CN115575222A - Hopkinson pressure bar test device for controllable continuous multi-pulse loading - Google Patents
Hopkinson pressure bar test device for controllable continuous multi-pulse loading Download PDFInfo
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- CN115575222A CN115575222A CN202211408174.2A CN202211408174A CN115575222A CN 115575222 A CN115575222 A CN 115575222A CN 202211408174 A CN202211408174 A CN 202211408174A CN 115575222 A CN115575222 A CN 115575222A
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N3/32—Investigating strength properties of solid materials by application of mechanical stress by applying repeated or pulsating forces
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Abstract
The invention discloses a Hopkinson pressure bar test device for controllable continuous multi-pulse loading, belongs to the technical field of material high-strain-rate dynamic mechanical property tests, and aims to solve the problem that the pulse width of each loading pulse cannot be accurately controlled in the conventional multi-pulse loading test. The invention comprises a bullet rod launching unit, a multi-stage bullet rod and an incident rod, wherein the bullet rod launching unit launches the multi-stage bullet rod to strike the incident rod; the multi-stage bullet rod is of an n-stage sleeve type structure, n circles of shapers are arranged at the tail end of the incident rod, and each circle of shapers respectively corresponds to the position of the first-stage bullet rod; the bullet rod launching unit launches the multi-stage bullet rods, and n-stage bullet rods of the multi-stage bullet rods sequentially impact the shaper corresponding to the tail end of the incident rod from the outer stage to the inner stage, so that multi-pulse loading is achieved. The invention is matched with the shaper to independently design the loading pulse formed by n times of collision.
Description
Technical Field
The invention belongs to the technical field of dynamic mechanical property testing of high strain rate materials.
Background
In the engineering field, rocks and other brittle materials are often subjected to multiple impact loads over a short period of time, such as a blasting process. One important point of research in studying such problems is to study the effect of loading history paths at high strain rates on the mechanical response of the material.
A large number of researches show that the constitutive relation, damage, phase change, stress relaxation and other behaviors of the material are related to loading history. Studying the effect of historical loading paths on the mechanical response of materials is typically to perform cyclic loading and unloading tests on the materials, which are typically done using a universal material testing machine at quasi-static and low strain rates. The key to performing material loading and unloading tests at high strain rates is how to achieve continuous and precisely controllable multi-pulse loading. Although some researchers and engineers have conducted the test of multi-pulse loading, for example, patent CN11948074A discloses a multi-pulse loading bullet for simulating the penetration process, and patent CN113848132A discloses a gunpowder-driven long pulse width loading device. However, the problem of individually and accurately controlling the pulse width of each load in multi-pulse loading still exists, and therefore, a controllable continuous multi-pulse loading test device and a test method capable of individually and accurately controlling the amplitude, the pulse width, the waveform and the like of each pulse under laboratory conditions are urgently needed.
Disclosure of Invention
Aiming at the problem that the pulse width of each loading pulse cannot be accurately controlled in the conventional multi-pulse loading test, the invention provides a Hopkinson pressure bar test device for controllable continuous multi-pulse loading.
The Hopkinson pressure bar test device for controllable continuous multi-pulse loading comprises a bullet bar launching unit 2, a multi-stage bullet bar 3 and an incident bar 4, wherein the bullet bar launching unit 2 launches the multi-stage bullet bar 3 to be incident on the incident bar 4;
the multistage bullet rod 3 is of an n-stage sleeve type structure, n is greater than 2, the multistage bullet rod 3 comprises an outer barrel bullet rod, a central cylindrical bullet rod and n-2 middle cylindrical bullet rods, the outer barrel bullet rod is of a barrel-shaped structure with a closed tail end and an open head end, the n-2 middle cylindrical bullet rods are sleeved in the outer barrel bullet rod and outside the central cylindrical bullet rod, the n-stage bullet rods can relatively slide along the axial direction, and the axial lengths of all the bullet rods are sequentially shortened from outside to inside;
n circles of shapers are arranged at the tail end of the incident rod 4, and each circle of shapers respectively corresponds to the position of the first-stage bullet rod;
the bullet rod launching unit 2 launches the multi-stage bullet rods 3, and the n-stage bullet rods of the multi-stage bullet rods 3 sequentially impact the shapers corresponding to the tail ends of the incident rods 4 from the outer stage to the inner stage, so that multi-pulse loading is realized.
