Preparation method of modular wrinkle type curved surface protection structure

Abstract

The invention belongs to the field of structural engineering and material science, and particularly relates to a preparation method of a modular fold type curved surface protection structure. The invention aims to solve the problem that a complex curved surface is difficult to construct flexibly due to the adoption of a uniform-section design in the conventional wrinkle type structure. The method comprises the following steps: designing the cross section shape of the fold type unit cell in a differentiated manner, and uniformly changing the cross section size along the longitudinal axis direction, so as to realize the variable cross-section self-locking unit cell configuration. A plurality of discrete and modularized fold unit cells can be seamlessly lapped to form an integral structure with a complex curved surface. The structure can be tightly attached to the outer surface of a complex protection target, and the protection effect is remarkably improved.

Description

Technical Field

[0001] The present invention belongs to the fields of structural engineering and material science, and in particular relates to a method for preparing a modular pleated curved surface protective structure. Background Art

[0002] In today's engineering protection sector, the performance of protective structures plays a crucial role in ensuring the safety of various facilities and personnel. Traditional, monolithic, planar protective structures were once the mainstream choice, characterized by their simple design and mature manufacturing processes. However, with the rapid advancement of industrial technology and the increasing complexity of actual working conditions, the shortcomings of traditional planar protective structures have become increasingly apparent.

[0003] When dealing with complex load scenarios, due to its planar characteristics, the stress distribution is not uniform, and local areas are easily damaged due to excessive stress, resulting in overall protection failure. Especially when facing impact protection needs, planar structures are difficult to disperse and absorb energy efficiently, and the protection effect is greatly reduced. In some occasions with strict protection requirements, such as aerospace, high-speed trains and other fields, the protective structure is not only required to have high strength to withstand extreme external forces, but also to have high toughness to prevent brittle cracking. At the same time, it must have the ability to assemble quickly to meet the needs of emergency repairs and replacements. More importantly, it must be able to adapt to complex curved surfaces and fit the irregular surface of the protected object. Obviously, the traditional integral planar protective structure is powerless in these aspects.

[0004] In recent years, discrete, modular pleated structures have gradually entered the field of vision of scientific researchers and engineers. Relying on a unique self-locking mechanism, when subjected to external force, the modules can restrain and cooperate with each other, thereby efficiently absorbing energy and building a reliable line of defense for internal facilities and personnel. However, most existing pleated structures adopt a uniform cross-section design. Although this design simplifies the manufacturing process, it also creates great limitations. When unit cells of uniform cross-section are spliced ​​and combined, they can only construct relatively regular and simple geometric shapes. When faced with complex and irregular curved surfaces, it is difficult to accurately adapt and achieve a tight fit, and the integrity and reliability of the protection cannot be guaranteed.

[0005] The present invention carefully and differently designs the cross-sections of the pleated unit cells and combines these units using a scientific stacking strategy. The resulting modular pleated curved surface protection structure can perfectly fit the outer surface of complex protection targets. It can demonstrate excellent impact protection capabilities and high adaptability under various complex working conditions, providing an effective solution to practical engineering protection problems. Summary of the Invention

[0006] The present invention aims to solve the problem that existing pleated structures mostly adopt a uniform cross-section design and are difficult to flexibly construct complex curved surfaces, and provides a method for preparing a modular pleated curved surface protective structure.

[0007] A method for preparing a modular pleated curved surface protective structure is carried out in the following steps:

[0008] Modular pleated cells are designed based on actual needs. Their cross-sections always maintain a corrugated shape. The cell exhibits a gradient change in cross-sectional dimensions along the axial direction, forming a continuously changing cross-sectional profile and obtaining a variable-section self-locking cell.

[0009] Ensure that the variable-section self-locking cells fit tightly together and that adjacent cells have a fixed assembly angle for assembly; during the assembly process, ensure that each cell is accurately docked to form a curved, wrinkled overall structure.

