Honeycomb edge reinforcing structure based on polystyrene foam filling and filling method

Abstract

The invention discloses a honeycomb edge reinforcing structure based on polystyrene foam filling and a filling method, and relates to the technical field of plastic reinforcing design. And high-strength, fatigue-resistant and directional expansion filling connection between the honeycomb core material and the plastic shell is realized. Finite element analysis and sensitivity calculation are introduced, support arrangement and injection molding hole positions are optimized, and a stress path is guided in combination with the main modal direction; layered quantitative glue injection matched with stress is achieved by adjusting the injection direction, speed and duration in real time. According to the system, polystyrene foam expansion, interface crosslinking and buffer attachment are completed at the same time under the temperature control or ultraviolet condition, a composite interface system integrating chemical adhesion, structural force bearing and stress absorption is constructed, the size stability of the honeycomb edge structure is remarkably improved, the fatigue life of the honeycomb edge structure is remarkably prolonged, and the bonding reliability of the honeycomb edge structure is remarkably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of plastic reinforcement design, and in particular to a honeycomb edge reinforcement structure based on foamed glue filling and a filling method. Background Art

[0002] In the manufacture of lightweight honeycomb sandwich structures, edge areas often need to be filled with foam glue to enhance structural stability and improve interface connection strength. However, existing technologies mostly use single-directional glue injection or simple geometric support structure layout methods, lacking dynamic perception and regulation of the true stress response of the honeycomb core material. This leads to unstable expansion paths of the injected glue and local stress concentration, which can easily cause problems such as cracking of the honeycomb wall and interface delamination. Especially in multi-temperature environments or under long-term fatigue loads, there is a lack of a synergistic curing mechanism between the foam glue and the honeycomb structure, and the interface is prone to micro-cracks, aging, or peeling, seriously affecting the service reliability of the structure.

[0003] In addition, traditional honeycomb structures often use overall glue injection or adhesive encapsulation when wrapping the edges or connecting the shells. These methods have problems such as weak foam interface bonding, disordered filling paths, concentrated stress due to thermal expansion and contraction, and delamination under fatigue loads. These problems seriously restrict their application life and reliability in lightweight structural parts and shell composite structures for transportation equipment.

[0004] In view of this, the present invention provides a honeycomb edge reinforcement structure and a filling method based on foam filling to solve the above problems. Summary of the Invention

[0005] The purpose of the present invention is to provide a honeycomb edge reinforcement structure and filling method based on foam glue filling, a honeycomb edge filling reinforcement structure with glue injection path guidance and multi-interface fatigue protection functions, so as to solve the technical problems of weak foam glue bonding, stress concentration, and uneven glue injection in the prior art.

[0006] In order to achieve the above object, the present invention provides the following technical solutions: In a first aspect, the present invention provides a honeycomb edge reinforcement structure based on foam filling, which is arranged between a honeycomb core material and a plastic shell, with the position of the plastic shell relative to the honeycomb core material being the outer side, comprising: A roughened layer is provided on the outer surface of the honeycomb core material facing the plastic shell and has grooves; a functional coating covering the outer surface of the roughened layer, comprising a coupling agent and / or a block polymer that undergoes a cross-linking reaction with both the roughened layer and the foamed rubber filling layer; At least one space frame support, based on which a plurality of foam-filled cavity areas are enclosed and formed, and a space frame support is provided on the top of each filled cavity area; the space frame support includes: at least one injection hole; The injection molding positioning member includes an injection hole for defining the injection position of the foam glue. The injection holes are arranged coaxially through the thickness direction of the honeycomb and are distributed in a staggered array in the planar direction to form a non-overlapping arrangement structure of the glue injection path; a pressure-limiting cavity and a flexible sealing sheet are provided below each injection hole. The flexible sealing sheet seals the injection hole after the glue expands to form a self-sealing structure; Flexible locating edge, used to connect the injection molded locating piece and the rigid locating edge; The rigid positioning edge and the flexible positioning edge together enclose a cavity filling area; The foamed rubber filled in the filling cavity area constitutes a foamed rubber filling layer; A buffer transition layer is provided between the plastic shell and the outermost space frame support, and a flexible buffer membrane with an elastic modulus is provided as a transition section between the foam rubber and the plastic shell; The foaming rubber components used in the foaming rubber filling layer, the interface functional coating and the buffer transition layer respectively complete their respective reactions or bonding processes under uniform temperature control or ultraviolet excitation conditions to construct a multi-layer composite structure interface system.

[0007] Injection molded positioning parts also include: A supporting anchoring structure, arranged at the periphery of the injection hole, for fixing the injection hole; A pressure-limiting mechanical engaging part is provided in the pressure-limiting cavity. Under the action of the pressure-limiting mechanical engaging part, the flexible sealing sheet is pressed onto the injection hole to form a self-sealing structure.

[0008] The setting logic of the space frame support: Step A1: constructing a finite element model for the honeycomb edge reinforcement structure to obtain boundary conditions; the boundary conditions include honeycomb edge constraint conditions, foam expansion load constraint conditions, and plastic shell external load constraint conditions; Step A2: performing custom mesh discretization processing on the honeycomb edge reinforcement structure, wherein the filling cavity area corresponding to the foam filling layer is locally meshed and encrypted to generate structural discrete units, and material properties are annotated for each structural discrete unit; Step A3: Based on the boundary conditions established in step A1 and the mesh model and material property annotations generated in step A2, a static finite element method is performed on the honeycomb edge reinforcement structure to obtain the node stress response and displacement distribution of the structure under the combined action of the foam expansion internal pressure and the external load, and a stress-displacement mapping relationship of the honeycomb structure is established; Step A4: Based on the node stress response obtained by solving step A3, perform eigenvalue processing on the honeycomb structure stiffness matrix to obtain the honeycomb unit flexibility matrix and calculate the response sensitivity of each discrete unit of the structure; Step A5: Divide the normal stress area and the concentrated stress area based on the sensitivity threshold; arrange multiple space frame supports in the concentrated stress area and fill them with high-density foam glue, and arrange space frame supports around the normal stress area and fill them with low-density foam glue.

[0009] As a preferred technical solution of the first aspect of the present invention, the wall thickness and area of ​​the concentrated stress area are analyzed to calculate the required number of space frame brackets.

[0010] As a preferred technical solution of the first aspect of the present invention, the logic for obtaining the injection hole position is: Determining the number of space frame supports based on an arrangement plan of the space frame supports, wherein the space frame supports are a multi-layer stacked structure in a honeycomb thickness direction; Based on the honeycomb structure stiffness matrix, eigenvalue decomposition is performed to extract the main modal direction vector and determine the injection path axis and injection hole layout direction; A foaming expansion response model was established to simulate the colloid expansion path, local deformation, and stress concentration distribution at multiple injection points. The deformation field stability coefficients under different injection point layout conditions were calculated, and the set of points with the lowest stability coefficient was selected as the injection hole layout location. Based on a multi-stage inverse finite element analysis framework, an objective function for minimizing the total strain energy of the honeycomb structure is constructed. Combined with the stiffness matrix constraints and the loading boundary, the injection point layout problem is inversely solved to obtain a set of injection positions. This optimal solution is used for the layout of injection holes to form an ordered array of injection introduction points.