Preferably, n-1 screws are arranged at the tail end of the outer barrel elastic rod, the n-1 screws are screwed in from the tail end of the outer barrel elastic rod and are pressed against the tail end of each stage of elastic rod, and each screw is screwed in different depths to adjust the distance between each stage of elastic rod and the head end of the multi-stage elastic rod 3.
Preferably, each screw is secured in its axial position with a nut.
Preferably, each circle of shapers is in a circular arrangement mode that m shapers are arranged in the circumferential direction, m = 1-12, the 1 st circle, the 2 nd circle and the 8230are sequentially arranged from outside to inside, the nth circle is provided with 1 shaper or provided with even numbers of shapers symmetrically in the circumferential direction, the 1 st circle, the 2 nd circle and the 8230, and the n-1 th circle is provided with even numbers of shapers symmetrically in the circumferential direction.
Preferably, the bullet rod of the multi-stage bullet rod 3 is defined as 1 st, 2 nd and 8230from outside to inside, the axial length of the bullet rod of the n th and n th stages is L1, L2, \8230, the axial gap between the head end of the Ln and the head end of the bullet rod of the 2 nd stage and the head end of the bullet rod of the 1 st stage is d1, so that the axial gap between the head ends of the two adjacent stages is d1, d2, d3, \8230, dn-1, n stages is defined as A1, A2, \8230, the total area of each turn of the shaper of the rings is B1, B2 and 8230, bn, the total area of each turn of the bullet rod of the n stages is adjusted as B1, d2, d3, \8230303030, dn-1, and the total area of the bullet rod of the n stages is adjusted as B1, B2, \\\\ 8230.
Preferably, the material of the shaper is brass or lead.
Preferably, the size of the shaper is smaller than the wall thickness of the bullet rod of the corresponding stage.
Preferably, the axial gaps d1, d2, d3, \8230anddn-1 of the head ends of the two adjacent stages are selected to be 5 mm-10 mm.
The invention has the beneficial effects that:
1. the invention is based on the Hopkinson pressure bar platform, improves the bullet to form controllable continuous multi-pulse in the incident bar, has low improvement cost on the existing equipment, and is easy to popularize and use.
2. The invention adopts a semi-open type multi-stage bullet structure, namely, the first-stage bullet at the outermost layer is a hollow tail part closed structure, the impact end is an open semi-open type structure, the second-stage bullet at the secondary outer layer is also a hollow cylindrical structure with a uniform cross section, and the third-stage bullet at the innermost layer is a solid round rod structure. The pulse width is determined by the bullet length and the shaper together, and the three times of impact are three levels of bullet rods which sequentially and respectively impact the bullet rods independently, and each level of bullet can be shaped independently without mutual interference when impacting, so that the loading pulse formed by the three times of impact can be independently designed by matching with the shaper, and each loading pulse is independently controllable, so that the strain rate of the sample during each loading is maintained at a constant level.
Drawings
FIG. 1 is a schematic structural diagram of a Hopkinson pressure bar test device for controllable continuous multi-pulse loading according to the present invention;
FIG. 2 is a view of the multi-stage bullet rod and the entrance rod;
FIG. 3 is a profile of an incident rod end shaper;
FIG. 4 is a graph of pulse propagation in an incident beam during operation of a bullet beam without the use of a shaper;
FIG. 5 is a diagram of an unshaped typical multi-pulse loading signal: the loading pulse amplitudes are equal;
fig. 6 is a diagram of a typical multi-pulse loading signal using shaping: the loading pulse amplitude is decreased in sequence;
fig. 7 is a diagram of a typical multi-pulse loading signal using shaping: the amplitude of the loading pulse is sequentially increased.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
It should be noted that the embodiments and features of the embodiments of the present invention may be combined with each other without conflict.
