Manufacturing method and testing method of macadam pile asteroid simulant

Abstract

The invention relates to the technical field of asteroid simulants, and discloses a manufacturing method and a testing method of a gravel heap asteroid simulant, and the manufacturing method comprises the following steps: mixing raw material powder and magnetic powder, putting the mixture into stirring equipment, and wetting; controlling the stirring equipment to rotate so as to obtain a plurality of nuclear particles with different diameters; after the surfaces of the core-shaped particles are coated with an adhesive, the core-shaped particles are bonded and fixed to form spherical particles; and carrying out high-temperature hardening on the spherical particles to obtain the macadam pile asteroid simulant. Compared with the problems of particle interaction model simplification, experimental verification difficulty, high parameter uncertainty, limited computing resources and the like in the existing computer simulation gravel pile asteroid technology, the manufacturing method disclosed by the invention has the advantages that the raw material powder and the magnetic powder are mixed and treated by a special process, so that the physical characteristics of the asteroid can be truly restored; the method is directly used for laboratory experiments to enhance verification capability.

Description

Technical Field

[0001] The present invention relates to the technical field of asteroid simulants, and in particular to a manufacturing method and a testing method of a rubble pile asteroid simulant. Background Art

[0002] Currently, researchers primarily study rubble-pile asteroids through computer modeling and numerical simulation. Common methods include the discrete element method (DEM), smoothed particle hydrodynamics (SPH), and finite element analysis (FEA). These methods construct mathematical models that incorporate physical parameters such as solar gravity, planetary perturbations, and particle interactions. These methods can simulate asteroid motion, collisions, and internal structural changes to a certain extent. For example, when simulating the disintegration of an asteroid after an impact, the discrete element method can visually demonstrate the ejection, migration, and re-accumulation of particles.

[0003] However, existing research methods have significant limitations. Computer simulations rely on numerous assumptions and simplifications, such as simplifying particle interactions into rigid collisions and ignoring weak but critical forces such as van der Waals and electrostatic forces. Furthermore, model parameters (such as particle friction coefficient and porosity distribution) are difficult to accurately obtain from observational data, resulting in deviations between simulation results and actual conditions.

[0004] Existing technologies lack a mature method for producing rubble-pile asteroid simulants. This lack of physical simulants prevents researchers from verifying the accuracy of computer models through experimental means and from directly observing the asteroid's response characteristics under real-world physical conditions.

[0005] In view of this, the existing technology still needs to be improved and developed. Summary of the Invention

[0006] In view of the above-mentioned shortcomings of the existing technology, the purpose of the present invention is to provide a method for manufacturing and testing a rubble pile asteroid simulant, aiming to solve the problem that the existing technology mostly uses computers to model and simulate rubble pile asteroids, and there is no mature method for manufacturing rubble pile asteroid simulants.

[0007] The technical solutions adopted by the present invention to solve the technical problems are as follows: A method for manufacturing and testing a rubble pile asteroid simulant, comprising: Mix the raw material powder and magnetic powder and put them into the stirring equipment and wet them; controlling the rotation of the stirring device to obtain a plurality of core-shaped particles with different diameters; After applying an adhesive on the surface of the core-shaped particles, the core-shaped particles are bonded and fixed to form spherical particles; The spherical particles are subjected to high temperature hardening to obtain a rubble pile asteroid simulant.

[0008] Furthermore, the spherical particles are subjected to high temperature hardening to obtain a rubble pile asteroid simulant, and then the method further includes: Magnetic powder is applied to the surface of the rubble pile asteroid simulant.

[0009] Furthermore, after applying the adhesive on the surface of the core-shaped particles, the core-shaped particles are bonded and fixed to form spherical particles, including: Holding the core-shaped particles with tweezers, and applying adhesive; A plurality of core-shaped particles coated with the adhesive are randomly placed into a preset mold until the entire mold is filled.

[0010] Furthermore, the step of randomly placing a plurality of core-shaped particles coated with the adhesive into a preset mold until the entire mold is filled includes: When a plurality of core-shaped particles coated with the adhesive are randomly placed into the preset mold, the raw material powder is sprinkled in to simulate the dust surrounding the rubble pile asteroid.

