A deep-sea landing buffer design method and system based on filling optimization TPMS structure

Abstract

The application belongs to the technical field of deep-sea lander, and discloses a design method and system of a deep-sea landing buffer based on a filled TPMS structure, which comprises the following steps: S1, designing and preparing a filled TPMS structure; S2, performing a quasi-static compression test on the filled TPMS structure; S3, performing a dynamic impact performance test on the filled TPMS structure; S4, selecting a filled TPMS structure meeting preset requirements based on the results of the quasi-static compression test and the dynamic impact performance test, and designing a buffer system of a deep-sea lander; and S5, optimizing the buffer system of the deep-sea lander according to different application scenarios and equipment requirements. The application further explores the possibility of filling a magnetic fluid into a TPMS structure and applies the novel filled TPMS structure to a deep-sea landing buffer, thereby providing an efficient buffer solution for deep-sea exploration equipment.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of deep-sea landers, and particularly relates to a deep-sea landing buffer design method and system based on a filled optimized TPMS structure. BACKGROUND

[0002] Deep sea has attracted human beings since ancient times because of its mystery and unknown. Exploring marine resources and environment has been a long-term goal of human beings. Before the middle of the 20th century, detection equipment was mainly put into water through a cable to measure the environment and explore resources. However, with the increase of the detection depth, the length of the required cable and the complexity of the supporting system are significantly improved, which not only increases the inconvenience of transportation and operation, but also causes the equipment to be disturbed under the action of the sea current, seriously affecting the detection function. To solve this problem, Maurice Ewing and Allyn Vine of the Woods Hole Oceanographic Institution in the United States first proposed the concept of "free vehicle" in 1938, which separates the center of gravity and buoyancy by heavy objects and floating balls, so as to realize the stable bottom of the detection equipment. This innovation promotes the development of the cable-free deep-sea detection equipment.

[0003] With the rapid development of deep-sea detection technology, high-performance and integrated buffer energy-absorbing materials have become an indispensable key technology in deep-sea landers. There are significant differences between deep-sea environment and ground conditions, and complex water loads and uncertain terrain put strict requirements on the impact buffering performance of the equipment. Improper design of the buffer structure not only accelerates the aging of the equipment and shortens the service life, but also may even cause the failure of the detection task. In the deep-sea landing process, efficient energy-absorbing performance has become a core factor to ensure the reliability of the detection equipment.

[0004] In recent years, lightweight porous structures and thin-walled energy-absorbing structures have shown great potential in deep-sea landers due to their high energy absorption characteristics. These new energy-absorbing structures, through optimized design, effectively dissipate energy using structural deformation, providing reliable device protection. However, traditional foam materials and honeycomb structures have limitations such as random microstructure, poor adjustability, short service life, and insufficient ability to process complex shapes, making it difficult to meet the demand for high-performance energy-absorbing structures in deep-sea exploration missions. Therefore, developing high-efficiency energy-absorbing materials suitable for deep-sea environments and their design methods has become a top priority. The three-period minimal surface (TPMS) structure based on porous material filling has become a potential solution. This type of material has excellent mechanical properties and cushioning performance due to its unique periodicity and pore distribution. Studies have shown that a well-designed TPMS structure not only has lightweight advantages but also can further enhance energy absorption efficiency by filling various materials. For example, filling elastic materials such as aluminum foam and polymer foam in porous materials such as honeycomb steel tubes and truss structures has been proven to significantly improve the strength and energy absorption capacity of the structure. However, the matching problem between the filler and the structure during compression still affects the energy dissipation efficiency and the reusability of the structure. In addition, granular materials exhibit broad application potential in external impact energy absorption and pulse wave dissipation due to their unique rheological properties. Granular fillers not only adapt to the compression of porous structures but also improve overall performance through inter-particle friction and energy dissipation paths within the material.

[0005] During the landing process of a deep-sea lander, lattice structures may encounter low-speed impact events. Although no significant damage can be observed on the surface, serious damage such as cracks, fractures, or interlayer separation may have occurred inside the structure. These damages gradually accumulate, reducing the load-bearing capacity of the structure and even leading to functional failure, resulting in economic losses and safety risks. Existing research mainly focuses on the performance evaluation of metal TPMS structures and gradient structures, while the response and energy absorption capacity of material-filled TPMS structures under dynamic impact conditions and quasi-static compression tests are relatively less studied. Therefore, in-depth study of the impact resistance and energy absorption characteristics of material-filled TPMS structures during the landing of deep-sea landers is of great significance and can effectively improve the performance of such filler structures in high-demand application fields.

[0006] Although previous studies have shown that the type and proportion of fillers have a significant impact on energy absorption characteristics, the mechanism by which fillers in TPMS structures enhance energy absorption efficiency has not been systematically analyzed. The influence of different proportions of material filling on the energy absorption performance of TPMS structures under quasi-static and dynamic conditions still has significant research space. Therefore, the development of TPMS structures filled with high-performance materials and their optimization design methods have important application value in improving the cushioning performance and energy absorption efficiency of deep-sea landers. SUMMARY

[0007] To solve the problems in the prior art, the application provides a deep-sea landing buffer design method and system based on a filling-optimized TPMS structure. Three different configurations of TPMS structures are designed through implicit functions and three-dimensional modeling technology, and sealing and end cap designs are combined to adapt to the filling material requirements. High-precision sample parts are manufactured using fused deposition modeling (FDM) technology, and structures with three filling material proportions (0%, 50%, and 100%) are designed. The filling effect is verified by mass analysis evaluation. Based on the quasi-static compression test, the energy absorption characteristics of the TPMS structure under different filling material proportions are systematically studied. The differences in deformation mode and energy absorption performance of the three configurations are compared. Through single-factor tests of different placement times, filling material particle sizes, and loading speeds, the influence of multiple factors on the performance of the TPMS structure is further explored. In the dynamic impact test, impact tests from 20J to 300J energy levels are carried out on TPMS structures with different filling material proportions. High-speed camera technology is used to accurately capture the dynamic deformation mode, obtain the stress-strain curve and time-energy curve. Through quantitative analysis, the influence of the filling material proportion on the impact resistance of the TPMS structure is revealed. The research shows that the filling material significantly improves the energy absorption performance of the TPMS structure, providing an important idea for the development and application of high-performance filling materials. In addition, the application further explores the possibility of filling magnetic fluid into the TPMS structure, and applies this new filling TPMS structure to the deep-sea landing buffer, providing an efficient buffer solution for deep-sea exploration equipment.

[0008] To achieve the above object, the application provides the following scheme:

[0009] A deep-sea landing buffer design method based on filling-optimized TPMS structure, the method comprises:

[0010] S1: design and prepare a filling TPMS structure;

[0011] S2: quasi-static compression test of the filling TPMS structure;

[0012] S3: dynamic impact performance test of the filling TPMS structure;

[0013] S4: based on the results of the quasi-static compression test and the results of the dynamic impact performance test, select a filling TPMS structure that meets the predetermined requirements, and design a buffer system for a deep-sea lander;

[0014] S5: according to different application scenarios and equipment requirements, optimize the buffer system of the deep-sea lander.

[0015] Preferably, in S1, the design and preparation of the filling TPMS structure comprises:

[0016] Design three different configurations of TPMS structure;

[0017] Design TPMS sealing structure, wherein the design of the TPMS sealing structure includes: thin wall design and end cap design;

[0018] Prepare a filled TPMS structure sample;

[0019] Prepare a filling material;

[0020] Fill the prepared filling material into the prepared filled TPMS structure sample, and conduct repeated experimental tests;

[0021] Among them, the design of three different configurations of TPMS structure includes:

[0022] φ p (x,y,z)=cosx+cosy+cosz=c

[0023] φ G (x,y,z)=cosxsiny+cosysinz+coszsinx=c

[0024] φ D (x,y,z)=sinxsinysinz+cosxinysinz+

[0025] sinxcosysinz+sinxsinycosz=c

[0026] Among them, φ P (x,y,z), φ G (x,y,z), φ D (x,y,z) are the equations of Primitive surface (P), Gyroid surface (G) and Diamond surface (D) respectively, x, y, z are the coordinates of three-dimensional space, which describes the geometric position of TPMS, and c is a constant, which is used to describe the value of the level set corresponding to the TPMS surface;

[0027] Among them, the preparation of the filled TPMS structure sample includes: using 3D printing technology to manufacture TPMS lattice structure and top sealing piece;

[0028] Among them, the preparation of the filling material includes: drying treatment of the filling material; after drying, store the filling material in a constant temperature and humidity box; further pre-screen the filling material, and divide it into three types according to particle size: 0.15mm, 0.65mm and 0.85mm.

