Cultural relic building reduced scale model reproduction method based on ancient mortise and tenon joint structure and 3D printing

Abstract

The invention relates to a cultural relic building reduced scale model reproduction method based on an ancient tenon-and-mortise structure and 3D printing, and the method comprises the steps: S1, three-dimensional data collection: scanning a cultural relic building entity through a three-dimensional scanner, and obtaining three-dimensional point cloud data; s2, dismantling and parametric modeling: processing the three-dimensional point cloud data, dismantling the whole model of the cultural relic building, constructing a standard beam component library, a standard column component library, a beam-beam, beam-column and column-column mortise and tenon joint node library according to a standard modulus, and constructing a model library of other parts of the cultural relic building; s3, reduced scale proportion 3D printing is conducted, specifically, the three-dimensional models of all the parts in the model library are scaled according to the reduced scale proportion, slicing processing is conducted, and all the parts of the cultural relic building model are printed in batches; and S4, assembly and verification: carrying out structure assembly, finally forming an overall reduced scale model, and finally verifying the structure stability. The device has the advantages of being stable in structure, high in detail reduction degree and high in manufacturing efficiency.

Description

Technical Field

[0001] This invention relates to the field of architectural technology, and more specifically, to a method for reproducing scaled-down models of cultural relics and buildings based on ancient mortise and tenon structures and 3D printing. Background Technology

[0002] Heritage buildings (including ancient and modern wooden and brick-and-stone structures) are important carriers of cultural heritage, but they are susceptible to natural weathering and human damage, leading to structural damage or paint fading. Heritage building restoration is the material reconstruction of cultural relics and historical sites that have been lost or severely damaged, including forms such as restoration, reconstruction, and restoration. This process is not only about restoring the physical structure but also about inheriting historical context and cultural value.

[0003] Many of my country's historical buildings were constructed using mortise and tenon joinery techniques. Replicating these buildings using traditional methods is a labor-intensive and challenging task. Therefore, how to combine traditional mortise and tenon joinery with modern manufacturing technology to achieve efficient and high-precision reproduction of scaled-down models of historical buildings has become an urgent technical problem to be solved. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a method for replicating scaled-down models of cultural relics and buildings based on ancient mortise and tenon structures and 3D printing, which has the advantages of structural stability, high detail reproduction, and high production efficiency.

[0005] The above-mentioned technical objective of the present invention is achieved through the following technical solution: A method for reproducing scaled-down models of cultural relics and buildings based on ancient mortise and tenon structures and 3D printing includes the following steps: S1. 3D Data Acquisition: Use a 3D scanner to scan the cultural relic building entity, obtain 3D point cloud data, simultaneously acquire appearance color information, extract key components of the building, and mark the mortise and tenon joints with marker points. S2. Disassembly and Parametric Modeling: The 3D point cloud data is processed, and 3D reverse engineering software is used to preprocess the 3D scanned data to obtain an overall 3D model containing size and appearance color information. The overall model of the cultural relic building is disassembled using 3D modeling software. A standard beam component library, a standard column component library, and a beam-beam, beam-column, and column-column mortise and tenon node library are constructed according to the standard module. A model library for the remaining components of the cultural relic building is also constructed. The mortise and tenon nodes obtained from the scan are disassembled to construct a mortise and tenon node model library. Each model in each model library contains color information, and each component in each model library is designed with tenon and mortise interfaces that can be connected by mortise and tenon joints. The corresponding mortise size is slightly smaller than the tenon size. S3. Scaled-down 3D printing: According to the actual size of the cultural relic building and the required size of the building model, the three-dimensional models of each component built according to the standard module in the model library are scaled down and sliced. Multi-color 3D printers are used to print each component of the cultural relic building model in batches. S4. Assembly and Verification: Assemble the overall architectural model from bottom to top, from inside to outside, and from components to the whole. Reinforce key nodes to enhance structural stability. Finally, verify the structural stability.

[0006] In one embodiment, in step S1, the key components include one or more of the following: brackets, columns, beams, beam-beam mortise and tenon joints, column-column mortise and tenon joints, and beam-column mortise and tenon joints.

[0007] In one embodiment, in step S1, the spatial coordinates of the tenon joints of the tenon and the bracket tenon, as well as the beam-beam tenon joints, column-column tenon joints, and beam-column tenon joints are marked.

