Load generating device and loading method for long-pulse impact acceleration

Abstract

The invention discloses a long pulse impact acceleration load generating device and a loading method, which can apply long pulse width impact overload load to dozens of to hundreds of kilograms of mass structure target test pieces through controllable expected plastic large deformation and plastic splitting generated by a cylindrical shell in the process that an impact component impacts a rigid target surface; the stability of the posture of the cylindrical shell in the target touching process can be controlled through contact between the truncated cone of the mold and the inner surface of the cylindrical shell; the cylindrical shell generates expected controllable plastic large deformation and plastic splitting through the impact of the circular truncated cone body of the mold on the top of the cylindrical shell; the wall thickness of the cylindrical shell is designed in advance, so that the acceleration load amplitude loaded on the target test piece can be controlled; the initial speed of the touch target is changed by increasing the free falling height of the impact part, and the impact acceleration pulse width can be adjusted and controlled, so that the loading time of the target test piece is controllable.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of impact load loading, in particular to a long pulse impact acceleration load generating device and loading method. BACKGROUND

[0002] In the impact dynamics research of many engineering problems such as aircraft crash and ship collision, the target test piece is equivalent to the real impact loading environment through the load generating device, which can effectively obtain the response behavior of the key component, thereby greatly reducing the experimental scale and cost. The existing public technical research on impact loading design technology generally uses drop hammer, pendulum, Hopkinson bar, explosion and other loading test technologies to realize the impact dynamics loading of the structure. In these loading technologies, drop hammer, pendulum and other methods can only perform local concentrated load loading, and it is difficult to realize surface load loading of the structure, especially the whole stage impact load loading; although the Hopkinson bar and other methods can realize surface load loading, they can only load small mass test pieces and the loading time is usually only microsecond level, which cannot meet the long pulse impact loading demand of millisecond level time; the explosion loading method has the problems of difficult long pulse continuous loading process, large test difficulty and large safety risk. In addition, the existing impact loading technology is mostly used for loading small component structures, and the target test piece structure is relatively single, which cannot meet the conditions of large mass and size and complex components in the engineering problem research, and it is also difficult to simulate the whole stage loading demand of long pulse impact acceleration.

[0003] Therefore, it is necessary to develop a simple and effective load generating device and loading method which can apply long pulse impact overload to structures with mass of dozens to hundreds of kilograms to solve the above problems. SUMMARY

[0004] The purpose of the present application is to design a long pulse impact acceleration load generating device and loading method to solve the above problems.

[0005] The present application achieves the above-mentioned purpose through the following technical solutions: A long pulse impact acceleration load generating device, comprising: An aerodynamic tail wing assembly for attitude stability control during free falling of the load generating device; A counterweight, the aerodynamic tail wing assembly and the target test piece are fixedly installed on the upper end of the counterweight; A mold, the mold comprises a truncated cone and a cylinder, the large end surface of the truncated cone is connected with the bottom of the counterweight, the small end surface of the truncated cone is connected with the first end of the cylinder, and the truncated cone is used to produce expected controllable plastic large deformation and plastic splitting of the cylindrical shell; The inner diameter of the cylindrical shell is slightly larger than the outer diameter of the cylinder of the mold, the second end of the cylinder of the mold is placed in the cylindrical shell, the aerodynamic tail wing assembly, the mold and the cylindrical shell are coaxially arranged, the mass centers of the target test piece and the counterweight are arranged on the axial line of the cylindrical shell, and the cylindrical shell is made of a ductile metal material.

[0006] The load test method comprises the steps of: S1, fixing the target test piece, the aerodynamic tail wing assembly and the mold to the counterweight, and sleeving the cylindrical shell on the cylinder of the mold; S2, installing acceleration sensors on the target test piece and the counterweight, and connecting the acceleration sensors to corresponding signal processing equipment on the ground through sensor lead lines of a relatively large length; S3, fixing the impact component to the lifting end of the hoisting equipment through a lifting rope, and lifting the impact component to a preset height, wherein the impact component comprises the aerodynamic tail wing assembly, the counterweight, the mold and the cylindrical shell; S4, cutting the lifting rope, instantaneously releasing the impact component, and making the impact component freely fall according to gravity, so that a preset initial target hitting speed is obtained; S5, applying an impact acceleration load to the target test piece through the transient impact process of the impact component on the rigid target surface after free falling; S6, stopping the motion of the impact component after hitting the target, reading the data measured by the acceleration sensors by the signal processing equipment, and obtaining the instantaneous process of the impact component hitting the target surface by high-speed photography.

