Design method for enhancing toughness of bearing structure stacked in lightweight space

Abstract

The invention discloses a toughness enhancement design method for a lightweight space-stacked bearing structure. Inputting the design requirement of the space stacking bearing structure, and determining the stress size and direction of the space stacking bearing structure, the size of a panel and the size of a sandwich layer cellular bottom surface containing surface; determining the cellular nesting type of the bearing sandwich layer according to the size and the direction of the stress of the bearing structure stacked in the space; according to the size of the cell bottom surface containing surface and the size of the panel, determining the arrangement mode of the space-stacked bearing structure sandwich layer cells of the N-1 type cells; and according to the nesting type and the arrangement mode of the cells, selecting and calculating the position coordinates of the feature points, determining the types of the cells, and establishing a space-stacked bearing structure superposition model of the N-1 type cells. The method provided by the invention is a design method for the space stacking bearing structure of the N-1 type cells, and solves the problem that the N-1 type cells cannot be stacked in a sandwich layer space due to unreasonable arrangement of the N-1 type cells in a top plate and a bottom plate of the space stacking bearing structure.

Description

Technical Field

[0001] The present invention relates to a plate structure and design method of a mechanical product, and more specifically to a design method for enhancing the toughness of a lightweight space-stacked load-bearing structure. Background Art

[0002] The load-bearing structure form based on space stacking is widely used in fields such as high-speed railways, airplanes, wind power, and automated warehousing systems. The space-stacked structure form is a functional structure integrating physical structure and performance, composed of a panel, a core, and a bonding layer. The core uses a cellular space stack, and the space stack form of the cells is related to the performance of the load-bearing structure. It can exert advantages such as high specific strength and high specific modulus, and can simultaneously meet the extreme service performance requirements such as high strength, large stiffness, and light weight, and realize special functional requirements such as heat dissipation, vibration isolation, and electromagnetic shielding. It has important applications in fields such as aerospace, ships, high-speed trains, and armor protection, and is the key structure for major equipment products such as aerospace aircraft, high-speed rail vehicles, and high-performance CNC machine tools to achieve large-scale structures, lightweight weights, and extreme working conditions.

[0003] The load-bearing structure based on cellular space stacking is a type of composite structure with excellent performance. Its physical and mechanical properties are not only related to the specific structural dimensions of a single cell, but also related to the arrangement of cells on the upper and lower plates. Therefore, the design research on different types of cellular composite structures is particularly important. Currently, the space-stacked load-bearing structure lacks a systematic design method for the cellular space stacking method. There is little methodological support for the space stacking method of cells, and the space stacking method of cells plays a crucial role in the load-bearing structure.

[0004] The invention patent with the application number 201810638181.9 discloses an N-1 type cell design method for a space-stacked load-bearing structure. According to the design requirements of the space-stacked load-bearing structure, the arrangement of the panel and the core layer cells of the space-stacked load-bearing structure is determined, and the design constraints of the core layer cells are obtained. According to the design constraints of the core layer cells, a two-dimensional unfolded geometric shape feature model of the cells in the core layer is constructed, and the three-dimensional formability coefficient and three-dimensional structure parameters of the two-dimensional unfolded geometric shape feature model of the cells in the core layer are calculated. However, it does not conduct research on the design method of the cell arrangement method, and it is difficult to provide theoretical guidance for the cell arrangement design method.

[0005] The invention patent with the application number 201710380638.6 discloses a design method for a space-stacked load-bearing structure for irregular cells. By constructing the envelope space of the irregular cells, a space superposition method suitable for the geometric characteristics of the irregular cells is established, and each type of irregular cell of the sandwich-like composite structure is reasonably designed and arranged on the premise of ensuring the cell arrangement density. However, the cell arrangement method is not mentioned. Summary of the Invention