The invention is further described with reference to the following drawings and specific examples, which are not intended to be limiting.
The first embodiment is as follows: the following describes the present embodiment with reference to fig. 1 to 7, and the hopkinson pressure bar test apparatus for controllable continuous multi-pulse loading in the present embodiment is described with reference to fig. 1, where the test platform is based on a hopkinson pressure bar platform and includes a fixed support platform 1, a bullet rod launching unit 2, a multi-stage bullet rod 3, an incident rod 4, a transmission rod 5, an absorption rod 6, a buffer 7, and a sample 8, and the fixed support platform 1 is used to support the launching unit 2, the incident rod 4, the transmission rod 5, the absorption rod 6, and the buffer 7. The multi-stage bullet rod 3 is positioned in a launching tube of the launching unit 1, and sequentially impacts the incident rod 4 through each stage of the multi-stage bullet rod 3 to generate multiple stress wave pulses to load a sample 8 between the incident rod 4 and the transmission rod 5. The bullet rod launching unit 2 is provided with launching power by high-pressure gas and comprises a gas chamber, a control valve and a launching tube. The materials of each stage of bullet rod, the incident rod 4 and the transmission rod 5 in the multi-stage bullet rod 3 can be the same or different.
The multistage bullet rod 3 is of an n-stage sleeve type structure, n is greater than 2, the multistage bullet rod 3 comprises an outer barrel bullet rod, a central cylindrical bullet rod and n-2 middle cylindrical bullet rods, the outer barrel bullet rod is of a barrel-shaped structure with a closed tail end and an open head end, the n-2 middle cylindrical bullet rods are sleeved in the outer barrel bullet rod and outside the central cylindrical bullet rod, the n-stage bullet rods can relatively slide along the axial direction, and the axial lengths of all the bullet rods are sequentially shortened from outside to inside;
n circles of shapers are arranged at the tail end of the incident rod 4, and each circle of shapers respectively corresponds to the position of the first-stage bullet rod;
the bullet rod launching unit 2 launches the multi-stage bullet rods 3, the n-stage bullet rods of the multi-stage bullet rods 3 sequentially impact the shapers corresponding to the tail ends of the incident rods 4 from the outer stage to the inner stage, and multi-pulse loading is achieved.
The tail end of the outer barrel elastic rod is provided with n-1 screws, the n-1 screws are screwed in from the tail end of the outer barrel elastic rod and are propped against the tail end of each level of elastic rod, and each screw is screwed in to different depths so as to adjust the distance between each level of elastic rod and the head end of the multi-level elastic rod 3. Each screw is secured in its axial position by a nut.
Each circle of shapers is in a circular arrangement mode that m shapers are arranged in the circumferential direction, m = 1-12, the 1 st circle, the 2 nd circle, \ 8230, and the nth circle are sequentially arranged from outside to inside, wherein the nth circle is provided with 1 shaper or is circumferentially symmetrically provided with even shapers, the 1 st circle, the 2 nd circle, \ 8230, and the n-1 st circle is circumferentially symmetrically provided with even shapers.
The axial length of the bullet rod of the multi-stage bullet rod 3 is L1, L2, \ 8230;, the axial length of the bullet rod of the n stage and the n stage bullet rod is L1, L2, \ 8230;, the axial gap between the head end of the bullet rod of the Ln stage 2 and the head end of the bullet rod of the 1 stage is d1, the axial gap between the head ends of the adjacent two stages is d1, d2, d3, \ 8230; the cross-sectional area of the bullet rod of the dn-1, n stage is A1, A2, \ 8230;, the total area of each ring of the An n rings is B1, B2, \ 8230;, bn, and the total cross-sectional area of the bullet rod of the dn-1, n stage A1, A2, \\\ \ 8230, the total area of each ring of the rings of the ann and n rings is B1, B2, \\\\\\ 8230, B2, \\\\\ n and Bn, and the total area of the n rings is adjusted by adjusting the multi-pulse wave shape of the shaper.
