A dot-matrix structure design method of a river clam hinge

Abstract

The application relates to the field of shoe soles, and particularly relates to a design method of a dot matrix structure of a simulated river clam hinge, which comprises the following steps: S1: constructing a simulated river clam hinge cell structure; S2: defining parameters of the simulated river clam hinge cell structure; S3: periodically arraying the simulated river clam hinge cell structure along X, Y and Z directions to obtain a test structure; S4: assigning values to the parameters defined in step S3, constructing test structures with different structures, and obtaining a test structure database; S5: observing deformation states of the test structures through simulation and analog test, obtaining deformation recovery rates and residual energy consumption percentages of the test structures through cyclic compression test, selecting a test structure with the highest deformation recovery rate and residual energy consumption percentage to fill a shoe midsole, and obtaining a 3D shoe midsole printing scheme; and the shoe midsole can better realize uniform load distribution and stable cyclic performance.

Description

Technical Field

[0001] This invention relates to the field of shoe sole design, specifically to a dot matrix structure design method that mimics a clam hinge. Background Technology

[0002] Shoe midsoles need to withstand long-term cyclic loads or repeated impacts during use, and they must maintain integrity and performance stability during repeated loading. Therefore, developing lightweight structures with both high energy dissipation capacity and good shape recovery capability has always been a key requirement in the manufacture of shoe midsoles.

[0003] Lattice structures, due to their excellent designability and high specific strength, have become a potential solution to meet this requirement. However, most widely used lattice structures currently employ homogeneous and singular topologies, resulting in a single force flow path under cyclic compression, making it difficult to effectively differentiate between load-bearing and energy absorption. Specifically, this manifests in two ways: firstly, energy dissipation performance decreases with increasing cycle count, leading to insufficient stability; secondly, the overall stiffness and local flexibility of the structure cannot simultaneously meet requirements, making it prone to permanent deformation due to deformation accumulation or local instability, resulting in poor resilience. Summary of the Invention

[0004] The purpose of this invention is to provide a lattice structure design method that improves stability and recovery performance.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A method for designing a dot matrix structure that mimics a clam hinge includes the following steps performed sequentially:

[0007] S1: Constructing a mussel-like hinge unit cell structure: The mussel-like hinge unit cell structure includes a first support rod, a middle rod, and two second support rods. The middle rod is connected to the axial midpoint of the first support rod, and the two second support rods are respectively connected to the two ends of the first support rod, and the two second support rods are symmetrically distributed about the middle rod.

[0008] A third support rod is used to connect the end of the second support rod located above, away from the first support rod, to the end of the middle rod, away from the first support rod, to form the first structure;

[0009] The first structure is symmetrically arranged along the middle rod to obtain the second structure;

[0010] Rotate the second configuration 180° around its geometric center to obtain the third configuration;

[0011] The third structure is rotated 90° radially along the middle rod and then combined with the second structure to obtain a mussel-like hinge unit cell structure.

[0012] S2: Defined parameters: The simulated freshwater mussel hinge unit cell structure is a cube; the side length of the simulated freshwater mussel hinge unit cell structure is L; the projection distance of the second support rod on the horizontal plane is... The length of the first support rod is 2V, the length of the intermediate rod is M, and the distance between the ends of two adjacent intermediate rods furthest from the first support rod is 2H. ;

[0013] S3: The simulated mussel hinge unit cell structure is periodically arrayed along the X, Y, and Z directions to obtain the test structure;

[0014] S4: L is 30mm, V is 2.0mm, 2.5mm, 3.0mm, or 3.5mm, H is 2.0mm, 2.5mm, 3.0mm, or 3.5mm, and M is... mm mm mm or mm constructs test structures with different structures and obtains a test structure database;

[0015] S5: Observe the deformation state of each test structure through simulation test, obtain the deformation recovery rate and remaining energy consumption percentage of each test structure through cyclic compression test, select the test structure with the highest deformation recovery rate and remaining energy consumption percentage to fill the shoe midsole, and obtain the 3D shoe midsole printing scheme.

[0016] By adopting the aforementioned design scheme, the beneficial effects of the present invention are: the first structure of this application forms a rigid-flexible partition unit in the shape of a "9", and the upper part of the first structure reduces the relative motion degree of freedom between the members in this area by forming a complete force loop, so that it has higher bending and buckling resistance under compressive load.