[0006] Aiming at the deficiencies of the existing technology, the purpose of the present invention is to provide a design method for the spatial stacking bearing structure of N-1 type cells. Input the design requirements of the spatial stacking bearing structure, determine the force magnitude and direction, panel size, and the size of the bottom surface inclusion area of the sandwich layer cells of the spatial stacking bearing structure; according to the force magnitude and direction of the spatial stacking bearing structure, determine the nesting type of the sandwich layer cells of the N-1 type cells; according to the size of the bottom surface inclusion area of the cells and the panel size, determine the arrangement method of the sandwich layer cells of the spatial stacking bearing structure of the N-1 type cells; according to the nesting type and arrangement method of the cells, select and calculate the position coordinates of the characteristic points, determine the cell type, and establish a superposition model of the spatial stacking bearing structure of the N-1 type cells. The method proposed by the present invention solves the problem that the unreasonable arrangement of the top and bottom plates of the spatial stacking bearing structure of the N-1 type cells leads to non-superimposability of the N-1 type cells in the sandwich layer space.

[0007] To achieve the above object, the present invention provides the following technical solutions: A method for enhancing the toughness of a lightweight spatial stacking bearing structure, characterized in that it includes the following steps: Step 1, input the design requirements of the spatial stacking bearing structure, and determine the force magnitude and direction, panel size, and the size of the bottom surface inclusion area of the sandwich layer cells of the spatial stacking bearing structure; Step 2, according to the force magnitude and direction of the spatial stacking bearing structure, determine the cell nesting type of the sandwich layer cells of the spatial stacking bearing structure of the N-1 type cells; Step 3, according to the size of the bottom surface inclusion area of the sandwich layer cells and the panel size, determine the cell arrangement method of the sandwich layer cells of the spatial stacking bearing structure of the N-1 type cells; Step 4, according to the nesting type arrangement method of the N-1 type cells, select the characteristic points of the sandwich layer of the spatial stacking bearing structure; Step 5, calculate the position coordinates of the characteristic points of the sandwich layer of the spatial stacking bearing structure ( ); Step 6, select the cell type of the sandwich layer of the spatial stacking bearing structure, establish a superposition model of the spatial stacking bearing structure of the N-1 type cells, and realize the design of the bearing structure according to the established model.

[0008] As a further improvement of the present invention, the design requirements of the spatial stacking bearing structure in Step 1 include the force magnitude , force direction , the long side length a of the panel size, the short side length b, and the radius r of the bottom surface inclusion area of the sandwich layer cells; Among them, the force direction Define the lower left point of the panel of the spatially stacked load-bearing structure as the coordinate origin, define the positive direction of the X-axis along the long side direction of the panel, and the included angle between the force direction and the positive direction of the X-axis.

[0009] As a further improvement of the present invention, the specific steps for determining the cell nesting type of the sandwich layer cells of the spatially stacked load-bearing structure of the N-1 type cells in step two are as follows: Step 2-1, determine the force direction Whether it is equal to 0 or π. If so, determine it as the horizontal nesting type. Otherwise, continue to the next step. Specifically: for the cell bottom containing surface being a circle with a radius of r, horizontally tangent the cell bottom containing surfaces in the same direction, and the tangent point coincides with the center of the cell bottom containing surface in the other direction; Step 2-2, determine the force direction Whether it is equal to π / 2. If so, determine it as the vertical nesting type. Otherwise, continue to the next step. Specifically: for the cell bottom containing surface being a circle with a radius of r, vertically tangent the cell bottom containing surfaces in the same direction, and the tangent point coincides with the center of the cell bottom containing surface in the other direction; Step 2-3, determine the force direction Whether it is equal to π / 4 or 3π / 4. If so, determine it as the diagonal nesting type. Otherwise, continue to the next step. Specifically: for the cell bottom containing surface being a circle with a radius of r, tangent the cell bottom containing surfaces in the same direction along the northwest or northeast direction, and the tangent point coincides with the center of the cell bottom containing surface in the other direction; Step 2-4, if the force direction is not equal to 0, π, π / 2, π / 4 or 3π / 4, then determine it as the triangular nesting type. Specifically: for the cell bottom containing surfaces being circles with a radius of r and , tangent the cell bottom containing surfaces with a radius of r in the same direction pairwise, and their centers are located at the vertices of a regular triangle with a side length of 2r; the centers of the cell bottom containing surfaces with a radius of in the other direction are located at the center of a regular triangle with a side length of 2r.

