Parabolic arch dam model creation method and system

Abstract

The invention provides a parabolic arch dam model creation method and system, and relates to the technical field of hydraulic engineering modeling. The invention provides a parabolic arch dam model creation method, which comprises the following steps: through a continuous technical chain of parameter-driven asymmetric modeling (S1-S2), cubic spline interpolation encryption (S4), and finally BIM automatic lofting and skin (S6-S7), the modeling precision and the smoothness of the model are improved; the three core problems of arch ring shape distortion, poor curved surface continuity and low modeling efficiency in a traditional method are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of hydraulic engineering modeling, and particularly to a method and system for creating a parabolic arch dam model. Background Art

[0002] As a typical spatial thin-walled structure, the design and modeling accuracy of an arch dam directly affects the structural safety and economy. Traditional arch dam design mostly relies on empirical formulas or two-dimensional drawing deduction, which has problems such as weak parameter correlation and unintuitive three-dimensional form expression. With the development of Building Information Modeling (BIM) technology, parametric modeling has gradually become the mainstream, but the existing methods still have the following limitations: First, the lack of flexibility in parametric modeling: Traditional methods mostly use symmetric parabolas or circular arc arch rings to simplify models, making it difficult to meet the design requirements of asymmetric arch dams under complex terrains. Especially when the curvature and thickness differences between the left and right half arches are significant, the model accuracy drops severely. Second, the lack of arch ring densification technology: Existing parametric tools only generate intermediate arch rings through linear interpolation between elevations, resulting in poor continuity of the arch dam surface and unable to meet the refined modeling requirements of high-stress areas (such as the crown and ends of the arch). Third, the weak coordination between BIM and mechanical models: Most methods rely on manual modeling with general BIM software, lacking automatic association with special parameters of arch dams (such as radius of curvature, thickness gradient). The model modification efficiency is low, and it is difficult to directly output geometric data for finite element analysis.

[0003] Therefore, there is an urgent need for a method for creating an arch dam model that integrates parametric design, high-precision interpolation algorithms, and BIM automated modeling technology to improve the geometric expression accuracy and modeling efficiency of asymmetric arch dams and provide a reliable three-dimensional digital foundation for subsequent mechanical analysis. Summary of the Invention

[0004] In view of the above problems existing in the prior art, the first aspect of the present invention proposes a method for creating a parabolic arch dam model, including: S1: Input the basic parameter set of the arch dam, where the basic parameter set includes the longitudinal coordinates of the crown of each elevation horizontal arch ring, thickness parameters, and curvature parameters; S2: Based on the longitudinal coordinates of the crown of the horizontal arch ring and the curvature parameters, construct the central axis equation of each elevation horizontal arch ring, and calculate the discrete point coordinates of the upstream arch curve and the discrete point coordinates of the downstream arch curve according to the offset of the thickness parameter of the horizontal arch ring along the normal direction of the central axis; S3: Call the curve generation tool of the building information model software, and respectively generate the continuous upstream arch curve and the continuous downstream arch curve of each elevation horizontal arch ring based on the discrete point coordinates of the upstream arch curve and the discrete point coordinates of the downstream arch curve; S4: Insert encrypted arch rings between adjacent elevation-level arch rings, generate a parameter set for the encrypted arch rings based on the cubic spline interpolation algorithm, and generate the upstream arch curve and the downstream arch curve of the encrypted arch rings based on the parameter set of the encrypted arch rings; S5: Invoke the geometric merging tool of the building information model software to merge the continuous upstream arch curves of each elevation-level arch ring generated in step S3 with the upstream arch curve of the encrypted arch ring generated in step S4 into an upstream contour line set, and merge the continuous downstream arch curves of each elevation-level arch ring generated in step S3 with the downstream arch curve of the encrypted arch ring generated in step S4 into a downstream contour line set; S6: Use the upstream contour line set and the downstream contour line set as inputs respectively, and perform spatial lofting along the central axis constructed in step S2 to generate the upstream arc surface and the downstream arc surface correspondingly; S7: Extract the boundary lines of the upstream arc surface and the downstream arc surface, and perform four-way skinning processing by connecting the corresponding boundary lines to generate the three-dimensional model body of the arch dam.