[0010] The beneficial effects of the present invention are:

[0011] 1. Surface adaptability: By differentially designing the cross-sectional shape and size of the unit cell, the present invention can construct a pleated structure with complex curved surfaces to meet the needs of different application scenarios.

[0012] 2. High energy absorption capacity: The pleated structure has excellent energy absorption capacity, which can effectively absorb and dissipate energy during impact, protecting the internal structure and personnel safety.

[0013] 3. Modularity and scalability: The modular design concept makes the structure easy to assemble and disassemble, and facilitates functional expansion and upgrading.

[0014] 4. Lightweight and high strength: The material system can select polymer materials, metal materials and fiber-reinforced composite materials, so that the structure has a low weight while ensuring strength, which is convenient for transportation and installation. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 Schematic diagram of the planar structure of the modular pleated unit cell model;

[0016] Figure 2 Schematic diagram of the three-dimensional structure of the modular folded unit cell model;

[0017] Figure 3 It is a schematic diagram of the plane structure of the curved folded overall structure;

[0018] Figure 4 It is a schematic diagram of the three-dimensional structure of the curved surface wrinkle type overall structure;

[0019] Figure 5 This is a photo of the three-point bending test of the curved surface wrinkle integral structure prepared in the embodiment;

[0020] Figure 6 This is a three-point bending test curve of the curved wrinkled integral structure prepared in the embodiment. DETAILED DESCRIPTION

[0021] Specific embodiment 1: In this embodiment, a method for preparing a modular pleated curved surface protection structure is carried out in the following steps:

[0022] Modular pleated cells are designed based on actual needs. Their cross-sections always maintain a corrugated shape. The cell exhibits a gradient change in cross-sectional dimensions along the axial direction, forming a continuously changing cross-sectional profile and obtaining a variable-section self-locking cell.

[0023] Ensure that the variable-section self-locking cells fit tightly together and that adjacent cells have a fixed assembly angle for assembly; during the assembly process, ensure that each cell is accurately docked to form a curved, wrinkled overall structure.

[0024] The unit cell of this embodiment exhibits a gradient of cross-sectional dimensions along the axial direction (e.g., a continuous gradient in height and width), resulting in a continuously gradient, wavy cross-sectional profile. This variable cross-sectional characteristic allows the unit cell to form non-uniform geometric torsions in space. When the cross-sectional dimensions of the unit cell are larger at one end and smaller at the other, the axially gradient profile naturally conforms to the curvature variations of convex or concave surfaces, like a "wedge" inserted into the contour of a curved surface, thus breaking through the planar limitations of uniform cross-sectional structures. The unit cell cross section always maintains a wavy shape, which inherently provides multi-directional bending freedom. When the wavy cross-section gradients along the axial direction, the spatial curves formed by the apex and valley of each section can approximate the variations in the normal vector of a complex surface.

[0025] Specific embodiment 2: This embodiment differs from specific embodiment 1 in that different unit cell cross-sectional size variation patterns are designed according to specific needs. By adjusting these patterns, pleated curved surface structures with different curvatures and shapes are constructed. Other aspects are the same as specific embodiment 1.

[0026] Specific embodiment 3: This embodiment differs from specific embodiment 1 in that the cross-sectional dimensions include height and width. Other aspects are the same as specific embodiment 1.

[0027] Specific embodiment 4: This embodiment differs from specific embodiment 1 in that the preparation method of the modular pleated curved surface protection structure is carried out according to the following steps:

[0028] A modular wrinkle unit cell model is established according to actual needs. The fan-shaped area in the modular wrinkle unit cell model is stretched along the normal direction to form an initial fan-shaped body. The initial fan-shaped body is divided into m levels along the thickness direction using an equidistant layering algorithm, and (m+1) equidistantly distributed surfaces are generated accordingly. Where m is the preset variable section number parameter.