[0011] As a preferred technical solution of the first aspect of the present invention, the process of obtaining the structural response through the foaming expansion response model includes: Input the foam density, expansion ratio and injection point location; Establish the colloid volume growth function and boundary force propagation function; Calculate the diffusion paths of different colloid fillings using a path tracking algorithm; Obtain the maximum displacement and peak stress of the structure node under each injection path.

[0012] As a preferred technical solution of the first aspect of the present invention, the acquisition logic of the multi-layer composite structure interface system is: Forming a roughened layer on the surface of the honeycomb core material and applying a functional coating, wherein the functional coating serves as a main reaction interface to provide chemical adhesion between the honeycomb core material and the foaming glue; Install the space frame bracket and inject foam through the injection hole. The foam acts as the structural load-bearing core, filling and reinforcing the edge structure. Directional expansion forms a foam filling layer within the confines of the space frame bracket. A buffer transition layer is provided between the foam filling layer and the plastic shell as a stress buffer and edge sealing protection layer to absorb the interface stress concentration caused by heat-load. The buffer transition layer is an elastic film material with thermal softening or UV response performance. The buffer transition layer is treated with plasma activation or coated with a photosensitive initiation layer, and forms a surface-level interlocking with the uncured surface of the foam under UV irradiation conditions; The functional coating, foam and buffer transition layer are processed synchronously under uniformly controlled temperature control conditions or ultraviolet excitation conditions, and the interface reaction between the functional coating and the foam, the volume expansion and shaping of the foam and the attachment of the buffer film are completed in sequence to form a multi-layer composite structure interface system.

[0013] In a second aspect, the present invention provides a filling method for a honeycomb edge reinforcement structure based on foam filling, which is used to design the first aspect, comprising the following steps: S1: Based on the preset honeycomb structure finite element model, the partition boundary information of the target cavity is extracted, the injection path planning coordinate system is established, the injection point position and injection direction vector of the injection nozzle are determined, and the corresponding foam density parameters are matched for subsequent precise control of the filling process; S2: The glue injection nozzle performs a directional, speed-adjustable, and duration-adjustable foam injection operation into the target cavity based on the injection point location and partition boundary information. During the injection process, the nozzle posture and injection parameters are automatically adjusted according to the compliance matrix and stress gradient direction in the target cavity. S3: After the foaming glue is injected, the interface reaction between the foaming glue and the functional coating, the volume expansion and shaping of the colloid, and the thermal attachment process of the flexible buffer film are driven in sequence under a uniformly controlled temperature or UV excitation environment to construct a multi-layer composite structure interface system.

[0014] As a preferred technical solution of the second aspect of the present invention, the logic for obtaining the partition boundary information is as follows: Based on the preset finite element analysis model of the honeycomb edge reinforcement structure, a structural mesh model is established for the honeycomb core material, space frame bracket, and foam filling layer. The material properties of each area are annotated and the stress-displacement response data is extracted. Identifying normal stress areas and concentrated stress areas in the honeycomb structure based on the stress-displacement response data, and marking the corresponding foam filling layers as target cavities; The spatial distribution boundary of each target cavity is extracted, wherein the boundary information includes the geometric shape of the area enclosed by the spatial structure support, the stress bearing capacity and the expected filling volume parameters.

[0015] As a preferred technical solution of the second aspect of the present invention, the injection parameters include injection direction, real-time injection rate and injection duration; the adjustment logic of the nozzle posture and injection parameters is: The stress gradient direction vector is calculated based on the stress field corresponding to the target cavity, and the rotation angle of the injection nozzle is set so that the injection direction forms an angle of 10° to 30° with the stress gradient direction to achieve stress-guided filling path planning; In order to adapt to the assembly deviation of the honeycomb structure, the injection direction is set with a posture tolerance of ±15°; The real-time injection rate takes the basic injection rate as the initial value and is corrected in combination with the target cavity flexibility value to form a real-time injection rate associated with the flexibility. The injection time is calculated by integrating the target injection volume and the real-time injection rate. When the injection volume reaches the preset threshold, the injection operation is automatically terminated in a closed loop.

[0016] In the above technical solution, the technical effects and advantages provided by the present invention are: The present invention achieves high adhesion, low stress accumulation and long-lasting interface stability of the foam glue in the edge area of ​​the honeycomb structure through the interface dual reinforcement mechanism of microstructure + coupling agent, the setting of 3 rigid-flexible space frame brackets, finite element optimized injection path guidance design and thermal-mechanical strain buffering design of flexible membrane materials, thereby significantly improving the service life of the honeycomb structure under complex working conditions such as thermal cycling and vibration impact. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments described in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0018] Figure 1 It is a schematic diagram of the honeycomb edge reinforcement structure of the present invention.

[0019] Figure 2 Schematic diagram of the honeycomb edge reinforcement structure with multiple space frame supports of the present invention.

[0020] Figure 3 This is a schematic diagram of the space frame support structure of the present invention.

[0021] Figure 4 This is a cross-sectional view of the injection molded positioning piece of the present invention.

[0022] Figure 5 This is a flow chart of the logic method for obtaining the foam glue injection position of the present invention.

[0023] Figure 6 This is a flow chart of the filling method of the honeycomb edge reinforcement structure of the present invention.

[0024] Description of reference numerals: 1. Roughening layer; 2. Functional coating; 3. Space frame bracket; 301. Injection molding positioning part; 3011. Injection molding hole; 3012. Support anchoring structure; 3013. Pressure limiting cavity; 3014. Flexible sealing sheet; 302. Rigid positioning edge; 303. Flexible positioning edge; 4. Foam filling layer; 5. Buffer transition layer. DETAILED DESCRIPTION

[0025] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the examples set forth herein; rather, these example embodiments are provided so that the description of this disclosure will be more comprehensive and complete, and will fully convey the concepts of the example embodiments to those skilled in the art. The accompanying drawings are merely schematic illustrations of the present disclosure and are not necessarily drawn to scale. Identical reference numerals in the figures indicate identical or similar parts, and thus repeated descriptions thereof will be omitted.

[0026] In addition, the described features, structures or characteristics can be combined in any suitable manner in one or more example embodiments. In the following description, many specific details are provided to provide a full understanding of the example embodiments of the present disclosure. However, those skilled in the art will appreciate that the technical solutions of the present disclosure can be practiced while omitting one or more of the specific details, or methods, components, steps, etc. In other cases, well-known structures, methods, implementations or operations are not shown or described in detail to avoid obscuring various aspects of the present disclosure.