The present embodiment will be described with n =3 as an example.
The multi-level bullet rods 3 are three-level bullets, and the structure of the three-level bullet is shown in fig. 2, wherein the length of the 3 rd-level bullet rod 3-3 at the innermost layer is smaller than that of the 2 nd-level bullet rod 3-2 at the middle layer, and the length of the 2 nd-level bullet rod 3-2 is smaller than that of the 1 st-level bullet rod 3-1 at the outer layer, namely L3< L2< L1, but the length difference between the three-level bullets is not too large, preferably 5-10 mm. The 1 st level bullet rod 3-1 at the outermost layer of the multi-level sandwich bullet is a semi-open type barrel-shaped bullet with a closed tail part; gap adjusting screws 3-4 and 3-5 are arranged at the positions, corresponding to the 2 nd level bullet rod and the 3 rd level bullet rod, of the tail part of the bullet of the 1 st level bullet rod 3-1 and are respectively used for adjusting gaps d1 and d2 of impact surfaces between bullets of all levels so as to control the interval time between loading pulses of all levels; the 2 nd-level bullet rod 3-2 is a round cylindrical bullet with an equal section; the 3 rd-level bullet rod 3-3 is a cylindrical bullet. In order to avoid the relative position sliding of bullets at all levels in the launching process of the launching tube, the adjusting screws 3-4 are fastened by the nuts 3-6, and the adjusting screws 3-5 are fastened by the nuts 3-7 to determine the axial positions of the two screws, so that the gap values of the head ends of the bullets of the 1 st, 2 nd and 3 rd levels are determined. The 3 rd level bullet rod 3-3 can freely slide in the 2 nd level bullet rod 3-2, and the 2 nd level bullet rod 3-2 can freely slide in the 1 st level bullet rod 3-1.
The cross-sectional area of tertiary bullet pole is A1, A2, A3 in proper order, and the priority scheme is in this embodiment: a1= A2= A3. The cross-sectional area of the incident rod 4 is A0.
Taking m =4 as an example to explain the shaper part, 1 shaper is a3 rd-stage shaper 11 arranged in the middle of the tail end of the incident rod 4, the sectional area of the 3 rd-stage shaper 11 is smaller than that of the 3 rd-stage bullet rod 3-3, the two are opposite, the 3 rd-stage bullet rod 3-3 will hit the 3 rd-stage shaper 11 after being emitted, and the 3 rd-stage bullet rod 11 adopts a shaper scheme in the embodiment; a2 nd circle of shaper 10 is arranged at a position corresponding to the 3-2 position of the 2 nd level bullet rod, the 2 nd circle of shaper 10 is symmetrically arranged by 4 shapers 10-1 to 10-4, the 2 nd level bullet rod 3-2 can impact on 10-1 to 10-4 in the 2 nd circle of shaper 10 after being launched, and the 10-1 to 10-4 size in the 2 nd circle of shaper 10 is smaller than the 3-2 wall thickness of the 2 nd level bullet rod; similarly, a1 st circle of shapers 9 is arranged at the position corresponding to the position of the 1 st level of bullet rod 3-1, the 1 st circle of shapers 9 are circularly arranged and are symmetrically arranged by 4 shapers 9-1-9-4, the 1 st level of bullet rod 3-1 can impact on 9-1-9-4 of the 1 st circle of shapers 9 after being emitted, and the size of 9-1-9-4 in the 1 st circle of shapers 9 is smaller than the wall thickness of the 1 st level of bullet rod 3-1.
The total area of each circle of the n-circle shaper is B1, B2 and B3 in sequence, and the shaper material is recommended to use copper, lead and the like.