[0029] Generate n rhombuses with equal size and equal distance on each upper and lower surface respectively, connect the rhombuses with straight lines and project them on the curved surface, and realize the continuous adjustment of the crease angle by controlling the XY displacement of the upper layer relative to the lower layer; then cut and scale the rhombuses to perform similar transformation cutting and hole digging, and complete the modular integration to obtain the modularized folded cell model;

[0030] Arrange the modularized folded cell models horizontally, then vertically stack them, and adopt the "bricklaying" staggered paving method to lock the adjacent two layers of cells with each other, and stack them layer by layer in the above-mentioned manner to obtain the curved folded overall structure. The other aspects are the same as those in the first embodiment.

[0031] In the embodiment, the adjacent cells are assembled at a specific angle, so that the cell array forms an angle difference in the horizontal and vertical directions, and then accumulates into a curved surface curvature. When vertically stacking, the cells of the upper and lower layers are staggered, and the cell array is forced to adapt to the curved radius through the geometric constraint between the layers; this method is like laying bricks to form an arched structure, and the planar units are combined into a curved surface through staggered stacking; the cells with variable cross sections are locked with each other through self-locking, and when the cells are assembled at a specific angle, the self-locking force forms a constraint force along the normal direction of the curved surface, which inhibits the displacement and rotation of the cells, and ensures the stability of the curved surface structure.

[0032] The fifth embodiment is different from the fourth embodiment in that the sizes and projection positions of the two contact surfaces of the adjacent two layers of cells are consistent. The other aspects are the same as those in the fourth embodiment.

[0033] The sixth embodiment is different from the fourth embodiment in that the central angle of the initial sector is 5-10°, the inner-to-outer diameter ratio is 0.53-0.75, and the thickness is 24-30 mm. The other aspects are the same as those in the fourth embodiment.

[0034] The seventh embodiment is different from the fourth embodiment in that the crease angle ranges from 15° to 75°. The other aspects are the same as those in the fourth embodiment.

[0035] The eighth embodiment is different from the fourth embodiment in that the modularized folded cell model is made by a 3D printing process. The other aspects are the same as those in the fourth embodiment.

[0036] The ninth embodiment is different from the fourth embodiment in that the material of the modularized folded cell model is a metal material system, a ceramic material system, or a composite material system. The other aspects are the same as those in the fourth embodiment.

[0037] Specific embodiment 10: This embodiment differs from specific embodiment 4 in that the wall thickness of the modular pleated unit cell is measured after the modular pleated unit cell model is completed, and the processing error of the wall thickness is ±0.02 mm. Other aspects are the same as specific embodiment 4.

[0038] The following examples are used to verify the beneficial effects of the present invention:

[0039] Example: The preparation method of the modular pleated curved surface protection structure is carried out according to the following steps:

[0040] A modular pleated unit cell model is established based on actual needs. The fan-shaped area in the modular pleated unit cell model is stretched along the normal direction to form an initial fan-shaped body. The outer arc radius of the fan-shaped body corresponding to the modular pleated unit cell is 93.3mm, the inner arc radius is 69.3mm, the corresponding central angle is 5°, and the thickness is 24mm. It is divided into six parts with equal spacing in the horizontal direction, and each part is 4mm thick. Three equally spaced rhombuses connected by a 1.86mm platform are drawn on each layer. The line connecting the corresponding points of the rhombuses between the two layers of each part is at an angle of 45° to the horizontal direction, and the part entity is cut to obtain the part entity. The unit cell contains seven groups of rhombuses with different geometric sizes, and the side lengths are 9.06mm, 8.99mm, 8.91mm, 8.84mm, 8.77mm, 8.70mm, and 8.63mm respectively. Taking the center point of the rhombus as the reference point, the three equal-sized rhombuses of each layer are scaled by 0.7 times, and the entity is excavated and cut to obtain the modular pleated unit cell model.

[0041] The modular pleated unit cell model is arranged horizontally and then stacked vertically. The adjacent two layers of unit cells are locked with each other using a "bricklaying" staggered stacking method. The curved pleated overall structure is obtained by stacking layer by layer in the above manner.