[0017] The lower part of the first structure retains the configuration of an open rod, giving it a large deformation space to bear various forms of flexible deformation such as bending, buckling and stretching. This achieves a biomimetic design strategy consistent with the mechanical division of labor in the folding fan area of ​​the clam hinge, where "the high-stiffness area provides support and the surrounding area coordinates deformation". Attached Figure Description

[0018] Figure 1 This is a schematic diagram illustrating the biomimetic inspiration of the present invention;

[0019] Figure 2 This is a schematic diagram of the structure of the load-bearing frame of the present invention;

[0020] Figure 3 This is a schematic diagram of the structure of the first configuration of the present invention;

[0021] Figure 4 This is a schematic diagram of the structure of the second configuration of the present invention;

[0022] Figure 5 This is a schematic diagram of the third configuration of the present invention;

[0023] Figure 6 This is a schematic diagram of the imitation freshwater clam hinge unit cell structure of the present invention;

[0024] Figure 7 This is a schematic diagram of the test structure of the present invention;

[0025] Figure 8 The test structure of the present invention is in ε Displacement contour plot when =0.3;

[0026] Figure 9 The test structure of the present invention is in ε Equivalent stress contour plot when σ = 0.3;

[0027] Figure 10 This is a schematic diagram of the printed test structure of the present invention. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0029] The terms "first," "second," "third," etc., used in the specification, claims, and accompanying drawings of this invention are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0030] A method for designing a lattice structure mimicking a clam hinge, this application is subject to the following: Figure 1Inspired by the hinge structure of a freshwater mussel, which remains stable during long-term repeated opening and closing, this structure consists of an external ligament and a fan-shaped region. The external ligament stores elastic strain energy and bears circumferential stress, while the fan-shaped region provides rigid support through restricted radial deformation. Internally, radially oriented calcium carbonate nanowires and elastic organic matter form a rigid-flexible synergistic structure. The nanowires provide directional stiffness support, while the organic matter absorbs and disperses stress through shear deformation, thus achieving stress buffering and deformation coordination. This provides biological inspiration for the design of the mussel-inspired hinge unit cell structure in this application, specifically including the following sequentially executed steps:

[0031] S1: Constructing a mussel-inspired hinge unit cell structure: This mussel-inspired hinge unit cell structure includes a first support b, a middle support a, and two second supports c. The middle support a is connected at the axial midpoint of the first support b, and the two second supports c are respectively connected to the two ends of the first support b, and the two second supports c are symmetrically distributed about the middle support a. The first support b is used to control the longitudinal dimensions of the frame, and the middle support a is used to control the lateral deformation behavior of the frame, such as... Figure 2 As shown, a load-bearing frame resembling the number "3" is formed by constructing straight rods;

[0032] A third support rod d is used to connect the end of the upper second support rod c, which is furthest from the first support rod b, to the end of the middle rod a, which is furthest from the first support rod b, forming a structure as follows: Figure 3 The first structure shown incorporates a third support rod d on the load-bearing frame, forming a figure-9-shaped rigid-flexible partition unit. Analysis of the mechanical characteristics of the clamshell hinge fan-shaped region reveals that the nanowires in some areas exhibit a more consistent orientation and closer spacing, making these areas less prone to slippage or bending deformation under load, thus resulting in higher directional stiffness in the overall response. To simulate this biomimetic characteristic of "local stiffness enhancement" in engineering structures, this invention adds a closed quadrilateral connecting rod to the upper part of the figure-3-shaped load-bearing frame. By forming a complete force loop, it reduces the relative degrees of freedom of motion between the members in this region, giving it higher resistance to bending and buckling under compressive loads.

[0033] The lower part of the supporting frame retains the open member configuration, providing ample deformation space to accommodate various forms of flexible deformation, including bending, buckling, and tension. This aligns with the biomimetic design strategy of "high-stiffness areas providing support while surrounding areas coordinate deformation" in the clamshell hinge's folding fan area. After the aforementioned topological adjustment, the overall structure takes the shape of a figure "9," with the upper part exhibiting enhanced stiffness and the lower part displaying a clear flexible response. This achieves a distinct rigid-flexible partitioning within the unit, representing a key configuration upgrade step in the biomimetic abstraction process of this application.