[0027] Example 1 like Figure 1As shown, the present invention provides a honeycomb edge reinforcement structure based on foam filling, which is arranged between the honeycomb core material and the plastic shell. Through the coordinated design of multi-layer materials and support structures, the controlled expansion of the filling path and the significant improvement of the interface fatigue life are achieved. The honeycomb core material is a carrier for providing main structural strength; the plastic shell is a boundary carrier, and foam glue is filled between the honeycomb core material and the plastic shell. From the honeycomb core material outward, it includes a roughening layer 1, a functional coating 2, a space frame support 3, a foam glue filling layer 4 and a buffer transition layer (5). The space frame support 3 is divided into multiple filling cavity areas, each filling cavity area is provided with an independent injection hole (3011), and the injection holes (3011) between adjacent space frame supports 3 are arranged in a coaxial through-type structure in the honeycomb thickness direction and are distributed in a staggered array in the plane direction; the center distance between each injection hole (3011) is matched with the foam cavity structure, allowing the same injection equipment to pass through multiple injection holes (3011) in sequence to complete the layered injection process, and each layer of injection is limited by the injection hole pressure limiting structure to achieve limited injection and automatically close after the colloid expands, thereby avoiding interference of colloid penetration between different layers.

[0028] After injection molding, it can automatically seal to form a foam filling layer 4; the rigid boundary and flexible boundary arrangement of the space frame bracket 3 are based on the stress path calculation results of finite element analysis, and the injection path control and stress guiding structure form a coordinated force guiding system; the outermost buffer transition layer (5) provides dynamic rebound and dimensional buffering for the entire filling structure, adapting to thermal load and dynamic impact requirements.

[0029] Further explanation: the roughening layer 1 is arranged on the side surface of the honeycomb core material facing the plastic shell, and controllable microstructure pits such as pits and grooves are formed on the outer surface of the honeycomb core material to form a micro "support structure" system. The roughening layer 1 is formed by plasma etching, laser micro-engraving or mechanical sandblasting to enhance the micro-mechanical bite force; increase the actual contact area, form a physical bite similar to a mortise and tenon or anchor structure, and improve the bonding retention of the foam glue to the inner wall of the honeycomb after curing. Even if micro-stress is generated at the interface, it is not easy to peel off or slip, thereby avoiding insufficient interface bonding force, which leads to delamination under thermal cycling or mechanical fatigue.

[0030] The functional coating 2, covering the surface of the roughened layer 1, comprises a coupling agent or a block polymer that undergoes a cross-linking reaction simultaneously with the roughened layer 1 and the foamed rubber filling layer 4, thereby establishing a bidirectional chemical bridge at the interface, significantly improving the initial bonding strength and durability, reducing the possibility of aging peeling, and improving the interfacial chemical adhesion.

[0031] At least one space frame support 3 is arranged on the outside of the functional coating (2), and a foamed rubber filling layer 4 is formed by filling the filling cavity area enclosed by the space frame support 3 with foamed rubber, so that the space frame support 3 enhances the space supporting capacity; It should be noted that: Figure 1 As shown, a space frame support 3 is provided, and the area between the space frame support 3 and the functional coating (2) is a foam filling layer (4); it can also be as follows Figure 2 As shown, on the basis of the space frame support 3, another space frame support 3 is added; then the area between the space frame support 3 and the space frame support 3 is still the foam filling layer 4, and foams of different densities are filled in different enclosed filling cavity areas to ensure the stress strength of the honeycomb structure while achieving lightweight, that is, in the same enclosed filling cavity area, the filled foams have different densities under the same foam system.

[0032] Further explanation, the setting logic of the space frame support 3 is as follows: Step A1, constructing a finite element model for the honeycomb edge reinforcement structure to obtain boundary conditions; the boundary conditions include honeycomb edge constraint conditions, foam expansion load constraint conditions, and plastic shell external load constraint conditions, wherein; Honeycomb edge constraint conditions: Fixed constraints are imposed on the nodes at the outer edge of the honeycomb core, that is, the freedom constraints of all nodes at the outer boundary of the honeycomb core. and ; represents the displacement degree of freedom, Represents the rotational degree of freedom, simulating the actual working condition of the honeycomb core being fixed by the plastic shell; Foam expansion load constraint: A uniform internal pressure load is applied to the surface of the cavity enclosed by the space frame support 3 (i.e., the foam filling layer) to simulate the internal pressure generated during the foam expansion process. The pressure is set to 0.1-0.5 MPa, and the specific pressure is adjusted according to the colloid density and expansion ratio. External load constraints for plastic shells: Apply the actual external load used in the structure (such as a vertical load of 100-500N or a uniformly distributed load) to the plastic shell to further clarify the load conditions of the structure under actual working conditions.

[0033] It should be noted that: the honeycomb core material and the plastic shell are used as the frame load boundaries; all displacement and rotational degrees of freedom are constrained by the edge nodes of the honeycomb core material; the internal pressure boundary condition is applied to the foam filling layer, and the space frame bracket 3 is used to apply the equivalent boundary load and constraint to simulate the expansion force generated by the foam expansion process; the force conditions of foams of different densities in different target areas of the foam filling layer are simulated, and the relative displacement and stress response distribution between nodes are extracted to determine the optimal injection path and the most appropriate injection hole position distribution scheme.

[0034] Step A2, performing custom mesh discretization processing on the honeycomb edge reinforcement structure, wherein the filling cavity area corresponding to the foam filling layer 4 is locally meshed and encrypted to generate structural discrete units, and material properties are annotated for each structural discrete unit; Specifically, the structural discrete units include: The roughened layer 1 is marked as a rough element to capture the microstructural stress concentration effect; Functional coating 2 is marked as a coating bonding unit, which has nonlinear response characteristics of shear and peeling behaviors; The space frame support 3 is marked as a mixed form of beam elements and shell elements to simulate the rigid-flexible connection boundary structure; The foam filling layer 4 is marked as a solid element, and the volume growth function is defined by combining the material expansion coefficient and the foam expansion load constraint. Based on the actual analysis requirements, local mesh refinement is used to capture the local stress concentration areas, deformation paths, and node displacement characteristics under the foam expansion load. The buffer transition layer 5 is marked as a flexible shell element to express the interface energy absorption effect under thermal expansion and contraction; The material properties include elastic modulus, Poisson's ratio, nonlinear constitutive parameters, volume expansion rate and interface separation energy, which are used to analyze the mapping relationship between the structural stiffness matrix, node displacement vector and external load, providing a numerical basis for subsequent foam injection path optimization and structural response analysis.

[0035] In step A3, based on the boundary conditions established in step A1 and the mesh model and material property annotations generated in step A2, a static finite element method is performed on the honeycomb edge reinforcement structure to obtain the node stress response and displacement distribution of the structure under the combined action of the foam expansion internal pressure and external load. The stress-displacement mapping relationship of the honeycomb structure is established, which is expressed as: ; in: is the external load vector including the internal pressure of the foam and the external working load, is the honeycomb stiffness matrix, is the node displacement vector; Step A4: Based on the node stress response obtained in step A3, the honeycomb structure stiffness matrix Perform eigenvalue processing to obtain the honeycomb unit flexibility matrix , the structural response sensitivity is extracted according to the following formula; Further explanation, such as Figure 5 As shown, the stiffness matrix of the honeycomb structure The characteristic decomposition formula is: ; in: is the eigenvalue; The main deformation direction of the structure under loading is identified as the main modal direction, and the main modal direction is used as the rigid edge of the space frame bracket (3) to set the guide reference; the candidate injection points are uniformly projected to the edge area of ​​the honeycomb structure along the main modal direction; a modal axis coordinate system is established as a reference framework for subsequent path simulation and hole layout, ensuring the consistency of the expansion direction and the structural response direction during the foam filling process, thereby realizing stress-guided control and path structure coordinated optimization.

