CN115655978B - An experimental device and method for measuring the evolution of a disturbance shock wave front in a material - Google Patents

Abstract

The invention relates to the technical field of dynamic high-pressure shock compression, and provides an experimental device and method for measuring the evolution of a disturbance shock wave front in a material. The experimental device includes a target plate base, an experimental sample, a bracket, a fixed back seat, and a measurement system, and the target plate The base is provided with a sample holding groove, and one end of the base of the target disk is provided with a target disk gap, and the target disk gap is connected with the sample holding groove; the experimental sample is placed in the sample holding groove, and the front interface of the experimental sample has a curved corrugated structure and faces the target disk The target plate notch of the base. In the present invention, the high-speed flyer is used to impact the experimental sample, a disturbance shock wave is generated in it, and the spectrum signal in the movement process of the interface behind the sample is measured, and the change law of the particle velocity at the interface behind the sample with time is obtained by using methods such as Fourier transform, and then it can be described The evolution process of the shock wave front is analyzed. Further, continuous pressure points are selected for multiple measurements, and the phase transition of the tested experimental sample is analyzed by using the quantitative relationship between particle velocity and pressure.

Description

An experimental device and method for measuring the evolution of a disturbance shock wave front in a material

technical field

The invention relates to the technical field of dynamic high-pressure shock compression, in particular to an experimental device for measuring the evolution of a disturbance shock wave front in a material.

Background technique

Under high temperature and high pressure conditions, condensed matter is often treated as a fluid, and its dynamic process is described by a system of fluid mechanics equations. The viscosity coefficient of a substance is an important physical parameter for studying the dynamic process of any actual fluid. The viscosity coefficient can describe the correlation between the viscous stress in the flow field of a substance and the deformation rate of the microelement of the substance. Whether it can accurately reflect the evolution law of the disturbance shock wave in the material determines whether it can accurately measure the viscosity coefficient of the material shock under high pressure. Therefore, it is of great significance to accurately reflect the evolution law of the disturbance shock wave front in the material.

Regarding the viscosity of the material, due to the existence of the partial effect of the material strength, the currently defined viscosity represents an equivalent viscosity. A large number of previous studies have confirmed that the equivalent viscosity of the high-temperature and high-pressure material flow field is closely related to the momentum diffusion in the flow field. And energy dissipation, the dissipation process needs to be realized by the interaction of material microscopic particles. Therefore, the change of material equivalent viscosity can sensitively reflect the structural phase transition of the material, and the measurement of the equivalent viscosity coefficient under extreme conditions provides a new idea for the study of material phase transition.

In order to obtain the viscosity coefficient of the material, it was mainly obtained through theoretical calculation and static high pressure experiment in the early stage. Theoretical calculations are difficult to be recognized because they are based on idealized models and idealized conditions. Due to the limitation of experimental conditions, it is difficult to create an environment of ultra-high temperature and high pressure in static high-pressure experiments, which makes the viscosity data of substances under high temperature and high pressure conditions relatively vacant.

The development of light gas gun technology provides a new method for studying the viscosity of substances under high temperature and high pressure conditions. The methods for studying the viscosity of substances in the field of dynamic high pressure mainly include:

1. Indirect measurement method, indirect measurement method includes metal cylinder movement method under impact loading, ionic conductivity measurement method, fluorescence lifetime method and diffusion condensation method, etc. However, since these measurement methods need to be calibrated in advance and compared with the results of the parameters of the substance to be measured, there are uncertainties in these methods, and the results obtained are difficult to be accepted by the academic community.

2. Direct measurement method, direct measurement method includes shock wave front thickness measurement method and disturbance shock wave amplitude attenuation measurement method. For the shock wave front thickness measurement method, due to the low precision of the experimental equipment, the measurement result is only a rough average value; the current experimental methods for measuring the viscosity coefficient of materials using the idea of perturbed shock wave amplitude attenuation include Sakharov small perturbation experiment and flyer collision perturbation experiment , for the Sakharov small disturbance experiment, because the amplitude of the corrugation at the rear interface of the substrate is set too large in the experiment, when the sinusoidal shock wave is introduced into the sample material, ejection occurs and the waveform is distorted, which makes the experimental results have certain uncertainties; while the flyer collision disturbance It is difficult to assemble the experimental device, and because the position of the measuring end of the electric probe may change uncertainly during the assembly and detection process, there are large errors in the experimental results.