[0010] As a further improvement of the present invention, the specific method of the cell arrangement method of the sandwich layer cells of the spatially stacked load-bearing structure in step three is as follows: Step 3-1, according to the panel size and the size of the cell bottom containing surface of the sandwich layer, determine the maximum number of arrangements n in the X-axis direction. The specific calculation formula is ; Step 3-2, according to the determined nesting type, determine the maximum number of arrangements m in the Y-axis direction. The specific calculation formula is ; Step Three: Select any panel as the bottom plate, define the lower left corner of the panel as the coordinate origin, define the long side direction of the panel as the X-axis, the short side direction as the Y-axis, start arranging from the point where it is tangent to both the X-axis and the Y-axis, continuously arrange n cells along the positive X-axis direction, and continuously arrange m cells along the positive Y-axis direction according to the selected nesting method.

[0011] As a further improvement of the present invention, the N-1 type cell in Step Four is specifically a three-dimensional regular polyhedron with a regular N-sided polygon as the bottom surface, isosceles triangles with the side length of the N-sided polygon as the base on the sides, and the sides are folded along the sides of the regular N-sided polygon on the bottom surface.

[0012] As a further improvement of the present invention, the space-stacked load-bearing structure in Step Four is a composite structure formed by arranging and stacking N-1 type cells on the upper and lower two panels according to a certain nesting method.

[0013] As a further improvement of the present invention, the method for selecting the characteristic points of the sandwich layer of the space-stacked load-bearing structure in Step Four is: place the regular polygon upright and select the vertices of the N-1 type cell as its characteristic points.

[0014] As a further improvement of the present invention, the coordinate positions ( ) of the characteristic points of the sandwich layer of the space-stacked load-bearing structure in Step Five are calculated as follows: Step Five One: Place the N-1 type cell upright, use the lower left corner of the bottom plate or the top plate as the coordinate origin, use the long side of the top plate or the bottom plate as the x-axis, and the other side perpendicular to it as the y-axis, and use the direction parallel to the height direction of the three-dimensional structure of the cell as the z-axis; Step Five Two: For each upright cell, calculate the coordinates ( ) of the vertex farthest from the bottom surface, where the subscript represents the arrangement of the cell in the x-axis direction of the bottom plate, and the subscript represents the arrangement of the cell in the y-direction of the bottom plate; Step Five Three: Calculate the x-axis coordinate of the vertex of the cell in the th column and th row. corresponds to the x-axis coordinate of the center position of the circumscribed surface of the bottom surface of the N-1 type cell, specifically as follows: For the N-1 type cells arranged on the bottom plate: ; For the N-1 type cells arranged on the top plate: ; Step Five Four: Calculate the y-axis coordinate of the vertex of the cell in the th column and th row. It corresponds to the y-axis coordinate of the center position of the bottom containment surface of the cell, specifically as follows: For the N-1 type cells arranged on the bottom plate: ; For the N-1 type cells arranged on the top plate: ; Step 5, calculate the z-axis coordinate of the vertex of the cell located in column row. The z-axis coordinate , corresponds to the height of the three-dimensional structure of the cell.