[0029] Preferably, in S2, the quasi-static compression test of the filled TPMS structure includes:

[0030] Select a testing machine and force sensor range that meet the preset requirements, combine three structural configurations, different resting times, particle sizes and loading speeds, and select three samples for repeated testing;

[0031] Five key indicators were used to analyze the experimental results, and the energy absorption results of three configurations with different filling ratios were obtained.

[0032] The settling time, particle size of the filling material, and loading speed were analyzed.

[0033] By analyzing the deformation records of the first cyclic compression, different configurations of TPMS with the same relative density were selected, and the influence of different filling ratios on the deformation mode of the TPMS structure was analyzed.

[0034] The five key indicators include:

[0035] Energy absorption (EA): Where S is the displacement due to strain, F(s) represents the force at a certain point during deformation, m represents the mass, and SEA represents the specific energy absorption, i.e. the energy absorbed per unit mass.

[0036] Specific energy dissipation (SED): Where ED is the energy dissipated during the cyclic compression test, and is the area under the hysteresis curve;

[0037] Percentage of remaining energy dissipated: Here, @current cycle represents the current loop, and @1st cycle represents the first loop;

[0038] Deformation recovery rate; R = (1-ε r )×100%; where, ε r R represents the residual strain, and R represents the deformation recovery rate.

[0039] Damping characteristics;

[0040] The experimental results were analyzed using five key indicators, including: separate comparative analysis of different filling ratios for different configurations, and comprehensive comparative analysis of different filling ratios for different configurations.

[0041] Preferably, in step S3, the dynamic impact performance test of the TPMS-filled structure includes:

[0042] The test specimen to be tested is placed on the rigid plate, the hammer is caused to freely and vertically fall to the surface of the test specimen under the action of gravity by the double guide rail system to apply an impact force, the voltage change of the contact point between the punch and the test specimen during the impact process is captured and recorded, the voltage data is converted to generate curves representing the contact force, displacement, speed and energy of the punch and the test specimen with respect to time, and the dynamic response of the test specimen under different impact energies is analyzed, wherein the dynamic response includes deformation, crack generation and internal damage expansion;

[0043] The initial impact energy is controlled by adjusting the mass of the hammer head or the height between the hammer head and the test specimen, the impact test is carried out, and the energy absorption capacity and impact resistance of the test specimen under different impact energies are analyzed;

[0044] The efficiency of the test specimen in absorbing energy under different impact energies is analyzed by applying different levels of impact energy to simulate from slight to extreme impact conditions;

[0045] The deformation of the first cycle compression is recorded and analyzed, different configurations of TPMS under the same relative density are selected, and the influence of different filling ratios on the deformation mode of the TPMS structure is analyzed;

[0046] The initial impact energy is controlled by adjusting the mass of the hammer head or the height between the hammer head and the test specimen, the impact test is carried out, and the energy absorption capacity and impact resistance of the test specimen under different impact energies are analyzed;

[0047] During the impact process, the falling of the hammer head is regarded as free fall motion, and the reduced gravitational potential energy is converted into impact kinetic energy E applied to the test specimen:

[0048]

[0049] In the formula, v0 is the initial speed when the hammer head contacts the test specimen, and U is the gravitational potential energy of the falling hammer;

[0050] The high-energy impact test is controlled by adjusting the weight and height of the falling hammer; the test equipment captures the load data when the punch contacts the sample, and calculates the change of the falling hammer speed with respect to time:

[0051]

[0052] In the formula, v(t) is the speed of the hammer head at time t, v(t)>0 when the punch moves downward, and v(t)<0 when the punch rebounds and moves upward; t is time; F(t) is the contact force between the hammer head and the test specimen at time t;

[0053] After the test specimen is impacted, the absorbed energy of the test specimen is converted from the kinetic energy of the punch:

[0054]

[0055] In the formula, E aenergy absorbed by the test piece during the impact process;

[0056] wherein simulating from slight to extreme impact conditions by applying different levels of impact energy includes:

[0057]

[0058] wherein E a represents the energy absorbed by the test piece; E i represents the impact energy; and η is the energy absorption efficiency.

[0059] Preferably, in the S4, based on the results of the quasi-static compression test and the results of the dynamic impact performance test, the TPMS structure satisfying the preset requirements is selected, and the buffer system of the deep-sea lander is designed, including:

[0060] Based on the results of the quasi-static compression test and the results of the dynamic impact performance test, the P configuration with the optimal filling effect and the D structure with the strongest bearing capacity are selected;

[0061] The P configuration with the optimal filling effect and the D structure with the strongest bearing capacity are designed as a two-stage energy absorption structure.

[0062] The application also provides a deep-sea landing buffer design system based on a filling-optimized TPMS structure, which is used to implement any one of the methods, and the system comprises a first design module, a static test module, a dynamic test module, a second design module and an optimization module.

[0063] The first design module is used to design and prepare the filling TPMS structure.

[0064] The static test module is used to perform a quasi-static compression test on the filling TPMS structure.

[0065] The dynamic test module is used to perform a dynamic impact performance test on the filling TPMS structure.

[0066] The second design module is used to select a filling TPMS structure satisfying preset requirements based on the results of the quasi-static compression test and the results of the dynamic impact performance test, and design a buffer system of a deep-sea lander.

[0067] The optimization module is used to optimize the buffer system of the deep-sea lander according to different application scenarios and equipment requirements.

[0068] Preferably, in the first design module, the design and preparation of the filling TPMS structure comprises:

[0069] Designing three different configurations of TPMS structures.

[0070] The TPMS sealing structure is designed, wherein the design of the TPMS sealing structure comprises a thin-wall design and an end cap design;

[0071] The filled TPMS structure sample is prepared;

[0072] The filled material is prepared;

[0073] The prepared filled material is filled into the prepared filled TPMS structure sample, and a repetitive experiment test is performed;

[0074] The three different configurations of the TPMS structure are designed, including:

[0075] φ p (x,y,z)=cosx+cosy+cosz=c

[0076] φ G (x,y,z)=cosxsiny+cosysinz+coszsinx=c

[0077] φ D (x,y,z)=sinxsinysinz+cosxinysinz+

[0078] sinxcosysinz+sinxsinycosz=c

[0079] wherein φ P (x,y,z), φ G (x,y,z), and φ D (x,y,z) are equations of the Primitive surface (P), the Gyroid surface (G), and the Diamond surface (D) respectively, x, y, and z are coordinates of a three-dimensional space, describing the geometric position of the TPMS, and c is a constant, used to describe the value of the level set corresponding to the TPMS surface;

[0080] The filled TPMS structure sample is prepared, including manufacturing the TPMS lattice structure and the top sealing piece by using a 3D printing technology;

[0081] The filled material is prepared, including drying the filled material; after the drying is completed, storing the filled material in a constant-temperature and constant-humidity box; further pre-screening the filled material, and dividing the filled material into three types according to particle sizes, i.e., 0.15 mm, 0.65 mm, and 0.85 mm.

[0082] Preferably, in the static test module, the quasi-static compression test on the filled TPMS structure comprises:

[0083] Selecting the test machine and force sensor range that meet the preset requirements, combining three structural configurations, different standing times, particle sizes and loading speeds, and selecting three samples for repeated tests;

[0084] Five key indicators are used to analyze the test results to obtain the energy absorption results of the three configurations with different filling ratios;

[0085] The standing time, particle size of the filling material and loading speed are analyzed;

[0086] Through the analysis of the deformation record of the first cycle compression, different configurations of TPMS with the same relative density are selected, and the influence of different filling ratios on the deformation mode of the TPMS structure is analyzed;

[0087] The five key indicators include:

[0088] Energy absorption EA: Where S is the displacement of strain, F(s) represents the force corresponding to a certain point during deformation, m represents the mass, and SEA represents the specific energy absorption, i.e. the energy absorbed per unit mass;

[0089] Specific energy dissipation SED: Where ED is the energy dissipated during the cyclic compression test, and A is the area under the hysteresis curve;

[0090] Residual energy dissipation percentage: Where @current cycle represents the current cycle, and @1st cycle represents the first cycle;

[0091] Deformation recovery rate R = (1-ε r )×100%; Where ε r is the residual strain, and R is the deformation recovery rate;

[0092] Damping characteristics;

[0093] The five key indicators used to analyze the test results include: separate comparative analysis of different filling ratios of different configurations, and comprehensive comparative analysis of different filling ratios of different configurations.