[0036] The sensitivity formula is:

[0037] in: For the The sensitivity of a discrete structural unit, For the The node displacement corresponding to each discrete structural element is: For the Material property variable parameters of each structural discrete unit; For the The stiffness variation derivative of the material property variable parameter corresponding to each structural discrete unit, and the negative sign comes from the directionality of the chain derivation.

[0038] It should be noted that the sensitivity formula is used to express the changing trend of the node displacement vector under changes in the material property variable parameters of the structure. It is used for the optimized layout and material partitioning control of the space frame bracket 3 and is the theoretical basis for the structural partition layout and injection path optimization. Among them, the linear static analysis constructed in step A3 solves the global displacement response of the honeycomb edge reinforcement structure and provides a complete displacement field. Based on this displacement solution, step A4 performs partial derivative analysis on the structural stiffness parameters and constructs displacement sensitivity derivatives, thereby identifying the local areas where the structural response changes most significantly. The above two steps constitute a continuous mapping path from stress distribution to structural optimization, serving as an important theoretical basis for the subsequent partitioning of the space frame bracket 3 and the design of the injection hole (3011).

[0039] Step A5: The sensitivity is analyzed by threshold comparison to obtain the normal stress area and the concentrated stress area; Analyze the wall thickness and area of ​​the concentrated stress area to calculate the required number of space frame brackets 3; fill the concentrated stress area with a preset high threshold density foam to form a high modulus support; Merge adjacent normal stress areas, set a space frame support 3 on the periphery, and fill the normal stress area with foam glue of a preset low threshold density; The spatial frame bracket 3 is used to effectively separate the different stress areas, forming a layout plan for the spatial frame bracket. The filling density of the foam in different areas is controlled by the expansion coefficient and the stress response peak, ensuring rapid release of local stress and adaptive rebound deformation. This improves the crack resistance and controls the dimensional stability of the edge area of ​​the honeycomb structure under dynamic impact and thermal expansion conditions.

[0040] It should be noted that the space frame bracket 3 is used to divide the conventional stress area and the concentrated stress area, ensuring that different stress areas are filled with foam glue of different densities, ensuring that local stress is quickly dispersed in the initial stage of filling and expansion, controlling the local stress peak, and improving the adaptive rebound ability and fatigue recovery performance of the filling area. It is particularly suitable for the crack protection and dimensional stability improvement of honeycomb structures under dynamic loads or deformation impacts.

[0041] The logic for obtaining the position of the injection hole (3011) is: The number of the space frame supports 3 is determined based on the arrangement scheme of the space frame supports 3, and each space frame support 3 is provided with at least one injection hole (3011), and the injection holes (3011) are arranged in a coaxial through-type manner along the thickness direction of the honeycomb in space, allowing the glue injection equipment to penetrate the multiple injection holes layer by layer in the Z-axis direction to perform layered glue injection, and in the XY plane direction of the honeycomb panel surface, the injection holes (3011) are distributed in a staggered array; It should be noted that the space frame bracket 3 is a multi-layer stacked structure in the direction of honeycomb thickness, and is divided into multiple independent foaming cavity areas inside. Each foaming cavity area is provided with at least one injection hole (3011), and the injection holes (3011) are coaxially arranged along the honeycomb thickness direction in space, allowing the injection equipment to penetrate multiple injection holes layer by layer in the Z-axis direction for layered injection, avoiding cross-interference of the multi-layer injection path, and improving the uniformity of the injection path and the stability of stress expansion.

[0042] The main modal direction vector is obtained based on the eigenvalue decomposition of the honeycomb structure stiffness matrix to identify the main stress expansion direction of the honeycomb structure when it is filled with foam glue. This is used to determine the main axis of the glue injection path and the confining direction of the space frame bracket. A foaming expansion response model was established, and the colloid diffusion path, local node stress response, and honeycomb structure displacement distribution under different injection point conditions were simulated using an expansion path tracking algorithm. The deformation field stability coefficient under different injection point layout conditions was calculated. It is further explained that the foaming expansion response model includes the density of the foam glue, the expansion ratio and the position of the initial injection point, and is used to simulate the filling process of the foam glue under different injection point injection conditions and the local deformation and stress response of the honeycomb structure; During the model solving process, an expansion path tracking algorithm was established in combination with the boundary constraints of the predefined spatial structure bracket. Multiple candidate injection points were simulated to obtain the volume expansion path of the colloid during the filling process, the colloid boundary advancement trend, the local node displacement response and the stress concentration distribution.

[0043] In order to quantitatively evaluate the adaptability of each injection point layout scheme to the honeycomb structure, the deformation field stability coefficient is introduced, and its calculation is based on the following function: ; in: is the node displacement field during the filling process; The maximum allowable deformation limit of the structure; is the local element strain energy; is the energy weight factor; is the strain energy threshold.

[0044] The lower the stability coefficient, the milder the structural response caused by the injection point, and the closer the system is to mechanical equilibrium. By comparing the simulation results of different injection points, the group of injection points with the lowest stability coefficient is selected as the optimization result to guide the layout of the injection holes (3011) in the space frame bracket, forming an orderly array of injection introduction points.

[0045] Based on the multi-stage inverse finite element analysis framework, an objective function for minimizing the total strain energy of the honeycomb structure is constructed. Combined with the stiffness matrix constraints and the loading boundary, the injection point layout problem is solved in reverse to obtain the injection position set. The optimal solution is used for the layout of the injection holes (3011) to form an ordered array of injection introduction points, thereby completing the coupled coordinated optimization of the spatial structure bracket layout and the injection path, realizing structural response balancing, stress-guided filling and injection path controllability.

[0046] To further illustrate, the objective function is: ; in: is the total strain energy of the structure, which represents the elastic energy stored after the structure is deformed. Minimizing strain energy means that the structure achieves the optimal stress distribution and the minimum overall deformation. is the node displacement vector of the structure, which is a vector composed of the node displacements of the finite element model, indicating the displacement of each node in the structure under stress; is the structural stiffness matrix, which describes the structure's ability to resist deformation. The stiffness matrix is ​​determined by factors such as material properties, geometric characteristics, and element type, and reflects the rigid connection relationship between structural nodes; is the transposed matrix of the displacement vector.

[0047] Using genetic algorithms, gradient optimization methods or other numerical optimization algorithms, combined with the structural stiffness matrix The optimal injection position of the structure is inversely solved with stress-deformation inversion mapping to obtain a plurality of injection position points, which form an ordered injection introduction point array. The installation position of the actual injection molding positioning part (301) in the honeycomb structure is determined based on the injection introduction point array.