The multi-pulse waveform is adjusted by adjusting the axial gaps d1, d2 and d3 at the head ends of two adjacent stages, the cross sectional areas A1, A2 and A3 of the three-stage bullet rods and the total area B1, B2 and B3 of each circle in the three-circle shaper. The specific process is as follows: the gap between each level of bullet rods in the multi-level bullet rods 3 is adjusted by screwing in the screw depth, the bullet rod launching unit 2 launches bullets, and the same initial impact speed V0 is obtained before the impact of the three levels of bullet rods; the three-stage bullet rods sequentially impact the shaper at the tail end of the incident rod 4, three loading pulses are sequentially formed in the incident rod 4, and a sample 8 is loaded; connecting a strain gauge and an oscilloscope through strain gauges adhered to the incident rod 4 and the transmission rod 5, and measuring and storing signals; and processing the signals according to a Hopkinson pressure bar data processing method to obtain the cyclic loading and unloading mechanical property of the test sample 8 under the high strain rate.
Referring to fig. 4, in an initial position, after a1 st and a2 nd level bullet rod gaps d1 and a2 nd and a3 rd level bullet rod gaps d2, a1 st level bullet rod impacts an incident rod 4, a first incident loading pulse is formed in the incident rod 4, and simultaneously the first level bullet and the incident rod 4 move towards the impact direction during the process that the first level bullet impacts the incident rod 4 until the first level bullet impacts, after the first level bullet impacts, because the generalized wave impedance of the first level bullet is smaller than the generalized wave impedance of the incident rod 4, the first level bullet after the impact is completed obtains a speed opposite to the impact direction and moves in the opposite direction, and the end surface of the incident rod 4 stops moving, at this time, the end surface of the incident rod 4 moves forward by a distance d1 before the first level bullet impacts the incident rod 4, while the second level bullet and the third level bullet are not interfered by the first level bullet before they impact the incident rod 4, and move forward by an initial speed V0 Δ t, obviously, the second level bullet impacts the second level bullet by a distance Δ t + 1 t + after the movement (d 1 +)/t, and the second level bullet impacts the incident rod 4, and the second bullet impact time interval of the second bullet is equal to 0 + after the second bullet impact time; and at the moment that the second-stage bullet just starts to impact the incident rod 4, the distance from the third-stage bullet to the incident rod 4 is d2, similarly, in the process that the second-stage bullet impacts the incident rod 4, the incident rod 4 will move forward together with the second-stage bullet again, after the second-stage bullet impacts, the incident rod 4 moves forward by the distance of Δ d2 again, and obviously, after the third-stage bullet impacts the incident rod 4, the third-stage bullet will move forward by the distance of (d 2+ Δd 2) at the speed of V0, and then impact the incident rod 4 to form a third loading pulse, and the time interval between the second loading pulse and the third loading pulse is easily obtained to be t2= (d 2+ Δd 2)/V0.
The impact shaper of the bullet rods in three stages has time difference, and the pulse width is adjusted by adjusting the gaps in all stages. The adjustment of the pulse amplitude is related to various factors, and several waveform adjustment embodiments are given below, and those skilled in the art can make corresponding adjustments according to their own needs.
When the loading waveform required by the measured material is rectangular wave, a shaper is not needed at the moment, the sectional areas of the bullet rods of the 1 st, 2 nd and 3 rd grades are respectively A1, A2 and A3, the sectional area of the incident rod 4 is A0, and the adjusting screw is adjusted to ensure that the gap between the impact surfaces of the bullet rods of the 1 st and 2 nd grades is d1 and the gap between the bullet rods of the 2 nd and 3 rd grades is d2. Launch multistage bullet pole 3, 1 st level bullet, 2 nd level bullet pole, 3 rd level bullet pole can strike incident rod 4 respectively in proper order with the same speed V0, form the strong discontinuous elastic wave of right propagation at 4 striking ends of incident rod, form the elastic wave of a left bank simultaneously in the bullet. After the impact is finished, the loading pulse amplitudes of the three-stage bullets formed in the incident rod 4 are set to be sigma 1, sigma 2 and sigma 3 in sequence; FIG. 5 shows the length L1=400mm of the first bullet rod, L2=380mm of the second bullet, L3=375mm of the third bullet rod, and the cross-sectional area of the three bullet rods is 418mm 2 Three loading pulses generated in the incident rod at impact velocity V0=10m/s and bullet gap set at d1= d2=1.5mm, the resulting three loading amplitudes are seen to be equal.
