GJB150A standard tolerance band for evaluation, this half-sine impact waveform meets the standard half-sine impact waveform tolerance band requirements of 8000g peak acceleration and 0.5ms pulse width. This example demonstrates that the present invention effectively solves the problem of generating high-g half-sine impact waveforms, achieving the required high-g peak value and meeting the tolerance band standard.

[0074] The implementation steps of this invention are as follows:

[0075] 1) Turn off the gas supply switch and confirm that all pressure gauge readings are zero to ensure safety.

[0076] 2) Install the test specimen and the acceleration sensor. Fix the test specimen inside the impact piston 8 with a clamp and fix the acceleration sensor at the tail of the impact piston 8.

[0077] 3) Insert the impact piston 8 containing the test specimen into the loading chamber 2, lock the loading chamber 2 door, and the clamping is complete.

[0078] 4) Install the combined waveform generator 5 and fix it on the clamp at the front end of the buffer tailstock 6.

[0079] 5) The control software moves the buffer tailstock 6 along the guide rail 7 to a suitable position at the port of the launch tube 4.

[0080] 6) Start the test by filling the air tank 3 with air and observing the air pressure through the pressure sensor inside the air tank 3. Once the air pressure reaches the set pressure, use the quick release mechanism to release the air from the air tank 3 instantly.

[0081] 7) Driven by compressed air, the impact piston 8 moves in an accelerated linear motion along the launch tube 4, impacting the buffer tailstock 6 and completing one impact.

[0082] 8) After the impact ends, the control software causes the buffer tailstock 6 to reset along the guide rail 7.

[0083] 9) Replace the test piece, push the impact piston 8 from the port of the launch tube 4 into the loading chamber 2, replace the combined waveform generator 5, and conduct the next test.

[0084] In summary, this invention provides a combined high-g half-sine impulse waveform generator, which is highly designable and low-cost. It effectively solves the nonlinearity problem of half-sine impulse waves under high overload conditions, meets the tolerance band requirements of relevant waveform standards, and fills the research gap of high-g waveform generators in my country.

Claims

1. A combined high-g half-sine impulse waveform generator, characterized in that, It includes a base, loading compartment, gas tank, launch tube, combined waveform generator, buffer tailstock, guide rail and impact piston; the combined high-g half-sine impact waveform generator is used to generate high overload half-sine impact waveforms of 8000g or more. The ammunition loading compartment, launch tube, and guide rail are fixedly mounted on the base; the ammunition loading compartment is connected to the launch tube. The buffer tailstock is mounted on a guide rail and can slide along the guide rail to adjust the relative position of the buffer tailstock and the launch tube. The combined waveform generator is installed in a clamp on the buffer tailstock near the launching tube end; the material medium of the combined waveform generator, from the near end of the buffer tailstock, consists of: two layers of nonwoven fiber fabric for filtering noise in high overload impact, one layer of polyurethane for generating a half-sine waveform, and two layers of asbestos for providing stiffness support; wherein, the thickness of the nonwoven fiber fabric, polyurethane and asbestos is 5mm. The test specimen and acceleration sensor are fixedly installed inside the impact piston, which is initially placed in the loading compartment; the impact piston has a mass of 11.37 kg, and the acceleration sensor is fixed at the tail of the impact piston. The loading compartment is connected to the gas storage tank; the gas storage tank stores compressed air, and a quick-release device is installed in the gas storage tank to release the compressed gas instantly. The compressed gas pushes the impact piston to move in an accelerated linear motion along the launch tube; the impact piston and the combined waveform generator collide to complete one test; the acceleration sensor on the impact piston records the acceleration signal of the entire impact process, reflecting the impact waveform experienced by the test piece.

2. The combined high-g half-sine impulse waveform generator according to claim 1, characterized in that, The gas storage tank is equipped with a pressure sensor to detect air pressure in real time.

3. A combined high-g half-sine impulse waveform generator according to claim 1, characterized in that, The nonwoven fiber fabric is industrial wool felt.

4. A waveform generation method using the waveform generator as described in claim 1, applied to the combined high-g half-sine impulse waveform generator as described in any one of claims 1 to 3, characterized in that, Includes the following steps: Step 1: Install the specimen and acceleration sensor. Fix the specimen inside the impact piston with a clamp and fix the acceleration sensor to the tail of the impact piston. Step 2: Insert the impact piston containing the test specimen into the loading chamber, lock the loading chamber door, and the clamping is complete; the test specimen and acceleration sensor are fixedly installed inside the impact piston. The impact piston is initially placed in the loading chamber, the impact piston has a mass of 11.37 kg, and the acceleration sensor is fixed at the tail of the impact piston. Step 3: Install the combined waveform generator and fix it on the clamp near the launch tube end of the buffer tailstock. The material medium of the combined waveform generator, from the closest to the buffer tailstock, consists of: two layers of nonwoven fiber fabric for filtering noise during high overload impacts, one layer of polyurethane for generating a half-sine waveform, and two layers of asbestos for providing stiffness support. The thickness of the nonwoven fiber fabric, polyurethane, and asbestos is 5mm. Step 4: Move the buffer tailstock along the guide rail to the specified position at the distance from the launch tube port; Step 5: Inflate the air tank. Observe the air pressure through the pressure sensor inside the air tank. Once the air pressure reaches the set pressure, use the quick-release mechanism to release the air from the air tank instantly. Step 6: Driven by compressed air, the impact piston moves in an accelerated linear motion along the launch tube, impacting the combined waveform generator to complete one impact; the acceleration sensor on the impact piston records the acceleration signal of the entire impact process, reflecting the impact waveform experienced by the specimen. Step 7: After the impact ends, allow the buffer tailstock to reset along the guide rail; Step 8: Replace the test piece, push the impact piston from the launch tube port to the loading chamber, replace the combined waveform generator, and conduct the next test.

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