[0094] Preferably, in the dynamic test module, the dynamic impact performance test of the filled TPMS structure includes:

[0095] The test specimen to be tested is placed on the rigid plate, the hammer is caused to freely and vertically fall to the surface of the test specimen under the action of gravity to apply an impact force through the double guide rail system, the voltage change of the contact point between the punch and the test specimen during the impact process is captured and recorded, the voltage data is converted to generate curves representing the contact force, displacement, speed and energy of the punch and the test specimen changing with time, and the dynamic response of the test specimen under different impact energies is analyzed, wherein the dynamic response includes deformation, crack generation and internal damage expansion;

[0096] The initial impact energy is controlled by adjusting the mass of the hammer head or the height between the hammer head and the test specimen, the impact test is carried out, and the energy absorption capacity and impact resistance of the test specimen under different impact energies are analyzed;

[0097] The efficiency of the test specimen in absorbing energy under different impact energies is analyzed by applying different levels of impact energy to simulate from slight to extreme impact conditions;

[0098] The deformation of the first cycle compression is recorded and analyzed, different configurations of TPMS under the same relative density are selected, and the influence of different filling ratios on the deformation mode of the TPMS structure is analyzed;

[0099] The initial impact energy is controlled by adjusting the mass of the hammer head or the height between the hammer head and the test specimen, the impact test is carried out, and the energy absorption capacity and impact resistance of the test specimen under different impact energies are analyzed;

[0100] During the impact process, the falling of the hammer head is regarded as free fall motion, and the reduced gravitational potential energy is converted into impact kinetic energy E applied to the test specimen:

[0101]

[0102] In the formula, v0 is the initial speed when the hammer head contacts the test specimen, and U is the gravitational potential energy of the falling hammer;

[0103] The high-energy impact test is controlled by adjusting the weight and height of the falling hammer; the test equipment captures the load data when the punch contacts the sample, and calculates the change of the falling hammer speed with time:

[0104]

[0105] In the formula, v(t) is the speed of the hammer head at time t, v(t)>0 when the punch moves downward, and v(t)<0 when the punch rebounds and moves upward; t is time; F(t) is the contact force between the hammer head and the test specimen at time t;

[0106] After the test specimen is impacted, the energy absorbed by the test specimen is converted from the kinetic energy of the punch:

[0107]

[0108] In the formula, E athe energy absorbed by the test piece during the impact process;

[0109] wherein simulating from slight to extreme impact conditions by applying different levels of impact energy includes:

[0110]

[0111] wherein E a represents the energy absorbed by the test piece; E i represents the impact energy; and η is the energy absorption efficiency.

[0112] Preferably, in the second design module, based on the results of the quasi-static compression test and the results of the dynamic impact performance test, a TPMS structure satisfying a preset requirement is selected, and a bumper system of the deep-sea lander is designed, including:

[0113] Based on the results of the quasi-static compression test and the results of the dynamic impact performance test, a P configuration with optimal filling effect and a D structure with strongest bearing capacity are selected;

[0114] The P configuration with optimal filling effect and the D structure with strongest bearing capacity are designed as a two-stage energy absorption structure.

[0115] Compared with the prior art, the present application has the following beneficial effects:

[0116] 1. The present application studies TPMS structures with different sand filling ratios, which exhibit significantly different stress-strain relationships and deformation modes under quasi-static compression load. Compared with the unfilled structure, the 50% filled TPMS structure shows a more significant stress increase in the plastic plateau stage after the elastic stage, which indicates that the filling treatment not only changes the deformation mode of the TPMS structure, but also improves its energy absorption capacity and recoverability.

[0117] 2. The influence of filling on TPMS structures of different configurations under quasi-static compression test has certain differences. Among them, under the same filling ratio conditions, the specific energy consumption (SED) of the Diamond (D) curved surface structure is better than that of the Gyroid (G) curved surface structure and higher than that of the Primitive (P) curved surface structure. The filling material increases the bearing capacity of the structure and improves the energy absorption performance of the structure. In terms of improving the energy absorption performance of the structure, the SED of the filled structure can be increased by 1.48 times at most, and the energy dissipation rate can be increased by 20.5% at most. In addition, the improvement of the energy absorption performance of the P structure by filling is the best among the three TPMS configurations, which indicates that the improvement of filling on the TPMS structure with weak energy absorption is more obvious.

[0118] 3、The deformation mode and stress-strain curve change rule of the filled TPMS structure in the drop hammer dynamic impact process are similar to those under the quasi-static loading condition at low energy impact (20J). At medium energy impact (40J, 80J), the unfilled TPMS structure shows higher bearing capacity and higher stiffness, but at the same time, obvious damage occurs in the structure, while the 50% filled and 100% filled structures show lower peak load and less structural damage. The friction of the filling material absorbs most of the energy, and at the same time, reduces the damage degree of the structure. At high energy impact (160J, 300J), the unfilled TPMS structure shows complete failure and complete densification, but the 100% filled material TPMS structure shows similar force-displacement curve trend to that at low energy impact. This shows that the filling material significantly improves the energy absorption characteristics of the structure under high-speed impact, and at the same time, plays a significant protective role for the structure, so that it can cope with higher energy impact without affecting the performance. This fully embodies the excellent performance of the filled material TPMS structure in impact energy absorption and protection and shock absorption.

[0119] 4、The application explores the performance of the filled material TPMS structure under quasi-static and dynamic loading conditions through experimental means, finds that the filled material significantly improves the energy absorption characteristics of the TPMS structure, and provides a new idea for the development of high-performance filling materials. The possibility of filling magnetic fluid into the TPMS structure is explored, and the new type of filled TPMS structure is applied to the deep sea landing buffer, providing an efficient buffer solution for deep sea exploration equipment. BRIEF DESCRIPTION OF DRAWINGS

[0120] In order to more clearly illustrate the technical solutions of the present application, the following briefly introduces the drawings needed to be used in the embodiments. Obviously, the drawings described in the following only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without paying creative labor.

[0121] Figure 1 The schematic diagram of the reliable sealing design method of the TPMS structure of the embodiment of the present application;

[0122] Figure 2 The energy absorption result schematic diagram of three configurations with different filling ratios of the embodiment of the present application, wherein (a) is specific energy consumption; (b) is residual energy dissipation rate; (c) is energy dissipation rate; (d) is deformation recovery rate;

[0123] Figure 3 The test result schematic diagram of three filled P structures under different filling particle size test conditions of the embodiment of the present application, wherein (a) is specific energy consumption; (b) is residual energy dissipation rate; (c) is deformation recovery rate; (d) is energy dissipation rate;

[0124] Figure 4 This is a schematic diagram illustrating some experimental analysis results of an embodiment of the present invention, which simulates impact conditions ranging from mild to extreme by applying different levels of impact energy.

[0125] Figure 5 This is a schematic diagram of a circular mapping structure based on the P structure according to an embodiment of the present invention;

[0126] Figure 6 This is a schematic diagram of the buffer system of the deep-sea lander according to an embodiment of the present invention;

[0127] Figure 7 This is a schematic diagram of a deep-sea landing buffer design method based on a padded optimized TPMS structure according to an embodiment of the present invention;

[0128] Figure Descriptions: 1—Circular mapping structure based on TPMS-filled P structure; 2—Circular mapping structure based on TPMS-filled D structure; 3—Electromagnetic coil; 4—Spring; 5—Recompressible soft film; 6—Structural design of the landing legs and base of the buffer lander. Detailed Implementation

[0129] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0130] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0131] Example 1

[0132] like Figure 7 As shown, this invention provides a deep-sea landing buffer design method based on a padded optimized TPMS structure, the method comprising:

[0133] S1: Design and fabrication of TPMS-filled structures;

[0134] S2: Quasi-static compression test on the TPMS-filled structure;

[0135] S3: Dynamic impact performance test of the TPMS-filled structure;

[0136] S4: Based on the results of quasi-static compression test and dynamic impact performance test, select a filled TPMS structure that meets the preset requirements and design the buffer system of the deep-sea lander;

[0137] S5: According to different application scenarios and device requirements, the buffer system of the deep-sea lander is optimized.