[0005] Combined with the first aspect, in some implementation manners of the first aspect, step S1 includes: S1-1: Import the elevation sequence of the horizontal arch rings by using a parametric table; S1-2: Read the longitudinal coordinates of the crowns of each elevation-level arch ring in the elevation sequence; S1-3: Load the thickness parameters of each elevation-level arch ring in the elevation sequence, and the thickness parameters include the left half-arch thickness value and the right half-arch thickness value; S1-4: Load the curvature parameters of each elevation-level arch ring in the elevation sequence, and the curvature parameters include the left crown curvature radius value, the right crown curvature radius value, the left half-arch width value, and the right half-arch width value.

[0006] Combined with the first aspect, in some implementation manners of the first aspect, the curvature parameters include the left crown curvature radius value and the right crown curvature radius value, the thickness parameters include the left half-arch thickness value and the right half-arch thickness value, and step S2 includes: S2-1: Based on the left crown curvature radius value, construct the central axis equation of the left half-arch ring, and the central axis equation of the left half-arch ring is a quadratic function equation of the longitudinal coordinate and the horizontal coordinate of the crown of the horizontal arch ring; S2-2: Based on the right crown curvature radius value, construct the central axis equation of the right half-arch ring, and the central axis equation of the right half-arch ring is also a quadratic function equation of the longitudinal coordinate and the horizontal coordinate of the crown of the horizontal arch ring; S2-3: According to the left half-arch thickness value, offset the central axis of the left half-arch ring constructed in step S2-1 by half of the left half-arch thickness value along its normal direction to the upstream side to generate the coordinate points of the discrete points of the upstream arch curve; S2-4: According to the right half-arch thickness value, shift the central axis of the right half-arch ring constructed in step S2-2 downward along its normal direction by half of the right half-arch thickness value to generate the discrete point coordinates of the downstream arch arc curve.

[0007] Combined with the first aspect, in some implementation manners of the first aspect, the quadratic function equations in steps S2-1 and S2-2 are as follows: The equation of the central axis of the left half-arch ring is: (x ≤ 0), The equation of the central axis of the right half-arch ring is: (x ≥ 0), In the formula, B is the longitudinal coordinate of the crown of the horizontal arch ring, R L is the left crown curvature radius value, R R is the right crown curvature radius value, x is the horizontal coordinate, and y is the longitudinal coordinate of the central axis of the horizontal arch ring. Among them, with the crown as the origin, x of the left half-arch is negative, and x of the right half-arch is positive.

[0008] Combined with the first aspect, in some implementation manners of the first aspect, step S4 includes: S4-1: Use the longitudinal coordinate of the crown, thickness parameter, and curvature parameter of each elevation horizontal arch ring input in step S1 as the end point constraint conditions; S4-2: Based on the cubic spline interpolation algorithm, generate a parameter set of the encrypted arch ring in the elevation direction between adjacent elevation horizontal arch rings. The parameter set of the encrypted arch ring includes the longitudinal coordinate of the crown of the encrypted arch ring, the thickness distribution gradient, and the curvature change parameter; S4-3: Based on the longitudinal coordinate of the crown of the encrypted arch ring, the thickness distribution gradient, and the curvature change parameter of the encrypted arch ring, generate the discrete point coordinates of the encrypted arch ring; S4-4: Call the curve generation tool to generate the upstream arch arc curve and the downstream arch arc curve of the encrypted arch ring based on the discrete point coordinates of the encrypted arch ring.