In view of the shortcomings of the above methods, the present invention proposes an experimental device and method for measuring the evolution of the disturbance shock wave front in materials based on the Doppler effect, so as to at least overcome the shortcomings of the above methods.

Contents of the invention

The object of the present invention is to provide an experimental device and method for measuring the evolution of the shock wave front in the material, so as to at least overcome the inaccurate measurement results and the high difficulty of assembling the experimental device in the existing methods for studying the viscosity of substances in the field of dynamic high pressure. technical problem.

The object of the present invention is achieved through the following technical solutions:

On the one hand, the present invention provides an experimental device for measuring the evolution of a disturbance shock wave front in a material, for measuring the evolution process of a disturbance shock wave wave front in an experimental sample, the experimental device comprising:

A target disk base, the target disk base is provided with a sample holding tank, one end of the target disk base is provided with a target disk gap, and the target disk gap communicates with the sample holding groove;

An experimental sample, the experimental sample is placed in the sample holding tank, the front interface of the experimental sample has a curved corrugated structure and faces the target plate gap of the target plate base;

A bracket, the bracket is fixed on the rear end of the experimental sample, and the front surface of the bracket is in contact with the rear interface of the experimental sample, and the bracket is provided with an optical fiber hole;

The fixed back seat is arranged on the end of the target plate base away from the target plate gap, the front end surface of the fixed back seat is in contact with the rear end surface of the bracket, and the fixed back seat is detachably connected to the target plate base;

A measuring system, the measuring system comprising a measuring fiber, a Doppler displacement velocimetry system and an oscilloscope, one end of the measuring fiber is connected to the fiber hole on the support, and the other end of the measuring fiber is connected to the Doppler displacement velocimetry system, The Doppler displacement velocimetry system is connected with an oscilloscope, and the oscilloscope is used to record the movement process of the rear interface of the experimental sample during the experiment.

In some possible embodiments, the rear interface of the experimental sample has a stepped structure, and the front surface of the support also has a stepped structure, and the stepped structure of the front surface of the support is the same as the stepped structure of the rear interface of the experimental sample. match;

The bracket is in close contact with the rear interface of the experimental sample through the stepped structure of the front face, and is fixed to the rear end of the experimental sample.

In some possible embodiments, the experimental sample is a solid sample or a powder sample;

When the experimental sample is a powder sample, one side surface of the powder sample with a stepped structure is coated with aluminum foil, and the bracket is in close contact with the aluminum foil at the rear interface of the powder sample through the stepped structure of the front surface.

In some possible embodiments, when the experimental sample is a powder sample, the experimental device also includes a pressing device, and the pressing device includes:

A pressing seat, the pressing seat is provided with a pressing cavity, and the pressing cavity is set through the top of the pressing seat;

A forming die, the forming die is arranged at the inner bottom of the pressing cavity, and the top of the forming die is in a curved corrugated structure;

The top anvil of the press, the bottom of the top anvil of the press is in a stepped structure, and the top anvil of the press is adapted to the pressing chamber.

In some possible embodiments, there are multiple optical fiber holes on the support, the measuring optical fibers correspond to the optical fiber holes one by one, and the end of the measuring optical fiber connected to the support extends into the optical fiber hole;

The multiple optical fiber holes respectively correspond to the back interfaces of the crests and troughs of the curved surface corrugated structure at different thicknesses of the experimental samples.

In some possible embodiments, the connector of the measuring optical fiber adopts a UPC connector, and the light source used by the Doppler displacement velocimetry system is a laser with a wavelength of 1550 nm.

In another aspect, the present invention provides an experimental method for measuring the evolution of a disturbance shock wave front in a material, using the above-mentioned experimental device for measuring the evolution of a disturbance shock wave front in a material, the experimental method comprising the following steps:

Step S1. Prepare experimental samples;

When the experimental sample is a solid sample, the front interface of the solid sample is processed into a curved corrugated structure; the rear interface of the solid sample is processed into a stepped structure;

When the experimental sample is a powder sample, the powder sample is put into a pressing device and pressed into shape to ensure that the shape of the powder sample is the same as that of the solid sample, and on the side where the powder sample has a stepped structure The surface is coated with uniform aluminum foil;

Step S2. place the experimental sample;

When the experimental sample is a solid sample, the solid sample is placed in the sample holding groove of the target disc base, and the front interface of the solid sample faces the target disc gap of the target disc base, and then the bracket is installed, Ensure that the front surface of the support is in close contact with the rear interface of the solid sample;