[0015] The beneficial effects of the present invention are as follows: By inputting the design requirements of the space-stacked load-bearing structure, the magnitude and direction of the force on the space-stacked load-bearing structure, the panel size, and the size of the bottom containment surface of the sandwich layer cell are determined; according to the magnitude and direction of the force on the space-stacked load-bearing structure, the nesting type of the sandwich layer cell is determined; according to the size of the bottom containment surface of the cell and the panel size, the arrangement method of the sandwich layer cells of the space-stacked load-bearing structure of the N-1 type cell is determined; according to the nesting type and arrangement method of the cell, the position coordinates of the characteristic points are selected and calculated to determine the cell type, and a superposition model of the space-stacked load-bearing structure of the N-1 type cell is established. The method proposed by the present invention solves the problem that the unreasonable arrangement of the N-1 type cells on the top plate and the bottom plate of the space-stacked load-bearing structure results in non-superimposability of the N-1 type cells in the sandwich layer space. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 FIG. 3-1 is a schematic diagram of a load-bearing structure based on cell space stacking; Figure 2 FIG. 3-2 is a schematic diagram of the bottom plate of a load-bearing structure based on cell space stacking; Figure 3 FIG. 3-3 is a schematic diagram of the top plate of a load-bearing structure based on cell space stacking; Figure 4 FIG. 3-4 is a schematic diagram of the arrangement method of horizontally nested cell space stacking; Figure 5 FIG. 3-5 is a schematic diagram of the arrangement method of vertically nested cell space stacking; Figure 6 FIG. 3-6 is a schematic diagram of the arrangement method of 127° diagonal nested cell space stacking; Figure 7 FIG. 3-7 is a schematic diagram of the arrangement method of 45° diagonal nested cell space stacking; Figure 8 FIG. 3-8 is a schematic diagram of the arrangement method of triangular nested cell space stacking; DETAILED DESCRIPTION OF THE INVENTION

[0017] The following will further elaborate on the present invention in conjunction with the embodiments given in the accompanying drawings.

[0018] Referring to Figures 1 to 8 As shown, a design method for enhancing the toughness of a lightweight space-stacked load-bearing structure in this embodiment is used to design a high-performance material with high lightweight, high specific strength, and large specific modulus, which is widely applied to scenarios such as the skin of high-speed aircraft, the shell of rail transit vehicles, and solar photovoltaic panels. Without exception, high requirements for lightweight are imposed in these application scenarios. The operating speeds of high-speed aircraft and rail transit vehicles are very high, and lightweight design can effectively reduce energy consumption. Moreover, solar photovoltaic panels are mostly arranged in vast hilly, gobi, and wilderness areas, and are constantly exposed to strong winds, thus having high requirements for specific strength. In addition, space-stacked structures are also widely used in scenarios such as construction machinery and heavy-duty machine tools. For example, the top plate of a heavy hydraulic press (attached Figure 1 ). To prevent uneven load distribution, resulting in structural deformation and affecting working accuracy, lightweight design is required, and at the same time, high requirements for stiffness and strength are imposed. The toughness design can be carried out by designing multiple-layer space-stacked methods according to different models. In these application scenarios, the N-1 type of cellular space-stacked load-bearing structure involved in the present invention can exhibit excellent performance. Especially under extreme working conditions, when higher requirements for lightweight, specific strength, etc. are imposed, its performance can be improved by stacking multiple layers in a tough manner. It is specifically implemented by the following steps: Step 1: Input the design requirements of the space-stacked load-bearing structure, and determine the magnitude and direction of the force on the space-stacked load-bearing structure, the panel size, and the size of the bottom surface of the sandwich layer cell that encloses the cell. Step 2: According to the magnitude and direction of the force on the space-stacked load-bearing structure, determine the cell nesting type of the sandwich layer cell of the N-1 type of cellular space-stacked load-bearing structure. Step 3: According to the size of the bottom surface of the sandwich layer cell that encloses the cell and the panel size, determine the cell arrangement method of the sandwich layer cell of the N-1 type of cellular space-stacked load-bearing structure. Step 4: Select the characteristic points of the sandwich layer of the space-stacked load-bearing structure according to the nesting type arrangement method of the N-1 type of cell. Step 5: Calculate the position coordinates of the characteristic points of the sandwich layer of the space-stacked load-bearing structure ( ). Step 6: Select the type of sandwich layer cell of the space-stacked load-bearing structure, establish a superposition model of the N-1 type of cellular space-stacked load-bearing structure, and realize the design of the load-bearing structure according to the established model.

[0019] Furthermore, in the above Step 1, the design requirements of the space-stacked load-bearing structure include the magnitude of the force on the space-stacked load-bearing structure , the direction of the force , the long side length a, short side length b of the panel size, and the radius r of the circumscribed area of the core cell bottom surface; Among them, the force direction refers to defining the lower left point of the panel of the load-bearing structure stacked in space as the coordinate origin, defining the positive direction of the X-axis along the long side direction of the panel starting from the coordinate origin, and the angle between the force direction and the positive direction of the X-axis.