[0009] Combined with the first aspect, in some implementation manners of the first aspect, step S4-2 includes: S4-2-1: Based on the cubic spline interpolation algorithm, establish a continuous constraint equation for the first derivative of the longitudinal coordinate of the crown of the encrypted arch ring between adjacent elevation horizontal arch rings; S4-2-2: Based on the cubic spline interpolation algorithm, establish a continuous constraint equation for the second derivative of the thickness distribution gradient of the encrypted arch ring between adjacent elevation horizontal arch rings; S4-2-3: Based on the cubic spline interpolation algorithm, establish a continuous constraint equation for the second derivative of the curvature change parameter of the encrypted arch ring between adjacent elevation horizontal arch rings; S4-2-4: Simultaneously solve the constraint equations in steps S4-2-1 to S4-2-3 to generate the parameter set of the encrypted arch ring.

[0010] In combination with the first aspect, in some implementation manners of the first aspect, step S3 includes: S3-1: Invoke the B-spline curve generation module of the building information model software; S3-2: Use the B-spline curve generation module to respectively fit the discrete point coordinates of the upstream arch curve and the discrete point coordinates of the downstream arch curve, and correspondingly generate the continuous upstream arch curve and the continuous downstream arch curve of each elevation level arch ring.

[0011] In combination with the first aspect, in some implementation manners of the first aspect, step S7 includes: S7-1: Extract the top edge line, bottom edge line, left boundary line, and right boundary line of the upstream arc surface generated in step S6; S7-2: Extract the top edge line, bottom edge line, left boundary line, and right boundary line of the downstream arc surface generated in step S6; S7-3: Invoke the boundary surface generation tool of the building information model software, connect the top edge line of the upstream arc surface and the top edge line of the downstream arc surface to generate the dam top surface, connect the bottom edge line of the upstream arc surface and the bottom edge line of the downstream arc surface to generate the dam base surface, connect the left boundary line of the upstream arc surface and the left boundary line of the downstream arc surface to generate the left bank surface, connect the right boundary line of the upstream arc surface and the right boundary line of the downstream arc surface to generate the right bank surface, and the upstream arc surface, the downstream arc surface, the dam top surface, the dam base surface, the left bank surface, and the right bank surface constitute the arch dam three-dimensional model body.

[0012] In the second aspect, the present invention provides a parabolic arch dam model creation system. The creation system is applied to the creation method provided in any of the above embodiments. The creation system includes: An input module, configured to input a set of basic parameters of the arch dam. The set of basic parameters includes the longitudinal coordinates of the crown of each elevation level arch ring, the thickness parameter, and the curvature parameter; A construction module, connected to the input module, configured to construct the central axis equation of each elevation level arch ring based on the longitudinal coordinates of the crown of the horizontal arch ring and the curvature parameter, and calculate the discrete point coordinates of the upstream arch curve and the discrete point coordinates of the downstream arch curve according to the offset of the thickness parameter of the horizontal arch ring along the normal direction of the central axis; A first generation module, connected to the construction module, configured to invoke the curve generation tool of the building information model software, and respectively generate the continuous upstream arch curve and the continuous downstream arch curve of each elevation level arch ring based on the discrete point coordinates of the upstream arch curve and the discrete point coordinates of the downstream arch curve; A second generation module, connected to the construction module, configured to insert encrypted arch rings between adjacent elevation level arch rings, generate a set of parameters of the encrypted arch rings based on the cubic spline interpolation algorithm, and generate the upstream arch curve and the downstream arch curve of the encrypted arch rings based on the set of parameters of the encrypted arch rings; A merging module, connected to the first generation module and the second generation module, is used to call the geometric merging tool of the building information model software to merge the continuous upstream arch curve of each elevation horizontal arch ring and the upstream arch curve of the encrypted arch ring into an upstream contour line set, and merge the continuous downstream arch curve of each elevation horizontal arch ring and the downstream arch curve of the encrypted arch ring into a downstream contour line set; A third generation module, connected to the construction module and the merging module, is used to perform spatial lofting along the central axis with the upstream contour line set and the downstream contour line set as inputs respectively, and correspondingly generate an upstream arc surface and a downstream arc surface; A fourth generation module, connected to the third generation module, is used to extract the boundary lines of the upstream arc surface and the downstream arc surface, and perform four-way skinning processing by connecting the corresponding boundary lines to generate a three-dimensional arch dam model body.