When the experimental sample is a powder sample, place the powder sample in the sample holding tank of the target disc base, and make the front interface of the powder sample face the target disc notch of the target disc base, and then install the bracket, Ensure that the front end of the support is in close contact with the aluminum foil at the rear interface of the powder sample;

After completing the installation of the experimental sample and the bracket, install the fixed back seat, and ensure that the front end of the fixed back seat is in close contact with the rear end face of the bracket;

Step S3. Target disc base installation;

Install the target disc base on the target frame of the light gas gun, and make the target disc notch of the target disc base face the flyer of the light gas gun;

Step S4. Measurement system connection;

Inserting one end of the measuring fiber into the corresponding fiber hole of the bracket, the other end of the measuring fiber is connected to a Doppler displacement velocimetry system, and the Doppler displacement velocimetry system is connected to an oscilloscope;

Step S5. Measurement;

The light gas cannon emits flying pieces, and uses the flying pieces to impact the corrugated surface of the experimental sample to generate a disturbance shock wave in the experimental sample, and then uses the measured frequency spectrum signal during the rear interface movement of the sample , using methods such as Fourier transform to obtain the change law of particle velocity at the back of the sample with time, and then describe the evolution process of the shock wave front; and select continuous pressure points for multiple measurements, using the quantitative relationship between particle velocity and pressure Analyze the phase transition of the tested experimental samples.

The technical solutions of the embodiments of the present invention have at least the following advantages and beneficial effects:

1. The experimental device and method for measuring the evolution of the disturbance shock wave front in the material provided by the present invention is based on the loading of a light gas cannon, through the impact of high-speed flyers, a disturbance shock wave is generated in the experimental sample, and the interface movement process of the measured sample is used The spectrum signal measured in the sample is obtained by Fourier transform and other methods to obtain the change law of the particle velocity at the interface of the sample with time, and then the evolution process of the shock wave front can be described. Further, continuous pressure points are selected for multiple measurements. The phase transition of the tested experimental sample is analyzed by using the quantitative relationship between particle velocity and pressure.

2. The structure of the experimental device provided by the present invention is simpler than that of the electrical probe experimental device, and has more advantages compared with the electrical probe experimental device. From a macroscopic point of view, the experimental device can measure the characteristic points of the disturbance shock wave front at different thicknesses of the experimental sample, and use the evolution law of the disturbance wave front to obtain the viscosity coefficient of the tested experimental sample; from a microscopic point of view, the experimental device can measure The movement of the corresponding interface at different thicknesses of the experimental sample is obtained, and the particle velocity of the corresponding interface is obtained, and further, the possible phase transition information of the tested experimental sample is obtained. Therefore, the experimental device can meet the measurement work of shock wave front, viscosity coefficient, interface particle velocity and phase change information in the tested experimental sample, with higher experimental success rate and lower experimental cost, and has wider application prospects.

Description of drawings

Fig. 1 is the front sectional view of the experimental device when measuring the solid sample provided by the embodiment of the present invention;

Fig. 2 is the top sectional view of the experimental device when measuring solid samples provided by the embodiment of the present invention;

Fig. 3 is a structural cross-sectional view of the target plate base and the fixed back seat provided by the embodiment of the present invention;

Figure 4 is an exploded view of some components of the experimental device when measuring solid samples provided by an embodiment of the present invention;

5 is a half-sectional view of the assembled structure of some components of the experimental device when measuring solid samples provided by the embodiment of the present invention;

Fig. 6 is the front cross-sectional view of the experimental device when measuring the powder sample provided by the embodiment of the present invention;

Figure 7 is a top sectional view of the experimental device for measuring powder samples provided by the embodiment of the present invention;

Figure 8 is an exploded view of some components of the experimental device when measuring powder samples provided by the embodiment of the present invention;

9 is a half-sectional view of the assembled structure of some components of the experimental device when measuring the powder sample provided by the embodiment of the present invention;

Fig. 10 is a spectrum signal diagram of the rear interface of the experimental sample corresponding to one of the measurement optical fibers during the experiment provided by the embodiment of the present invention;

Fig. 11 is a diagram of the transformation relationship of the particle velocity at the interface behind the experimental sample with time during the experiment provided by the embodiment of the present invention.