[0011] Furthermore, the raw material powder is a powder obtained by grinding a meteorite sample into micron-sized powder.

[0012] Furthermore, the stirring device is controlled to rotate to obtain a plurality of core-shaped particles with different diameters, and then comprises: The diameter range of the core-shaped particles is preset, and a plurality of the core-shaped particles are screened to select core-shaped particles that meet the conditions.

[0013] Furthermore, the presetting of the diameter range of the core-shaped particles and screening of the plurality of core-shaped particles to select core-shaped particles meeting the conditions includes: When the diameter of the core-shaped particle reaches the diameter range, applying an adhesive on the surface of the core-shaped particle; When the diameter of the core-shaped particles does not reach the diameter range, the core-shaped particles are put into a grinder and ground into raw material powder.

[0014] Furthermore, when the diameter of the core-shaped particle reaches the diameter range, applying an adhesive on the surface of the core-shaped particle includes: Selecting a plurality of the core-shaped particles from the same batch and measuring the average moisture content of each of the core-shaped particles; When the core-shaped particles meet the preset range of the average moisture content, applying an adhesive on the surface of the core-shaped particles; When the core particles do not meet the preset range of the average moisture content, the core particles are crushed to form the raw material powder.

[0015] A method for testing a rubble pile asteroid simulant, wherein the rubble pile asteroid simulant is manufactured based on the above-mentioned method for manufacturing and testing a rubble pile asteroid simulant, comprising: performing multiple free-fall experiments on the rubble pile asteroid simulant and recording the number of core-like particles detached during the multiple experiments; Calculating a bonding failure rate of the rubble pile asteroid simulant based on the number of detached core particles; Measuring the hardening strength of the rubble pile asteroid simulant with a qualified bonding failure rate; The hysteresis loop of the rubble pile asteroid simulant with qualified hardening strength is measured to determine whether the rubble pile asteroid simulant meets the requirements.

[0016] Furthermore, measuring the hysteresis loop of the rubble pile asteroid simulant with qualified hardening strength and determining whether the rubble pile asteroid simulant meets the requirements includes: measuring the circumference and cross-sectional area of the rubble pile asteroid simulant; placing the rubble pile asteroid simulant in an alternating magnetic field, inputting different currents into the alternating magnetic field, and performing hysteresis loop measurements; The magnetic powder distribution and magnetization level in the rubble pile asteroid simulant are judged based on the parameters of the hysteresis loop, and a conclusion is drawn as to whether the rubble pile asteroid simulant is qualified.

[0017] Compared with the prior art, the present invention has the following beneficial effects: In the present invention, raw material powder and magnetic powder are mixed, placed in a stirring device, and wetted; the stirring device is controlled to rotate to produce multiple core-shaped particles of varying diameters; a binder is applied to the surface of the core-shaped particles, and then the core-shaped particles are bonded and fixed to form spherical particles; and the spherical particles are hardened at high temperature to produce a rubble-pile asteroid simulant. Compared to existing computer simulations of rubble-pile asteroids, which suffer from simplified particle interaction models, difficult experimental verification, high parameter uncertainty, and limited computing resources, the present manufacturing method, by mixing raw material powder and magnetic powder and subjecting them to a special process, can realistically reproduce the physical properties of asteroids, enabling direct laboratory experimentation and enhanced verification capabilities. Key parameters can also be flexibly adjusted, overcoming computing resource bottlenecks, and enabling rapid testing of various operating conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Flow chart of the method for manufacturing a rubble pile asteroid simulant of the present invention.

[0019] Figure 2 Flowchart of the testing method of the rubble pile asteroid simulant of the present invention.

[0020] Figure 3 This is a test diagram of the hysteresis loop of the rubble pile asteroid simulant of the present invention.

[0021] Figure 4 This is a connection schematic diagram of the hysteresis loop test of the rubble pile asteroid simulant of the present invention.

[0022] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solution and effect of the present invention clearer and more specific, the present invention is further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0024] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0025] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0026] In view of the shortcomings of the existing technology, this embodiment provides a method for manufacturing and testing a rubble pile asteroid simulant, which can be specifically referred to as follows: As attached Figure 1As shown, a method for manufacturing a rubble pile asteroid simulant includes the following steps: Step S100: Mix the raw material powder and the magnetic powder, put them into a stirring device, and wet them.