[0008] In one embodiment, in step S2, point cloud data is imported into 3D software to obtain a preliminary 3D model. Based on surveying work, the model is used to accurately measure the dimensions and / or to construct the dimensions of the cultural relic building based on physical photographs using a scale. The physical photographs of the model must include at least 8 detailed drawings of the components from different angles, and the drawings include a scale.

[0009] In one embodiment, in step S2, the components are designed using parametric design, and each component is designed with tenons and mortises that can be connected by tenon and mortise. The beam component can be installed on the mortises provided on the column component, the upper column component can be installed on the mortises of the lower column component through tenons, and the bracket component can be installed on the mortises of the upper column component through tenons.

[0010] In one embodiment, during step S2, when building the model, the edges of the roof tile components are designed with interlocking snap-fit ​​structures, and the overlap length of adjacent tiles is 1 / 4 of the tile width, to simulate the traditional tile overlapping effect.

[0011] In one embodiment, in step S2, the structure is designed for integrity, and the remaining components (including walls, doors, windows, roof, floors, etc.) are reliably connected to the structure formed by the beam and column components.

[0012] In step S3, the parametric models of different parts are sliced ​​and arranged in a reasonable manner for batch printing to improve production efficiency. Color information is collected by 3D scanning to select multi-color printing materials. For parts with mechanical performance requirements, one or both PLA and PETG can be used. For parts that need to represent details in a refined manner, photocurable materials can be used.

[0013] In one embodiment, in step S3, when printing components, printing efficiency and material utilization are considered. The parametric models of different components are divided into slices and arranged in a reasonable manner for batch printing.

[0014] In one embodiment, in step S3, the printing material is selected as needed. For parts with mechanical performance requirements, one or both of PLA and PETG can be used. For parts that require fine detail representation, a photocurable material can be used.

[0015] In one embodiment, in step S3, FDM printing is used, with a layer thickness of 0.1-0.2.

[0016] In one embodiment, in step S4, when assembling the mortise and tenon joint, a slight external force is applied to make the tenon and mortise tightly connected based on an interference fit, or by heating / cooling, the mortise and tenon joint is locally heated with a hot air gun to soften it, and then quickly cooled after being inserted to achieve a reinforced assembly effect.

[0017] In one embodiment, in step S2, the overall three-dimensional model obtained after disassembly is processed for geometric modeling and mesh generation, and then mechanical performance is verified using general finite element analysis software to perform preliminary calculations on the overall structural stiffness, stability, etc.

[0018] In one embodiment, in step S4, after the structural assembly is completed, counterweight loads are simulated in all directions on the scaled-down model to check the maximum deformation of the model. If the mortise and tenon joints are found to be loose or broken, it indicates that the structure is stable.

[0019] In summary, the present invention has the following beneficial effects: Structural fidelity: This invention can fully reproduce the mechanical characteristics of mortise and tenon joints that are "detachable and have clear force transmission". By using parametric modeling and multiphysics simulation to predict problems in advance, it can achieve performance-driven design in combination with actual conditions, reduce construction risks and costs, and improve sustainability and cross-disciplinary collaborative efficiency. Efficiency Improvement: Compared with traditional manual production, this invention allows for batch production and improves reproducibility. Cost reduction: The PLA / PETG material used in this invention has a relatively lower cost compared to traditional processes.

[0020] Color synchronization: This invention uses multi-color printing without post-processing, and the visual color reproduction meets the needs of cultural relic display.

[0021] Detail reproduction: This invention uses multi-color printing to meet display requirements for color reproduction, and adopts interference fit with no gaps, resulting in high precision of decorative components. Attached Figure Description

[0022] Figure 1 This is a flowchart of the present invention. Detailed Implementation

[0023] The present invention will now be described in detail with reference to the embodiments.

[0024] It is worth noting that the directional terms such as "up" and "down" used in this article are all relative to the perspective of the attached figures and are only for the purpose of description. They should not be interpreted as limitations on the technical solutions.