Icons: a-solid sample, b-powder sample, 10-target plate base, 10a-sample holding groove, 10b-target plate gap, 20-bracket, 20a-fiber hole, 30-measurement fiber, 40-fixed back seat, 50-Doppler displacement velocity measurement system, 60-oscilloscope, 70-aluminum foil.

Detailed ways

Please refer to Figures 1 to 9, this embodiment provides an experimental device for measuring the evolution of the wave front of the disturbance shock wave in the material, which is used to measure the evolution of the wave front of the disturbance shock wave in the experimental sample, through the wave front of the shock wave The surface evolution process can obtain the shock wave oscillation attenuation curve, combined with the numerical simulation method to obtain the viscosity coefficient of the tested sample under different pressures. It can be understood that the experimental samples to be tested in this embodiment include solid sample a and powder sample b, and the experimental device is slightly different for different types of experimental samples, and the specific structure of the experimental device will be described in detail below.

In this embodiment, the experimental devices for measuring the evolution process of the disturbance shock wave front in the solid sample a and the powder sample b all include a target plate base 10 , a bracket 20 , a fixed back seat 40 and a measurement system.

1, 2, 3, 6 and 7, in this embodiment, the target plate base 10 is provided with a sample holding groove 10a, and the sample holding groove 10a runs through one side of the target plate base 10 The wall is set, and the sample holding groove 10a is used to place and fix the solid sample a or powder sample b in the experiment. At this time, one end of the target disk base 10 is provided with a target disk gap 10b communicating with the sample holding groove 10a to pass through the target disk. The disc notch 10b limits the position of the experimental sample. It should be noted that the target base 10 of this embodiment can be made of aluminum, but not limited to, and the size of the target base 10 is determined according to the size of the light gas gun target frame, which is not limited here. 10. The solid sample a or powder sample b, bracket 20 and fixed back seat 40 of the experimental device can be fixed to the target frame of the light gas gun for subsequent measurement of the evolution of the disturbance shock wave front in the experimental sample material.

1, 2, 6 or 7, in this embodiment, the bracket 20 is arranged on the side of the target disc base 10 away from the target disc notch 10b, and when the bracket 20 is installed, the bracket 20 It is fixed at the rear end of the experimental sample to limit the position of the experimental sample through the bracket 20. It can be understood that the bracket 20 of this embodiment can be made of aluminum, but is not limited to, and the bracket 20 is provided with an optical fiber hole 20a communicating with the sample holding groove 10a, so as to facilitate subsequent connection with the measurement system.

1, FIG. 2, FIG. 3, FIG. 6 or FIG. 7, in this embodiment, the fixed rear seat 40 is arranged on the end of the target disc base 10 away from the target disc notch 10b, and the fixed rear seat 40 and The target plate base 10 is detachably connected. Wherein, the fixed back seat 40 can be made of aluminum, but not limited to, and the fixed back seat 40 and the target plate base 10 can be threaded, but not limited to, that is, the corresponding position of the fixed back seat 40 is provided with external threads, and the target plate base 10 The rear end is provided with an internal thread, and when the fixed rear seat 40 is installed, the front end of the fixed rear seat 40 can extend into the sample holding groove 10a and be in close contact with the rear end surface of the bracket 20, so as to be limited by the fixed rear seat 40. The position of the bracket 20.

In this embodiment, if the experimental sample is a solid sample a or a powder sample b, the solid sample a or powder sample b needs to be processed into a specific shape before the experiment.

Specifically, the size of the solid sample a or the powder sample b is jointly determined by the positions of the target base 10 and the bracket 20 . Wherein, in conjunction with the content shown in Figure 2 or Figure 7, when the experimental sample is a solid sample a or a powder sample b, the solid sample a or powder sample b is located in the sample holding tank 10a, and the front of the solid sample a or powder sample b The interface (that is, the solid sample a or the powder sample b is located on the side facing the notch 10b of the target disk in the sample holding tank 10a, and the front interface is the surface impacted by the flyer at high speed under impact loading conditions) has a curved corrugated structure. At this time, A curved corrugated structure has crests and troughs.

Wherein, for the solid sample a, the solid sample a is further divided into metal solid samples and non-metal solid samples. If it is a metal solid sample, a curved corrugated structure can be processed on the front interface of the solid sample a by using a wire cutting device. If it is a non-metallic solid sample, an engraving machine can be used to process a curved corrugated structure on the front interface of the solid sample a. For the powder sample b, the powder sample b needs to be pressed into a shape that matches the sample holding tank 10a, and the shape of the pressed powder sample b is the same as that of the solid sample a, so as to facilitate the installation and fixation of the powder sample b.