[0007] The beneficial effects of the present application are as follows: 1. The controllable expected plastic large deformation and plastic splitting of the cylindrical shell during the process of the impact component hitting the rigid target surface can realize the application of long pulse width impact overload load to the structure target test piece with a mass of dozens to hundreds of kilograms; 2. The stability of the posture of the cylindrical shell during the target hitting process can be controlled through the contact between the truncated cone of the mold and the inner surface of the cylindrical shell; the expected controllable plastic large deformation and plastic splitting of the cylindrical shell can be generated through the impact of the mold circular table body on the top of the cylindrical shell; 3. The acceleration load amplitude applied to the target test piece can be controlled by pre-designing the wall thickness of the cylindrical shell; 4. The impact acceleration pulse width can be adjusted and controlled by changing the initial target hitting speed through the free falling height of the impact component, so that the loading time of the target test piece is controllable; 5. The free falling posture of the impact component can be controlled through the aerodynamic tail wing assembly, and the normal collision posture when initially colliding with the rigid target surface can be maintained in a complex external field test environment. BRIEF DESCRIPTION OF DRAWINGS

[0008] Figure 1 It is a structural schematic diagram of the impact component in the present application. Figure 2 Figure 1 is a structural schematic diagram of a pneumatic tail assembly in the present application; Figure 3 Figure 2 is a top view of the pneumatic tail assembly in the present application; Figure 4 Figure 3 is a structural schematic diagram of the cooperation between a mold and a cylindrical shell in the present application; Figure 5 Figure 4 is a structural schematic diagram of a load generating device in the present application; Figure 6 Figure 5 is a front view of the deformation morphology of a cylindrical shell after plastic large deformation and plastic splitting in the present application; Figure 7 Figure 6 is a top view of the deformation morphology of a cylindrical shell after plastic large deformation and plastic splitting in the present application; Figure 8 Figure 7 is a schematic diagram of the overload time history curve applied to a target test piece after the impact between an impact component and a rigid target surface in the present application.

[0009] Figure 1 is a structural schematic diagram of a pneumatic tail assembly in the present application; DETAILED DESCRIPTION

[0010] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0011] Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without making creative efforts fall within the scope of protection of the present application.

[0012] It should be noted that: similar reference numerals and letters represent similar items in the following drawings, therefore, once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.

[0013] In the description of the present application, it should be understood that the terms "upper", "lower", "inner", "outer", "left", "right", and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship commonly understood by those skilled in the art, or the orientation or positional relationship commonly understood by those skilled in the art, only for the convenience of describing the present application and simplifying the description, and cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0014] In addition, the terms "first", "second", and the like are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0015] In the description of the present application, it should be noted that, unless otherwise specified and limited, the terms "provided", "connected" and the like should be understood broadly, for example, "connected" can be fixedly connected, or can be detachably connected, or integrally connected; can be mechanically connected, or can be electrically connected; can be directly connected, or can be indirectly connected through an intermediate medium, or can be internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0016] The specific embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0017] As shown in Figure 1 and 4 A long-pulse impact acceleration load generating device can apply long-pulse impact overload to a structure with a mass of dozens to hundreds of kilograms, and the load generating device comprises: A pneumatic tail wing assembly 9 for attitude stability control during free falling of the load generating device; A counterweight 14; the pneumatic tail wing assembly 9 and the target test piece 13 are fixedly installed on the upper end of the counterweight 14; the target test piece 13 is installed on the upper end of the counterweight 14 by bolts or by tooling and the like; A mold 15; the mold 15 comprises a truncated cone 19 and a cylinder 20, and the mold 15 is a rotating body structure integrated by the lower cylinder 20 and the upper truncated cone 19, the large end surface of the truncated cone 19 is connected with the bottom of the counterweight 14, the small end surface of the truncated cone 19 is connected with the first end of the cylinder 20, and the truncated cone 19 is used to produce expected controllable plastic large deformation and plastic splitting of the cylindrical shell 16 downward; Cylindrical shell 16; the inner diameter of the cylindrical shell 16 is slightly larger than the outer diameter of the cylindrical body 20 of the mold, the second end of the cylindrical body 20 of the mold is placed in the cylindrical shell 16; the aerodynamic tail wing assembly 9, the mold 15, and the cylindrical shell 16 are coaxially arranged along the axis, the mass centers of the target test piece 13 and the counterweight 14 are all arranged on the axis of the cylindrical shell 16; the cylindrical shell 16 is made of a metal material with good ductility.