[0013] In a third aspect, the present invention provides a computer-readable storage medium storing a computer program for executing the creation method provided in any one of the above embodiments.

[0014] In a fourth aspect, the present invention provides an electronic device, which includes: A processor; A memory for storing instructions executable by the processor; Wherein, the processor is used to execute the creation method provided in any one of the above embodiments.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: Through the continuous technical chain of "parameter-driven asymmetric modeling (S1-S2), then cubic spline interpolation encryption (S4), and finally BIM automatic lofting and skinning (S6-S7)", the present invention solves the three core problems of arch ring shape distortion, poor surface continuity, and low modeling efficiency in traditional methods. The innovative synergistic effect of the present invention is reflected in: First, the deep integration of asymmetric parametric modeling and BIM tools: the normal offset calculation of the central axis in S2 is seamlessly connected with the BIM curve generation in S3, ensuring the accurate expression of the asymmetric geometric shape and improving the modeling accuracy; Second, the collaborative optimization of high-precision interpolation and contour merging: the cubic spline interpolation in S4 and the merging of contour line sets in S5 break through the smoothness limitation of traditional interpolation methods and improve the smoothness of the model; Third, the geometric closure guarantee of spatial lofting and four-way skinning: the lofting and skinning logic based on the central axis in S6-S7 eliminates the cracks in the BIM model and directly outputs a model available for mechanical analysis. Description of the Drawings

[0016] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0017] Figure 1 The figure shows a schematic flow chart of a method for creating a parabolic arch dam model provided by an embodiment of the present invention.

[0018] Figure 2 The figure shows a schematic structural diagram of the upstream arc surface or the downstream arc surface provided by an embodiment of the present invention.

[0019] Figure 3 The figure shows a schematic structural diagram of a system for creating a parabolic arch dam model provided by an embodiment of the present invention. Specific Embodiments

[0020] To make the objectives, technical solutions, and advantages of the present invention clearer, the following will clearly and completely describe the technical solutions of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope protected by the present invention.

[0021] The following will explain the specific embodiments of the present invention.

[0022] In view of the above problems existing in the prior art, the first aspect of the present invention proposes a method for creating a parabolic arch dam model. Through the continuous technical chain of "parameter-driven asymmetric modeling (S1 - S2), then cubic spline interpolation for encryption (S4), and finally BIM automated lofting and skinning (S6 - S7)", the modeling accuracy and the smoothness of the model are improved, and the three core problems of arch ring shape distortion, poor surface continuity, and low modeling efficiency in the traditional method are solved.

[0023] Embodiment 1 As Figure 1 shown, the present invention proposes a method for creating a parabolic arch dam model, including: S1: Input the basic parameter set of the arch dam, and the basic parameter set includes the longitudinal coordinates of the arch crown of the horizontal arch rings at each elevation, the thickness parameter, and the curvature parameter; S2: Based on the longitudinal coordinates of the arch crown of the horizontal arch rings and the curvature parameter, construct the axis equations of the horizontal arch rings at each elevation, and calculate the discrete point coordinates of the upstream arch curve and the discrete point coordinates of the downstream arch curve according to the offset of the thickness parameter of the horizontal arch ring along the normal direction of the axis; S3: Invoke the curve generation tool of the building information modeling software, and respectively generate the continuous upstream arch curve and the continuous downstream arch curve of each elevation-level arch ring based on the discrete point coordinates of the upstream arch curve and the discrete point coordinates of the downstream arch curve; S4: Insert encrypted arch rings between adjacent elevation-level arch rings, generate the parameter set of the encrypted arch rings based on the cubic spline interpolation algorithm, and generate the upstream arch curve and the downstream arch curve of the encrypted arch rings based on the parameter set of the encrypted arch rings; S5: Invoke the geometric merging tool of the building information modeling software, merge the continuous upstream arch curves of each elevation-level arch ring generated in step S3 with the upstream arch curves of the encrypted arch rings generated in step S4 into an upstream contour line set, and merge the continuous downstream arch curves of each elevation-level arch ring generated in step S3 with the downstream arch curves of the encrypted arch rings generated in step S4 into a downstream contour line set; S6: Respectively use the upstream contour line set and the downstream contour line set as inputs, perform spatial lofting along the central axis constructed in step S2, and correspondingly generate the upstream arc surface and the downstream arc surface; S7: Extract the boundary lines of the upstream arc surface and the downstream arc surface, and perform four-way skinning processing by connecting the corresponding boundary lines to generate the three-dimensional model body of the arch dam.