[0138] In this embodiment, step S1: design and preparation of TPMS structure filling:

[0139] S11: Geometric design of traditional TPMS structure:

[0140] In the above method, step S1, the parametric coordinates of the three-period minimal surface (TPMS) can be derived by the Weierstrass function. The geometric structure of TPMS can be solved by the following mathematical expression:

[0141]

[0142] where Re is the coefficient obtained by calculating the numerical value from the fixed point ω0 to a variable point ω, x, y, z are the coordinates of three-dimensional space, which are calculated by the parametric equation, describing the geometric position of TPMS, R(τ) is a function related to the TPMS surface, describing the surface shape and geometric structure, θ is a variable describing the polar coordinate angle on the surface, τ is a variable describing the change of TPMS surface parameterization, defining the integral path. Through this form, the parametric coordinates of TPMS surface can be obtained. Next, the level set approximation equation defined by Fourier series is used to derive the geometric structure of TPMS. The equation is as follows:

[0143]

[0144] where Ψ(r) is a function representing the level set, used to generate the geometric structure of TPMS by Fourier series expansion, k is the inverse vector, α(k) is the phase shift, the structure factor F(k) is the amplitude related to the given k, and r is the vector of spatial position. When the series is truncated to the leading term, a function φ composed of trigonometric functions is generated, which satisfies the following equation:

[0145] φ(x,y,z)=c

[0146] where c is a constant, used to describe the value of the level set corresponding to the TPMS surface. It determines the specific shape and position of the generated TPMS surface in space. By adjusting the value of c, the geometric characteristics of TPMS surface can be adjusted, such as the thickness, curvature and other parameters of the surface.

[0147] Finally, the mathematical expression of TPMS surface is obtained:

[0148]

[0149] where, Equations of the Primitive surface (P), Gyroid surface (G) and Diamond surface (D) respectively. And by adjusting the value of c, the size, volume fraction, pore size and thickness of the TPMS opening structure are adjusted.

[0150] S12: TPMS closed structure design:

[0151] The TPMS opening structure size, volume fraction, pore size and thickness obtained in step S11 are completely unchanged, and the structure is further designed to increase the thin wall and end cap to realize structural sealing, thereby obtaining the design of the TPMS sealed structure. In order to reduce the influence of the thin wall on the subsequent test, the thin wall design needs to be as thin as possible (30x30x0.65mm thin wall), while meeting the processing requirements of the additive manufacturing equipment. A thin wall is added outside the original opening structure using a commercial modeling software (Materialise Magics 23.0) to minimize the influence on the deformation of the structure (Primitive (P), Diamond (D) and Gyroid (G) three configurations). In addition, an independent end cap is designed by interference fit for connection with the sealed structure. The thickness and size of the end cap (the internal size of the end cap is 29.8x29.8mm, and the wall thickness is 0.65mm) are optimized to ensure that the sealing requirement is met and the influence on the performance of the structure is minimized. This design method realizes the reliable sealing of the TPMS structure and provides a solid foundation for subsequent tests. The design method is shown in Figure 1

[0152] S13: Preparation of TPMS structure sample filled with material:

[0153] The 3D printing technology is used to manufacture the TPMS lattice structure and the top sealing piece. First, the 3D printer JG Maker A6 (JG Aurora, China) is used to generate slice files according to the "STL" file of the TPMS lattice structure. Then, the filament thermoplastic polyurethane (TPU) material is heated to an appropriate melting temperature, extruded through the printer nozzle, and stacked layer by layer to form the required mechanical device structure. The process includes adjustment of the setting parameters and material parameters of the 3D printer as shown in Tables 1 and 2 to ensure the printing quality and product performance.

[0154] Table 1 Setting parameters of 3D printer

[0155]

[0156] Table 2 3D printing material parameters

[0157] ​

[0158] S14: Preparation of the filler material:

[0159] The solid particulate filler is pretreated to ensure the stability of its mechanical properties. First, the filler material is dried using an electric heating air drying oven, with a temperature setting of 60°C and a drying time of 12 hours. After drying is complete, the filler material is stored in a constant temperature and humidity box, maintaining a temperature of 25°C and a humidity of 50%. Given that the mechanical properties of granular materials are significantly affected by their size and shape, the filler material is further pre-screened and classified by particle size into three categories: 0.15mm, 0.65mm, and 0.85mm.

[0160] S15: The filler material from step S14 is filled into the TPMS structure prepared in step S13, and repeated experimental tests are conducted (the mass of each configuration is measured before and after filling. The average value of the mass after filling is taken as the standard mass of filling in the structure (100% filling ratio) to minimize the impact of structure printing errors). In four repeated tests, the mass of the filler material, the mass of the TPMS structure, and the mass of the TPMS after filling are measured and recorded, and their average values are calculated.

[0161] Step S2: The present application studies the energy absorption characteristics and recoverability of TPMS structures under three different filler material ratios (0%, 50%, 100%), covering three configurations: Primitive (P), Diamond (D), and Gyroid (G). Further univariate experiments are conducted on the filled Primitive (P) structure to investigate factors such as placement time, particle size, and loading speed of the filler material, and to analyze the influence of different loading conditions and filler material ratios on the recoverability of TPMS structures. Twenty cyclic quasi-static compression tests are conducted, and through force-displacement curve analysis, the energy absorption and recoverability of structures without filler material, loosely filled filler material, and densely filled filler material under quasi-static compression conditions are evaluated. This step helps to optimize the energy absorption and recovery capabilities of TPMS structures and demonstrates the potential of filler-containing structures.

[0162] Step S21: Preparation phase of TPMS filled structure quasi-static compression test, select appropriate testing machine and force sensor range. To ensure the safety of the equipment and improve the accuracy of the data, select the appropriate force sensor range, so as to avoid damage to the instrument due to excessive stress, and ensure the sensitivity to small changes in force value. The present application adopts 3369 Instron testing machine (range 50kN) to carry out the test, and carries out quasi-static compression test on TPMS structure with filling ratio of 0%, 50% and 100%. The crosshead rate of the testing machine is set to 2mm / min, 20 cycles of loading, and the displacement is 15mm. During the test, three structure configurations, different standing time (four standing times: 0, 5, 30 and 60 minutes; particle diameter, respectively 0.15mm and 0.85mm; two quasi-static compression loading speeds of 2mm / min and 500mm / min), particle size and loading speed are considered, and three samples are selected for repeated test to verify the reliability of the results. The test piece is placed in the center of the instrument platform, the loading direction is parallel to the FDM construction direction, the deformation behavior and damage mode are recorded by the camera, and the mechanical properties and energy absorption capacity of the TPMS structure are evaluated.

[0163] Step S22: Through the test, set the capacity analysis index, and analyze the test results by using five key indexes. These indexes are used to systematically evaluate the effectiveness and reliability of the test data.

[0164] Performance index one: energy absorption (EA) refers to the total energy absorbed by the structure; defined as the envelope area of the force-displacement curve:

[0165]

[0166] Where S is the displacement of strain, usually the strain point to the beginning of densification, F(s) represents the force corresponding to a certain point in the deformation process, usually the force acting on the material at strain S, m represents the mass, usually the total mass of the material or system involved in energy absorption or deformation, and SEA (Specific Energy Absorption) represents the specific energy absorption, i.e. the energy absorbed per unit mass, which is an important index to measure the energy absorption performance of materials or structures, defined as the ratio of total absorbed energy EA to mass m. Because of the change of the porous characteristics of the structure in the filling process of the TPMS structure, the trend of the force-displacement curve changes with the characteristics of early densification, which also affects the energy efficiency and the appearance rule of peak force. Therefore, the densification starting strain is predefined as 50% of the strain value, and the compression displacement is set to 15mm to ensure consistency. m is the mass of the structure. To ensure the consistency of the structure size, the construction size of all structures in this paper is 30*30*30mm.

[0167] Performance indicator two: specific energy dissipation (SED) is one of the important indicators for evaluating energy absorption performance. The larger the SED, the stronger the energy dissipation capacity of the structure. SED is calculated by the area under the hysteresis loop:

[0168]

[0169] where ED is the energy dissipated during the cyclic compression test, and A is the area under the hysteresis curve.

[0170] Performance indicator three: residual energy dissipation percentage is a measure of the proportion of SEA change in the cyclic test, i.e. energy attenuation, defined as the SED of the current cycle divided by the SED of the first cycle, i.e.

[0171]

[0172] where @current cycle represents the current cycle, and @1st cycle represents the first cycle.

[0173] Performance indicator four: deformation recovery rate is the ratio of the sample height at the end of compression to the original height before compression of the sample, which is an important indicator for measuring the shape recovery ability of the structure.

[0174] R = (1 - ε r ) × 100%

[0175] where ε r is the residual strain, and R is the deformation recovery rate.

[0176] Performance indicator five: damping characteristic refers to the ability of a material to absorb vibration (cyclic stress) through internal friction and convert mechanical energy into heat energy. The specific damping capacity SDC of the present invention is used to evaluate the damping capacity of the structure.

[0177]

[0178] A higher SDC indicates a greater proportion of energy dissipation relative to total energy absorption, which is beneficial for energy absorbers. This means that if more energy is dissipated after an impact with the same energy input, less energy is returned to the impact component, thereby protecting the external structure from impact.

