A design method of a bionic ribbed wallboard based on a Fibonacci spiral and a bionic ribbed wallboard

Abstract

The application discloses a design method of a bionic reinforced wallboard based on a Fibonacci spiral line and the bionic reinforced wallboard. The reinforced wallboard structure comprises a series of wallboard reinforcements generated according to a Fibonacci key point rule and based on an interpolation curve, the wallboard reinforcement is designed by a plurality of curve drives, and the wallboard reinforcement can be designed as a rectangular section, a T-shaped section and the like. In addition, the Fibonacci spiral line is generated in two directions, the generated curve has a plurality of intersection points, and a planar area is divided into a plurality of areas with different sizes. The application provides a reinforcing mode for a wallboard with high bearing performance. The reinforced wallboard structure based on the Fibonacci spiral line can improve the bearing capacity of a single hole by introducing more materials near the hole of the wallboard, and the wallboard near the hole is not easy to lose stability due to buckling, and is beneficial to further realize lightweight design of the structure.

Description

Technical Field

[0001] This invention belongs to the field of engineering structure technology, and specifically relates to a biomimetic stiffened wall panel design method based on the Fibonacci spiral and a biomimetic stiffened wall panel. Background Technology

[0002] As a research hotspot in the field of structural engineering, the balance between lightweight and high load-bearing capacity has long been a focus of attention. Stiffened wall panels, with their advantages of being lightweight, efficient, and resistant to buckling, are increasingly widely used. Currently, common stiffened wall panel layouts in engineering applications include equally spaced stiffening and grid-type stiffening. However, in practical applications, we have found that common equally spaced stiffening and grid-type stiffening methods are prone to structural failure modes due to localized buckling at locations such as skin openings. Moreover, these conventional stiffening layouts still have shortcomings in terms of wall panel structural performance. Furthermore, existing stiffened wall panel structures are relatively simple, lacking corresponding stiffening structures for different locations, failing to maximize the load-bearing capacity of the material, reducing the flexibility of structural design, and hindering lightweight structural design. Summary of the Invention

[0003] This invention addresses the shortcomings of traditional reinforced panel layouts in terms of structural performance and load-bearing capacity optimization for local openings. By incorporating biomimetic principles, it proposes a biomimetic reinforced panel design method and a biomimetic reinforced panel based on the Fibonacci spiral. This effectively improves the structural performance of the reinforced panel, as well as the strength and buckling resistance at local openings. Through the design of the reinforced layout, areas prone to buckling near the openings in the panel skin are specifically reinforced, thus locally strengthening the openings that are susceptible to buckling failure under load. Consequently, the openings exhibit excellent compressive and torsional resistance.

[0004] Invention Effects

[0005] The technical effects of this invention are as follows:

[0006] 1. This invention employs a biomimetic approach, fully utilizing the characteristics of plants such as sunflowers and pine nuts in nature to perform biomimetic reinforcement design on the easily buckling parts of the skin-reinforced wall panel structure, thereby significantly improving the buckling resistance of the skin-reinforced structure. Optimizing the reinforced wall panel using the solution of this application can achieve the purpose of targeted structural reinforcement.

[0007] 2. By selecting different reinforcement parameters, this invention allows for a wide range of adjustments to the reinforced wall panels to suit different working conditions.

[0008] The buckling resistance of the structure is universally applicable to stiffened panel structures.

[0009] 3. The reinforced wall panel structure derived from this invention has high strength and rigidity. Its series of reinforcements can be used for the covering parts of aerospace vehicles and military vehicles and ships, which is of great significance for improving the load-bearing capacity of the ship hull and fuselage, thereby achieving the purpose of improving product performance. Attached Figure Description

[0010] Figure 1 , 2 Figures 3 and 4 show a stiffened panel structure based on the Fibonacci spiral.

[0011] Figure 1 (a) is a schematic diagram of a typical model. Figure 1 (b) is a schematic diagram of the reinforcement parameters;

[0012] Figure 2 (a) shows the generation of the Fibonacci key points of the Fibonacci spiral. Figure 2 (b) is the process of updating the radius increment Δ for the Fibonacci key points. Figure 2 (c) is a schematic diagram of the connection method of Fibonacci key points. Figure 2 (d) is a schematic diagram of the fitting of the Fibonacci spiral;

[0013] Figure 3 A schematic diagram of a stiffened panel model based on the Fibonacci sequence;

[0014] Figure 4 This invention relates to a reinforced wall panel structure based on Fibonacci spirals with different parameters.

[0015] Figure 5 Buckling modes of stiffened panels under different parameters

[0016] Figure 6 Schematic diagrams for four operating conditions

[0017] Figure 7 For structures with circular edge projections, the first-order buckling modes under various working conditions

[0018] Figure 8 A schematic diagram of a structure with rectangular edge projections.

[0019] Figure 9 For structures with rectangular edge projections, the first-order buckling modes under various working conditions Detailed Implementation

[0020] The present invention is described below with reference to specific embodiments. In the description of the embodiments, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the present invention.