Please refer to Fig. 1 or Fig. 6, in this embodiment, the rear interface of solid sample a or powder sample b (that is, the side of solid sample a or powder sample b facing the support 20) is then processed into a slope, and set on the slope The stepped structure includes but is not limited to six steps, and the size of each step is the same. In this embodiment, the front end of the support 20 (that is, the side of the support 20 facing the solid sample a or the powder sample b) is also set to a stepped structure that matches the rear interface of the experimental sample. At this time, the front end of the support 20 The stepped structure coincides with the stepped structure of the rear interface of the experimental sample, and when the bracket 20 is installed at the rear end of the experimental sample, the bracket 20 is in close contact with the rear interface of the experimental sample through the stepped structure of the front face, so as to ensure that the bracket 20 It can be matched with the solid sample a or powder sample b, so as to realize the fixing of the relative position between the bracket 20 and the solid sample a or powder sample b, and facilitate the fixing of the measurement optical fiber 30 in the fiber hole 20a on the bracket 20 to different thicknesses The disturbance shock wave is measured.

It can be understood that, in order to realize the preparation of powder sample b, when the experimental sample is powder sample b, the experimental device also includes a pressing device (not shown in the figure), so that the powder sample b in powder form can be pressed by the pressing device It is convenient to put the powder sample b into the sample holding groove 10a of the target disk base 10 and carry out subsequent measurement experiments. Specifically, the pressing device includes a pressing base, a forming die and an anvil of the press, wherein the pressing base is provided with a pressing cavity adapted to the shape of the powder sample b, the pressing cavity is set through the top of the pressing base, and the forming die is arranged on The inner bottom of the pressing cavity, and the top of the forming mold has a curved surface corrugated structure, and the bottom of the anvil of the press has a stepped structure and is adapted to the pressing cavity, so that the anvil of the press can extend into the pressing cavity or extend Out of the compression chamber. When actually preparing the powder sample b, put the powdery powder sample b into the compression cavity of the pressing seat, and then use the press to make the anvil of the press press the powder sample b downward along the compression cavity to realize the powder sample b. Press forming, and the powder sample b which is finally press-formed and in a solid state has the same shape as the solid sample a.

In addition, in actual implementation, the material for preparing the bracket 20 can also change with the change of the experimental pressure. In this embodiment, the material for the bracket 20 is aluminum. If multiple impacts need to be considered, the material for preparing the bracket 20 can be different according to the experimental pressure. Choose quartz glass, sapphire or lithium fluoride (LiF), specifically, when the experimental pressure is low pressure (within 10GPa), the support 20 can be made of quartz glass, when the experimental pressure is medium pressure (10-40GPa) , the bracket 20 can be made of sapphire, and when the experimental pressure is high pressure (greater than 40GPa), the bracket 20 can be made of lithium fluoride.

On the other hand, when the experimental sample is powder sample b, considering that the powder sample b is loose and porous, and the retroreflectivity is low, for this reason, combined with the content shown in Figure 6 or Figure 7, the powder sample b can be stepped One side of the structure (that is, the rear interface of the powder sample b) is coated with aluminum foil 70, and the bracket 20 is in close contact with the aluminum foil 70 at the rear interface of the powder sample b through the stepped structure of the front surface. By adding the aluminum foil 70 to reflect light, it can Improve the retroreflectivity of the back interface of the powder sample b, so as to ensure that the movement law of the vertical back interface of each step of the powder sample b during the experiment can be detected by the measurement system.

In this embodiment, the measurement system can measure the time for the disturbance shock wave to reach the interface with different thicknesses in the solid sample a or the powder sample b. For the same thickness interface, the disturbance amplitude of the corresponding interface can be calculated by using the difference in the arrival time of the disturbance shock wave at the interface. The evolution process of the disturbance shock wave in the experimental sample can be obtained from the measurement information of multiple interfaces with different thicknesses. Further, combined with the numerical simulation method, the corresponding experimental pressure of the solid sample a or powder sample b can be obtained. Viscosity coefficient.

