Grasshopper-based modeling method for complex curved surface curtain wall

Abstract

The application discloses a complex curved surface curtain wall modeling method based on Grasshopper, and relates to the technical field of building digital design and construction, and the method comprises the following steps: firstly, inputting the geometric size, load parameter, thermal expansion coefficient, material attribute and environmental parameter of the curtain wall to a parameterization platform at an input end to generate an original curtain wall model; then, performing topological optimization and geometric correction on the original curtain wall model through surface reconstruction to obtain a benchmark curtain wall model; performing mesh cutting on the benchmark surface based on a discrete differential geometry method, and calculating the size of a unit plate; constructing a structure system by using a finite element analysis module and the parameterization platform; according to the deformation characteristics of the glass plate and the installation component, parameterizing and adjusting the construction node to compensate for errors, optimize the planarization size of the unit plate and the cross-sectional size of the frame, and finally output construction data, so that the multi-parameter digital automatic linkage from design to construction of the complex curved surface curtain wall is realized, and the precision and efficiency of complex curtain wall modeling are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of digital design and construction of buildings, and particularly relates to a complex curved surface curtain wall modeling method based on Grasshopper. BACKGROUND

[0002] With the development of architectural design complexity, curved surface curtain wall gradually becomes an important trend in the design of modern building facades. Complex curved surface curtain wall not only meets the demand of design diversification in aesthetics, but also embodies the deep combination of structural mechanics, material science and computer-aided design. However, in the existing modeling and design process, the modeling method of complex curved surface curtain wall often relies on traditional three-dimensional modeling software to construct and modify the details of geometric shape; although this method can complete the modeling to a certain extent, it has great limitations for subsequent parameter modification and performance optimization.

[0003] At present, the widely used parametric modeling tool such as Grasshopper has been introduced into the curtain wall modeling process. Grasshopper enables designers to quickly establish geometric models and perform certain parameterized control on the models through node-based logical connection.

[0004] However, in the existing application, the modeling of complex curved surface curtain wall still focuses on single or limited input parameter control; for example, only some geometric dimensions are parameterized in the design process, and once the initial input condition needs to be adjusted or new external constraints are introduced, the whole model will often fail, and manual intervention is needed to re-adjust the modeling logic; this not only causes low modeling efficiency, but also increases the time cost and labor cost in the design and optimization process.

[0005] In addition, the existing modeling process is insufficient in expressing multi-dimensional and multi-specialty data input; complex curved surface curtain wall design often needs to consider architectural morphology parameters, structural stress conditions, curtain wall grid logic and material properties and other multiple factors, but the existing method is difficult to realize the automatic linkage of multi-parameter input and result feedback; when the design input condition changes, there is a lack of effective automatic update and optimization mechanism, which easily causes the model and optimization process to be forced to rebuild, thereby causing a huge waste of human and time cost in the project implementation cycle.

[0006] In summary, the existing technology at least has the following technical problems:

[0007] The existing complex curved surface curtain wall modeling process lacks an automatic linkage mechanism for multi-parameter input, resulting in low modification and reconstruction efficiency in the modeling process, high labor and time cost. SUMMARY

[0008] The application aims to provide a complex curved surface curtain wall modeling method based on Grasshopper, so as to solve the technical problem that the existing complex curved surface curtain wall modeling process lacks automatic linkage mechanism of multi-parameter input, resulting in low modification and reconstruction efficiency, high labor and time cost.

[0009] The preferred technical solutions in the various technical solutions provided by the application can produce the technical effects described below.

[0010] To solve the above technical problems, the application provides the following technical solutions.