[0179] Step S23: Analyze the experimental results according to the performance indicators in step S22. First, separately compare and analyze different filling ratios for different configurations, and finally conduct a comprehensive comparative analysis. Some test results are shown in the following table: Figure 2 where the energy absorption results (a) specific energy consumption (b) residual energy dissipation rate (c) energy dissipation rate (d) deformation recovery rate of three configurations with different filling ratios.

[0180] where separate comparative analysis:

[0181] 1、Filler material on the performance of P structure analysis

[0182] The force-displacement curve of P under three filling ratios (0%, 50%, 100%) is drawn. The test results of the first, 10th and 20th cycle periods of the same filling ratio and the same configuration are compared and analyzed.

[0183] Then the four energy parameter indicators mentioned above (specific energy consumption, residual energy dissipation rate, deformation recovery rate, energy dissipation rate) are used to draw their curves. The test results of 1-20 cycles are selected, and the P configurations with different filling ratios (0%, 50%, 100%) are compared and analyzed.

[0184] 2、Filler material on the performance of G structure analysis and filler material on the performance of P structure analysis method.

[0185] 3、Filler material on the performance of D structure analysis and filler material on the performance of P structure analysis method.

[0186] Comprehensive comparative analysis: The P, D and G configurations studied are compared, and the common exploration, Figure 2 The (a) specific energy consumption (b) residual energy dissipation rate (c) energy dissipation rate (d) deformation recovery rate of all sand-filled structures of the three TPMS configurations in the first, second and 20th cycles is shown.

[0187] Step S24: In addition to the comparative analysis of different filling ratios and different configurations in step S23, the present application also analyzes the remaining influencing factors:

[0188] Resting time: It is the time interval between the end of each loading cycle and the start of the next loading cycle. The present application sets four resting times: 0, 5, 30 and 60 minutes. Among them, the resting time: compares the specific energy consumption of the structure under different resting times, specific energy consumption, residual energy dissipation rate, energy dissipation rate, deformation recovery. The figure is roughly like Figure 2 , and the other two are the same as above.

[0189] Filler particle size: A variety of filler particle diameters with the most significant difference within the size limit are selected to explore the influence of particle size on the performance of the filled structure. This difference in particle size leads to the formation of different gap sizes inside the structure, which in turn affects the change in filling quality. Among them, the filler particle size is 0.15mm and 0.85mm.

[0190] Loading speed: The present application sets two quasi-static compression loading speeds of 2mm / min and 500mm / min to study the influence of loading speed on the filled TPMS structure.

[0191] Some of the test results are as follows Figure 3 are shown in FIGS. 6A-6D. Figure 3 Test results of three filled P structures under different filling particle size test conditions are shown in FIGS. 7A-7D. (a) Specific energy dissipation (SED), (b) residual energy dissipation rate, (c) deformation recovery rate, and (d) energy dissipation rate.

[0192] Step S25: By detailed analysis of the deformation record of the first cycle compression, different configurations TPMS under the same relative density are selected, and the influence of different filling ratios on the deformation mode of TPMS structure is studied. This method includes using visual observation technology to check the significant damage types on the surface of the sample, such as surface indentation, matrix material crack, and structure fracture, etc., so as to reveal the influence of filling ratio on the structure performance.

[0193] Among them, the influence of filling ratio on the deformation mode is:

[0194] 0% filling: significant local thin-walled fold and elastic buckling are shown, and deformation band is easy to form, especially at high compression rate, which is easy to densify.

[0195] 50% filling: the local existence of sand particles changes the deformation mode, making the unfilled area show similar deformation characteristics to 0% filling, while the filled area is more stable, and the load resistance is significantly improved.

[0196] 100% filling: complete filling of sand particles inhibits local buckling of the hole wall, and overall buckling is significant, and the structure shows higher stability and load resistance.

[0197] Influence of structure type on deformation mode:

[0198] D structure has the highest load resistance and delayed elastic buckling characteristics.

[0199] P structure shows more obvious thin-walled fold and "one" shaped deformation band.

[0200] The deformation and load resistance of G structure is between P structure and D structure.

[0201] Step S3: Dynamic impact test is carried out on the TPMS configuration designed in step S1. The main purpose of the dynamic impact test is to explore how different impact energy levels affect the dynamic response of the test piece and the resulting damage types.

[0202] Step S31: The test specimen is accurately placed on the rigid plate to ensure stability during impact. The weight is allowed to freely and vertically fall towards the specimen surface under the action of gravity to exert impact force through a double guide rail system. The tip of the punch is equipped with a voltage sensor to capture and record the voltage change at the contact point between the punch and the specimen during impact. By converting the voltage data, curves representing the contact force, displacement, speed and energy of the punch and specimen over time are generated, providing key data on the physical behavior of the specimen under low-speed impact. A high-speed camera (30000 fps) is used to record the deformation process of the specimen to ensure data integrity. Subsequently, the dynamic response of the specimen under different impact energies, including deformation, crack initiation and internal damage propagation, is analyzed.

[0203] Step S32: The initial impact energy is controlled by adjusting the mass of the hammer head or the height between the hammer head and the sample, and the impact test is carried out. Five exponentially increasing impact energies (20 J, 40 J, 80 J, 160 J, 300 J, with 300 J being the maximum range of the testing machine) are used in the study, and specific impact energy values are set in the test. According to the principle of potential energy, the testing device precisely controls the impact energy by changing the mass and lifting height of the falling hammer:

[0204] U = mgH

[0205] Where: H - the height between the falling hammer and the sample (m); U - the gravitational potential energy of the falling hammer (J); m - the mass of the falling hammer (kg); g - the acceleration of gravity (m / s 2 ).

[0206] During impact, the falling of the hammer head is considered as free fall motion, and the reduced gravitational potential energy is converted into impact kinetic energy E exerted on the specimen:

[0207]

[0208] Where: v0 - the initial speed of the hammer head when it contacts the specimen (m / s).

[0209] By adjusting the weight and height of the falling hammer, high-energy impact tests are controlled. The testing device captures the load data when the punch contacts the specimen, and calculates the change of the falling hammer speed over time through the following formula:

[0210]

[0211] Where: v(t) - the speed of the hammer head at time t (m / s), v(t) > 0 when the punch moves downward, v(t) < 0 when the punch rebounds and moves upward; t - time (s); F(t) - the contact force between the hammer head and the specimen at time t (N).

[0212] After the specimen is impacted, the absorbed energy of the specimen is converted from the kinetic energy of the punch, which is calculated by the following formula:

[0213]

[0214] E = 1 / 2mv2 a The absorbed energy of the specimen (J). Through this step, the energy absorption capacity and impact resistance of the specimen under different impact energies can be analyzed in depth.

[0215] Step S33: Simulate impact conditions from slight to extreme by applying different levels of impact energy. The selected impact energies are 20J, 40J, 80J, 160J and 300J, aiming to cover a wide range of possible impact scenarios, so as to more comprehensively evaluate the performance of the TPMS structure. In addition to the evaluation indicators of step S23, the present application also calculates the energy absorption ratio of each structure under different impact energies by the energy absorption formula;

[0216]

[0217] E = 1 / 2mv2 a E represents the absorbed energy of the specimen, with the unit of J; E i E represents the impact energy, with the unit of J; η is the energy absorption efficiency, with the unit of %. Part of the test analysis results are shown in Table 2, which shows the energy absorption efficiency of P structure under different impact energies. Figure 4

[0218] Step S34: By detailed analysis of the deformation record of the first cycle compression, different configurations of TPMS with the same relative density are selected, and the influence of different filling ratios on the deformation mode of TPMS structure is studied. This method includes using visual observation technology to check the significant damage types on the surface of the sample, such as surface indentation, matrix material crack and structure fracture, etc., so as to reveal the influence of filling ratio on the performance of TPMS structure.

[0219] Step S4: According to the research results of step 2 and step 3, the P configuration with the best filling effect and the D structure with the strongest bearing capacity are selected. These two structures are further designed as two-stage energy absorption structures for the buffer system of the deep sea lander. The detailed buffer structure is shown in the following figure, which details the configuration and working principle of the two-stage energy absorption structure.

[0220] Step S41: Since the TPMS structure exhibits periodic symmetry in three independent directions, this symmetry can be reproduced by repeating its unit cell infinitely. Using modeling software, the cylindrical model can be discretized using a mapped mesh, as shown in the figure, and the TPMS unit is twisted using a shape function. Fill it in the mapped mesh to form a cylindrical mapped structure. Figure 5 ​Only the circular mapping structure based on P structure is shown.

[0221] Step S42: And design the structure as shown Figure 6 .