[0048] like Figure 3 As shown, the space frame bracket 3 includes at least one injection molded positioning member 301, and the two ends of the injection molded positioning member 301 are connected to the rigid positioning edge 302 through the flexible positioning edge 303 respectively, based on the joint action of the rigid positioning edge (302) and the flexible positioning edge (303) to enclose a filling cavity area filled with the same density.

[0049] Further description, the space frame support 3 includes: Injection molding positioning member 301, injection molding hole 3011 for defining the injection position of foam glue, such as Figure 4 As shown, the injection molding positioning member 301 includes: The injection hole 3011, the injection position of the foam glue, is directionally set on the injection positioning part 301, and the corresponding support anchoring structure 3012 is provided on the outside of the injection hole (3011) to ensure the stability of the injection equipment. A pressure-limiting cavity 3013 is provided at the lower end of the injection hole 3011. The injection equipment passes through the injection hole (3011) and enters the pressure-limiting cavity 3013 to inject foam glue into the foam glue filling layer 4. After the foam glue is filled, the injection equipment is pulled out of the injection hole 3011. A pressure-limiting mechanical clamping part is provided in the pressure-limiting cavity 3013. Under the action of the closing parts, the flexible sealing sheet (3014) is closely attached to the glue injection device. As the glue injection device is withdrawn, the foam glue moves toward the pressure-limiting cavity 3013. The pressure-limiting cavity 3013 is provided with a flexible sealing sheet 3014. After the foam glue is filled, the flexible sealing sheet 3014 is pressed against the inner wall of the cavity by the expansion pressure of the colloid. The flexible sealing sheet (3014) corresponding to the outer periphery of the injection hole (3011) seals the injection hole (3011) under the action of pressure, forming a self-sealing structure; the injection channel is automatically closed, the colloid is prevented from overflowing, and the internal colloid structure is stable. The material of the flexible sealing sheet 3014 includes but is not limited to an elastic polyurethane film, a heat-sealed polyester film, or a low-melting-point sealing sheet.

[0050] The rigid positioning edge 302 forms a closed cavity with the functional coating 2, provides expansion boundary rigidity, prevents the honeycomb from warping and shifting after filling, and is the end surface of the foam expansion direction, thereby improving the stability of the internal structure.

[0051] The flexible positioning edge 303 has a corrugated flexible edge and is used to provide a micro-elastic limiting force in the initial stage of foaming and expansion to prevent the colloid from overflowing before initial solidification. At the same time, it releases the interface stress under thermal expansion and contraction to avoid the focus being concentrated on the injection hole 3011.

[0052] It should be noted that the foam is a liquid foam with high permeability, adjustable density, and strong adhesion. It is used in applications requiring high-strength filling, structural reinforcement, sealing and sound insulation, or complex cavities. After being injected through injection hole 3011, the foam expands directionally under boundary constraints, forming a multi-layered structure that interlocks with the honeycomb core, effectively improving the interfacial adhesion and fatigue life between the foam and the honeycomb structure. Flexible positioning edges 303 absorb stress caused by microscopic thermal expansion and contraction, preventing aging and delamination. Rigid positioning edges 302 maintain overall deformation control in the filling area, ensuring edge dimensional consistency. This reduces the overall injection molding volume and consumables, ensuring both structural stability and lightweight design.

[0053] To further illustrate, each space frame support 3 partitions the foam filling layer 4, and each area forms a closed rigid boundary of the foam expansion path through the rigid positioning edge 302, providing reverse support and guiding the expansion direction away from the injection hole. The flexible positioning edge 303 is set in the direction adjacent to the injection hole, and uses a corrugated structure to provide an initial elastic buffer space; when the foam is just injected, it provides micro-expansion absorption capacity to prevent stress concentration from impacting the injection hole, and at the same time has long-term stress relaxation capacity for later temperature change buffering. The entire structure is shaped like a pressure relief channel that expands from flexible to rigid, and the injection hole becomes the "back" of stress release; the coordinated design of geometry and materials enables the foam expansion force to actively "avoid" the injection hole, realizing directional expansion and internal stress diversion. Figure 1 As shown, in the foam filling layer 4, the rigid positioning edge 302 and the flexible positioning edge 303 together form an expansion stress guide system.

[0054] Among them, after the foam glue is injected, its volume expands in the direction indicated by the arrow. The initial expansion force is buffered and absorbed by the flexible positioning edge 303, avoiding the stress impact from being concentrated on the injection positioning part 301 and destroying the solidified sealing structure of the injection hole 3011. Then the main stress is guided to the rigid positioning edge 302 and terminated and closed, thereby achieving controllable stress path, stable interface and reliable structure.

[0055] An injection hole 3011 is provided at the center of the injection positioning piece 301 of each space frame bracket 3, and a composite path of quantitative foam introduction + local buffering + stress back expansion is constructed by combining the pressure limiting cavity and the flexible sealing mechanism.

[0056] In summary, the honeycomb core edge area is first roughened to form a microstructure-enhanced roughened layer 1. A functional coating 2 composed of a coupling agent or block polymer is then applied to the surface of the roughened layer 1. After the functional coating 2 is completed and naturally dried, a space frame support 3 is installed to ensure a continuous and complete interface, avoiding coating loss due to structural obstruction during the spraying process. This ensures the chemical reaction coverage and bonding uniformity of the subsequent foaming adhesive. The foaming adhesive should be injected while the functional coating 2 is still within its reaction window (e.g., before aging or moisture absorption failure) to ensure that the terminal isocyanate groups can effectively cross-link with the hydroxyl / amino reactive end groups in the functional coating, forming a strong chemical bond interface. During the filling of the foaming adhesive filling layer 4, the foaming adhesive expands directionally within the physical confines of the space frame support 3, forming a continuous adhesion with the functional coating. The injection hole is sealed by a pressure-limiting cavity and a sealing plate structure, thereby improving the stability of the injection and the service reliability of the edge structure. The process flow must be strictly executed in the above order to ensure the consistency of multi-interface linkage reaction, the rationality of structural stress distribution and the integrity of the filling area, and supplemented by injection path control and interface protection measures to achieve the best use effect.

[0057] The functional coating 2 and the foamed rubber undergo a chemical crosslinking reaction between isocyanate and hydroxyl / amino functional groups, forming a primary interface bonding structure, thereby enhancing the chemical adhesion between the foamed rubber filling layer 4 and the honeycomb core. The buffer transition layer 5 is a thermo-softening or UV-responsive elastic membrane, separated from the foamed rubber filling layer 4 by a space frame 3.

[0058] The buffer transition layer 5, located between the plastic shell and the outermost space frame support 3, comprises a flexible buffer membrane with a moderate elastic modulus, serving as an "elastic transition zone" between the honeycomb core and the foam. This layer mitigates interfacial stress concentration caused by thermal expansion and contraction, as well as fatigue loading, delaying crack initiation and propagation and improving the fatigue life of the interface under cyclic loading. This layer can be selectively filled with flexible buffer material or low-density foam as needed, or it can serve as an unfilled flexible deformation buffer zone to absorb structural micro-displacements and interfacial stresses caused by thermal expansion and contraction, dynamic loading, and so on.