[0018] In some embodiments, the truncated cone 19 is preferably a truncated cone.

[0019] In other embodiments, the truncated cone 19 is preferably a circular truncated cone.

[0020] In some embodiments, as shown in Figure 1 the upper end of the cylindrical shell 16 is axially provided with a plurality of notches 17 with a certain depth. The plurality of notches 17 are uniformly distributed around the axis of the cylindrical shell 16. By providing the plurality of notches 17, the number of petals of the initial split of the cylindrical shell 16 after plastic deformation during the target hitting process is controlled. In this embodiment, the cylindrical shell 16 is a cylindrical shell 16 structure with a certain thickness, the thickness of the cylindrical shell 16 is the same or variable, and the length of the cylindrical shell 16 is set to: the second end of the cylindrical body 20 is not in contact with the rigid target after the impact component 1 hits the target (the length is greater than the distance of the downward movement of the mold 15 after the initial target hitting), and the impact component includes the aerodynamic tail wing assembly, the counterweight, the mold, and the cylindrical shell.

[0021] In some embodiments, as shown in Figures 1-3 the aerodynamic tail wing assembly 9 includes six support rods 11, two support rings 12, and an aerodynamic blade 10, the support ring 12 is provided with six limiting holes, the support ring 12 is sleeved on the six support rods 11 through the six limiting holes, the lower end of the support rod 11 is fixed into the six threaded holes preformed on the counterweight 14 through threaded connection, and the aerodynamic blade 10 is sleeved outside the upper support ring 12. The two support rings 12 are respectively located at the middle and upper end of the support rod 11, and are used for fixing the support rod 11 and limiting the transverse movement of the support rod 11.

[0022] In some embodiments, as shown in Figures 1-3 the aerodynamic blade 10 includes a thin-walled cylindrical shell 16-like structure distributed in the circumferential direction and six rectangular thin-walled structures distributed in the radial direction, the outer end of the rectangular thin-walled structure is connected with the thin-walled cylindrical shell 16-like structure, the inner end of the rectangular thin-walled structure is connected with the outer wall of the support ring 12, and the six rectangular thin-walled structures are uniformly distributed around the axis of the thin-walled cylindrical shell 16-like structure.

[0023] In some embodiments, as shown in Figures 1-3As shown, the thin-walled cylindrical shell 16 structure includes coaxial line arrangement of large-diameter thin-walled cylindrical shell 16 structure and small-diameter thin-walled cylindrical shell 16 structure, the large-diameter thin-walled cylindrical shell 16 structure is arranged outside the small-diameter thin-walled cylindrical shell 16 structure, and the rectangular thin-walled structure is connected with the large-diameter thin-walled cylindrical shell 16 structure and the small-diameter thin-walled cylindrical shell 16 structure respectively. The aerodynamic tail wing assembly 9 selects a light material and has a high and narrow shape to reduce the transverse wind load area, and the aerodynamic wind blade 10 of the inner and outer two large-diameter thin-walled cylindrical shell 16 structures and the small-diameter thin-walled cylindrical shell 16 structure is used to increase the area of the aerodynamic force stabilization effect.

[0024] In some embodiments, as Figure 5 As shown, the load generating device further comprises: An acceleration sensor 18; the acceleration sensor 18 is installed on the target test piece 13 and the weight body 14; A signal processing device 5; the signal processing device 5 is connected with the acceleration sensor 18 through the sensor lead 4, and is used for processing the signal measured by the acceleration sensor 18; A rigid target surface 6; the rigid target surface 6 is installed on the ground 7 and is arranged directly below the cylindrical shell; A high-speed camera 8; the high-speed camera 8 is installed on one side of the rigid target, and the purpose of the high-speed camera 8 is to record the collision process of the impact component and the rigid target; A hanging rope 2; A hoisting device 3; the lifting end of the hoisting device 3 is connected with the upper end of the hanging rope 2, and the lower end of the hanging rope 2 is connected with the upper end of the aerodynamic tail wing assembly.