[0011] The application provides a complex curved surface curtain wall modeling method based on Grasshopper, comprising the following steps: S1, inputting modeling parameters: inputting the geometric size, load parameter, thermal expansion coefficient, material attribute and environmental parameter required by the curtain wall with complex curved surface to be constructed into a Grasshopper parameterization platform at an input end, to generate an original curtain wall model;

[0012] S2, reference curved surface reconstruction: topological optimization and geometric precision correction are performed on the original curtain wall model through NURBS curved surface reconstruction, to generate a reference curtain wall model with at least C2 order continuity, so as to ensure the smoothness of the reference curved surface of the reference curtain wall model in position, tangent and curvature;

[0013] S3, curved surface segmentation and unit size calculation: grid segmentation is performed on the reference curved surface based on a discrete differential geometry method to form a plurality of unit blocks, and the size parameters of the long side, short side and thickness of each unit block are calculated and determined in combination with the maximum deflection formula and thermal expansion formula of the glass plate of the curtain wall under uniform pressure;

[0014] S4, structural system parameterization modeling: the cross-sectional size of the main force bar and the secondary force bar of the installation component of the curtain wall is calculated through a finite element analysis module of the Grasshopper parameterization platform, and the topological relationship is input into the Grasshopper parameterization platform, to intelligently generate a structural system for installing the curtain wall;

[0015] S5, parameterization calculation of construction node: according to the material deformation value of the glass plate and the installation component, the adjustable deformation variable of the construction node of the structural system is set, to compensate for the installation error and thermal expansion difference, so as to ensure the assembly feasibility of the curtain wall;

[0016] S6, economic optimization and construction deepening: a material cost database is introduced and called in combination with a gradient descent method, to optimize the planarization cutting size of the unit block, adaptively adjust the frame cross section of the unit block, and finally adjust the construction node of the structural system.

[0017] S7, construction data output: outputting construction drawings, spatial coordinate matrix and numerical control machining data through the data interface of the Grasshopper parametric platform, for digital construction of the curtain wall with complex surfaces.

[0018] In one embodiment, in step S2, the process of NURBS surface reconstruction includes the following sequentially implemented steps: discretization sampling: mesh sampling of the surface of the original curtain wall model for extracting the coordinates, normal vector and curvature radius data of key sampling points, and dataizing the original surface;

[0019] Control point fitting and reconstruction: based on the data extracted from the sampling points, generating an array of NURBS control points through least squares fitting, and introducing curvature continuity constraints in the fitting process to make the generated surface meet the aesthetic and stress requirements under at least C2 order continuity, for generating a reconstructed surface;

[0020] Surface error correction: comparing the reconstructed surface with the original surface, and automatically adjusting the position of the NURBS control points when the deviation exceeds the preset tolerance threshold;

[0021] Topology optimization: using constraint optimization method to reduce the number of redundant NURBS control points, generating a simplified surface that meets the construction requirements in terms of accuracy, for reducing the calculation complexity and improving the construction accuracy;

[0022] Output reference surface: outputting the simplified surface as the reference surface, and taking the reference surface as the geometric basis for surface subdivision and unit size calculation, structural system parametric modeling and construction node parametric calculation of the curtain wall.

[0023] In one embodiment, the preset tolerance threshold in the error correction is ±2mm.

[0024] In one embodiment, in step S3, the mechanical size calculation formula of the unit plate is:

[0025] ;

[0026] wherein, P is the uniform pressure, l is the short side of the glass, E is the elastic modulus, I is the cross-sectional moment of inertia; in a rectangular cross-section, , b is the long side of the glass, h is the thickness of the glass; and in combination with the thermal expansion formula: ; wherein, is the area change amount of glass thermal expansion, and the coefficient 2 is the length and width of the glass plate. a linear expansion coefficient of the glass, a temperature change amount, an initial area of the glass; after calculation, the area of the glass plate of the unit panel of the curtain wall is determined, so that the size parameter is determined.

[0027] In one of the embodiments, in step S4, the spacing between the primary force-bearing members and the secondary force-bearing members of the mounting member of the curtain wall is optimized by combining the rules of ergonomics and architectural visual factors, so that the mounting member forms a numerically matched structural system with the architectural members such as beams, columns and railings to which the curtain wall is attached while meeting the mechanical properties, for determining the position of the mounting member.

[0028] In one of the embodiments, in step S5, the construction node adopts parameterized calculation of adjustable deformation amount, and compensates the thermal expansion amount and the force deformation amount of the glass plate of the unit panel in real time, for adaptively compensating the size deviation and position deviation in the installation process.