[0021] This invention employs a biomimetic design method based on the Fibonacci spiral for the design of a biomimetic reinforced wall panel. The reinforced wall panel structure 33 is generated by merging wall panel 31 and wall panel reinforcement 32 through geometric Boolean operations. The Fibonacci spiral is generated by fitting Fibonacci key points according to certain principles. The Fibonacci key points are generated by the radius update increment Δ according to certain principles. The generation principles of Fibonacci key points and Fibonacci spirals are well-known technical methods to those skilled in the art.

[0022] The wall panel is reinforced with a Fibonacci spiral. The starting point of the first Fibonacci spiral is located on the wall panel, preferably at the geometric center of the wall panel. If there is an opening in the wall panel, the starting point of the first Fibonacci spiral is preferably at the center of the opening in the wall panel.

[0023] The layout of the wall panel reinforcement is determined by the number of Fibonacci spirals c and ac, as well as the radius update increment Δ.

[0024] The number of Fibonacci spirals, c and ac, are two consecutive integers in the Fibonacci sequence, such as 3 and 5, 5 and 8, 8 and 13, etc.

[0025] The Fibonacci spiral is obtained by interpolating Fibonacci key points using cubic splines, B-splines, or other curves.

[0026] The cross-sectional shape of the wall panel reinforcement 32 can be arbitrary, such as T-shaped reinforcement and Z-shaped reinforcement.

[0027] To make the technical features, objectives, and effects of the present invention clearer, a detailed description is provided below with reference to the accompanying drawings.

[0028] like Figure 1 As shown, the reinforcing rib is a solid object made of the same material as the wall panel, and its shape is not limited to a rectangular form; it can be designed as a Z-shaped rib or a T-shaped rib. Here, w is the width of the reinforcing rib 2, h is the height of the reinforcing rib 32, t is the thickness of the reinforcing wall panel 31, and R is the radius of the opening in the reinforcing wall panel 31.

[0029] Figure 2 The diagram shown is a structural schematic of the Fibonacci key points and connection method in the spiral of the present invention. Figure 2 (a) and Figure 2 (b) illustrates the process of updating the Fibonacci keypoints with respect to the radius increment Δ. A larger Fibonacci keypoint number indicates a greater distance from the geometric center. (Fibonacci keypoint numbering reference...) Figure 2 (c) Starting from the origin (e.g., the geometric center of the opening), the coordinates of the Fibonacci key points increase outwards, with the spiral connecting in both clockwise and counterclockwise directions. Hereinafter, "Fibonacci key points" will be referred to as "nodes." Node 1 connects clockwise to nodes 14, 27, 40, 53, 66, 79, 92, 105, 118, 131, 144, 157, 170, 183, and 196. The node number increases by 13 each time. Similarly, node 2 connects clockwise to nodes 15, 28, 41, 54, 67, 80, 93, 106, 119, 132, 145, 158, 171, 184, and 197, with the node number increasing by 13 each time. The remaining clockwise curves will not be described further. Node 1 is connected counter-clockwise to nodes 22, 43, 64, 85, 106, 127, 148, 169, and 190, with the node number increasing by 21 each time. Similarly, node 2 is connected counter-clockwise to nodes 33, 54, 75, 96, 117, 138, 159, and 180, with the node number increasing by 21 each time. The increments in the clockwise and counter-clockwise node numbers satisfy the condition of two consecutive numbers in the Fibonacci sequence 1, 1, 2, 3, 5, 8, 13, 21, 34, 55.

[0030] Figure 2 (d) is based on Figure 2 (c) shows the Fibonacci spiral generated by fitting the Fibonacci key points.

[0031] Figure 3 The image shows a schematic diagram of a reinforced wall panel model based on the Fibonacci sequence. Figure 2 Interpolating the Fibonacci key points and connection methods shown, a Fibonacci spiral is formed. The spiral is stretched, and the stretched surface is thickened, finally forming a flower-like stiffened panel structure, which greatly improves the strength and buckling resistance around the holes.

[0032] Figure 4The diagram shows the stiffened wall panel structure based on Fibonacci spirals with different parameters according to the present invention. The structure in the first row is a model for changing the number of stiffeners in the wall panel (c is the number of curves in the clockwise direction, and ac is the number of curves in the counterclockwise direction). The structure in the second row is a model for changing the size of the curve radius update increment Δ, and the volume is controlled to be equal by adjusting the thickness of the stiffeners in the wall panel.

[0033] See Figure 5 The biomimetic stiffened panel design based on the Fibonacci spiral has a stiffening layout determined by the number of Fibonacci spirals (c and ac) and the radius update increment (Δ). The number of Fibonacci spirals and the radius update increment (Δ) can adjust the buckling resistance of the biomimetic stiffened panel based on the Fibonacci spiral within a certain range. Figure 4 The diagram shows the stiffened wall panel structure based on the Fibonacci spiral with different parameters according to the present invention. Linear elastic instability analysis (eigenvalue buckling analysis) was performed on all structures, and the first-order mode yielded the following results: Figure 5 The result.