[0025] A load test method, comprising the steps of: S1, fixing the target test piece 13, the aerodynamic tail wing assembly 9, the mold 15 to the weight body 14, and sleeving the cylindrical shell 16 to the cylinder 20 of the mold 15; S2, installing the acceleration sensor 18 on the target test piece 13 and the weight body 14, and connecting the acceleration sensor 18 to the corresponding signal processing device 5 on the ground 7 through a sensor lead 4 with a large length; S3, fixing the impact component 1 to the lifting end of the hoisting device 3 through the hanging rope 2, and raising it to a preset height, the impact component including the aerodynamic tail wing assembly, the weight body, the mold, and the cylindrical shell; S4, cutting the hanging rope 2 by means of an explosive bolt or the like, instantaneously releasing the impact component 1, and making the impact component 1 free-fall according to gravity to obtain a preset initial speed of hitting the target; S5, achieving the impact acceleration load applied to the target test piece 13 through the transient impact process of the impact component 1 on the rigid target surface 6 after free-falling; S6, the impact component 1 stops moving after hitting the target, the signal processing device 5 reads the data measured by the acceleration sensor 18, and the high-speed camera obtains the instantaneous process of the impact component hitting the target surface.

[0026] The test method of the load test device further comprises adjusting the preset impact acceleration load amplitude by changing the thickness of the cylindrical shell 16; adjusting and controlling the pulse width of the preset impact acceleration load by adjusting the initial hitting speed; and making the load generating device obtain the predetermined initial speed when hitting the target by changing the lifting height of the load generating device.

[0027] In the present application, the load generating device with a certain initial speed makes the cylindrical shell 16 stop moving rapidly by colliding with the rigid target surface 6, and the stopped cylindrical shell 16 is subjected to a certain duration of impact process by the inertial motion of the remaining parts of the load generating device; the stability of the posture of the cylindrical shell 16 during the impact process is controlled by the limiting and guiding cooperation between the outer surface of the cylinder 20 in the mold 15 and the inner surface of the cylindrical shell 16; the cylindrical shell 16 produces controllable expected plastic large deformation and plastic splitting by the impact of the truncated cone 19 of the mold 15 on the top of the cylindrical shell 16 during the impact process, so as to realize the loading of long-pulse impact acceleration on the target test piece 13, as shown in Figures 6-8 .

[0028] In the present application, the load generating device realizes the impact acceleration loading of the expected g value on the test piece by presetting the thickness of the cylindrical shell 16, and adjusts the initial hitting speed to change the pulse width of the impact acceleration load applied to the target test piece 13.

[0029] In the present application, the counterweight 14 has a certain mass and strong rigidity, and is used to fix the mold 15, the target test piece 13, and the aerodynamic tail wing assembly 9, and is connected as a whole. The counterweight 14 is made of metal material with good hardness, and does not produce plastic deformation during the hitting process.

[0030] In the present application, the target test piece 13 is fixed to the counterweight 14, so as to move together with the counterweight 14 during the hitting process, and realize the loading of long-pulse impact acceleration.

[0031] In the present application, the lead wire of the measuring element is connected to the sensor signal processing instrument on the ground 7, and the lead wire is long enough to meet the preset lifting height of the load generating device.

[0032] In the application, the small end of the truncated cone 19 has the same radius as the cylinder 20, and the large end of the truncated cone 19 is fixed to the bottom of the weight body 14 by connection or tooling, etc. The mold 15 is made of metal material with high hardness and strength, and does not occur plastic deformation and damage when touching the target. During the process of touching the target, the truncated cone 19 of the mold 15 presses the head of the cylindrical shell 16 downward and makes it occur plastic large deformation and plastic splitting. The outer surface of the cylinder 20 of the mold 15 is in contact with the inner surface of the cylindrical shell 16 to control the posture of the cylindrical shell 16 to be stable, so that the axis of the cylindrical shell 16 is consistent with the axis of the mold 15.

[0033] In the application, the acceleration sensor lead 4 is synchronous with the load generating device to fall freely, and the sensor signal processing instrument is always placed on the ground 7, so that the online dynamic test of the acceleration response of the target test piece 13 can be conveniently realized. In the application, the structure of each component of the load generating device can be conveniently disassembled, and the structure except the cylindrical shell 16 can be reused, so that the loading test can be realized efficiently and conveniently.

[0034] The above only describes the preferred embodiments of the application, and it should be noted that for ordinary skilled in the art, without departing from the technical principles of the application, a number of improvements and refinements can be made, and these improvements and refinements should also be considered as the protection scope of the application.