[0042] By changing the central angle of the fan-shaped body corresponding to the modular pleated unit cell, the unit cell angle and the number of units that make up the fixed-span curved surface protection structure can be controlled; by changing the geometric length size parameters of the fan-shaped body corresponding to the modular pleated unit cell, the geometric size parameters of each layer of rhombus are indirectly changed, and the overall size of the unit cell can be controlled.

[0043] The arched structure of this embodiment is several times stronger than a flat plate structure, even an order of magnitude stronger, while having comparable flexibility. The peak three-point bending force of a flat plate structure is approximately 800N, while the peak three-point bending force of an arched structure of the same size is approximately 13,000N.

Claims

1. A method for preparing a modular pleated curved surface protective structure, characterized in that The preparation method of the modular pleated curved surface protection structure is carried out in the following steps: Modular pleated cells are designed based on actual needs. Their cross-sections always maintain a corrugated shape. The cell exhibits a gradient change in cross-sectional dimensions along the axial direction, forming a continuously changing cross-sectional profile and obtaining a variable-section self-locking cell. Ensure that the variable-section self-locking cells fit tightly together and that adjacent cells have a fixed assembly angle for assembly; during the assembly process, ensure that each cell is accurately docked to form a curved, wrinkled overall structure.

2. The method for preparing a modular pleated curved surface protective structure according to claim 1, characterized in that According to specific needs, different unit cell cross-sectional size change patterns are designed. By adjusting these patterns, wrinkled surface structures with different curvatures and shapes are constructed.

3. The method for preparing a modular pleated curved surface protective structure according to claim 1, characterized in that Cross-sectional dimensions include height and width.

4. The method for preparing a modular pleated curved surface protective structure according to claim 1, characterized in that The preparation method of the modular pleated curved surface protection structure is carried out in the following steps: A modular wrinkle unit cell model is established according to actual needs. The fan-shaped area in the modular wrinkle unit cell model is stretched along the normal direction to form an initial fan-shaped body. The initial fan-shaped body is divided into m levels along the thickness direction using an equidistant layering algorithm, and (m+1) equidistantly distributed surfaces are generated accordingly. Where m is the preset variable section number parameter. On the upper and lower surfaces of each layer, n rhombuses of equal size and equidistant arrangement are generated. The rhombuses are connected by straight lines and projected onto the curved surface. By controlling the XY displacement of the upper mesh relative to the lower mesh, the crease angle is continuously adjustable. Then, cutting is performed, and the rhombuses are scaled proportionally, similarity transformation is performed, and cutting and digging are performed to complete modular integration to obtain a modular pleated unit cell model. The modular pleated unit cell model is arranged horizontally and then stacked vertically. The adjacent layers of unit cells are locked together using a "bricklaying" staggered stacking method. Layer by layer, this method is used to obtain a curved pleated overall structure.

5. The method for preparing a modular pleated curved surface protective structure according to claim 4, characterized in that The size and projection position of the two contact surface diamonds of two adjacent layers remain consistent.

6. The method for preparing a modular pleated curved surface protective structure according to claim 4, characterized in that The central angle of the initial sector is 5-10°, the ratio of the inner diameter to the outer diameter is 0.53-0.75, and the thickness is 24-30 mm.

7. The method for preparing a modular pleated curved surface protective structure according to claim 4, characterized in that Crease angles range from 15° to 75°.

8. The method for preparing a modular pleated curved surface protective structure according to claim 4, characterized in that The modular wrinkle unit cell model adopts a 3D printing process.

9. The method for preparing a modular pleated curved surface protective structure according to claim 4, characterized in that The material of the modular wrinkle unit cell model is a metal material system, a ceramic material system or a composite material system.

10. The method for preparing a modular pleated curved surface protective structure according to claim 4, characterized in that After the modular pleated unit cell model was completed, the wall thickness of the modular pleated unit cell was measured, and the processing error of the wall thickness was ±0.02mm.

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