[0034] The first component is symmetrically arranged along the middle rod to obtain the second component; in this embodiment, as shown... Figure 4As shown, the upper rigid region 111 of the second structure consists of a closed loop formed by six rods, creating a complete load transfer loop that maintains high stability under axial compression and bending loads. The lower flexible region 112 of the second structure consists of two second support rods c and half of the first support rod, forming an open topology that does not form a closed loop. Its high degree of geometric freedom allows it to exhibit large deformation behaviors such as bending, buckling, or tension under compressive loading. This top-rigid, bottom-flexible regional distribution enables the structural unit to bear the main load during compression while also providing energy dissipation in the flexible region, achieving a biomimetic mechanical characteristic inspired by the clamshell hinge: "local reinforcement + local buffering."

[0035] Rotate the second configuration 180° around its geometric center to obtain the following: Figure 5 The third structure shown includes an upper flexible region 122 and a lower rigid region 121;

[0036] After rotating the third component 90° radially along the intermediate rod, it is combined with the second component to obtain the following: Figure 6 The illustrated clam-like hinge unit cell structure features an upper rigid region 111 of the second structure and a lower rigid region 121 of the third structure arranged opposite each other in the vertical direction, providing a continuous and stable load-bearing support network. The lower flexible region 112 of the second structure and the upper flexible region 122 of the third structure form a regular energy dissipation path, enabling the structure to form a symmetrical large deformation mode under compressive loading. This clam-like hinge unit cell structure is a centrosymmetric structure; the centrosymmetric geometric arrangement together constitutes a stable structure with consistent mechanical response in the vertical direction and coordinated load-bearing and energy dissipation.

[0037] S2: Defined parameters: The simulated freshwater mussel hinge unit cell structure is a cube; the side length of the simulated freshwater mussel hinge unit cell structure is L; the projection distance of the second support rod c on the horizontal plane is... The length of the first support rod is 2V, the length of the intermediate rod a is M, and the distance between the ends of two adjacent intermediate rods furthest from the first support rod is 2H. ;

[0038] S3: The simulated clam hinge unit cell structure is periodically arrayed along the X, Y, and Z directions to obtain the test structure; In this embodiment, it is constructed by periodically arranging the structure in a 3×3×3 form along the three-dimensional direction as shown below. Figure 7 The test structure shown;

[0039] In the test structure, in the plane perpendicular to the compression direction, the rigid and flexible regions of adjacent unit cells are connected to each other; in the compression direction, the rigid and flexible regions are arranged alternately to form a force transmission path of "load-energy dissipation-load-energy dissipation".

[0040] S4: L is 30mm, V is 2.0mm, 2.5mm, 3.0mm, or 3.5mm, H is 2.0mm, 2.5mm, 3.0mm, or 3.5mm, and M is... mm mm mm or mm constructs 16 different test structures and obtains a test structure database;

[0041] S5: Observe the deformation state of each test structure through simulation test, obtain the deformation recovery rate and remaining energy consumption percentage of each test structure through cyclic compression test, select the test structure with the highest deformation recovery rate and remaining energy consumption percentage to fill the shoe midsole, and obtain the 3D shoe midsole printing scheme.

[0042] In this implementation, the finite element analysis method is used for simulation calculation: the bottom of the test structure is set as a fixed constraint, and a vertically downward displacement load is applied to the top for quasi-static compression analysis. For example... Figure 8 shown ε When the displacement is 0.3, the rigid zone formed by the closed quadrilaterals (upper rigid zone 111 of the second structure and lower rigid zone 121 of the third structure) forms the main load-bearing path, bearing most of the compressive load and exhibiting significant overall compressive displacement. Its main function is to maintain the overall stability of the structure and suppress overall buckling. At the same time, the flexible zone formed by the open members (lower flexible zone 112 of the second structure and upper flexible zone 122 of the third structure) exhibits completely different mechanical behavior: although its vertical displacement is not obvious, its local strain is significant, mainly undergoing multimodal deformation such as lateral bending, local buckling, and tension. This displacement difference of "overall compression (rigid zone) + local bending (flexible zone)" is a direct manifestation of the rigid-flexible cooperative structure mechanism.

[0043] In such Figure 9 shown ε The mechanism is further confirmed in the equivalent stress cloud diagram at a coefficient of performance (COP) of 0.3. The flexible regions of the unit cell (lower flexible region 112 of the second structure and upper flexible region 122 of the third structure) exhibit a deep high-stress distribution, indicating that significant bending, buckling, and local deformation occurred during compression, and they bear the main function of energy dissipation. In contrast, the rigid regions (upper rigid region 111 of the second structure and lower rigid region 121 of the third structure), due to their closed cross-sections and high overall stiffness, exhibit a more uniform stress distribution and lower peak values, primarily bearing the axial force transmission. This significant difference in stress distribution verifies the successful implementation of the "rigid-flexible synergy" design concept of this application.