Claims

1. A load generating device for long pulse impact acceleration, characterized in that: include: An aerodynamic tail assembly for attitude stability control during the free fall of the load generating device; The aerodynamic tail assembly and the target test piece are fixedly mounted on the upper end of the counterweight body; The mold includes a truncated cone and a cylinder, wherein the large end surface of the truncated cone is connected to the bottom of the counterweight body, the small end surface of the truncated cone is connected to the first end of the cylinder, and the truncated cone is used to cause the cylindrical shell to produce the expected controllable large plastic deformation and plastic splitting; Cylindrical shell; the inner diameter of the cylindrical shell is slightly larger than the outer diameter of the cylinder of the mold, and the second end of the cylinder of the mold is placed in the cylindrical shell; the aerodynamic tail assembly, the mold, and the cylindrical shell are arranged coaxially, and the center of mass of the target test piece and the counterweight are both placed on the axis of the cylindrical shell; the cylindrical shell is made of a ductile metal material.

2. A long pulse impact acceleration load generating device according to claim 1, characterized in that: The length of the cylindrical shell is set so that the second end of the cylinder does not contact the rigid target after the load generating device touches the target, and the length of the cylindrical shell is greater than the critical length when the contact occurs.

3. The long pulse impact acceleration load generating device according to claim 1, characterized in that: The upper end of the cylindrical shell is provided with a plurality of notches along the axial direction.

4. A long pulse impact acceleration load generating device according to claim 3, characterized in that: The plurality of notches are evenly distributed around the axis of the cylindrical shell.

5. The long pulse impact acceleration load generating device according to claim 1, characterized in that: The aerodynamic tail assembly includes multiple support rods, multiple support rings, and pneumatic blades. The support ring is provided with multiple limiting holes corresponding to the number of support rods. The support ring is mounted on the multiple support rods through the multiple limiting holes. The lower end of the support rod is connected to the upper end of the counterweight body, and the pneumatic blades are mounted on the outside of the support ring.

6. The long pulse impact acceleration load generating device according to claim 5, characterized in that: The aerodynamic blade includes a thin-walled cylindrical shell structure distributed along the circumferential direction and multiple rectangular thin-walled structures distributed along the radial direction. The outer end of the rectangular thin-walled structure is connected to the thin-walled cylindrical shell structure, and the inner end of the rectangular thin-walled structure is connected to the outer wall of the support ring. The multiple rectangular thin-walled structures are evenly distributed around the axial line of the thin-walled cylindrical shell structure.

7. The long pulse impact acceleration load generating device according to claim 6, characterized in that: The thin-walled cylindrical shell structure includes a large-diameter thin-walled cylindrical shell structure and a small-diameter thin-walled cylindrical shell structure arranged coaxially. The large-diameter thin-walled cylindrical shell structure is placed outside the small-diameter thin-walled cylindrical shell structure, and the rectangular thin-walled structure is connected to the large-diameter thin-walled cylindrical shell structure and the small-diameter thin-walled cylindrical shell structure respectively.

8. The long pulse impact acceleration load generating device according to claim 1, characterized in that: The load generating device also includes: Acceleration sensor; the acceleration sensor is installed on the target test piece and the counterweight; A signal processing device; the signal processing device is connected to the acceleration sensor through a sensor lead; Rigid target surface; the rigid target surface is installed on the ground and placed directly below the cylindrical shell; High-speed camera: The high-speed camera is installed on one side of the rigid target to record the collision process between the impact component and the rigid target.

9. The long pulse impact acceleration load generating device according to claim 8, characterized in that: The load generating device also includes a lifting rope and a lifting device. The lifting end of the lifting device is connected to the upper end of the lifting rope, and the lower end of the lifting rope is connected to the upper end of the aerodynamic tail assembly.

10. Load test method, characterized in that, Including steps; S1. Fix the target test piece, the aerodynamic tail assembly, and the mold to the counterweight body, and put the cylindrical shell onto the cylinder of the mold; S2. Install acceleration sensors on the target test piece and the counterweight, and connect the acceleration sensors to the corresponding signal processing equipment on the ground through relatively long sensor leads; S3. Fixing the impact component to the lifting end of the lifting equipment through a lifting rope and raising it to a preset height, the impact component including the aerodynamic tail assembly, the counterweight, the mold, and the cylindrical shell; S4. Cut the suspension rope and instantly release the impact component, causing it to fall freely under gravity and obtain a preset initial speed before hitting the target; S5. Applying an impact acceleration load to the target test piece through the transient impact process of the impact component on the rigid target surface after free fall; S6. The impact component stops moving after touching the target, the signal processing device reads the data measured by the acceleration sensor, and the high-speed photography obtains the instantaneous process of the impact component hitting the target surface.

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