[0020] Furthermore, in the above step two, the specific steps for determining the cell nesting type of the core cell of the load-bearing structure with N-1 type cell space stacking are as follows: Step 2-1, judge the force direction Whether it is equal to 0 or π. If so, it is determined as the horizontal nesting type; otherwise, continue to the next step. Specifically: for the circumscribed surface of the cell bottom surface with a radius of r, the circumscribed surfaces of the cell bottom surfaces in the same direction are tangent horizontally, and the tangent point coincides with the center of the circumscribed surface of the cell bottom surface in the other direction; Step 2-2, judge the force direction Whether it is equal to π / 2. If so, it is determined as the vertical nesting type; otherwise, continue to the next step. Specifically: for the circumscribed surface of the cell bottom surface with a radius of r, the circumscribed surfaces of the cell bottom surfaces in the same direction are tangent vertically, and the tangent point coincides with the center of the circumscribed surface of the cell bottom surface in the other direction; Step 2-3, judge the force direction Whether it is equal to π / 4 or 3π / 4. If so, it is determined as the diagonal nesting type; otherwise, continue to the next step. Specifically: for the circumscribed surface of the cell bottom surface with a radius of r, the circumscribed surfaces of the cell bottom surfaces in the same direction are tangent along the northwest or northeast direction, and the tangent point coincides with the center of the circumscribed surface of the cell bottom surface in the other direction; Step 2-4, if the force direction is not equal to 0, π, π / 2, π / 4 or 3π / 4, it is determined as the triangular nesting type. Specifically: for the circumscribed surfaces of the cell bottom surfaces with a radius of r and of the circle, the circumscribed surfaces of the cell bottom surfaces with a radius of r in the same direction are tangent to each other, and their centers are located at the vertices of a regular triangle with a side length of 2r; the centers of the circumscribed surfaces of the cell bottom surfaces with a radius of in the other direction are located at the center of a regular triangle with a side length of 2r.

[0021] Furthermore, in the above step three, the specific arrangement method of the core cells of the stacked load-bearing structure sandwich layer cells is as follows: Step 3-1, according to the panel size and the size of the circumscribed surface of the core cell bottom surface, determine the maximum number of arrangements n in the X-axis direction. The specific calculation formula is ; Step 3-2, according to the determined nesting type, determine the maximum number of arrangements m in the Y-axis direction. The specific calculation formula is ; Step 3: Select any panel as the bottom panel, define the lower left corner of this panel as the coordinate origin, define the long side direction of this panel as the X-axis, the short side direction as the Y-axis, start arranging from the position tangent to both the X-axis and the Y-axis, continuously arrange n cells along the positive X-axis direction, and continuously arrange m cells along the positive Y-axis direction according to the selected nesting method.

[0022] Furthermore, in the above Step 4, the N-1 type cell is specifically a three-dimensional regular polyhedron with a regular N-sided polygon as the bottom surface, isosceles triangles with the side length of the N-sided polygon as the base on the sides, and the sides are folded along the sides of the regular N-sided polygon on the bottom surface. The space-stacked load-bearing structure is a composite structure formed by arranging and stacking N-1 type cells on the upper and lower two panels according to a certain nesting method. The method for selecting the characteristic points of the sandwich layer of the space-stacked load-bearing structure is: place the regular polygon upright and select the vertices of the N-1 type cell as its characteristic points.