[0029] In one of the embodiments, in step S6, the planarization cutting size optimization of the unit panel adopts a panel planarization algorithm, performs unfolding calculation on the curved surface of the unit panel based on the minimum surface unfolding principle, for determining the planar cutting size of the glass plate of each unit panel within the bending range.

[0030] In one of the embodiments, in step S6, the adaptive adjustment of the frame section of the unit panel includes: compensating the height difference and thickness difference of the node size of the planar cut glass plate, so that the planar cut glass plate matches the corresponding curved surface position of the unit panel of the curtain wall.

[0031] In one of the embodiments, in step S7, the output construction data includes: two-dimensional construction drawings, three-dimensional spatial coordinate matrix, digital processing data compatible with numerical control processing system or robot processing system.

[0032] In one of the embodiments, the multi-parameter correlation logic is established on the Grasshopper parameterization platform through steps S1 to S7, and when the geometric size, load parameter, thermal expansion coefficient, material attribute and environmental parameter at the input end are adjusted, the updating of the reference curtain wall model and the construction data is automatically driven.

[0033] The present application aims at the technical problem that the existing complex curved surface curtain wall modeling process lacks multi-parameter input automatic linkage mechanism, resulting in low modification and reconstruction efficiency, high labor and time cost, and proposes a complex curved surface curtain wall modeling method based on Grasshopper, which has the following beneficial effects:

[0034] (1) Multi-parameter automatic linkage; the present application establishes the linkage relationship between the input conditions of geometric size, load parameter, thermal expansion coefficient, material property and environmental parameter through the Grasshopper parameterization platform, realizes the dynamic driving of the input end parameter, enables the modeling process to be automatically updated when the input condition changes, avoids the problem of repeated modification and reconstruction by artificial in the traditional method, and greatly improves the design efficiency.

[0035] (2) Geometric precision improvement; the present application introduces NURBS surface reconstruction and C2 order continuity constraint in the process of reference surface reconstruction, carries out topology optimization and geometric correction on the original model, ensures that the generated reference surface keeps smooth in position, tangent and curvature, so as to meet the aesthetic requirements of building appearance and ensure the accuracy of subsequent construction and processing.

[0036] (3) Mechanical and environmental adaptability; by combining the deflection formula and thermal expansion formula of the glass plate of the curtain wall under uniform pressure, the size parameters of each unit plate of the curtain wall are accurately determined, so that the curtain wall has good stability and safety under the conditions of structural stress and temperature change.

[0037] (4) Intelligent structure system generation; with the help of finite element analysis module, the cross section size of the main and secondary stress members is automatically calculated, and the complete structure system is generated by driving the Grasshopper parameterization platform through the topological relationship, which ensures the rationality of the curtain wall structure and the feasibility of construction.

[0038] (5) Enhanced installation adaptability; adjustable deformation variables are introduced in the design of the construction nodes of the curtain wall, which can compensate for the installation errors in construction and the differences caused by the thermal expansion and contraction of glass, improving the flexibility and reliability of curtain wall assembly.

[0039] (6) Economy and constructability; by introducing material cost database and gradient descent optimization method, the cutting size of glass plate and the cross section of frame are optimized, which can reduce material waste and construction cost under the premise of ensuring mechanical properties and aesthetic effect.

[0040] (7) Direct connection of digital construction; the output includes construction drawing, spatial coordinate matrix and machining data of numerical control machining system (CNC), realizing the full-process digital connection from design to construction, avoiding manual secondary conversion, and improving construction efficiency and accuracy.