[0027] The process of preparing a rubble-pile asteroid simulant begins with meticulous preparation of the required materials. The powdered raw materials selected are rigorously screened based on the specific characteristics of the simulated asteroid and the experimental requirements. For example, if the asteroid is to be simulated, rich in a certain mineral, the raw materials should include the corresponding mineral powder to facilitate subsequent experiments and observational analysis. Magnetic powder is also carefully selected, with parameters such as magnetic strength and particle size that meet specific experimental requirements. The addition of magnetic powder aims to impart specific magnetic characteristics to the simulant, simulating the magnetic field that the asteroid may experience in the cosmic environment.

[0028] Accurately weighed powdered raw materials and magnetic powder are placed into the turntable of the mixing equipment. This equipment features a unique turntable design and optimized internal structure, ensuring excellent material loading capacity and mixing adaptability. The mixing equipment can be implemented using existing technologies. The turntable surface is typically treated with special anti-slip and wear-resistant treatments to prevent material slippage during the subsequent mixing process, ensuring uniform mixing and extending the equipment's service life. When placing materials, ensure that they are evenly distributed on the turntable to avoid any accumulation or gaps, laying the foundation for efficient subsequent mixing.

[0029] After the raw materials and magnetic powder are placed in the turntable, the watering operation is carried out. The watering device is precisely connected to the stirring equipment, and can evenly sprinkle water into the turntable according to the preset flow rate and spraying range. The watering device is an existing technology. The water used must be purified to remove impurities and microorganisms to prevent contamination of the raw materials and affect the performance of the simulant. During the watering process, closely observe the wetness of the material, and ensure that the material is moderately wetted by controlling the watering time and amount. Controlling the wetness is crucial. If too little water is sprinkled, the material cannot be fully bonded, which is not conducive to the subsequent formation of particles; if too much water is sprinkled, the material will become too viscous, affecting the stirring effect and the molding quality of the particles.

[0030] In this example, the raw material powder is a meteorite sample ground into a micron-sized powder. To simulate common carbonaceous asteroids (C-type asteroids), silica-dominated asteroids (S-type asteroids), and metal-rich asteroids (M-type asteroids), carbonaceous chondrites (CI and CM types), stony meteorites with a high silicate mineral content, and iron meteorites with a high iron and nickel content can be used, respectively. The raw material powder is a meteorite sample ground into a micron-sized powder. The magnetic powder is also ground to a micron-sized particle size. A laboratory planetary ball mill can be used for uniform grinding. The raw material powder and magnetic powder mix follows the principle of "raw material powder as the primary component, magnetic powder as the secondary component," and the appropriate mix ratio can be adjusted dynamically based on demand.

[0031] Step S200: Control the stirring device to rotate to obtain a plurality of core-shaped particles with different diameters.

[0032] Once the material is moistened to the desired state, the mixing equipment is started. The mixing equipment is equipped with a high-performance drive motor that provides stable and adjustable rotational power to the turntable. As the turntable rotates at high speed, the materials begin to tumble and mix under the combined effects of centrifugal force, friction, and the stirring blades. During this process, the powdered materials gradually aggregate and bond, forming core-like particles of varying sizes. By precisely controlling parameters such as the mixing equipment's rotational speed, mixing time, and the initial material ratio, the diameter distribution of the core-like particles can be effectively controlled. For example, higher rotational speeds and longer mixing times generally result in larger core-like particles, while lower speeds and shorter times favor smaller particles. During the mixing process, real-time monitoring equipment can be used to observe particle formation, allowing for timely adjustment of mixing parameters.

[0033] Specifically, in one implementation of this embodiment, step S200 includes the following steps: In step S210 , a diameter range of the core-shaped particles is preset, and a plurality of the core-shaped particles are screened to select core-shaped particles that meet the conditions.

[0034] In this embodiment, when the diameter range of the core-shaped particles is preset and screening is performed, the particle size range needs to be designed based on the measured data of the target asteroid or experimental requirements. A multi-stage screening system combining vibration screening and image recognition sorting is adopted. Unqualified particles are eliminated through vibration frequency, amplitude and machine learning algorithms to ensure the purity of each particle size range. The mixing ratio of particles of different particle sizes is optimized according to the inversion results of the porosity of the real asteroid to construct a simulant that is highly consistent with the particle size distribution and pore characteristics of the real asteroid, providing a highly controllable experimental sample for related research.