[0023] Furthermore, in the above Step 5, the calculation method of the coordinate position ( ) of the characteristic points of the sandwich layer of the space-stacked load-bearing structure is as follows: Step 5-1: Place the N-1 type cell upright, use the lower left corner of the bottom panel or the top panel as the coordinate origin, use the long side of the top panel or the bottom panel as the x-axis, the other side perpendicular to it as the y-axis, and use the direction parallel to the height direction of the three-dimensional structure of the cell as the z-axis; Step 5-2: For each upright cell, calculate the coordinate of the vertex farthest from the bottom surface ( ), where the subscript represents the arrangement of this cell in the x-axis direction of the bottom panel, and the subscript represents the arrangement of this cell in the y-direction of the bottom panel; Step 5-3: Calculate the x-axis coordinate of the vertex of the cell in the column and , which corresponds to the x-axis coordinate of the center position of the circumscribed surface of the bottom surface of this N-1 type cell, specifically as follows: For the N-1 type cells arranged on the bottom panel: ; For the N-1 type cells arranged on the top panel: ; Step 5-4: Calculate the y-axis coordinate of the vertex of the cell in the column and , which corresponds to the y-axis coordinate of the center position of the circumscribed surface of the bottom surface of this cell, specifically as follows: For the N-1 type cells arranged on the bottom panel: ; For the N-1 type cells arranged on the top plate: ; Step Five, calculate the z-axis coordinates of the vertices of the cells located in Column Row. The z-axis coordinates of the vertices of the cells correspond to the height of the three-dimensional structure of the cells. Taking a regular triangle as an example, , which is the height of the three-dimensional structure of the cell. .

[0024] Through the above steps, the design logic and rules of the load-bearing structure for the spatial stacking of N-1 type cells are standardized, facilitating the formation of a domain design knowledge base for developing dedicated computer-aided design tools and software, providing technical support for the corresponding domestic software development.

[0025] In this embodiment, taking the design of the load-bearing structure for the spatial stacking of 3-1 type cells as an example, the specific steps are as follows: By implementing Steps One to Three, the arrangement rules of 3-1 type cells on the top and bottom surfaces, the arrangement rules of N-1 type cells on the top and bottom surfaces, and the arrangement rules of 3-1 type cells on the top and bottom surfaces are achieved. Then, based on the design dimensions of the two-dimensional unfolded geometric figure of the cells and the given arrangement rules, the spatial point position coordinates ( ) are calculated.

[0026] According to the above design idea of the load-bearing structure for the spatial stacking of N-1 type cells, the three-dimensional geometric parameters of 3-1 type cells that meet the three-dimensional formability conditions can be obtained: the side length of the regular triangle at the bottom is , the height , and the dihedral angle . Calculate the vertex coordinate positions of the 3-1 type cells according to the bottom plate arrangement and top plate arrangement of the 3-1 type cell sandwich structure shown in the attached drawings: Bottom plate Calculate the x-axis coordinates of the vertices of the 3-1 type cells located in Column Row , which corresponds to the x-axis coordinate of the midpoint of the regular triangle at the bottom of the 3-1 type cell, and the calculated value is ; Calculate the y-axis coordinates of the vertices of the 3-1 type cells located in Column Row , which corresponds to the y-axis coordinate of the midpoint of the regular triangle at the bottom of the 3-1 type cell, and the calculated value is ; Calculate the z-axis coordinates of the vertices of the 3-1 type cells located in Column Row , corresponds to the height of the three-dimensional structure of the 3-1 type cell , and the calculation gives ; Based on the above calculation results, the vertex coordinates of the 3-1 type cell located in column row are obtained top plate 2.1) Calculate the x-axis coordinate of the vertex of the 3-1 type cell located in column row. The corresponding x-axis coordinate is the midpoint position of the regular triangle at the bottom of the 3-1 type cell, and the calculation gives , ; ; 2.2) Calculate the y-axis coordinate of the vertex of the 3-1 type cell located in column row. The corresponding y-axis coordinate is the midpoint position of the regular triangle at the bottom of the 3-1 type cell, and the calculation gives , ; ; 2.3) Calculate the z-axis coordinate of the vertex of the 3-1 type cell located in column row. The corresponding z-axis coordinate is the height of the three-dimensional structure of the 3-1 type cell , and the calculation gives ; ; 2.4) Based on the above calculation results, the vertex coordinates of the 3-1 type cell located in column row are obtained .