[0041] In summary, the complex curved surface curtain wall modeling method and technical scheme of the present application not only solves the problems of low efficiency and high cost of complex curved surface curtain wall modeling in the prior art, but also improves the geometric precision, mechanical safety, construction feasibility and economy, thereby improving the integration level of complex curved surface curtain wall modeling and construction. BRIEF DESCRIPTION OF DRAWINGS

[0042] To more clearly illustrate the technical solution of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0043] Figure 1 This is a flowchart illustrating the complex curved surface curtain wall modeling method of the present invention;

[0044] Figure 2 This is a flowchart illustrating step S2 in the complex curved surface curtain wall modeling method of the present invention. Detailed Implementation

[0045] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0046] A specific implementation provides a Grasshopper-based method for modeling complex curved surface curtain walls. This method includes: first, inputting the curtain wall's geometric dimensions, load parameters, thermal expansion coefficient, material properties, and environmental parameters into a parametric platform to generate an original curtain wall model; then, performing topology optimization and geometric correction on the original curtain wall model through surface reconstruction to obtain a reference curtain wall model; meshing the reference surface based on discrete differential geometry and calculating the unit panel dimensions; constructing a structural system using a finite element analysis module and a parametric platform; adjusting the construction nodes parametrically to compensate for errors and optimize the planar dimensions of unit panels and the frame cross-sectional dimensions based on the deformation characteristics of the glass panels and installation components; finally, outputting construction drawings, spatial coordinate matrices, and CNC machining data to achieve digital construction of the complex curved surface curtain wall and multi-parameter digital automatic linkage from design to construction, thereby improving the accuracy, efficiency, and construction feasibility of complex curtain wall modeling; effectively solving the technical problem of the lack of an automated linkage mechanism for multi-parameter input in existing complex curved surface curtain wall modeling processes, leading to low efficiency in modification and reconstruction during the modeling process and excessive investment of manpower and time.

[0047] The first implementation of a complex curved surface curtain wall modeling method is as follows: Figure 1 As shown, the steps are as follows, implemented in the order of S1 to S7: S1, Input modeling parameters: Input the required geometric dimensions, load parameters, coefficient of thermal expansion, material properties and environmental parameters of the curtain wall with complex curved surfaces to be built into the Grasshopper parametric platform to generate the original curtain wall model.

[0048] S2, reference surface reconstruction: through NURBS surface reconstruction, topology optimization and geometric accuracy correction are performed on the original curtain wall model to generate a reference curtain wall model with at least C2 order continuity, so as to ensure the smoothness of the reference surface of the reference curtain wall model in position, tangent and curvature;

[0049] S3, surface segmentation and unit size calculation: based on the discrete differential geometry method, the reference surface is segmented into a plurality of unit blocks, and the maximum deflection formula and thermal expansion formula of the glass plate of the curtain wall under uniform pressure are combined to calculate and determine the size parameters of the long side, short side and thickness of each unit block;

[0050] S4, parameterized modeling of structural system: the main and secondary force members of the installation member of the curtain wall are calculated by the finite element analysis module of the Grasshopper parameterization platform, and the topological relationship is input into the Grasshopper parameterization platform to intelligently generate a structural system for installing the curtain wall;

[0051] S5, parameterized calculation of construction node: according to the material deformation value of the glass plate and the installation member, the adjustable deformation variable of the construction node of the structural system is set to compensate for installation errors and thermal expansion differences, thereby ensuring the assembly feasibility of the curtain wall;

[0052] S6, economic optimization and construction deepening: a material cost database is introduced and called to optimize the planar cutting size of the unit block, adaptively adjust the frame section of the unit block, and finally adjust the construction node of the structural system by using the gradient descent method;

[0053] S7, construction data output: construction drawings, spatial coordinate matrices and numerical control processing data are output through the data interface of the Grasshopper parameterization platform, which is used for digital construction of the curtain wall with complex surfaces.

[0054] Specifically, in view of the technical problems that the existing complex curved surface curtain wall modeling process lacks a multi-parameter input automatic linkage mechanism, resulting in low modification and reconstruction efficiency, and high labor and time cost, a complex curved surface curtain wall modeling method based on Grasshopper is proposed, which has multiple technical advantages for digital construction of complex curved surface curtain wall: multi-parameter automatic linkage, the linkage relationship between the input conditions of geometric size, load parameter, thermal expansion coefficient, material attribute and environmental parameter is established through the Grasshopper parameterization platform, the dynamic driving of the input parameter is realized, the modeling process can be automatically updated when the input condition changes, the problem of repeated modification and reconstruction by manual operation in the traditional method is avoided, and the design efficiency is greatly improved.