[0025] like Figure 1 As shown, this invention proposes a method for reproducing scaled-down models of cultural relics and buildings based on ancient mortise and tenon structures and 3D printing, including the following steps: S1. 3D Data Acquisition: Using a 3D scanner to scan the cultural relic building entity, obtain 3D point cloud data, simultaneously acquire appearance color information, extract key components of the building, and mark the spatial coordinates of mortise and tenon joints. S2. Disassembly and Parametric Modeling: The 3D point cloud data is processed, and 3D reverse engineering software is used to preprocess the 3D scan data to obtain a preliminary overall 3D model containing detailed dimensions and appearance color information. Then, the overall model of the cultural relic building is disassembled using 3D modeling software. Standard beam component library, standard column component library, beam-beam, beam-column, and column-column mortise and tenon node library are constructed according to standard modules. Model library of other components of the cultural relic building is constructed. The mortise and tenon nodes obtained from scanning are disassembled to construct mortise and tenon node model library. Each model in each model library contains color information, and each component in each model library is designed with tenon and mortise interfaces that can be connected by mortise and tenon joints. The corresponding mortise size is slightly smaller than the tenon size. S3. Scaled-down 3D printing: According to the actual size of the cultural relic building and the required size of the building model, the three-dimensional models of each component built according to the standard module in the model library are scaled down and sliced. Multi-color 3D printers are used to print each component of the cultural relic building model in batches. S4. Assemble the architectural model from bottom to top, from inside to outside, and from components to the whole. Reinforce key nodes to enhance structural stability. Finally, verify the structural stability.

[0026] In step S1, historical photographs are also used to assist in 3D modeling. Specifically, photographs of the exterior of the historical building are simultaneously obtained through scanning, and key components such as beams, columns, and joints are extracted. Alternatively, historical photographs can be used to assist in 3D modeling when there is no physical historical building.

[0027] Furthermore, in step S1, the key components include one or more of the following: brackets, columns, beams, beam-beam mortise and tenon joints, column-column mortise and tenon joints, and beam-column mortise and tenon joints.

[0028] Furthermore, in step S1, the spatial coordinates of the tenon joints of the pipe tenon and the bracket tenon, as well as the beam-beam tenon joint, column-column tenon joint, and beam-column tenon joint are marked.

[0029] Furthermore, in step S2, the point cloud data is imported into 3D reverse engineering software for processing to obtain a preliminary overall three-dimensional model. The surveying work based on the actual cultural relics and buildings is used to accurately measure the size data of each component and / or to construct the size data of the cultural relics and buildings based on the scale through photographs of the actual objects. The photographs of the actual objects used for the model must include detailed drawings of the components at different angles of the scale.

[0030] Furthermore, in step S2, in the scaled-down 3D model, the connection method of the components is an interference fit.

[0031] Furthermore, in step S2, the overall three-dimensional model is further decomposed according to the structural composition and the resulting parametric components are all designed with tenons and mortises that can be connected by tenon and mortise. Different components can be tightly connected. Beam components can be installed on the mortises set on the column components. Upper column components can be installed on the mortises of lower column components through tenons. Bracket components can be installed on the mortises of upper column components through tenons. The edges of the roof tile components are designed with interlocking snap-fit ​​structures. The overlap length of adjacent tiles is 1 / 4 of the tile width to simulate the traditional tile overlapping effect and reliably overlap with the beam components. The remaining components are reliably overlapped with the structure formed by the beam and column components.

[0032] The overall three-dimensional model obtained after disassembly is processed for geometric modeling and mesh generation. Then, general-purpose finite element analysis software is used to verify its mechanical properties and calculate the stiffness and stability of the overall structure.

[0033] In step S2, the model colors are preset using the color rendering function of the modeling software. After being exported to the slicing software, the printer automatically matches the pigments to complete multi-color synchronous printing, eliminating the need for manual coloring later.

[0034] Furthermore, in step S3, the printing materials include PLA and PETG. PLA has relatively low temperature requirements, while PETG has higher temperature requirements and better stability.

[0035] Furthermore, in step S3, FDM printing is used for parts with mechanical performance requirements, while photopolymer 3D printing is used for refined parts. The FDM printing process uses a layer thickness of 0.1-0.2 mm.

[0036] Specifically, in step S3, the parametric models of different parts are sliced ​​and arranged in a reasonable manner for batch printing to improve production efficiency. Color information is collected by 3D scanning to select multi-color printing materials. For parts with mechanical performance requirements, one or both PLA and PETG can be used. For parts that need to represent details in a refined manner, photocurable materials can be used.

[0037] In step S4, the structure is assembled from top to bottom and from inside to outside, forming beam components, column components, and beam-column components, ultimately creating a scaled-down model. Simultaneously, stability enhancements are embedded at key nodes, and the structural stability is verified. This invention offers advantages such as structural stability, high detail fidelity, and high manufacturing efficiency.