[0027] In summary, for the design method of enhancing the toughness of the lightweight space stacked load-bearing structure in this embodiment, the design requirements of the space stacked load-bearing structure are input, and the magnitude and direction of the force on the space stacked load-bearing structure, the panel size, and the size of the bottom containment surface of the core layer cell are determined; according to the magnitude and direction of the force on the space stacked load-bearing structure, the nesting type of the core layer cell is determined; according to the size of the bottom containment surface of the cell and the panel size, the arrangement method of the core layer cells of the space stacked load-bearing structure of the N-1 type cell is determined; according to the nesting type and arrangement method of the cells, the position coordinates of the characteristic points are selected and calculated, the cell type is determined, and the superposition model of the space stacked load-bearing structure of the N-1 type cell is established, solving the problem that the unreasonable arrangement of the N-1 type cell on the top and bottom plates of the space stacked load-bearing structure leads to non-superimposability of the N-1 type cell in the core layer space.

[0028] The above are only the preferred embodiments of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions falling within the concept of the present invention belong to the protection scope of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A design method for enhancing the toughness of a lightweight space-stacked load-bearing structure, characterized in that: It includes the following steps: Step 1: Input the design requirements of the space-stacked load-bearing structure, and determine the magnitude and direction of the force on the space-stacked load-bearing structure, the panel size, and the size of the bottom containment surface of the sandwich layer unit cell. Step 2: According to the magnitude and direction of the force on the space-stacked load-bearing structure, determine the cell nesting type of the sandwich layer cells of the space-stacked load-bearing structure of the N-1 type cells. Step 3: According to the size of the bottom containment surface of the sandwich layer cell and the panel size, determine the cell arrangement method of the sandwich layer cells of the space-stacked load-bearing structure of the N-1 type cells. Step 4: According to the nesting type arrangement method of the N-1 type cells, select the characteristic points of the sandwich layer of the space-stacked load-bearing structure. Step 5, calculate the position coordinates of the characteristic points of the sandwich layer of the spatial stacked load-bearing structure ( ); Step 6: Select the type of sandwich layer cells of the space-stacked load-bearing structure, establish a superposition model of the space-stacked load-bearing structure of the N-1 type cells, and realize the design of the load-bearing structure according to the established model.

2. The toughness enhancement design method of the lightweight space-stacked load-bearing structure according to claim 1, characterized in that: The design requirements of the space-stacked load-bearing structure in the first step include the magnitude of the force borne by the space-stacked load-bearing structure , the direction of the force , the long side length a, the short side length b of the panel size, and the radius r of the circumscribed area of the core cell bottom surface; Among them, the force direction refers to the angle between the positive X-axis direction defined along the long side direction of the panel starting from the origin of coordinates defined as the lower left point of the panel of the load-bearing structure stacked in space and the force direction.

3. The toughness enhancement design method of the lightweight space-stacked load-bearing structure according to claim 1 or 2, characterized in that: The specific steps for determining the cell nesting type of the sandwich layer cells of the space-stacked load-bearing structure of the N-1 type cells in Step 2 are as follows: Step 2-1, Determine the direction of force Check if it is equal to 0 or π. If so, it is determined as the horizontal nesting type; otherwise, proceed to the next step. Specifically, for the circumscribed surface of the cell bottom being a circle with a radius of r, the circumscribed surfaces of the cell bottoms in the same direction are tangent horizontally, and the tangent point coincides with the center of the circumscribed surface of the cell bottom in the other direction; Step 22, determine the direction of force Check if it is equal to π / 2. If so, it is determined as the vertical nesting type; otherwise, proceed to the next step. Specifically, for the circumscribed surface of the cell bottom being a circle with a radius of r, the circumscribed surfaces of the cell bottoms in the same direction are tangent in the vertical direction, and the tangent point coincides with the center of the circumscribed surface of the cell bottom in the other direction; Step 2-3: Determine the direction of force Check if it is equal to π / 4 or 3π / 4. If so, it is determined as the diagonal nesting type; otherwise, proceed to the next step. Specifically, for the circumscribed surface of the cell bottom being a circle with a radius of r, the circumscribed surfaces of the cell bottoms in the same direction are tangent along the northwest or northeast direction, and the tangent point coincides with the center of the circumscribed surface of the cell bottom in the other direction. Step 24, if the force direction is not equal to 0, π, π / 2, π / 4 or 3π / 4, it is determined as the triangular nesting type, specifically: for the cell bottom containment surface being a circle with a radius of r and , the cell bottom containment surfaces with a radius of r in the same direction are tangent to each other pairwise, and their centers are located at the vertices of a regular triangle with a side length of 2r; the centers of the cell bottom containment surfaces with a radius of in the other direction are located at the center of a regular triangle with a side length of 2r.