[0055] Geometric accuracy promotion; the present application introduces NURBS surface reconstruction and C2 continuity constraint in the process of reference surface reconstruction, optimizes the topology and geometry of the original model, and ensures that the generated reference surface maintains smoothness in position, tangent and curvature, thereby meeting the aesthetic requirements of building appearance and ensuring the accuracy of subsequent construction and processing.

[0056] Mechanical and environmental adaptability, by combining the deflection formula and thermal expansion formula of the glass plate of the curtain wall under uniform pressure, the size parameters of each unit plate of the curtain wall are accurately determined, so that the curtain wall has good stability and safety under the conditions of structural stress and temperature change.

[0057] Intelligent structure system generation, with the help of finite element analysis module, the cross-sectional size of the main and secondary force members is automatically calculated, and the complete structure system is generated through the topological relationship driven Grasshopper parameterization platform, which ensures the rationality of the curtain wall structure and the feasibility of construction.

[0058] Enhanced installation adaptability, adjustable deformation variables are introduced in the design of the structural nodes of the curtain wall, which can compensate for the installation errors in construction and the differences caused by the thermal expansion and contraction of glass, improving the flexibility and reliability of curtain wall assembly.

[0059] Economy and constructability, by introducing material cost database and gradient descent optimization method, the cutting size of the glass plate and the frame section of the unit plate are optimized, which can reduce material waste and construction cost under the premise of ensuring mechanical properties and aesthetic effect.

[0060] Digital construction direct connection, output includes construction drawing, spatial coordinate matrix and CNC machining data, realizes the full-process digital connection from design to construction, avoids manual secondary conversion, and improves construction efficiency and accuracy.

[0061] In summary, the complex curved surface curtain wall modeling method and technical scheme of the present application not only solves the problems of low efficiency and high cost of complex curved surface curtain wall modeling in the prior art, but also improves the geometric accuracy, mechanical safety, construction feasibility and economy, thereby improving the integration level of complex curved surface curtain wall modeling and construction.

[0062] As one of the optional embodiments:

[0063] The specific process of step S2 reference surface reconstruction is implemented as shown in the following steps: Figure 2 The process of NURBS surface reconstruction in step S2 includes the following steps:

[0064] Discrete sampling: mesh sampling on the surface of the original curtain wall model to extract the coordinates, normal vectors and curvature radius data of the key sampling points, and dataize the original surface;

[0065] Control point fitting and reconstruction: based on the data extracted from the sampling points, generate a NURBS control point array through least squares fitting, and introduce curvature continuity constraints in the fitting process to make the generated surface meet the aesthetic and stress requirements under at least C2 order continuity, for generating a reconstructed surface;

[0066] Surface error correction: compare the reconstructed surface with the original surface, and automatically adjust the position of the NURBS control points when the deviation exceeds the preset tolerance threshold; the preset tolerance threshold is ±2mm;

[0067] Topology optimization: use constraint optimization method to reduce the number of redundant NURBS control points, generate a simplified surface that meets the construction requirements in terms of accuracy, to reduce the calculation complexity and improve the construction accuracy;

[0068] Output reference surface: output the simplified surface as the reference surface, and use the reference surface as the geometric basis for surface subdivision and unit size calculation, structural system parameterized modeling and construction node parameterized calculation of the curtain wall.

[0069] In application, the coordinates, normal vectors and curvature radius data are extracted by mesh sampling on the surface of the original curtain wall model, a NURBS control point array is generated by least squares fitting, and C2 order continuity constraints are introduced in the fitting process to obtain a smooth and continuous reconstructed surface; then the control points are automatically corrected when the deviation exceeds ±2mm, and finally the reference surface that meets the construction accuracy requirements is output by reducing the number of redundant control points through topology optimization; through the above process, the curtain wall model avoids curvature discontinuity in appearance, improves geometric accuracy, and ensures matching with actual construction tolerance, solving the problem of disconnection between construction model and actual construction in the prior art.

[0070] In addition, the tolerance threshold can be adjusted according to different types of curtain walls, such as ±3mm for oversized glass curtain walls, to further match the installation process.