[0222] 1 is a circular mapping structure based on TPMS filling D structure

[0223] 2 is a circular mapping structure based on TPMS filling P structure

[0224] 1, 2 structures are made of memory alloy material, and the deformation of the structure is controlled by activating the thermal resistance effect through electrification. Specifically, when the memory alloy material is electrified, the local heating caused by the flow of current causes the material to undergo phase change, thereby causing the deformation of the structure. This process can accurately control the deformation of the 1, 2 structure, and further adjust the response characteristics of the buffer to achieve the optimal absorption and distribution of impact force. Through this method, dynamic adjustment of the buffer structure can be achieved according to different working environments and impact loads, improving its performance under complex conditions.

[0225] The magnetorheological fluid is filled into the structure 1, which is composed of tiny magnetic particles suspended in a base liquid. Under the action of no magnetic field, it shows a low resistance state, allowing the liquid to flow freely. When a magnetic field is applied, the magnetic particles quickly align to form a chain structure, significantly increasing the viscosity and resistance of the liquid, thereby changing the flow characteristics of the fluid.

[0226] 3, 4, 5 are electromagnetic coils, equipped with electromagnetic coils as the source of magnetic field, to control the state change of magnetorheological fluid, to realize the function of rapid response and dynamic adjustment

[0227] 6, 7 are springs, aiming at the characteristics of memory alloy material that is slow in deformation and recovery efficiency, and weak in response ability to rapid impact load, springs are introduced as auxiliary energy-absorbing elements in this design. The addition of springs not only can share part of the impact load, but also can improve the overall dynamic response ability of the system. Under the action of rapid impact load, the spring effectively absorbs part of the energy through its elastic deformation, thereby reducing the stress concentration of the memory alloy material and prolonging its service life.

[0228] 8, 9 are soft films that can be compressed repeatedly. The film can effectively prevent the overflow of the magnetic fluid. The film has excellent elasticity and compressibility, and can deform under external pressure or impact, but can quickly recover to its original state. This design not only can effectively limit the leakage of the magnetic fluid and maintain the stability of the magnetic fluid, but also can provide additional protection in various working environments, especially in extreme temperature or pressure changes, to ensure the efficient operation and reliability of the magnetic fluid system.

[0229] 10 is the structural design of the landing leg and base of the buffer lander. The landing leg and base are made of high-strength, lightweight materials that can provide the necessary cushioning effect during landing, reducing the impact force on the lander. The design of the landing leg takes into account multiple factors, including the diversity of landing surfaces and various environmental conditions that may be encountered during the landing process (such as changes in air pressure, ground hardness, etc.). The base part is designed to ensure the stability of the lander when it contacts the ground and can effectively absorb and disperse the impact force.

[0230] In addition, the installation position of the spring is optimized and cooperates with the structures in steps 1 and 2 to form a synergistic energy absorption mechanism. In the initial impact stage, the spring responds quickly to reduce the load on the shape memory alloy material through energy absorption and load distribution; in the subsequent energy absorption stage, the shape memory alloy material gradually recovers to ensure the overall stability and reliability of the energy absorption system. This design significantly improves the impact bearing capacity and recovery efficiency of the energy absorption system, providing a more efficient solution for complex dynamic loads.

[0231] Landing behavior description: During the landing process, when the lander contacts the ground, the electromagnetic coils of 1 and 2 structures are energized. When subjected to impact load, 1 structure and spring first undergo compression deformation. Due to compression, part of the magnetorheological fluid flows out of 1 structure and enters 2 structure. The bottom of 2 structure is equipped with an electromagnetic coil, which, when energized, causes the magnetorheological fluid to continue to exert resistance, effectively absorbing and relieving impact energy. When 1 structure reaches the dense point, 2 structure and spring continue to undergo compression deformation, forming a multi-stage energy absorption effect, further sharing the energy of the impact load.

[0232] When the lander lands stably, the shape memory alloy materials of 1 and 2 structures are energized and activated, and the electromagnetic coils of 2 structure are turned off. By adjusting the current size, the deformation state of 1 and 2 structures is controlled to ensure that the lander remains balanced. In addition, part of the magnetorheological fluid flows back to 1 structure, filling 1 structure and restoring its function, allowing it to continue to bear the weight of the lander and maintain stability.

[0233] When the lander floats, 1 and 2 structures are energized to restore the initial state, while generating a certain counterforce to assist the lander in floating from the seabed. During this process, the system can be recovered and reused to ensure the efficiency and reliability of the equipment.

[0234] Step S5: Steps S1-S3: Design and perform filling, static quasi-compression test and dynamic impact test of TPMS structure. Specifically, it includes optimizing the filling effect of TPMS structure, testing its static compression to evaluate its load-bearing capacity, and verifying its impact resistance through dynamic impact test. These steps provide basic data for designing high-efficiency energy absorption and buffer structure. Step S4: According to the specific application requirements of deep-sea lander, design the landing buffer structure that meets the requirements. In this step, according to the different equipment requirements for buffer performance, the appropriate design scheme is put forward to ensure the stability and high efficiency of the structure.

[0235] Summarize and summarize the design method and process in steps S1-S4 to form a systematic design idea. According to different application scenarios and equipment requirements, further optimize the buffer design to ensure reliable performance and buffering effect under various working conditions.

[0236] The technical scheme of the present application,

[0237] (1) The present application designs three different configurations of TPMS structure through the implicit function of TPMS and three-dimensional modeling software, and then designs the sealing and end cap of the structure to provide conditions for material filling. The sealing structure of TPMS is realized by thin-walled design around the structure, and the end cap is embedded with the structure by interference fit. At the same time, three different filling ratio structures are designed, i.e. 0%, 50% and 100% filling.

[0238] (2) The present application performs 20 cycle compression tests on the structure through the universal compression testing machine, explores the energy absorption capacity of the filled TPMS structure under quasi-static compression conditions, and compares the differences in deformation mode and energy absorption of three different configurations of TPMS structure under different sand particle filling ratios. At the same time, single-factor tests of different placement times, filling particles and loading speeds are carried out on the three filling ratio Primitive(P) structures, to further explore the influence of different quasi-static compression conditions and different size particle filling conditions on the performance of TPMS structure.

[0239] (3) In the present application, a series of in-depth experiments and analyses are conducted for the filled TPMS structure, especially considering its performance under dynamic impact conditions. First, by designing 20J, 40J, 80J, 160J, and 300J impact energies for the Primitive (P) structure with 0%, 50%, and 100% filling ratios, we have carried out a series of dynamic impact tests aimed at simulating the impact conditions that may be encountered in actual applications. In order to accurately capture the deformation process of the TPMS structure when it is impacted, the present application employs high-speed camera technology, which can record every instant of material deformation at high resolution, thus revealing the specific deformation mode of the TPMS structure under dynamic impact. Through the data collected at different impact energies, we obtain the stress-strain curves and time-energy curves of the filled TPMS structure. These curves provide the basis for quantitative analysis, enabling us to compare and analyze in detail the energy absorption characteristics and impact resistance of TPMS structures with different filling ratios under dynamic impact conditions. Through comparison, we find that the filling ratio has a significant impact on the dynamic response of the TPMS structure, especially in terms of improving its impact resistance and energy absorption efficiency.

[0240] Example Two

[0241] The present application also provides a deep-sea lander buffer design system based on filled optimized TPMS structure, which is used to implement any of the methods, and the system comprises a first design module, a static test module, a dynamic test module, a second design module, and an optimization module.

[0242] The first design module is used to design and prepare the filled TPMS structure.

[0243] The static test module is used to perform quasi-static compression tests on the filled TPMS structure.

[0244] The dynamic test module is used to perform dynamic impact performance tests on the filled TPMS structure.

[0245] The second design module is used to select a filled TPMS structure that meets the preset requirements based on the results of the quasi-static compression tests and the dynamic impact performance tests, and design a buffer system for the deep-sea lander.

[0246] The optimization module is used to optimize the buffer system for the deep-sea lander according to different application scenarios and equipment requirements.

[0247] In this embodiment, in the first design module, designing and preparing the filled TPMS structure includes:

[0248] Designing three different configurations of TPMS structures.