Specifically, referring to FIG. 1 , FIG. 2 , FIG. 6 or FIG. 7 , the measurement system includes a measurement optical fiber 30 , a Doppler displacement velocimetry system 50 and an oscilloscope 60 . Wherein, one end of the measuring fiber 30 is connected with the fiber hole 20a on the bracket 20, and the other end of the measuring fiber 30 is connected with the Doppler displacement velocimetry system 50, and the Doppler displacement velocimetry system 50 is connected with the oscilloscope 60 to record The movement process of the interface behind the test sample during the experiment. It can be understood that the oscilloscope 60 can be, but not limited to, adopt a high-resolution detection oscilloscope to improve the accuracy of the measurement result.

It should be noted that, in order to facilitate the measurement of the optical fiber 30 to be connected with the bracket 20, there are multiple fiber holes 20a provided on the bracket 20, and the measurement fiber 30 corresponds to the fiber holes 20a one by one, and the end of the measurement fiber 30 connected to the bracket 20 extends to In the fiber hole 20a, it can be understood that in order to make the measuring fiber 30 better match the fiber hole 20a on the bracket 20, the connector of the measuring fiber 30 adopts a UPC connector, and the size of the fiber hole 20a set on the bracket 20 Determine according to the fiber core length and fiber diameter of the measuring fiber 30, meanwhile, the light source used by the Doppler displacement velocity measurement system 50 is a laser with a wavelength of 1550nm, and the Doppler displacement velocity measurement system 50 includes a laser emission system and a return light receiving system , the laser emitting system is used to emit laser light with a wavelength of 1550nm, and the return light receiving system is used to transmit the detected return light amplitude information of the interface of the solid sample a or powder sample b to the oscilloscope 60, and record the entire experimental process through the oscilloscope 60 The return light amplitude signal in .

In addition, in actual implementation, the plurality of optical fiber holes 20a opened on the bracket 20 need to correspond to the back of the wave crests and troughs in the curved corrugated structure of the solid sample a or the powder sample b at different thicknesses of the solid sample a or the powder sample b respectively. interface.

For example, please refer to Fig. 4 or Fig. 8, in the present embodiment, eighteen fiber holes 20a are provided on the bracket 20, corresponding to eighteen channels of measuring fibers 30, at this time, the fiber holes 20a are distributed in a rectangular array; As shown in Fig. 1 or Fig. 6, the six optical fiber holes 20a located on the same vertical line correspond to the crests or troughs of the curved corrugated structure of the solid sample a or powder sample b respectively, as shown in Fig. 2 or Fig. 7 The three optical fiber holes 20a located on the same horizontal line correspond to one peak and two troughs of the curved corrugated structure of the solid sample a or powder sample b. It is worth noting that in actual implementation, the thickness of the bracket 20 needs to be reasonably controlled to ensure a certain distance between the end of the measurement optical fiber 30 and the rear interface of the solid sample a or powder sample b, so as to ensure the best light return effect.

On the other hand, this embodiment provides an experimental method for measuring the evolution of a disturbance shock wave front in a material, using the above-mentioned experimental device for measuring the evolution of a disturbance shock wave front in a material, and the experimental method includes the following steps:

Step S1. Prepare experimental samples;

When the experimental sample is a solid sample a, the front interface of the solid sample a (that is, the solid sample a is located on the side of the target disc base 10 facing the target disc notch 10b) is processed into a curved corrugated structure; the rear interface of the solid sample a (that is, the solid sample a is located on the side of the target plate base 10 facing the support 20) and processed into a stepped structure;

When the experimental sample is a powder sample b, the powder sample b is first put into a compacting device and pressed into shape, so that the shape of the powder sample b is the same as that of the solid sample a, and the surface of the powder sample b has a stepped structure. (i.e. the rear interface of the powder sample b) coated with a uniform aluminum foil 70;

Step S2. place the experimental sample;

When the experimental sample is a solid sample a, the solid sample a is placed in the sample holding groove 10a of the target disk base 10, and the front surface of the solid sample a faces the target disk gap 10b of the target disk base 10, and then the bracket 20 is installed, Let the solid sample a be located in the sample holding groove 10a formed by the bracket 20 and the target plate base 10, and ensure that the front surface of the bracket 20 is in close contact with the rear interface of the solid sample a;