[0059] The flexible buffer film can be a UV-responsive TPU or acrylate modified film material, the surface of which is plasma activated or pre-coated with an initiation layer to provide free radical initiation grafting sites, facilitating free radical-assisted grafting bonding between the active groups in the functional coating and the boundary of the film material. Further explanation: To achieve a long-term bond between the foam and the honeycomb structure interface, the foam components used in the foam filling layer 4, the interface functional coating 2, and the buffer transition layer 5 complete their respective reactions or bonding processes under unified temperature control or UV excitation conditions, thereby constructing a multi-layer composite structure interface system with structural continuity, adhesion stability, and service coordination. The acquisition logic of the multi-layer composite structure interface system is as follows: Steps to build the main reaction interface: A functional coating is provided between the honeycomb core material and the foam filling layer, wherein the functional coating contains functional groups capable of undergoing addition reaction with isocyanate groups (-NCO) in the foam, wherein the functional groups include hydroxyl groups (-OH) or amino groups (-NH2), and are used to form a main chemical bonding interface of a polyurethane or urea structure during the expansion process of the foam; Auxiliary grafting treatment steps: The buffer transition layer 5 is treated with plasma activation or coated with a photosensitive initiation layer to enhance the free radical affinity and form a surface-level mosaic with the uncured surface of the foam under ultraviolet irradiation conditions; The buffer transition layer 5, disposed between the foam filling layer 4 and the plastic shell, is a thermo-softening or UV-responsive elastic film, such as a modified TPU film or acrylic film. After the foam has expanded, the buffer transition layer forms a localized physical adhesion interface with the plastic shell and / or the upper surface of the outermost space frame support 3 through thermal bonding or surface-assisted grafting. This layer achieves a closed, encapsulating, and stress-buffering effect through structural compression and partial surface activation. To enhance adhesion reliability, the flexible buffer film material can be plasma-activated or coated with a photosensitive initiation layer to increase its free radical affinity, allowing it to form a surface-level bond with the uncured areas of the foam surface under UV irradiation.

[0060] Synchronous excitation curing steps: The functional coating 2, the foaming glue and the buffer transition layer 5 are processed simultaneously under uniform temperature control conditions (75±5°C) or ultraviolet excitation conditions to complete the following processes in sequence: a foam completes volume expansion and cross-linking reaction with the functional coating 2; b buffer transition layer 5 completes thermal softening deformation and attached to the surface of the plastic housing or the outermost space frame bracket 3; c. The cavity structure is completely closed and cooled and solidified to form a multi-layer composite structure with dimensional stability and interface durability; Functional layer collaborative system: In the constructed multi-layer composite interface system: a. The functional coating 2 serves as the main reaction interface, providing chemical adhesion between the honeycomb core material and the foam; b The foam filling layer 4 as the structural load-bearing core, filling and strengthening the edge structure; c. The buffer transition layer 5 serves as a stress buffer and edge protection layer, which is used to absorb the interface stress concentration caused by heat-load and improve the fatigue life and anti-peeling performance of the edge structure.

[0061] Example 2 like Figure 6 As shown, based on Example 1, this embodiment provides a filling method for a honeycomb edge reinforcement structure based on foam filling, comprising the following steps: S1: Based on the preset honeycomb structure finite element model, the partition boundary information of the target cavity is extracted, the injection path planning coordinate system is established, the injection point position and injection direction vector of the injection nozzle are determined, and the corresponding foam density parameters are matched for subsequent precise control of the filling process; Specifically, the logic for obtaining the partition boundary information is as follows: Based on the preset finite element analysis model of the honeycomb edge reinforcement structure, a structural grid model is established for the honeycomb core material, the space frame support 3, and the foam filling layer 4. The material properties of each area are annotated and the stress-displacement response data is extracted. According to the stress-displacement response data, the normal stress area and the concentrated stress area in the honeycomb structure are identified, and the corresponding foam filling layer 4 is marked as the target cavity; The spatial distribution boundary of each target cavity is extracted, wherein the boundary information includes the geometric area shape enclosed by the spatial framework support 3, the stress bearing capacity and the expected filling volume parameters.

[0062] S2: The glue injection nozzle performs a directional, speed-adjustable, and duration-adjustable foam injection operation into the target cavity based on the injection point location and partition boundary information. During the injection process, the nozzle posture and injection parameters are automatically adjusted according to the compliance matrix and stress gradient direction in the target cavity. Specifically, the glue injection nozzle performs a local foam injection operation on the target cavity according to the injection point position obtained in step A1; at the same time, the injection direction, injection rate and injection duration of the glue injection nozzle are dynamically adjusted according to the partition boundary shape and path length to achieve directional expansion, uniform filling and stress balance control of the foam in the cavity.

[0063] The adjustment logic of the nozzle posture and injection parameters: The gradient direction vector is calculated based on the stress field, and the nozzle rotation angle is set so that the injection direction forms an angle θ with the stress gradient direction. The angle is between 10° and 30°, and a posture tolerance of ±15° is set to adapt to the assembly error of the honeycomb structure. It should be noted that the current target cavity stress distribution field is extracted from the finite element model , calculate the stress change rate based on the stress distribution field, mark the direction with the largest stress change rate as the stress gradient direction, and set the rotation angle of the injection nozzle according to the stress gradient direction, so that the colloid expansion path is extended as far as possible along the stress gradient direction or at a safe angle of less than 30 degrees with it, so as to reduce the structural interference of stress-sensitive areas and improve the consistency of injection and local strength stability; The glue injection nozzle automatically adjusts the injection angle through the multi-degree-of-freedom robotic arm , so that the injection direction and the stress gradient direction form a safe angle , mark the injection angle as the target injection direction, and adjust the injection path along the structural stress gradient direction to improve filling uniformity; It should be noted that the safety angle is the angle between the injection direction and the stress gradient direction, and this angle is preferably between 10 and 30 degrees. Specifically, the safety angle sets a reference value based on simulation results. In actual application, the attitude is adaptively adjusted based on the assembly and fit between the honeycomb core, plastic shell, and injection molding locator. The injection nozzle is installed in the injection molding locator, allowing the injection attitude to be adjusted within a first adjustment angle range to automatically or manually align the injection direction with the optimal local boundary deviation. An operational tolerance of ±15 degrees is allowed to ensure that the injection path is controlled as a whole and adapts to manufacturing deviations.

[0064] Based on the honeycomb unit flexibility matrix The compliance value of each target cavity in the injection is combined with the basic injection rate , the real-time injection rate is obtained by modifying the velocity function model; It should be noted that: the greater the compliance value in the target cavity, the smaller the corresponding stiffness of the target cavity, which is more suitable for low-speed injection to avoid structural stress concentration caused by colloid impact; the smaller the compliance value in the target cavity, the greater the corresponding stiffness of the target cavity, which allows high-speed advancement and improves injection efficiency. The velocity function model is: ; in: The real-time injection rate corresponding to the target cavity injection position; is the basic injection rate corresponding to the target cavity injection position, is the reference compliance constant of the target cavity; For the The compliance of the target cavity: The adjustment coefficient is 0.5~1.