[0071] The specific process of the above step S3 surface subdivision and unit size calculation is as follows: in step S3, the mechanical size calculation formula of the unit plate is:

[0072] ;

[0073] wherein, P P is the uniform pressure, l L is the short side of the glass, E E is the elastic modulus,I is the cross-sectional moment of inertia;

[0074] in a rectangular cross-section, , b is the long side of the glass, h is the thickness of the glass;

[0075] and combined with the thermal expansion formula: ; wherein, is the area change amount of the glass thermal expansion, the coefficient 2 is the length and width of the two dimensions that the glass plate has, is the linear expansion coefficient of the glass, is the temperature change amount, is the initial area of the glass;

[0076] After calculation, the area of the glass plate of the unit block of the curtain wall is determined, so as to determine the size parameter.

[0077] In application, the calculation process can predict the change of the glass of the complex curved surface curtain wall under the stress and thermal effect in the design stage, so that each plate has reliable mechanical properties, and solves the problems of unreasonable plate size and insufficient stress safety in the traditional modeling method.

[0078] In addition, the wind load coefficient or regional climate parameter can be further introduced into the calculation parameter in the formula to improve the modeling applicability.

[0079] The specific process of the above step S4 structure parameterized modeling is that, in step S4, the spacing of the main stress bar and the secondary stress bar of the mounting component of the curtain wall is optimized by combining the rules of ergonomics and architectural visual factors, so that the mounting component forms a numerically matched structure system with the architectural components such as beams, columns and railings attached to the curtain wall while meeting the mechanical properties, for determining the position of the mounting component.

[0080] In application, the finite element analysis result is imported into the Grasshopper platform, the cross-sectional size of the main and secondary stress bars is automatically determined according to the stress condition of the bars, and the spacing is adjusted according to the ergonomics and architectural visual factors to be numerically matched with the components such as beams, columns and railings; this process not only meets the mechanical stability, but also takes into account the spatial aesthetics and use comfort, solving the problem of single structure and lack of coordination with the overall building in the prior art.

[0081] In addition, environmental simulation (such as daylighting and shading analysis) can be included in the optimization process to further improve the rationality of the structure system.

[0082] As to the specific process of constructing the node parameterization calculation in step S5, in step S5, the constructing node adopts the parameterization calculation of the adjustable deformation variable, allowing real-time compensation of the thermal expansion amount and stress deformation amount of the glass plate of the unit panel, for adaptive compensation of the size deviation and position deviation in the installation process.

[0083] In the application, according to the deformation data of the glass plate and the installation component, the adjustable deformation variable of the node is set, and the expansion amount and deformation variable of the thermal expansion and stress deformation of the glass in real time during installation are calculated by parameterization, which ensures the stability and flexibility of the node in construction and use, and solves the risk of cracks and falling caused by temperature or stress difference in traditional curtain wall installation.

[0084] In addition, a multi-stage buffer structure or intelligent sensing monitoring unit is arranged on the node, so as to improve the durability and long-term safety monitoring of the complex curved curtain wall under complex environmental factors.

[0085] As to the specific process of economic optimization and construction deepening in step S6, in step S6, the planarization cutting size optimization of the unit panel adopts a panel planarization algorithm, based on the minimum surface unfolding principle, to unfold and calculate the surface of the unit panel, for determining the planar cutting size of the glass plate of each unit panel within the bending range.

[0086] The adaptive adjustment of the frame section of the unit panel includes height difference and thickness difference compensation of the node size of the planar cut glass plate, so that the planar cut glass plate matches the corresponding curved surface position of the unit panel of the curtain wall.

[0087] The cutting size and frame section of the unit panel are optimized by using the material cost database and the gradient descent method; the surface is unfolded by the panel planarization algorithm to ensure that the cutting size is within the allowable range of glass bending; and the thickness difference and height difference compensation is performed at the frame node to enable the planar cutting plate to be accurately assembled with the frame; this process reduces material waste and processing errors under the premise of ensuring safety, solving the problems of high construction cost and large error in the prior art.