[0035] Specifically, in one implementation of this embodiment, step S210 includes the following steps: Step S211, when the diameter of the core-shaped particle reaches the diameter range, applying an adhesive on the surface of the core-shaped particle; Step S212: When the diameter of the core-shaped particles reaches the diameter range, the core-shaped particles are placed in a grinder and ground into raw material powder.

[0036] In this embodiment, the diameter of the core particles is screened by precise particle size detection equipment to monitor the particle size in real time. When the diameter of the core particles is detected to be within a preset target range (e.g., 0.5-5 mm), the particles are judged to be qualified and transferred to the next preparation process. If the diameter exceeds the allowable deviation (e.g., greater than 5 mm or less than 0.5 mm), the sorting device is automatically triggered to transport the unqualified particles to the grinder. The grinder uses a planetary ball milling process to refine large particles to the size of the initial raw material powder and re-enter the mixing process. The advantages of this closed-loop processing method are that it not only ensures the consistency of the particle size of the particles participating in the subsequent molding steps through precise screening, improving the similarity of the simulant structure to the real asteroid, but also reduces raw material waste and production costs through a recycling and reuse mechanism. At the same time, it prevents unqualified particles from affecting the physical properties of the final simulant, ensuring the reliability and repeatability of the experimental results.

[0037] Specifically, in one implementation of this embodiment, the following steps are included after step S211: Step S211-A, selecting a plurality of the core-shaped particles from the same batch and measuring the average moisture content of each of the core-shaped particles; Step S211-B, when the core-shaped particles meet the preset range of the average moisture content, applying an adhesive on the surface of the core-shaped particles; Step S211-C: When the core-shaped particles do not meet the preset range of the average moisture content, the core-shaped particles are crushed to form the raw material powder.

[0038] In this embodiment, several core-shaped particles of different sizes from the same batch of manufacturing processes but without the use of a binder are selected as the test particles. The mass m1 of the test particles of the same size is first weighed at room temperature, and then the mass m2 is weighed after drying. The percentage of the mass difference m1-m2 before and after heating to the mass m1 before heating is calculated, which is the average moisture content α of the test particles at that particle size. The formula is as follows: ; In this way, the average moisture content of all particles with different particle sizes is measured, where these different particle sizes need to cover all particle sizes of the simulant.

[0039] When the core-shaped particles meet the preset range of the average moisture content, the process proceeds to the next step; when the core-shaped particles do not meet the preset range of the average moisture content, the core-shaped particles are crushed to form raw material powder.

[0040] In step S300 , after applying an adhesive on the surface of the core-shaped particles, the core-shaped particles are bonded and fixed to form spherical particles.

[0041] After the core-shaped particles are formed, they are taken out from the turntable of the stirring equipment and enter the adhesive application stage. The selected adhesive has good viscosity and curing properties, which can play a key bonding role in the simulation molding process to ensure that the various parts are tightly combined. The adhesive can be applied using professional spray equipment or manual application tools to ensure that the surface of the core-shaped particles is evenly covered with a layer of adhesive. After the application is completed, the core-shaped particles coated with adhesive are quickly placed in a special ellipsoidal mold. The ellipsoidal mold is made of high-strength, high-temperature resistant and smooth-surfaced materials. Its internal shape is precisely designed to guide the core-shaped particles to further shape in the mold, and finally form particles that are close to the ideal spherical shape. When placing the particles, attention should be paid to the distribution and arrangement of the particles in the mold to avoid overlapping or extrusion deformation, so as to ensure that each particle can be fully shaped in the mold.

[0042] Specifically, in one implementation of this embodiment, step S300 includes the following steps: Step S310, clamping the core-shaped particles with tweezers and applying an adhesive; In step S320 , a plurality of core-shaped particles coated with the adhesive are randomly placed into a preset mold until the entire mold is filled.