When the shaper is used, a pre-impact test without adding a sample is required to be carried out before a formal experiment, and the embodiment mode is as follows: adjusting the adjusting screw to enable the gap between the impact surfaces of the 1-grade bullet rod and the 2-grade bullet rod to be d1 and the gap between the 2-grade bullet rod and the 3-grade bullet rod to be d2. At the end of the entrance rod 4a shaper is arranged, which is arranged as shown in fig. 3, to fire the bullet at a certain velocity. FIG. 6 is a drawing showingThe length of the first-level bullet rod L1=400mm, the length of the second-level bullet L2=380mm, the length of the third-level bullet rod L3=375mm, and the cross-sectional areas of the three bullet rods are equal to A1= A2= A3=418mm 2 The impact velocity V0=10m/s, the bullet gap set to d1= d2=2mm, brass shapers are used, the total area of the shapers of each stage is equal B1= B2= B3=52mm 2 And then, three times of loading pulses are generated in the incident rod 4, and the amplitude of the formed three times of pulses is sequentially reduced as the material of the three-stage bullet is the same as that of the incident rod 4.
When the loading pulse which is enhanced in sequence needs to be generated, the implementation mode is as follows: adjusting an adjusting screw to enable a gap between impact surfaces of the bullet rods of the 1 and 2 levels to be d1 and a gap between the bullets of the 2 and 3 levels to be d2, arranging a shaper at the tail end of an incident rod 4, wherein the shaper is arranged as shown in figure 3, launching the bullets at a certain speed, recording a loading signal, and adjusting the gaps d1 and d2 and the sizes and the number of the shapers corresponding to the bullets of each level according to the loading signal; and the bullet firing speed, adjusted to a proper position, and a loading test was performed while placing the sample 8 between the incident rod 4 and the transmission rod 5. Fig. 7 shows the length L1=400mm of the first-stage bullet rod, L2=380mm of the second-stage bullet, L3=375mm of the third-stage bullet rod, and the cross-sectional areas of the three bullet rods are equal to A1= A2= A3=418mm 2 Impact velocity V0=10m/s, bullet gap set to d1= d2=2mm, brass shaper was used, total shaper area B1=52mm of stage 1 2 Total area of the shaper 2 nd stage B2=81mm 2 Total area of the 3 rd stage shaper B3=210mm 2 The 1 st-level bullet rod is made of aluminum alloy bullets, the 2 nd-level bullet rod and the 3 rd-level bullet rod are made of high-strength stainless steel as the incident rod 4, and the amplitude of the three-time loading pulse generated in the incident rod 4 is sequentially increased.
Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims. It should be understood that features described in different dependent claims and herein may be combined in ways different from those described in the original claims. It is also to be understood that features described in connection with individual embodiments may be used in other described embodiments.
Claims (8)
1. The Hopkinson pressure bar test device for controllable continuous multi-pulse loading is characterized by comprising a bullet bar launching unit (2), a multi-stage bullet bar (3) and an incident bar (4), wherein the bullet bar launching unit (2) launches the multi-stage bullet bar (3) to be incident on the incident bar (4);
the multistage bullet rod (3) is of an n-stage sleeve type structure, n is greater than 2, the multistage bullet rod (3) comprises an outer barrel bullet rod, a central cylindrical bullet rod and n-2 middle barrel bullet rods, the outer barrel bullet rod is of a barrel-shaped structure with a closed tail end and an open head end, the n-2 middle barrel bullet rods are sleeved inside the outer barrel bullet rod and outside the central cylindrical bullet rod, the n-stage bullet rods can relatively slide along the axial direction, and the axial lengths of all the bullet rods are sequentially shortened from outside to inside;
n circles of shapers are arranged at the tail end of the incident rod (4), and each circle of shapers respectively corresponds to the position of the first-stage bullet rod;
the bullet rod emission unit (2) emits a multi-stage bullet rod (3), and n stages of bullet rods of the multi-stage bullet rod (3) sequentially impact a shaper corresponding to the tail end of the incident rod (4) from an outer stage to an inner stage, so that multi-pulse loading is realized.