[0249] The TPMS sealing structure is designed, wherein the design of the TPMS sealing structure comprises a thin-wall design and an end cap design;

[0250] The filled TPMS structure sample is prepared;

[0251] The filled material is prepared;

[0252] The prepared filled material is filled into the prepared filled TPMS structure sample, and a repetitive experiment test is performed;

[0253] The design of the three different configurations of the TPMS structure comprises:

[0254] φ p (x,y,z)=cosx+cosy+cosz=c

[0255] φ G (x,y,z)=cosxsiny+cosysinz+coszsinx=c

[0256] φ D (x,y,z)=sinxsinysinz+cosxinysinz+

[0257] sinxcosysinz+sinxsinycosz=c

[0258] Wherein, φ P (x,y,z), φ G (x,y,z), φ D (x,y,z) are equations of Primitive surface (P), Gyroid surface (G) and Diamond surface (D) respectively, x, y, z are coordinates of three-dimensional space, which describe the geometric position of TPMS, and c is a constant, which is used to describe the value of the level set corresponding to the TPMS surface;

[0259] The filled TPMS structure sample is prepared, comprising: manufacturing the TPMS lattice structure and the top sealing piece by using a 3D printing technology;

[0260] The filled material is prepared, comprising: drying the filled material; after drying, storing the filled material in a constant temperature and humidity box; further pre-screening the filled material, and dividing the filled material into three types according to particle size, i.e., 0.15 mm, 0.65 mm and 0.85 mm.

[0261] In the static test module, the quasi-static compression test of the filled TPMS structure comprises:

[0262] Selecting the test machine and force sensor range that meet the preset requirements, combining three structural configurations, different standing times, particle sizes, and loading speeds, and selecting three samples for repeated tests;

[0263] Five key indicators are used to analyze the test results to obtain the energy absorption results of the three configurations with different filling ratios;

[0264] The standing time, particle size of the filling material, and loading speed are analyzed;

[0265] By analyzing the deformation record of the first cycle compression, different configurations of TPMS with the same relative density are selected, and the influence of different filling ratios on the deformation mode of the TPMS structure is analyzed;

[0266] The five key indicators include:

[0267] Energy absorption EA: Where S is the displacement of strain, F(s) represents the force corresponding to a certain point during deformation, m represents the mass, and SEA represents the specific energy absorption, i.e., the energy absorbed per unit mass;

[0268] Specific energy dissipation SED: Where ED is the energy dissipated during the cyclic compression test, and A is the area under the hysteresis curve;

[0269] Residual energy dissipation percentage: Where @current cycle represents the current cycle, and @1st cycle represents the first cycle;

[0270] Deformation recovery rate R = (1-ε r ) × 100%; Where ε r is the residual strain, and R is the deformation recovery rate;

[0271] Damping characteristics;

[0272] The five key indicators used to analyze the test results include: separate comparative analysis of different filling ratios of different configurations, and comprehensive comparative analysis of different filling ratios of different configurations.

[0273] In this embodiment, the dynamic test module includes dynamic impact performance testing of the filled TPMS structure, which includes:

[0274] The test specimen to be tested is placed on the rigid plate, the hammer is caused to freely and vertically fall to the surface of the test specimen under the action of gravity by the double guide rail system to apply an impact force, the voltage change of the contact point between the punch and the test specimen during the impact process is captured and recorded, the voltage data is converted to generate curves representing the contact force, displacement, speed and energy of the punch and the test specimen changing with time, and the dynamic response of the test specimen under different impact energies is analyzed, wherein the dynamic response includes deformation, crack generation and internal damage expansion;

[0275] The initial impact energy is controlled by adjusting the mass of the hammer head or the height between the hammer head and the test specimen, the impact test is carried out, and the energy absorption capacity and impact resistance of the test specimen under different impact energies are analyzed;

[0276] The efficiency of the test specimen in absorbing energy under different impact energies is analyzed by applying different levels of impact energy to simulate from slight to extreme impact conditions;

[0277] By analyzing the deformation record of the first cycle compression, different configurations of TPMS under the same relative density are selected, and the influence of different filling ratios on the deformation mode of the TPMS structure is analyzed;

[0278] The initial impact energy is controlled by adjusting the mass of the hammer head or the height between the hammer head and the test specimen, the impact test is carried out, and the energy absorption capacity and impact resistance of the test specimen under different impact energies are analyzed;

[0279] During the impact process, the falling of the hammer head is regarded as free fall motion, and the reduced gravitational potential energy is converted into impact kinetic energy E applied to the test specimen:

[0280]

[0281] In the formula, v0 is the initial speed when the hammer head contacts the test specimen, and U is the gravitational potential energy of the falling hammer;

[0282] The high-energy impact test is controlled by adjusting the weight and height of the falling hammer; the test equipment captures the load data when the punch contacts the sample, and calculates the change of the falling hammer speed with time:

[0283]

[0284] In the formula, v(t) is the speed of the hammer head at time t, v(t)>0 when the punch moves downward, and v(t)<0 when the punch rebounds and moves upward; t is time; F(t) is the contact force between the hammer head and the test specimen at time t;

[0285] After the test specimen is impacted, the absorbed energy of the test specimen is converted from the kinetic energy of the punch:

[0286]

[0287] In the formula, E athe energy absorbed by the test piece during the impact process;

[0288] wherein simulating from slight to extreme impact conditions by applying different levels of impact energy includes:

[0289]

[0290] wherein E a represents the energy absorbed by the test piece; E i represents the impact energy; and η is the energy absorption efficiency.

[0291] In the second design module, based on the results of the quasi-static compression test and the results of the dynamic impact performance test, the TPMS structure meeting the preset requirements is selected, and the buffer system of the deep-sea lander is designed, including:

[0292] Based on the results of the quasi-static compression test and the results of the dynamic impact performance test, the P configuration with the optimal filling effect and the D structure with the strongest bearing capacity are selected;

[0293] The P configuration with the optimal filling effect and the D structure with the strongest bearing capacity are designed as a two-stage energy absorption structure.

[0294] The above-described embodiments are only descriptions of the preferred modes of the present application, and do not limit the scope of the present application. Without departing from the design spirit of the present application, various modifications and improvements to the technical solutions of the present application made by those skilled in the art shall fall within the protection scope determined by the claims of the present application.

Claims

1. A method for designing a deep-sea landing bumper based on filling-optimized TPMS structure, characterized in that, The method comprises: S1: design and preparation of filled TPMS structure; S2: quasi-static compression test on the filled TPMS structure; S3: dynamic impact performance test on the filled TPMS structure; S4: based on the results of the quasi-static compression test and the results of the dynamic impact performance test, selecting a filled TPMS structure that meets the preset requirements, and designing a buffer system of a deep-sea lander; S5: optimizing the buffer system of the deep-sea lander according to different application scenarios and equipment requirements; In S1, the design and preparation of the filled TPMS structure comprises: designing three different configurations of TPMS structure; designing a TPMS sealing structure, wherein the design of the TPMS sealing structure comprises: thin-wall design and end cap design; preparing a filled TPMS structure sample; preparing a filling material; filling the prepared filling material into the prepared filled TPMS structure sample and conducting repeated experimental tests; wherein designing three different configurations of TPMS structure comprises: ； where φ P (x, y, z), φ G (x, y, z), φ D (x, y, z) are the equations of the Primitive surface (P), the Gyroid surface (G) and the Diamond surface (D) respectively, x , y , z is the coordinate of three-dimensional space, which describes the geometric position of the TPMS, c is a constant, which is used to describe the value of the level set corresponding to the TPMS surface; wherein preparing a filled TPMS structure sample comprises: using 3D printing technology to manufacture a TPMS lattice structure and a top sealing piece; wherein preparing a filling material comprises: drying the filling material; after drying, storing the filling material in a constant temperature and humidity box; further pre-screening the filling material, and dividing it into three types according to particle size: 0.15mm, 0.65mm and 0.85mm.

2. The method of claim 1, wherein, In S2, the quasi-static compression test on the filled TPMS structure comprises: selecting a test machine and a force sensor range that meet the preset requirements, combining three structural configurations, different standing times, particle sizes and loading speeds, and selecting three samples for repeated testing; using five key indicators to analyze the test results to obtain the energy absorption results of the three configurations with different filling ratios; analyzing the standing time, the particle size of the filling material and the loading speed; by analyzing the deformation record of the first cycle compression, selecting different configurations of TPMS under the same relative density, and analyzing the influence of different filling ratios on the deformation mode of the TPMS structure; wherein the five key indicators include: Energy absorption (EA): in, It is the displacement due to strain. F ( s () represents the force at a specific point during the deformation process. m Indicates quality, SEA This indicates specific energy absorption, which is the energy absorbed per unit mass. Specific energy dissipation, SED: ; wherein, ED is the energy dissipated during the cyclic compression test, is the area under the hysteresis curve; Percentage of residual energy dissipation: ; wherein, denotes the current cycle, denotes the first cycle; deformation recovery rate; ; wherein, is the residual strain, is the deformation recovery rate; damping properties ; using five key indicators to analyze the test results comprises: separately comparing and analyzing different filling ratios of different configurations, and comprehensively comparing and analyzing different filling ratios of different configurations.