When the experimental sample is a powder sample b, the pressed powder sample b is placed in the sample holding groove 10a of the target disc base 10, and the front surface of the powder sample b faces the target disc notch 10b of the target disc base 10, and then installed The bracket 20 allows the powder sample b to be located in the sample holding tank 10a formed by the bracket 20 and the target disk base 10, and the aluminum foil 70 is located on the side of the powder sample b away from the target disk gap 10b to ensure that the front surface of the bracket 20 and the rear interface of the powder sample b The aluminum foil 70 is in close contact;

Step S3. Target base 10 is installed;

The target disc base 10 is installed on the target frame of the light gas gun, and the target disc gap 10b of the target disc base 10 is facing the flyer of the light gas gun;

Step S4. Measurement system connection;

One end of the measuring fiber 30 is inserted into the fiber hole 20a provided on the support 20, the other end of the measuring fiber 30 is connected to the Doppler displacement velocity measurement system 50, and the Doppler displacement velocity measurement system 50 is connected to the oscilloscope 60;

Step S5. Measurement;

The light gas cannon fires the flying pieces, and uses the high-speed impact of the flying pieces on the corrugated surface of the experimental sample to generate a disturbance shock wave in the experimental sample. Using the measured spectrum signal during the movement of the interface behind the sample, Fourier transform, etc. The method obtains the change law of the particle velocity at the interface of the sample with time, and then can describe the evolution process of the shock wave front. Further, select continuous pressure points for multiple measurements, and use the quantitative relationship between particle velocity and pressure to analyze the measured experiment. Phase transition of the sample.

Experimental example

In the actual measurement experiment, metal aluminum is used as the experimental sample, and it is processed into a specific shape (that is, the front interface is a curved corrugated structure, and the rear interface is a stepped structure) to meet the requirements of the experimental device. The experimental device was fixed on the target frame of the light gas gun, and the aluminum flyer was used to impact the experimental sample at high speed. During the actual measurement, the speed of the flyer was 1.51km/s. In the actual measurement experiment, one of the measured experimental signal diagrams of the measuring optical fiber 30 is as shown in Figure 10, and Figure 10 is a spectrum signal diagram of the interface of the experimental sample corresponding to the measuring optical fiber 30, by which it can be judged that the disturbance shock wave arrives at the interface corresponding time.

In order to further process the spectrum signal diagram shown in Fig. 10, it is necessary to use Fourier transform to perform mathematical transformation. The Fourier transform relation is:

In the formula: w is the transformation frequency, which is the function variable after transformation; t is the transformation time, which is the function variable of the original function; e ^-iwt is a complex variable function; φ represents Fourier transform; dt represents differential; function F ( w ) is the Fourier transform of the function f ( t ), and f ( t ) is the inverse Fourier transform of F ( w ).

Through the Fourier transform, the transformation relationship of the interface frequency of the experimental sample with time can be obtained, as shown in Figure 11. Figure 11 can be used to obtain the transformation relationship of the particle velocity at the rear interface of the experimental sample as a function of time. Comparing the measurement results under multiple pressure values can be used to analyze the phase transition of experimental samples.

The above descriptions are only preferred embodiments of the present invention, and it should be understood that the present invention is not limited to the forms disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and Modifications can be made within the scope of the ideas described herein, by virtue of the above teachings or skill or knowledge in the relevant art. However, changes and changes made by those skilled in the art do not depart from the spirit and scope of the present invention, and should all be within the protection scope of the appended claims of the present invention.

Claims (6)