2. The Hopkinson pressure bar test device for controlled continuous multi-pulse loading according to claim 1, wherein n-1 screws are provided at the end of the outer barrel elastic bar, wherein n-1 screws are screwed in from the end of the outer barrel elastic bar and press against the end of each stage of elastic bar, and each screw is screwed in at different depths to adjust the distance of each stage of elastic bar from the head end of the multi-stage elastic bar (3).
3. The Hopkinson pressure bar test device for controlled continuous multi-pulse loading according to claim 2, wherein each screw is fastened at its axial position with a nut.
4. The Hopkinson pressure bar test device for controllable continuous multi-pulse loading according to claim 3, wherein each circle of shapers is in a circular arrangement mode that m shapers are arranged in the circumferential direction, m = 1-12, and the 1 st circle, the 2 nd circle, 8230, the nth circle are sequentially arranged from outside to inside, wherein the 1 st circle is provided with 1 shaper or an even number of shapers are symmetrically arranged in the circumferential direction, the 1 st circle, the 2 nd circle, the 8230, and the n-1 th circle are all symmetrically arranged in the circumferential direction with an even number of shapers.
5. The Hopkinson pressure bar test device for controllable continuous multi-pulse loading according to claim 4, wherein the bullet bars of the multi-stage bullet bar (3) are defined as 1 st stage, 2 nd stage, \8230, the axial lengths of the n th stage and the n th stage bullet bars are L1, L2, \8230, the axial gap between the head end of the Ln 2 nd stage bullet bar and the head end of the 1 st stage bullet bar is defined as d1, so as to define the axial gap between the head ends of two adjacent stages as d1, the cross-sectional areas of d2, d3, \8230, dn-1, n-level bullet rods are sequentially A1, A2, \8230, the total area of each circle of the An and n-level bullet rods in the shaper is sequentially B1, B2, \8230, bn, and the total area of each circle of the An and n-level bullet rods in the shaper is adjusted to be B1, d2, d3, \8230, the cross-sectional areas of the dn-1 and n-level bullet rods A1, A2, \8230, the total area of each circle of the An and n-level bullet rods in the shaper is adjusted to be B1, B2, \8230, and the Bn adjusts the waveform of multiple pulses.
6. The Hopkinson pressure bar test device for the controllable continuous multi-pulse loading according to claim 4, wherein the material of the shaper is brass or lead.
7. The Hopkinson pressure bar test device for controlled continuous multi-pulse loading according to claim 4, wherein the size of the shaper is smaller than the wall thickness of the corresponding stage of the bullet rod.
8. The Hopkinson pressure bar test device for the controllable continuous multi-pulse loading according to claim 5, wherein the axial clearance d1, d2, d3, \ 8230and dn-1 of the head ends of the two adjacent stages is selected to be 5 mm-10 mm.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211408174.2A CN115575222A (en) | 2022-11-10 | 2022-11-10 | Hopkinson pressure bar test device for controllable continuous multi-pulse loading |
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| CN202211408174.2A CN115575222A (en) | 2022-11-10 | 2022-11-10 | Hopkinson pressure bar test device for controllable continuous multi-pulse loading |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116698626A (en) * | 2023-06-08 | 2023-09-05 | 华中科技大学 | Single-pulse high strain rate tensile test device based on Hopkinson pressure bar |
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2022
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116698626A (en) * | 2023-06-08 | 2023-09-05 | 华中科技大学 | Single-pulse high strain rate tensile test device based on Hopkinson pressure bar |
| CN116698626B (en) * | 2023-06-08 | 2024-05-28 | 华中科技大学 | Single-pulse high strain rate tensile test device based on Hopkinson pressure bar |
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