[0034] According to the linear elastic instability analysis theory, the critical load for instability is the eigenvalue multiplied by the actual load, i.e.:

[0035] P cr =λ×F

[0036] Where P cr λ is the critical load for instability, λ is the characteristic value of buckling analysis, and F is the actual load. During the simulation loading, the actual load F = 1N.

[0037] Simulation results show that different parameter selections have a significant impact on the structural instability critical load. Since the number of Fibonacci spirals is a discrete variable, while the radius update increment Δ is a continuous variable, controlling these two variables allows for a wide range of adjustments to the buckling resistance of the wall panel.

[0038] To verify the performance of the biomimetic stiffened panel design based on the Fibonacci spiral, parabolic and radial stiffening methods commonly used in engineering were compared. For a more reasonable comparison, two models with boundary curve projections of circles and rectangles were selected for comparison. Four working conditions were considered. Figure 6 As shown.

[0039] See Figure 7The figure shows a comparison of the first-order buckling modes of a biomimetic stiffened panel based on the Fibonacci spiral and a radially stiffened panel under four working conditions. It can be seen that the applied external force in the case of curved stiffening is not along the distribution direction of the curved material; therefore, the external force mainly causes local instability in the stiffened structure due to bending. However, comparing the buckling characteristic values ​​of the two structures shows that the performance of the biomimetic stiffened panel based on the Fibonacci spiral is significantly better than that of the radially stiffened panel under all four working conditions. Working condition 4 shows that when the applied load is completely symmetrical with respect to the structure, the radially stiffened panel is prone to periodic instability. In contrast, the biomimetic stiffened panel based on the Fibonacci spiral is asymmetrical about the center, thus it is less prone to periodic instability.

[0040] Furthermore, to avoid the problem that circular arc boundaries are unsuitable for constraints and loading, a parabolic structure with an edge projection of a rectangle (such as...) is used. Figure 8 The results (as shown) were verified and obtained. Figure 9 (As shown) Similar to the structure with a circular edge projection, the buckling critical load of the radially stiffened wall panel based on the biomimetic stiffened wall panel with the Fibonacci spiral is increased by 42.62%. Since the curved stiffened surface will not buckle at the opening under edge loading conditions, there is no need to conduct further comparative verification on the curved surface without openings.

[0041] Table 1 Summary Statistics Table

[0042]

[0043]

[0044] Finally, it should be noted that: the embodiments of the present invention have been described above in conjunction with the accompanying drawings, but the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of the present invention.

Claims

1. A biomimetic stiffened wall panel design method based on the Fibonacci spiral, characterized in that, Includes the following steps: Step 1: Determine that the starting point of the first Fibonacci spiral is located on the wall panel; and the starting point of the first Fibonacci spiral is located at the geometric center of the wall panel. If there is an opening in the wall panel, the starting point of the first Fibonacci spiral is located at the center of the opening in the wall panel. Step 2: Based on the number of Fibonacci spirals c and ac, and the radius update increment Δ, establish key points of the Fibonacci spirals on the wall panel; where the number of Fibonacci spirals c and ac are two adjacent integers in the Fibonacci sequence, c is the number of Fibonacci spirals in the clockwise direction, and ac is the number of Fibonacci spirals in the counterclockwise direction. Step 3: Fit the key points of the Fibonacci spiral to obtain the overall layout of the Fibonacci spiral; Step 4: Use the Fibonacci spiral obtained in Step 3 to create a stiffened solid, and perform a geometric Boolean operation on the stiffened solid and the wall panel solid to merge them to generate a biomimetic stiffened wall panel based on the Fibonacci spiral, wherein the Fibonacci spiral layout is used to improve the buckling resistance at the openings of the wall panel.

2. The biomimetic stiffened wall panel design method based on the Fibonacci spiral as described in claim 1, characterized in that, In step 2, the coordinates of the Fibonacci key points increase outwards continuously, and the Fibonacci spiral is divided into two connection methods: clockwise and counterclockwise.

3. The biomimetic stiffened wall panel design method based on the Fibonacci spiral as described in claim 1, characterized in that, In step 3, the Fibonacci spiral is obtained by curve interpolation fitting using Fibonacci key points; the curve interpolation method includes cubic spline interpolation or B-spline interpolation.

4. A biomimetic reinforced wall panel designed using the method described in claim 1, characterized in that, It includes a wall panel (31) and a wall panel stiffener (32), wherein the wall panel stiffener (32) is designed based on the Fibonacci spiral. The wall panel (31) and the wall panel stiffener (32) are combined through geometric Boolean operations to generate the biomimetic stiffened wall panel. The layout of the wall panel stiffener (32) is adjusted to control the buckling resistance by controlling the number of Fibonacci spirals c, ac and the radius update increment Δ.

5. The biomimetic reinforced wall panel as described in claim 4, characterized in that, The cross-sectional shape of the wall panel reinforcement (32) is as follows: Reinforced cross section or Reinforced cross-section.

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