1. An experimental device for measuring the evolution of a disturbance shock wave front in a material, used to measure the evolution of a disturbance shock wave in a wave front in an experimental sample, characterized in that it comprises: A target disk base, the target disk base is provided with a sample holding tank, one end of the target disk base is provided with a target disk gap, and the target disk gap communicates with the sample holding groove; An experimental sample, the experimental sample is placed in the sample holding tank, the front interface of the experimental sample has a curved corrugated structure and faces the target plate gap of the target plate base; A bracket, the bracket is fixed on the rear end of the experimental sample, and the front surface of the bracket is in contact with the rear interface of the experimental sample, and the bracket is provided with an optical fiber hole; The rear interface of the experimental sample has a stepped structure, and the front end of the bracket also has a stepped structure, and the stepped structure of the front end of the bracket matches the stepped structure of the rear interface of the experimental sample; The bracket is in close contact with the rear interface of the experimental sample through the stepped structure of the front face, and is fixed to the rear end of the experimental sample; The fixed back seat is arranged on the end of the target plate base away from the target plate gap, the front end surface of the fixed back seat is in contact with the rear end surface of the bracket, and the fixed back seat is detachably connected to the target plate base; A measuring system, the measuring system comprising a measuring fiber, a Doppler displacement velocimetry system and an oscilloscope, one end of the measuring fiber is connected to the fiber hole on the support, and the other end of the measuring fiber is connected to the Doppler displacement velocimetry system, The Doppler displacement velocimetry system is connected with an oscilloscope, and the oscilloscope is used to record the movement process of the rear interface of the experimental sample during the experiment. 2. the experimental device of disturbance shock wave front evolution in the measurement material according to claim 1, is characterized in that, described experimental sample is solid sample or powder sample; When the experimental sample is a powder sample, one side surface of the powder sample with a stepped structure is coated with aluminum foil, and the bracket is in close contact with the aluminum foil at the rear interface of the powder sample through the stepped structure of the front surface. 3. the experimental device of disturbance shock wave front evolution in the measuring material according to claim 2, is characterized in that, when described experimental sample is powder sample, this experimental device also comprises pressing device, and described pressing device comprises: A pressing seat, the pressing seat is provided with a pressing cavity, and the pressing cavity is set through the top of the pressing seat; A forming die, the forming die is arranged at the inner bottom of the pressing cavity, and the top of the forming die has a curved corrugated structure; and, The top anvil of the press, the bottom of the top anvil of the press is in a stepped structure, and the top anvil of the press is adapted to the pressing chamber. 4. the experimental device of disturbance shock wave front evolution in the measuring material according to claim 1, it is characterized in that, the fiber hole that offers on the described support is a plurality of, and described measuring fiber is one-to-one correspondence with fiber hole, so One end of the measurement optical fiber connected to the bracket extends into the optical fiber hole; The multiple optical fiber holes respectively correspond to the back interfaces of the crests and troughs of the curved surface corrugated structure at different thicknesses of the experimental samples. 5. the experimental device of disturbance shock wave front evolution in the measuring material according to claim 1, it is characterized in that, the joint of described measurement optical fiber adopts UPC joint, and the light source used by described Doppler displacement velocimetry system is wavelength 1550nm laser. 6. An experimental method for the evolution of a disturbance shock wave front in a measurement material, adopting the experimental device for the evolution of a disturbance shock wave front in a measurement material as claimed in any one of claims 1 to 5, characterized in that, comprising the following steps : Step S1. Prepare experimental samples; When the experimental sample is a solid sample, the front interface of the solid sample is processed into a curved corrugated structure, and the rear interface of the solid sample is processed into a stepped structure; When the experimental sample is a powder sample, the powder sample is put into a pressing device and pressed into shape to ensure that the shape of the powder sample is the same as that of the solid sample, and on the side where the powder sample has a stepped structure The surface is coated with uniform aluminum foil; Step S2. place the experimental sample; When the experimental sample is a solid sample, the solid sample is placed in the sample holding groove of the target disc base, and the front interface of the solid sample faces the target disc gap of the target disc base, and then the bracket is installed, Ensure that the front surface of the support is in close contact with the rear interface of the solid sample; When the experimental sample is a powder sample, place the powder sample in the sample holding tank of the target disc base, and make the front interface of the powder sample face the target disc notch of the target disc base, and then install the bracket, Ensure that the front end of the support is in close contact with the aluminum foil at the rear interface of the powder sample; After completing the installation of the experimental sample and the bracket, install the fixed back seat, and ensure that the front end of the fixed back seat is in close contact with the rear end face of the bracket; Step S3. Target disc base installation; Install the target disc base on the target frame of the light gas gun, and make the target disc notch of the target disc base face the flyer of the light gas gun; Step S4. Measurement system connection; Inserting one end of the measuring fiber into the corresponding fiber hole of the bracket, the other end of the measuring fiber is connected to a Doppler displacement velocimetry system, and the Doppler displacement velocimetry system is connected to an oscilloscope; Step S5. Measurement; The light gas cannon emits flying pieces, and uses the flying pieces to impact the corrugated surface of the experimental sample to generate a disturbance shock wave in the experimental sample, and then uses the measured frequency spectrum signal during the rear interface movement of the sample , using the Fourier transform method to obtain the change law of particle velocity at the sample back interface with time, and then describe the evolution process of the shock wave front, further, select continuous pressure points for multiple measurements, and use the quantitative analysis of particle velocity and pressure The phase transition of the tested experimental samples was analyzed using the chemical relationship.

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