[0043] In this embodiment, a core-like particle is first gripped with tweezers and an adhesive is applied to its surface. The adhesive-coated core-like particles are then randomly loaded into a mold using a vibration blanking method until the entire mold is filled. As more and more particles are loosely packed together under the action of gravity, varying degrees of bonding (no bonding, just enough bonding, and over-bonding due to gravity) are generated between the particles, fully reflecting the actual physical state of the rubble-pile asteroid.

[0044] Specifically, in one implementation of this embodiment, step S320 includes the following steps: In step S321 , a plurality of core-shaped particles coated with the adhesive are randomly placed into the preset mold and the raw material powder is sprinkled therein to simulate dust surrounding a rubble pile asteroid.

[0045] In this embodiment, the rubble-pile asteroid is composed of rock and dust, loosely held together by gravity. The spherical particles are used to simulate rock, and during the bonding and forming process, raw material powder can be randomly sprinkled in to simulate dust.

[0046] By randomly introducing raw material powder between the spherical particles of simulated rubble pile asteroids, the "rock-dust" binary structure of rubble pile asteroids can be accurately reproduced, where the spherical particles simulate dense rock fragments, and the raw material powder simulates loose dust material on the surface and in the gaps of the asteroid; this method uses gravity to allow the powder to naturally fill the gaps between the particles, and can form a loose aggregation state consistent with the real asteroid without the need for additional bonding process. This not only simplifies the preparation process, but also can flexibly control the porosity, surface roughness and overall density of the simulated object by adjusting the powder particle size and scattering ratio, truly reflecting the dust aggregation characteristics of asteroids caused by collision and weathering in the cosmic environment, and providing a more realistic experimental model for studying the migration of material on the asteroid surface, impact response and dust dynamics.

[0047] Step S400: Hardening the spherical particles at high temperature to obtain a rubble pile asteroid simulant.

[0048] An ellipsoidal mold containing core-shaped particles coated with a binder is placed in a specific environment and left to stand for a predetermined time. During this time, the binder gradually takes effect, strengthening the bonds between the particles and initially solidifying the shape. After the predetermined time expires, the mold is opened, the spherical particles are removed, and transferred to a high-temperature curing machine. This high-temperature curing machine provides a stable and precisely controlled high-temperature environment. The temperature is raised to a specific high temperature and maintained for a specified period of time, depending on the material properties of the simulant and the experimental requirements. Under this high temperature, the internal components of the spherical particles undergo physical and chemical changes, the binder further solidifies, and the material structure is strengthened, ultimately forming a rubble-pile asteroid simulant with a certain strength and stability. High-temperature curing parameters such as temperature and time have a significant impact on the final performance of the simulant. For example, excessively high temperatures or prolonged times may cause defects such as cracking and deformation, while excessively low temperatures or short times may not achieve the desired curing effect. Therefore, the operating parameters of the high-temperature curing machine must be strictly monitored during operation to ensure that the simulant meets the required quality standards.

[0049] At high temperatures, certain elements in the raw materials expand, forming pores and a hard, vitrified layer on the surface of the spherulites. This ultimately creates a rubble-pile asteroid simulant suitable for subsequent experiments. Spherical particles of varying sizes, which possess a certain strength after sintering and hardening, simulate rubble. A collection of spherical particles, randomly placed and formed into a mold, simulates the rubble-pile structure. A binder coating between the spherical particles simulates the van der Waals adhesion required for the formation of a rubble-pile structure.

[0050] Specifically, in one implementation of this embodiment, step S400 includes the following steps: Step S410: Apply magnetic powder to the surface of the rubble pile asteroid simulant.

[0051] After forming the rubble-pile asteroid simulant, magnetic powder is applied to the surface to more fully simulate the magnetic properties of an asteroid in a cosmic environment. The selected magnetic powder is rigorously screened, and its magnetic parameters, particle size, and dispersion properties meet the specific requirements of the simulation experiment. This application requires extreme precision and can be accomplished with specialized application tools such as a specialized spray gun or a fine-grained smear brush. When using a spray gun, the air pressure and powder output are precisely controlled to ensure that the magnetic powder is evenly applied and adheres to the simulant surface. Using a smear brush requires skilled application, slowly and evenly applying the powder across the surface to ensure that every surface is covered with a suitable layer of magnetic powder. This process ensures that the rubble-pile asteroid simulant not only possesses the physical structure and strength of a real asteroid but also exhibits specific magnetic properties, providing a more comprehensive experimental subject for subsequent simulations of asteroids in magnetic fields.