[0038] Furthermore, in step S4, when assembling the mortise and tenon joint, external force is applied to make the tenon and mortise tightly connected based on interference fit, or by heating / cooling, the mortise and tenon joint is locally heated with a hot air gun to soften it, and then quickly cooled after insertion to achieve a reinforced assembly effect.

[0039] Furthermore, in step S4, counterweight loads are simulated and applied in all directions on the scaled-down model to check the maximum deformation of the model and to check that there is no loosening or breakage of the mortise and tenon joints, indicating that the structure is stable.

[0040] The technical solution of the present invention will be described below with reference to specific embodiments.

[0041] A method for reproducing scaled-down models of cultural relics and buildings based on ancient mortise and tenon structures and 3D printing specifically includes: S1. 3D Data Acquisition: Using a 3D scanner to scan the cultural relic building entity, obtain 3D point cloud data, simultaneously acquire appearance color information, perform detailed scanning of key building components, and mark the mortise and tenon joints with marker points. S2. Disassembly and Parametric Modeling: The 3D point cloud data is processed, and 3D reverse engineering software is used to preprocess the 3D scan data to obtain a preliminary overall 3D model containing detailed dimensions and appearance color information. Then, the overall model of the cultural relic building is disassembled using 3D modeling software. Standard beam component library, standard column component library, beam-beam, beam-column, and column-column mortise and tenon node library are constructed according to standard modules. Model library of other components of the cultural relic building is constructed. The mortise and tenon nodes obtained from scanning are disassembled to construct mortise and tenon node model library. Each model in each model library contains color information, and each component in each model library is designed with tenon and mortise interfaces that can be connected by mortise and tenon joints. The corresponding mortise size is slightly smaller than the tenon size. S3. Scaled-down 3D printing: According to the actual size of the cultural relic building and the required size of the building model, the three-dimensional models of each component built according to the standard module in the model library are scaled down and sliced. Multi-color 3D printers are used to print each component of the cultural relic building model in batches. S4. Assembly and Verification: Assemble the architectural model from bottom to top, from inside to outside, and from components to the whole. Reinforce key nodes to enhance structural stability. Finally, verify the structural stability.

[0042] (a) Experimental materials, equipment and software Equipment: 3D scanner; 3D modeling software; 3D reverse engineering software; multi-color 3D printer; photopolymer 3D printer; Materials: PLA wire (multiple colors); PETG wire (multiple colors); photosensitive resin material (multiple colors).

[0043] (II) Detailed Steps Data acquisition: A 3D scan and photograph of a four-cornered pavilion were conducted to obtain information such as dimensions in eight directions.

[0044] Parametric modeling: A scale model is created in the modeling software. The dimensions can be obtained from point cloud data or photos taken from various directions. For example, for a four-cornered pavilion, the actual dimensions can be obtained from parameter point cloud data such as column height, total height of brackets, diameter and length of the designed tenon, and embedding depth in the base. 3D printing implementation: Example component slice parameters: layer thickness 0.20mm, printing speed about 200mm / s, support type "tree" (easy to remove, and with the smallest area of ​​separation from the model, resulting in relatively little impact on the model); Multi-color printing strategy: The color of each component can be changed during the printing process by setting the color of the model through the slicing software, or the component color can be preset directly in the modeling software; After printing, remove the support using pliers.

[0045] Assembly and testing: The numbered components can be set in advance; after installing columns, beams and other components to form the main structure, counterweights are applied in all directions (simulating actual loading conditions), static loading is performed, and the inter-story displacement of the structure is measured to see if it meets the design requirements.

[0046] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A method for reproducing scaled-down models of cultural relics and buildings based on ancient mortise and tenon structures and 3D printing, characterized in that, Includes the following steps: S1. 3D Data Acquisition: Using a 3D scanner to scan the cultural relic building entity, obtain 3D point cloud data, simultaneously acquire appearance color information, perform detailed scanning of key building components, and mark the mortise and tenon joints with marker points. S2. Disassembly and Parametric Modeling: The 3D point cloud data is processed, and 3D reverse engineering software is used to preprocess the 3D scan data to obtain a preliminary overall 3D model containing detailed dimensions and appearance color information. Then, the overall model of the cultural relic building is disassembled using 3D modeling software. Standard beam component library, standard column component library, beam-beam, beam-column, and column-column mortise and tenon node library are constructed according to standard modules. Model library of other components of the cultural relic building is constructed. The mortise and tenon nodes obtained from scanning are disassembled to construct mortise and tenon node model library. Each model in each model library contains color information, and each component in each model library is designed with tenon and mortise interfaces that can be connected by mortise and tenon joints. The corresponding mortise size is slightly smaller than the tenon size. S3. Scaled-down 3D printing: According to the actual size of the cultural relic building and the required size of the building model, the three-dimensional models of each component built according to the standard module in the model library are scaled down and sliced. Multi-color 3D printers are used to print each component of the cultural relic building model in batches. S4. Assembly and Verification: Assemble the architectural model from bottom to top, from inside to outside, and from components to the whole. Reinforce key nodes to enhance structural stability. Finally, verify the structural stability.