[0088] Finally, adjusting the construction node of the structural system includes optimizing the position, angle and connector size of the construction node by parameterization modeling under the premise of meeting the stress transmission and connection stability, to coordinate the installation error and thickness difference between adjacent unit panels.

[0089] This process not only improves the connection reliability of the node, but also effectively reduces the deformation or misplacement of the curtain wall caused by local errors, ensuring the overall continuity and smoothness of the entire curtain wall system after installation, thereby solving the problem of rigid node design in the prior art that cannot adapt to the accumulation of curved surface errors.

[0090] As to the specific process of outputting the construction data in step S7, in step S7, the output construction data includes: two-dimensional construction drawings, three-dimensional spatial coordinate matrix, and digital processing data compatible with CNC processing system or robot processing system.

[0091] Therefore, by steps S1 to S7, the multi-parameter correlation logic is established in the Grasshopper parameterization platform, and when the input geometric size, load parameter, thermal expansion coefficient, material attribute and environmental parameter are adjusted, the updating of the reference curtain wall model and the construction data is automatically driven.

[0092] In the application, the system automatically generates two-dimensional construction drawings, three-dimensional spatial coordinate matrix and processing data which can be directly connected to CNC / robot system, realizes seamless connection from construction design to construction, and realizes digital construction of complex curved surface curtain wall. The process improves the automation level of construction design, avoids errors caused by manual data conversion, and solves the problem of design and construction information island in the prior art.

[0093] The data interface of the Grasshopper parameterization platform is connected through the external conversion module, so that the output parameter module is compatible with the BIM platform, and interconnection and intercommunication with other building information systems are realized.

[0094] The complex curved surface curtain wall modeling method is suitable for modeling of different types of curtain walls, including: glass curtain wall, considering glass bending degree and minimum thickness during modeling; metal curtain wall, considering the influence of reflection and glare on the environment during modeling; rotatable component curtain wall, considering shading, ventilation and solar heat radiation during modeling; photovoltaic curtain wall, considering the influence of solar elevation angle, sunshine duration and light intensity on the angle and size of the panel during modeling.

[0095] The technical features of the above embodiments can be combined arbitrarily, and to make the description concise, all possible combinations of the technical features in the above embodiments are not described.

Claims

1. A method for modeling complex curved surface curtain walls based on Grasshopper, characterized in that, Includes the following steps: S1. Input modeling parameters: Input the required geometric dimensions, load parameters, coefficient of thermal expansion, material properties and environmental parameters of the curtain wall with complex curved surfaces to be built into the Grasshopper parametric platform to generate the original curtain wall model. S2. Reference Surface Reconstruction: The original curtain wall model is topologically optimized and geometrically accurate by NURBS surface reconstruction to generate a reference curtain wall model with at least C2 order continuity, so as to ensure the smoothness of the reference surface of the reference curtain wall model in terms of position, tangent and curvature. S3. Surface segmentation and unit size calculation: Based on the discrete differential geometry method, the reference surface is segmented into multiple unit panels. Combined with the maximum deflection formula and thermal expansion formula of the glass sheet of the curtain wall under uniform pressure, the dimensional parameters of the long side, short side and thickness of each unit panel are calculated and determined. In step S3, the formula for calculating the mechanical dimensions of the unit plate is: ； in, P To distribute pressure evenly, l For the shorter side of the glass, E For elastic modulus, I The moment of inertia of the cross section; In a rectangular section, , b For the long side of the glass, h The thickness of the glass; And combine it with the thermal expansion formula: ; in, The coefficient 2 represents the change in surface area due to thermal expansion of the glass, and the coefficient 2 represents the length and width of the glass sheet. is the coefficient of linear expansion of glass. The change in temperature This represents the initial area of ​​the glass. After calculation, the area of ​​the glass sheet of the unit panel of the curtain wall is determined, thereby determining the dimensional parameters; S4. Parametric Modeling of Structural System: The cross-sectional dimensions of the main and secondary load-bearing members of the curtain wall installation components are calculated using the finite element analysis module of the Grasshopper parametric platform, and their topological relationships are input into the Grasshopper parametric platform to intelligently generate the structural system for installing the curtain wall. S5. Parametric calculation of structural nodes: Based on the material deformation values ​​of the glass sheet and the installation components, the adjustable deformation of the structural nodes of the structural system is set to compensate for installation errors and thermal expansion differences, thereby ensuring the assembly feasibility of the curtain wall. S6. Economic Optimization and Construction Refinement: By introducing and calling the material cost database and combining it with the gradient descent method, the planar cutting size of the unit plate is optimized, the frame cross section of the unit plate is adaptively adjusted, and finally the construction nodes of the structural system are adjusted. S7. Construction Data Output: Output construction drawings, spatial coordinate matrices, and CNC machining data through the data interface of the Grasshopper parametric platform for the digital construction of the curtain wall with complex curved surfaces.