[0052] As attached Figure 2 As shown, the present application also proposes a testing method for a rubble pile asteroid simulant. The rubble pile asteroid simulant manufactured based on the above-mentioned manufacturing method and testing method includes the following steps: Step S401, performing multiple free-fall tests on the rubble pile asteroid simulant, and recording the number of core-shaped particles detached during each test; Step S402, calculating the bonding failure rate of the rubble pile asteroid simulant based on the number of core-shaped particles detached multiple times; Step S403, measuring the hardening strength of the rubble pile asteroid simulant with a qualified bonding failure rate; Step S404: measuring the hysteresis loop of the rubble pile asteroid simulant with qualified hardening strength, and determining whether the rubble pile asteroid simulant meets the requirements.

[0053] In this embodiment, the rubble pile asteroid simulants are placed at appropriate heights l1, l2, ..., l n , let it fall freely, and record the number of outer particles peeled off n times u n and the number of inner layer particles falling off v n ; Then place the rubble pile asteroid simulant at successively increasing rotational speeds ω1, ω2...ω nPlace it on a centrifuge and let it rotate around the center for a period of time. Record the number of outer layer particles that fall off n times. n and the number of inner layer particles falling off y n Finally, calculate the number of outer layer particles peeling off n times u n 、Number of inner layer particles falling off v n 、Number of outer layer particles peeling off x n and the number of inner layer particles falling off y n The sum of the values of and the percentage of the total number of 2n known simulant particles A is the bonding failure rate β of the rubble pile asteroid simulant. The formula is as follows: ; The bonding failure rate β obtained by the above formula is used to determine whether the rubble pile asteroid simulant meets the requirements. If the rubble pile asteroid simulant meets the requirements, it proceeds to the next performance test; if it does not meet the requirements, it is crushed into raw material powder.

[0054] Select n particles from the particles peeled off in the previous process, first grind the surface of one of the particles flat, and then press a rigid indenter with a regular shape into the surface of the ground particle under the action of gradually increasing external force. After the external force reaches a predetermined peak, the external force is gradually removed. During this loading and unloading process, the indenter displacement h and the load P borne by the indenter are recorded simultaneously with the help of high-precision load-displacement testing technology. The obtained Ph curve is analyzed to obtain the average hardness H1 of the particle. Nanoindentation technology is used to measure the corresponding average hardness H of n particles in this way. n , calculate the corresponding average hardness H of n particles n The average value of is the hardening strength γ of the simulant. The formula is as follows: ; If no particles have fallen off during the previous process, the particles in the simulant are considered to be firmly bonded (an idealized situation with a very low probability of occurrence). A flat test area should be defined. The rebound hammer should be mounted on the surface of the simulant to be tested. Press the button to allow the striker to fall freely and impact the test area. Observe the height to which the striker rebounds and record the rebound value. Based on the rebound value and the concrete calibration curve, the hardened strength γ of the simulant is determined, referring to the strength of concrete.

[0055] The hardening strength γ obtained by the above formula is used to determine whether the rubble pile asteroid simulant meets the requirements. If the rubble pile asteroid simulant meets the requirements, it proceeds to the next performance test; if the rubble pile asteroid simulant does not meet the requirements, it is crushed into raw material powder.

[0056] Specifically, in one implementation of this embodiment, step S404 includes the following steps: Step S404-A, measuring the circumference and cross-sectional area of the rubble pile asteroid simulant; Step S404-B, placing the rubble pile asteroid simulant in an alternating magnetic field, inputting different currents into the alternating magnetic field, and completing hysteresis loop measurement; Step S404-C: judging the magnetic powder distribution and magnetization level in the rubble pile asteroid simulant based on the parameters of the hysteresis loop, and drawing a conclusion on whether the rubble pile asteroid simulant is qualified.