2. The method for reproducing scaled-down models of cultural relics and buildings based on ancient mortise and tenon structures and 3D printing as described in claim 1, characterized in that, In step S1, the key components include one or more of the following: brackets, columns, beams, beam-beam mortise and tenon joints, column-column mortise and tenon joints, and beam-column mortise and tenon joints.

3. The method for reproducing scaled models of cultural relics and buildings based on ancient mortise and tenon structures and 3D printing as described in claim 1, characterized in that, In step S1, the spatial coordinates of the tenon joints of the pipe tenon and the bracket tenon, as well as the beam-beam tenon joint, column-column tenon joint, and beam-column tenon joint are marked using marker points.

4. The method for reproducing scaled-down models of cultural relics and buildings based on ancient mortise and tenon structures and 3D printing as described in claim 1, characterized in that, In step S2, the point cloud data is imported into 3D reverse engineering software for processing to obtain a preliminary overall three-dimensional model. The surveying work based on the actual cultural relics and buildings is used to accurately measure the size data of each component and / or to construct the size data of the cultural relics and buildings based on the scale through photographs of the actual objects. The photographs of the actual objects used in the model should include detailed drawings of the components at different angles of the scale.

5. The method for reproducing scaled-down models of cultural relics and buildings based on ancient mortise and tenon structures and 3D printing as described in claim 4, characterized in that, In step S2, the overall three-dimensional model is further decomposed according to the structural composition and the resulting parametric components are all designed with tenons and mortises that can be connected by tenon and mortise. Different components can be tightly connected. Beam components can be installed on the mortises set on the column components. Upper column components can be installed on the mortises of lower column components through tenons. Bracket components can be installed on the mortises of upper column components through tenons. The edges of the roof tile components are designed with interlocking snap-fit ​​structures. The overlap length of adjacent tiles is 1 / 4 of the tile width to simulate the traditional tile overlapping effect and reliably overlap with the beam components. The remaining components are reliably overlapped with the structure formed by the beam and column components.

6. The method for reproducing scaled models of cultural relics and buildings based on ancient mortise and tenon structures and 3D printing as described in claim 1, characterized in that, In step S3, the parametric models of different parts are sliced ​​and arranged in a reasonable manner for batch printing to improve production efficiency. Color information is collected by 3D scanning to select multi-color printing materials. For parts with mechanical performance requirements, one or both PLA and PETG can be used. For parts that need to represent details in a refined manner, photocurable materials can be used.

7. The method for reproducing scaled models of cultural relics and buildings based on ancient mortise and tenon structures and 3D printing as described in claim 6, characterized in that, In step S3, FDM printing is used for parts with mechanical performance requirements, and photopolymerization 3D printing is used for fine parts.

8. The method for reproducing scaled models of cultural relics and buildings based on ancient mortise and tenon structures and 3D printing as described in claim 1, characterized in that, In step S4, when assembling the mortise and tenon joint, external force is applied to make the tenon and mortise tightly connected based on interference fit, or by heating / cooling, the mortise and tenon joint is locally heated with a hot air gun to soften it, and then quickly cooled after insertion to achieve a reinforced assembly effect.

9. The method for reproducing scaled models of cultural relics and buildings based on ancient mortise and tenon structures and 3D printing as described in claim 1, characterized in that, In step S2, the overall three-dimensional model obtained after disassembly is processed for geometric modeling and mesh generation, and then mechanical performance is verified using general finite element analysis software to calculate the stiffness and stability of the overall structure.

10. The method for reproducing scaled models of cultural relics and buildings based on ancient mortise and tenon structures and 3D printing as described in claim 1, characterized in that, In step S4, after the structural assembly is completed, counterweight loads are applied to the scaled-down model in various directions to check the maximum deformation of the model. The mortise and tenon joints are checked to ensure that there is no loosening or breakage, indicating that the structure is stable.

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