4. The design method for enhancing the toughness of the lightweight space-stacked load-bearing structure according to claim 1 or 2, characterized in that: The specific method of the cell arrangement method of the sandwich layer cells of the space-stacked load-bearing structure in Step 3 is as follows: Step 3-1: Determine the maximum number of arrangements n in the X-axis direction according to the panel size and the bottom surface enclosing surface size of the sandwich layer unit cell. The specific calculation formula is ; Step 32. Determine the maximum number m of arrangements in the Y-axis direction according to the determined nesting type. The specific calculation formula is ; Step 3-3: Select any panel as the bottom plate, define the lower left corner of this panel as the coordinate origin, define the long side direction of this panel as the X-axis, the short side direction as the Y-axis, start arranging from the position tangent to both the X-axis and the Y-axis, continuously arrange n cells along the positive X-axis direction, and continuously arrange m cells along the positive Y-axis direction according to the selected nesting method.

5. The method for enhancing the toughness of the lightweight space-stacked load-bearing structure according to claim 1 or 2, characterized in that: The N-1 type cells in Step 4 are specifically a three-dimensional regular polyhedron with a regular N-sided polygon on the bottom surface, isosceles triangles with the side length of the N-sided polygon as the base on the side surfaces, and the side surfaces are folded along the sides of the regular N-sided polygon on the bottom surface.

6. The method for enhancing the toughness of the lightweight space-stacked load-bearing structure according to claim 5, characterized in that: The space-stacked load-bearing structure in Step 4 is a composite structure formed by arranging and superposing the N-1 type cells on the upper and lower panels according to a certain nesting method.

7. The design method for enhancing the toughness of the lightweight space-stacked load-bearing structure according to claim 6, wherein: The method for selecting the characteristic points of the sandwich layer of the space-stacked load-bearing structure in Step 4 is: Place the regular polygon upright and select the vertices of the N-1 type cells as its characteristic points.

8. The design method for enhancing the toughness of the lightweight space-stacked load-bearing structure according to claim 1 or 2, characterized in that: The calculation method of the position coordinates of the characteristic points of the sandwich layer of the spatially stacked bearing structure in the fifth step is as follows: ) is as follows: Step 5-1: Place the N-1 type cells upright, take the lower left corner of the bottom plate or the top plate as the coordinate origin, take the long side of the top plate or the bottom plate as the x-axis, and the other side perpendicular to it as the y-axis, and take the direction parallel to the height direction of the three-dimensional structure of the cell as the z-axis; Step Five Two, for each upright cell, calculate the coordinates of the vertex farthest from the bottom surface ( ), where the subscript represents the arrangement of the cell in the x-axis direction of the bottom plate, and the following table represents the arrangement of the cell in the y-direction of the bottom plate; Step Five Three, calculate the x-axis coordinates of the vertices of the cells located in column row, which corresponds to the x-axis coordinate of the center of the bottom containment surface of the N-1 type cell, specifically as follows: , ​ For the N-1 type cells arranged on the bottom plate: ； For the N-1 type cells arranged on the top plate: ； Step Five Four, calculate the y-axis coordinates of the vertices of the cells located in column row, which corresponds to the y-axis coordinates of the center of the bottom containment surface of the cell, specifically as follows: , ​ For the N-1 type cells arranged on the bottom plate: ； For the N-1 type cells arranged on the top plate: ； Step Five Five, calculate the z-axis coordinates of the vertices of the cells located in columns rows, , which corresponds to the height of the three-dimensional structure of the cell.

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