[0057] In this embodiment, hysteresis loop testing was performed on a rubble-pile asteroid simulant that had passed the hardening strength test. A primary coil (excitation coil) was selected, wound with multiple strands of fine wire to reduce skin effect. The number of turns, N1, was large enough to reduce the required current (e.g., 100 to 500 turns). A secondary coil (induction coil) was selected, tightly and evenly wound, with the number of turns matching that of the primary coil to ensure a high signal-to-noise ratio. The primary coil was connected to an adjustable DC power supply and an ammeter, while the secondary coil was connected to an integrator and a data acquisition system. The high-current DC power supply had an output current of 10 to 50A, and the high-precision integrator was used to integrate the induced voltage in the secondary coil.

[0058] First, measure the circumference L and cross-sectional area A of the rubble pile asteroid simulant. Then, place the rubble pile asteroid simulant in an alternating magnetic field and slowly reduce the current I to zero. Starting from I = 0, gradually increase the current to saturation. Record the current I and the induced voltage V(t) of the secondary coil at each point, and calculate the corresponding H and B. After reaching saturation, gradually reduce the current to 0, then increase it in the opposite direction to negative saturation, completing the hysteresis loop measurement (e.g. Figure 1 The calculation formulas for H and B are as follows: ; Where H is the magnetic field strength, N1 is the number of turns of the primary coil (excitation coil); I is the current passing through the primary coil; L is the circumference of the rubble pile asteroid simulant; ; Where B is the magnetic induction intensity, N2 is the number of turns of the secondary coil (induction coil), A is the cross-sectional area of the rubble pile asteroid simulant, and t1 and t2 are the integration time intervals, indicating the start and end time points of the integration of the induced voltage V(t); The magnetic induction of the simulant can be determined based on the hysteresis loop, and its internal magnetic powder distribution and magnetization level can be analyzed.

[0059] As attached Figure 3 and attached Figure 4As shown, the horizontal axis H is the magnetic field intensity (related to the current source), and the vertical axis B is the magnetic induction intensity (related to the material and the magnetic field intensity). At point O, H=0, B=0, which is a magnetic neutral state; as H increases, B also increases. When H reaches H s When B reaches the saturation point B s , which also means that when H>H s After H decreases to 0, B is not 0, B=B r , the change of B lags behind the change of H, this phenomenon is called hysteresis, the retained B r It is called remanence; when the direction of the magnetic field increases in the opposite direction, H increases to -H c When B=0, H c It is called coercive force, which represents the ability of magnetic materials to maintain the remanent magnetic state; H increases in the reverse direction to -H s When B reaches the saturation point -B s ; When H decreases to 0 in the reverse direction, B=-B r ; H increases to H c , B=0; H increases to H s , B=B s , the curve is closed, repeated and alternating over and over again. Figure 3 The schematic diagram is divided into upper and lower circuits, with a simulated object placed in the middle. A represents an ammeter, V a voltmeter, R1 and R2 represent resistors, N1 and N2 represent coils, and C represents a capacitor. A rubble-pile asteroid simulated object is placed between R1 and R2. The upper circuit uses DC as its output, which is connected in series with the ammeter and then reaches primary coil N1. The current is regulated by controllable resistor R1. The lower circuit generates an induced voltage through secondary coil N2, which is connected in series with the voltmeter and then controlled by controllable resistor R2 through a basic inverting analog integrator. The high-precision integrator consists of an operational amplifier with a capacitor in the feedback path.

[0060] The above principle can be used to effectively measure the hysteresis loop of the rubble pile asteroid simulant, and analyze its internal magnetic powder distribution and magnetization level. When the rubble pile asteroid simulant meets the preset range, the simulation experiment can be carried out; when the rubble pile asteroid simulant does not meet the preset range, it will be crushed into raw material powder.

[0061] Indicators such as average moisture content α, bonding failure rate β, hardening strength γ, and hysteresis loop are listed as the finished product quality parameters of the simulant. If the finished product quality parameters obviously do not meet the normal experimental requirements, the simulant is considered to have poor quality and should be remade; if the finished product quality parameters meet the normal experimental requirements, various subsequent experiments can be carried out according to different experimental requirements.

[0062] Other embodiments of the present invention will readily occur to those skilled in the art after considering the specification and practicing the embodiments disclosed herein. The present invention is intended to cover any variations, uses, or adaptations of the present invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein. The description and examples are to be considered as exemplary only, with the true scope and spirit of the invention being indicated by the claims.