2. The method for modeling complex curved surface curtain walls according to claim 1, characterized in that, In step S2, the NURBS surface reconstruction process includes the following steps performed sequentially: Discretization sampling: The surface of the original curtain wall model is meshed for sampling to extract the coordinates, normal vectors and radius of curvature data of key sampling points, and to digitize the original surface; Control point fitting and reconstruction: Based on the data extracted from the sampling points, a NURBS control point array is generated by least squares fitting, and curvature continuity constraints are introduced during the fitting process to ensure that the generated surface meets aesthetic and stress requirements under at least C2 order continuity, which is used to generate the reconstructed surface; Surface error correction: The reconstructed surface is compared with the original surface. When the deviation exceeds the preset tolerance threshold, the position of the NURBS control point is automatically adjusted. Topology optimization: Constraint optimization methods are used to reduce the number of redundant NURBS control points and generate simplified surfaces with accuracy that meet construction requirements, thereby reducing computational complexity and improving construction accuracy; Output reference surface: The simplified surface is output as the reference surface, which serves as the geometric basis for surface segmentation and unit size calculation of the curtain wall, parametric modeling of the structural system, and parametric calculation of construction nodes.

3. The method for modeling complex curved surface curtain walls according to claim 2, characterized in that, The preset tolerance threshold for the error correction is ±2mm.

4. The method for modeling complex curved surface curtain walls according to claim 1, characterized in that, In step S4, by combining the rules of ergonomics and architectural visual factors, the spacing between the main load-bearing members and the secondary load-bearing members of the curtain wall installation components is optimized, so that the installation components, while meeting the mechanical performance requirements, form a numerically matched structural system with the building components of the beams, columns, and railings to which the curtain wall is attached, and this is used to determine the position of the installation components.

5. The method for modeling complex curved surface curtain walls according to claim 1, characterized in that, In step S5, the construction node uses parameterized calculation of adjustable deformation to compensate for the thermal expansion and stress deformation of the glass sheet of the unit plate in real time, so as to adaptively compensate for dimensional deviations and positional deviations during the installation process.

6. The method for modeling complex curved surface curtain walls according to claim 1, characterized in that, In step S6, the planar cutting size optimization of the unit plate adopts the plate planarization algorithm. Based on the principle of minimum surface unfolding, the surface of the unit plate is unfolded and calculated to determine the planar cutting size of the glass sheet of each unit plate within the bending range.

7. The method for modeling complex curved surface curtain walls according to claim 1, characterized in that, In step S6, the adaptive adjustment of the frame section of the unit panel includes: compensating for the height difference and thickness difference of the node dimensions of the planar cut glass sheet so that the planar cut glass sheet matches the curved surface position corresponding to the unit panel of the curtain wall.

8. The method for modeling complex curved surface curtain walls according to claim 1, characterized in that, In step S7, the output construction data includes: two-dimensional construction drawings, three-dimensional spatial coordinate matrix, and digital processing data compatible with CNC machining systems or robot machining systems.

9. The method for modeling complex curved surface curtain walls according to claim 1, characterized in that, By establishing multi-parameter correlation logic in the Grasshopper parametric platform through steps S1 to S7, the reference curtain wall model and construction data are automatically updated when the geometric dimensions, load parameters, thermal expansion coefficient, material properties and environmental parameters at the input end are adjusted.

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