3. The method of claim 2, wherein, In S3, the dynamic impact performance test on the filled TPMS structure comprises: placing the test sample on a rigid plate, allowing the weight to freely and vertically fall onto the surface of the test sample under the action of gravity through a double-rail system to apply an impact force, capturing and recording the voltage change of the contact point between the impact head and the test sample during the impact process, converting the voltage data to generate curves representing the contact force, displacement, speed and energy of the impact head and the test sample changing with time, and analyzing the dynamic response of the test sample under different impact energies, wherein the dynamic response includes deformation, crack generation and internal damage propagation; controlling the initial impact energy by adjusting the mass of the hammer head or the height between the hammer head and the test sample, conducting impact test, and analyzing the energy absorption capacity and impact resistance of the test sample under different impact energies; The efficiency of the specimen in absorbing energy under different impact energies is analyzed by applying different levels of impact energy to simulate impact conditions from slight to extreme; By analyzing the deformation record of the first cycle compression, different configurations of TPMS with the same relative density are selected, and the influence of different filling ratios on the deformation mode of the TPMS structure is analyzed; Among them, the initial impact energy is controlled by adjusting the mass of the hammer head or the height between the hammer head and the specimen, and the impact test includes: During the impact process, the falling of the hammer head is regarded as free fall motion, and the reduced gravitational potential energy is converted into impact kinetic energy E applied to the specimen: ； wherein v 0 is the initial velocity of the hammer head when it contacts the test specimen, U is the gravitational potential energy of the falling hammer. By adjusting the weight and height of the drop hammer, the high energy impact test is controlled; the test equipment captures the load data when the punch contacts the sample, and calculates the change of drop hammer speed with time: , wherein, is the velocity of the hammer head at time t, > 0, the punch moves downward, < 0, the punch bounces and moves upward; is time; is t is the contact force between the hammer head and the specimen at time t. After the specimen is impacted, the absorption energy of the specimen is converted from the kinetic energy of the ram: ， In the formula, E is the energy absorbed by the test specimen during the impact. Among them, different levels of impact energy are applied to simulate impact conditions from slight to extreme include: ， wherein represents the absorbed energy of the test piece; represents the impact energy; is the absorbed energy efficiency.

4. The method of claim 1, wherein, In the S4, based on the results of the quasi-static compression test and the results of the dynamic impact performance test, the filling TPMS structure meeting the preset requirements is selected, and the bumper system of the deep sea lander is designed including: Based on the results of the quasi-static compression test and the results of the dynamic impact performance test, the P configuration with the optimal filling effect and the D structure with the strongest bearing capacity are selected; The P configuration with the optimal filling effect and the D structure with the strongest bearing capacity are designed as a two-stage energy absorption structure.

5. A system for designing a deep-sea landing bumper based on a packing-optimized TPMS structure, the system being used to implement the method according to any one of claims 1 to 4, characterized in that, The system includes a first design module, a static test module, a dynamic test module, a second design module and an optimization module; The first design module is used to design and prepare a filling TPMS structure; The static test module is used to perform a quasi-static compression test on the filling TPMS structure; The dynamic test module is used to perform a dynamic impact performance test on the filling TPMS structure; The second design module is used to select a filling TPMS structure meeting the preset requirements based on the results of the quasi-static compression test and the results of the dynamic impact performance test, and design a bumper system of a deep sea lander; The optimization module is used to optimize the bumper system of the deep sea lander according to different application scenarios and equipment requirements.

6. The system of claim 5, wherein, In the first design module, designing and preparing a filling TPMS structure includes: Designing three different configurations of TPMS structures; Designing a TPMS sealing structure, wherein the design of the TPMS sealing structure includes thin wall design and end cap design; Preparing a filling TPMS structure sample; Preparing a filling material; Filling the prepared filling material into the prepared filling TPMS structure sample and performing a repeatability test; Among them, designing three different configurations of TPMS structures includes: ； where φ P (x, y, z), φ G (x, y, z), φ D (x, y, z) are the equations of the Primitive surface (P), Gyroid surface (G) and Diamond surface (D) respectively, x , y , z is the coordinate of three-dimensional space, which describes the geometric position of the TPMS, c is a constant, which is used to describe the value of the level set corresponding to the TPMS surface. Among them, preparing a filling TPMS structure sample includes using 3D printing technology to manufacture a TPMS lattice structure and a top sealing piece; Among them, preparing a filling material includes drying the filling material; after drying, storing the filling material in a constant temperature and humidity box; further pre-screening the filling material, and dividing it into three types according to particle size: 0.15mm, 0.65mm and 0.85mm.

7. The system of claim 5, wherein, In the static test module, the quasi-static compression test on the filling TPMS structure includes: Selecting a test machine and a force sensor range that meet preset requirements, combining three structural configurations, different standing times, particle sizes, and loading speeds, and selecting three sample pieces for repeated tests; Adopting five key indicators to analyze the test results to obtain the energy absorption results of the three configurations with different filling ratios; Analyzing the standing time, the particle size of the filling material, and the loading speed; Through analysis of the deformation record of the first cycle compression, selecting different configurations of TPMS under the same relative density, and analyzing the influence of different filling ratios on the deformation mode of the TPMS structure; The five key indicators include: Energy absorption (EA): in, It is the displacement due to strain. F ( s () represents the force at a specific point during the deformation process. m Indicates quality, SEA This indicates specific energy absorption, which is the energy absorbed per unit mass. Specific energy dissipation, SED: ; where ED is the energy dissipated during the cyclic compression test, is the area under the hysteretic curve; Percentage of residual energy dissipation: ; wherein, denotes the current cycle, denotes the first cycle; deformation recovery rate; ; wherein, is the residual strain, is the deformation recovery rate; damping properties; ; Adopting five key indicators to analyze the test results includes separately comparing and analyzing different filling ratios of different configurations, and comprehensively comparing and analyzing different filling ratios of different configurations.

8. The system of claim 7, wherein, In the dynamic test module, the dynamic impact performance test of the filled TPMS structure includes: Placing the test piece to be tested on a rigid plate, making the weight freely and vertically fall to the surface of the test piece under the action of gravity through a double-rail system to apply an impact force, capturing and recording the voltage change of the contact point between the punch and the test piece during the impact process, converting the voltage data to generate curves representing the contact force, displacement, speed, and energy of the punch and the test piece changing with time, and analyzing the dynamic response of the test piece under different impact energies, wherein the dynamic response includes deformation, crack generation, and internal damage propagation; Controlling the initial impact energy by adjusting the mass of the hammer head or the height between the hammer head and the test piece, performing impact tests, and analyzing the energy absorption capacity and impact resistance of the test piece under different impact energies; Analyzing the energy absorption efficiency of the test piece under different impact energies by applying different levels of impact energy to simulate from slight to extreme impact conditions; Through analysis of the deformation record of the first cycle compression, selecting different configurations of TPMS under the same relative density, and analyzing the influence of different filling ratios on the deformation mode of the TPMS structure; Controlling the initial impact energy by adjusting the mass of the hammer head or the height between the hammer head and the test piece, performing impact tests includes: During the impact process, the falling of the hammer head is regarded as free fall motion, and the reduced gravitational potential energy is converted into impact kinetic energy E applied to the test piece: ； wherein v 0 is the initial velocity of the hammer head when it contacts the test specimen, U is the gravitational potential energy of the falling hammer. By adjusting the weight and height of the drop hammer, the high energy impact test is controlled; the test equipment captures the load data when the punch contacts the sample, and calculates the change of drop hammer speed with time: , wherein, is the velocity of the hammer head at time t, > 0, the punch moves downward, < 0, the punch bounces and moves upward; is time; is t is the contact force between the hammer head and the specimen at time t. After the test piece is impacted, the absorbed energy of the test piece is converted from the kinetic energy of the punch: ， In the formula, Ea is the energy absorbed by the test specimen during the impact. Controlling the initial impact energy by adjusting the mass of the hammer head or the height between the hammer head and the test piece, performing impact tests includes: ， wherein represents the absorbed energy of the test piece; represents the impact energy; is the absorbed energy efficiency.

9. The system of claim 5, wherein, In the second design module, based on the results of the quasi-static compression test and the dynamic impact performance test, selecting a filled TPMS structure that meets the preset requirements to design a buffer system of a deep-sea lander includes: Based on the results of the quasi-static compression test and the dynamic impact performance test, selecting the P configuration with the optimal filling effect and the D structure with the strongest bearing capacity; Designing the P configuration with the optimal filling effect and the D structure with the strongest bearing capacity as a two-stage energy absorption structure.

Images