[0065] Further explanation: The real-time injection rate is adjusted based on the basic formula of the basic injection rate, and nonlinear correction is performed in combination with the stress gradient change rate in the target cavity and the real-time injection feedback state, thereby achieving dynamic adjustment and extracting the updated real-time injection rate; The formula is added as an example to construct the control function:

[0066] in: Indicates the local stress gradient modulus. When it is too large, it represents a structural stress mutation area. The resistance feedback value monitored in real time during the injection process; the coefficient 、 and is a regulating factor that controls the response strength of the injection rate to non-structural disturbances; The above control mechanism enables the injection rate to be automatically adjusted under the triple mechanism of structure dominance, gradient feedback and real-time expansion feedback, thereby achieving steady-state injection and structural adaptive matching.

[0067] Injection duration through target volume With real-time injection rate The integral is calculated and the injection operation is automatically terminated in a closed loop after the filling volume threshold is reached.

[0068] S3: After the foaming glue is injected, the interface reaction between the foaming glue and the functional coating, the volume expansion and shaping of the colloid, and the thermal attachment process of the flexible buffer film are driven in sequence under a uniformly controlled temperature or UV excitation environment to construct a multi-layer composite structure interface system.

[0069] Specifically, the acquisition logic of the multi-layer composite structure interface system is: The coupling component in the functional coating 2 reacts with the isocyanate group (–NCO) in the foaming glue and the hydroxyl / amino groups to form a polyurethane or urea network, forming the main chemical bonding interface between the honeycomb core material and the filling layer; The buffer transition layer 5 is composed of an elastic film material with heat-softening or UV-responsive properties, and forms an adhesive coating interface with the upper surface of the foamed adhesive through structural pressing, UV light activation or free radical-assisted grafting; The buffer transition layer 5, disposed between the foam filling layer 4 and the plastic shell, is a thermo-softening or UV-responsive elastic film, such as a modified TPU film or acrylic film. After the foam has expanded, the buffer transition layer forms a localized physical adhesion interface with the plastic shell and / or the upper surface of the outermost space frame support 3 through thermal bonding or surface-assisted grafting. This layer achieves a closed, encapsulating, and stress-buffering effect through structural compression and partial surface activation. To enhance adhesion reliability, the flexible buffer film material can be plasma-activated or coated with a photosensitive initiation layer to increase its free radical affinity, allowing it to form a surface-level bond with the uncured areas of the foam surface under UV irradiation.

[0070] The multi-interface linkage response is carried out synchronously at 75±5°C or under specified excitation conditions to form a triple structure: a main reaction interface, a stress-absorbing colloid, and a buffer coating layer, providing honeycomb edge stability and multi-cycle load fatigue adaptability.

[0071] The three layers of material are processed simultaneously under the same temperature control (e.g. 75±5°C) or UV excitation conditions to complete the following processes respectively: The foam completes volume expansion and reacts with the functional coating 2; the flexible buffer film completes thermal softening deformation and adhesion; the cavity is completely sealed and formed and cooled and solidified to form a composite edge structure with good dimensional stability and multi-interface durability.

[0072] In the multi-layer composite structure interface system thus constructed: Functional coatings construct the main reaction interface; The foamed rubber constructs the structural load-bearing core; Flexible buffer film constructs stress buffer + edge sealing protection functional layer; In summary, the various structures of this embodiment have clear functional division of labor, are synchronously stimulated in process response, and cooperate in a heat-load environment, significantly improving the fatigue durability, interface anti-peeling performance and edge connection reliability of the honeycomb structure.

[0073] A honeycomb edge reinforcement structure based on foam filling provided in an embodiment of the present invention is used to execute a filling method of a honeycomb edge reinforcement structure based on foam filling provided in the above-mentioned embodiments of the present invention. The specific methods and processes for realizing corresponding functions of each structure included in the honeycomb edge reinforcement structure based on foam filling are detailed in the embodiment of the above-mentioned filling method of a honeycomb edge reinforcement structure based on foam filling, and will not be repeated here.

[0074] The above description is merely illustrative of certain exemplary embodiments of the present invention. It goes without saying that those skilled in the art will be able to modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and description are illustrative in nature and should not be construed as limiting the scope of protection of the claims.

Claims

1. A honeycomb edge reinforcement structure based on foam filling, arranged between the honeycomb core material and the plastic shell, with the position of the plastic shell relative to the honeycomb core material as the outer side, characterized in that: include: A roughened layer (1) is provided on the outer surface of the honeycomb core material facing the plastic shell and has grooves; A functional coating (2) covering the outer surface of the roughened layer (1) includes a coupling agent and / or a block polymer that undergoes a cross-linking reaction with the roughened layer (1) and the foamed rubber filling layer (4); At least one space frame support (3), a plurality of foamed rubber filled cavity areas are formed based on the space frame support (3), and a space frame support (3) is provided on the top of each filled cavity area; the space frame support (3) comprises: at least one injection hole (3011); The injection molding positioning member (301) comprises an injection molding hole (3011) for defining the injection position of the foam glue, wherein the injection molding holes (3011) are arranged coaxially through the honeycomb thickness direction and are distributed in a staggered array in the plane direction to form a non-overlapping arrangement structure of the glue injection path; a pressure limiting cavity (3013) and a flexible sealing sheet (3014) are provided below each injection molding hole (3011), and the flexible sealing sheet (3014) seals the injection molding hole after the glue expands to form a self-sealing structure; A flexible positioning edge (303) for connecting the injection molded positioning piece (301) and the rigid positioning edge (302); The rigid positioning edge (302) and the flexible positioning edge (303) together enclose a cavity filling area; The foamed rubber filled in the filling cavity area constitutes a foamed rubber filling layer (4); A buffer transition layer (5) is provided between the plastic shell and the outermost space frame support (3), and a flexible buffer membrane with an elastic modulus is provided as a transition section between the foam rubber and the plastic shell; The foaming rubber components used in the foaming rubber filling layer (4), the interface functional coating (2) and the buffer transition layer (5) respectively complete their respective reactions or bonding processes under uniform temperature control or ultraviolet excitation conditions to construct a multi-layer composite structure interface system.

2. The honeycomb edge reinforcement structure based on foam filling according to claim 1, characterized in that: The injection molding positioning member (301) also includes: A supporting anchoring structure (3012), arranged on the periphery of the injection hole (3011) and used for fixing the injection hole (3011); A pressure-limiting mechanical engaging part is provided in the pressure-limiting cavity (3013), and under the action of the pressure-limiting mechanical engaging part, the flexible sealing sheet (3014) is pressed onto the injection hole (3011), forming a self-sealing structure.