Claims

1. A method for manufacturing a rubble pile asteroid simulant, characterized in that: include: Mix the raw material powder and magnetic powder and put them into the stirring equipment and wet them; controlling the rotation of the stirring device to obtain a plurality of core-shaped particles with different diameters; After applying an adhesive on the surface of the core-shaped particles, the core-shaped particles are bonded and fixed to form spherical particles; The spherical particles are subjected to high temperature hardening to obtain a rubble pile asteroid simulant.

2. The method for manufacturing a rubble pile asteroid simulant according to claim 1, characterized in that: The step of high-temperature hardening the spherical particles to form a rubble pile asteroid simulant further comprises: Magnetic powder is applied to the surface of the rubble pile asteroid simulant.

3. The method for manufacturing a rubble pile asteroid simulant according to claim 1, characterized in that: After applying the adhesive on the surface of the core-shaped particles, the core-shaped particles are bonded and fixed to form spherical particles, including: Holding the core-shaped particles with tweezers, and applying adhesive; A plurality of core-shaped particles coated with the adhesive are randomly placed into a preset mold until the entire mold is filled.

4. The method for manufacturing a rubble pile asteroid simulant according to claim 3, characterized in that: The step of randomly placing a plurality of core-shaped particles coated with the adhesive into a preset mold until the entire mold is filled includes: When a plurality of core-shaped particles coated with the adhesive are randomly placed into the preset mold, the raw material powder is sprinkled in to simulate the dust surrounding the rubble pile asteroid.

5. The method for manufacturing a rubble pile asteroid simulant according to claim 1, characterized in that: The raw material powder is a powder obtained by grinding a meteorite sample into micron-sized powder.

6. The method for manufacturing a rubble pile asteroid simulant according to claim 1, characterized in that: The stirring device is controlled to rotate to obtain a plurality of core-shaped particles with different diameters, and then includes: The diameter range of the core-shaped particles is preset, and a plurality of the core-shaped particles are screened to select core-shaped particles that meet the conditions.

7. The method for manufacturing a rubble pile asteroid simulant according to claim 6, characterized in that: The presetting of the diameter range of the core-shaped particles and screening the plurality of core-shaped particles to select core-shaped particles meeting the conditions include: When the diameter of the core-shaped particle reaches the diameter range, applying an adhesive on the surface of the core-shaped particle; When the diameter of the core-shaped particles does not reach the diameter range, the core-shaped particles are put into a grinder and ground into raw material powder.

8. The method for manufacturing a rubble pile asteroid simulant according to claim 7, characterized in that: When the diameter of the core-shaped particle reaches the diameter range, applying an adhesive on the surface of the core-shaped particle comprises: Selecting a plurality of the core-shaped particles from the same batch and measuring the average moisture content of each of the core-shaped particles; When the core-shaped particles meet the preset range of the average moisture content, applying an adhesive on the surface of the core-shaped particles; When the core particles do not meet the preset range of the average moisture content, the core particles are crushed to form the raw material powder.

9. A method for testing a rubble pile asteroid simulant, wherein the rubble pile asteroid simulant is manufactured based on the method for manufacturing a rubble pile asteroid simulant according to any one of claims 1 to 8, characterized in that: include: performing multiple free-fall experiments on the rubble pile asteroid simulant and recording the number of core-like particles detached during the multiple experiments; Calculating a bonding failure rate of the rubble pile asteroid simulant based on the number of detached core particles; Measuring the hardening strength of the rubble pile asteroid simulant with a qualified bonding failure rate; The hysteresis loop of the rubble pile asteroid simulant with qualified hardening strength is measured to determine whether the rubble pile asteroid simulant meets the requirements.

10. The method for testing a rubble pile asteroid simulant according to claim 9, characterized in that: Measuring the hysteresis loop of the rubble pile asteroid simulant with qualified hardening strength and determining whether the rubble pile asteroid simulant meets the requirements includes: measuring the circumference and cross-sectional area of the rubble pile asteroid simulant; placing the rubble pile asteroid simulant in an alternating magnetic field, inputting different currents into the alternating magnetic field, and performing hysteresis loop measurements; The magnetic powder distribution and magnetization level in the rubble pile asteroid simulant are judged based on the parameters of the hysteresis loop, and a conclusion is drawn as to whether the rubble pile asteroid simulant is qualified.

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