[0044] The performance advantages of the test structure in this application were verified through cyclic compression tests. To comprehensively verify the performance of the parametric design and determine the optimal solution, lattice samples with the aforementioned 16 parameter combinations were prepared and tested. Selective laser sintering (SLS) based on thermoplastic polyurethane (TPU) material was used to prepare… L A cubic lattice sample with a diameter of 30 mm was constructed, consisting of 3×3×3 lattice unit cells, with a relative density controlled at 28.23%. Twenty cyclic loading tests were conducted under conditions of 30% compressive strain and a loading rate of 20 mm / min. The results were compared with those of NBCC and BCC lattice structures of the same density under the same conditions. Figure 10 As shown.

[0045] Deformation recovery rate It is a quantitative indicator of strain recovery capability after unloading, calculated using the following formula:

[0046] ;

[0047] in, For residual strain, R The closer it is to 100%, the stronger the structure's elastic recovery ability.

[0048] Remaining energy consumption percentage This reflects the specific energy dissipation during the load-unload process. SED The change reflects the structure's ability to maintain its energy dissipation level as the number of cycles increases. Remaining energy dissipation percentage Defined as the current period SED Divided by the first period As shown in the following formula:

[0049] ;

[0050] Remaining energy consumption percentage The closer it is to 100%, the better the structure performs in maintaining its energy dissipation capacity.

[0051] The experimental results are shown in Table 1. A comprehensive comparison of the performance data for all 16 parameter combinations of this invention shows that when the structural parameters are... V =2.0mm H When the diameter is 3.5 mm, the shape recovery rate and the percentage of remaining energy dissipation of the lattice reach their maximum values ​​after 20 cycles. The performance of this optimal parameter structure is also significantly better than that of traditional BCC and NBCC lattices.

[0052] Table 1. Deformation recovery rate and percentage of remaining energy dissipation of the lattice after the 20th cycle:

[0053]

[0054] In summary, the first structure of this application forms a figure-9-shaped rigid-flexible partition unit. The upper part of the first structure reduces the relative degrees of freedom of motion between the members in this region by forming a complete force loop, so that it has higher bending and buckling resistance under compressive load.

[0055] The lower part of the first structure retains the configuration of an open rod, giving it a large deformation space to bear various forms of flexible deformation such as bending, buckling and stretching. This achieves a biomimetic design strategy consistent with the mechanical division of labor in the folding fan area of ​​the clam hinge, where "the high-stiffness area provides support and the surrounding area coordinates deformation".

[0056] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for designing a dot matrix structure mimicking a clam hinge, characterized in that: The steps are as follows, performed sequentially: S1: Constructing a mussel-like hinge unit cell structure: The mussel-like hinge unit cell structure includes a first support rod, a middle rod, and two second support rods. The middle rod is connected to the axial midpoint of the first support rod, and the two second support rods are respectively connected to the two ends of the first support rod, and the two second support rods are symmetrically distributed about the middle rod. A third support rod is used to connect the end of the second support rod located above, away from the first support rod, to the end of the middle rod, away from the first support rod, to form the first structure; The first structure is symmetrically arranged along the middle rod to obtain the second structure; Rotate the second configuration 180° around its geometric center to obtain the third configuration; The third structure is rotated 90° radially along the middle rod and then combined with the second structure to obtain a mussel-like hinge unit cell structure. S2: Defined parameters: The simulated freshwater mussel hinge unit cell structure is a cube; the side length of the simulated freshwater mussel hinge unit cell structure is L; the projection distance of the second support rod on the horizontal plane is... The length of the first support rod is 2V, the length of the intermediate rod is M, and the distance between the ends of two adjacent intermediate rods furthest from the first support rod is 2H. ; S3: The simulated mussel hinge unit cell structure is periodically arrayed along the X, Y, and Z directions to obtain the test structure; S4: L is 30mm, V is 2.0mm, 2.5mm, 3.0mm, or 3.5mm, H is 2.0mm, 2.5mm, 3.0mm, or 3.5mm, and M is... mm mm mm or mm constructs test structures with different structures and obtains a test structure database; S5: Observe the deformation state of each test structure through simulation test, obtain the deformation recovery rate and remaining energy consumption percentage of each test structure through cyclic compression test, select the test structure with the highest deformation recovery rate and remaining energy consumption percentage to fill the shoe midsole, and obtain the 3D shoe midsole printing scheme.

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