3. The honeycomb edge reinforcement structure based on foam filling according to claim 1, characterized in that: The setting logic of the space frame support (3) is: Step A1: constructing a finite element model for the honeycomb edge reinforcement structure to obtain boundary conditions; the boundary conditions include honeycomb edge constraint conditions, foam expansion load constraint conditions, and plastic shell external load constraint conditions; Step A2, performing a custom mesh discretization process on the honeycomb edge reinforcement structure, wherein the filling cavity area corresponding to the foam filling layer (4) is subjected to a local mesh encryption process to generate structural discrete units, and marking material properties of each structural discrete unit; Step A3: Based on the boundary conditions established in step A1 and the mesh model and material property annotations generated in step A2, a static finite element method is performed on the honeycomb edge reinforcement structure to obtain the node stress response and displacement distribution of the structure under the combined action of the foam expansion internal pressure and the external load, and a stress-displacement mapping relationship of the honeycomb structure is established; Step A4: Based on the node stress response obtained by solving step A3, perform eigenvalue processing on the honeycomb structure stiffness matrix to obtain the honeycomb unit flexibility matrix and calculate the response sensitivity of each discrete unit of the structure; Step A5: dividing the normal stress area and the concentrated stress area based on the sensitivity threshold; A plurality of space frame supports (3) are arranged in the concentrated stress area and filled with high-density foam glue, and a space frame support (3) is arranged on the periphery of the normal stress area and filled with low-density foam glue.

4. The honeycomb edge reinforcement structure based on foam filling according to claim 3, characterized in that: The wall thickness and area of ​​the concentrated stress area are analyzed to calculate the number of space frame brackets (3) required.

5. The honeycomb edge reinforcement structure based on foam filling according to claim 4, characterized in that: The logic for obtaining the position of the injection hole (3011) is: Determining the number of space frame supports (3) based on an arrangement scheme of the space frame supports (3), wherein the space frame supports (3) are a multi-layer stacked structure in a honeycomb thickness direction; Based on the honeycomb structure stiffness matrix, eigenvalue decomposition is performed to extract the main modal direction vector and determine the main axis of the injection path and the arrangement direction of the injection hole (3011); Establish a foaming expansion response model and simulate the colloid expansion path, local deformation, and stress concentration distribution under multiple injection points. Calculate the deformation field stability coefficient under different injection point layout conditions, and select the group of points with the lowest stability coefficient as the injection hole layout location. Based on the multi-stage inverse finite element analysis framework, the objective function of minimizing the total strain energy of the honeycomb structure is constructed. Combined with the stiffness matrix constraints and the loading boundary, the injection point layout problem is inversely solved to obtain the injection position set. The optimal solution is used for the layout of the injection holes (3011) to form an ordered array of injection introduction points.

6. The honeycomb edge reinforcement structure based on foam filling according to claim 5, characterized in that: The process of obtaining the structural response through the foaming expansion response model includes: Input the foam density, expansion ratio and injection point location; Establish the colloid volume growth function and boundary force propagation function; Calculate the diffusion paths of different colloid fillings using a path tracking algorithm; Obtain the maximum displacement and peak stress of the structure node under each injection path.

7. The honeycomb edge reinforcement structure based on foam filling according to claim 6, characterized in that: The acquisition logic of the multi-layer composite structure interface system is: forming a roughening layer (1) on the surface of the honeycomb core material and applying a functional coating (2), wherein the functional coating serves as a main reaction interface and provides chemical adhesion between the honeycomb core material and the foaming adhesive; A space frame support (3) is installed, and foam glue is injected through the injection hole (3011), the foam glue serving as the structural load-bearing core to fill and strengthen the edge structure; a foam glue filling layer (4) is formed by directionally expanding under the confinement of the space frame support (3); a buffer transition layer (5) is provided between the foam glue filling layer (4) and the plastic shell as a stress buffer and edge sealing protection functional layer for absorbing the interface stress concentration caused by heat-load; The buffer transition layer (5) is an elastic film material with thermal softening or ultraviolet response performance. The buffer transition layer (5) is subjected to plasma activation treatment or surface coating with a photosensitive initiation layer, and forms a surface-level interlocking with the surface of the foam that is not completely cured under ultraviolet irradiation conditions; The functional coating, foam and buffer transition layer are processed synchronously under uniformly controlled temperature control conditions or ultraviolet excitation conditions, and the interface reaction between the functional coating and the foam, the volume expansion and shaping of the foam and the attachment of the buffer film are completed in sequence to form a multi-layer composite structure interface system.

8. A filling method for a honeycomb edge reinforcement structure based on foam filling, used for designing a honeycomb edge reinforcement structure based on foam filling as claimed in any one of claims 1 to 7, characterized in that: The following steps are involved: S1: Based on the preset honeycomb structure finite element model, the partition boundary information of the target cavity is extracted, the injection path planning coordinate system is established, the injection point position and injection direction vector of the injection nozzle are determined, and the corresponding foam density parameters are matched for subsequent precise control of the filling process; S2: The glue injection nozzle performs a directional, speed-adjustable, and duration-adjustable foam injection operation into the target cavity based on the injection point location and partition boundary information. During the injection process, the nozzle posture and injection parameters are automatically adjusted according to the compliance matrix and stress gradient direction in the target cavity. S3: After the foaming glue is injected, the interface reaction between the foaming glue and the functional coating, the volume expansion and shaping of the colloid, and the thermal attachment process of the flexible buffer film are driven in sequence under a uniformly controlled temperature or UV excitation environment to construct a multi-layer composite structure interface system.

9. The filling method of the honeycomb edge reinforcement structure based on foam filling according to claim 8, characterized in that: The logic for obtaining the partition boundary information: Based on the preset finite element analysis model of the honeycomb edge reinforcement structure, a structural grid model is established for the honeycomb core material, the space frame bracket (3) and the foam filling layer (4), the material properties of each area are marked and the stress-displacement response data are extracted; According to the stress-displacement response data, the normal stress area and the concentrated stress area in the honeycomb structure are identified, and the corresponding foam filling layer (4) is marked as the target cavity; The spatial distribution boundary of each target cavity is extracted, wherein the boundary information includes the geometric area shape enclosed by the spatial structure support (3), the stress bearing capacity and the expected filling volume parameters.

10. The filling method of the honeycomb edge reinforcement structure based on foam filling according to claim 9, characterized in that: The injection parameters include injection direction, real-time injection rate and injection duration; the adjustment logic of the nozzle posture and injection parameters: The stress gradient direction vector is calculated based on the stress field corresponding to the target cavity, and the rotation angle of the injection nozzle is set so that the injection direction forms an angle of 10° to 30° with the stress gradient direction to achieve stress-guided filling path planning; In order to adapt to the assembly deviation of the honeycomb structure, the injection direction is set with a posture tolerance of ±15°; The real-time injection rate takes the basic injection rate as the initial value and is corrected in combination with the target cavity flexibility value to form a real-time injection rate associated with the flexibility. The injection time is calculated by integrating the target injection volume and the real-time injection rate. When the injection volume reaches the preset threshold, the injection operation is automatically terminated in a closed loop.

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