[0024] Figure 2 The figure shows the structural schematic diagram of the upstream arc surface or the downstream arc surface generated in step S6.

[0025] The creation method of the parabolic arch dam model significantly improves the modeling accuracy and efficiency of the asymmetric arch dam through parameter-driven modeling, cubic spline interpolation encryption, and BIM tool collaboration. This method constructs independent central axis equations for the left and right half arches by inputting a basic parameter set containing the longitudinal coordinates of the arch crown, thickness parameters, and curvature parameters, and precisely offsets along the normal direction to generate upper and lower discrete points, realizing the parametric expression of the asymmetric arch ring. For example, different curvature radii can be used for the left and right half arches (such as 80m for the left half arch and 120m for the right half arch), and the thickness parameters are independently defined, with a small error between the geometric shape of the model and the design value.

[0026] The cubic spline interpolation algorithm generates encrypted arch rings between adjacent elevations, ensuring continuous gradual changes in the arch crown coordinates, thickness gradient, and curvature parameters in the elevation direction, eliminating the problem of curvature mutation caused by traditional linear interpolation, making the arch dam surface continuous in any cross-section, and reducing the risk of stress concentration in finite element analysis.

[0027] The deep integration of BIM tools (such as curve generation, spatial lofting, and four-way skinning) realizes full-process automated modeling, avoids manual splicing errors, has a short modeling cycle, and the generated three-dimensional model body is strictly closed and can be directly used for mechanical simulation, reducing the post-processing time.

[0028] In combination with the first aspect, in some implementation manners of the first aspect, step S1 includes: S1-1: Import the elevation sequence of the horizontal arch ring using a parameterized table; S1-2: Read the longitudinal coordinates of the crown of the horizontal arch ring at each elevation in the elevation sequence; S1-3: Load the thickness parameters of the horizontal arch ring at each elevation, where the thickness parameters include the left half-arch thickness value and the right half-arch thickness value; S1-4: Load the curvature parameters of the horizontal arch ring at each elevation, where the curvature parameters include the left crown curvature radius value, the right crown curvature radius value, the left half-arch width value, and the right half-arch width value.

[0029] Step S1 imports the elevation sequence through a parameterized table and independently loads the left and right half-arch parameters, solving the problems of scattered parameter management and insufficient support for asymmetric data in traditional methods. Traditional designs rely on manual input or a single parameter file, which easily leads to data misalignment or omission. This method uses a structured table (such as Excel) to batch import the elevation sequence and separately reads the longitudinal coordinates of the crown, the left and right half-arch thicknesses, and the curvature parameters at each elevation.

[0030] For example, the left and right half-arch thicknesses (such as 2.5 m on the left and 3.0 m on the right) and the curvature radii (80 m on the left and 100 m on the right) of 5 elevations (such as 1000 m, 980 m, 960 m, etc.) of an arch dam are independently defined in the table, and the system automatically parses and generates a parameter set, reducing the data error rate. Independently loading the left and right half-arch parameters supports asymmetric design requirements. For example, the left half-arch has a smaller curvature radius (narrower opening) due to the steep terrain, and the right half-arch has a larger curvature radius (wider opening) due to the gentle terrain, making the model more conform to the actual terrain conditions. The parameterized table also supports rapid modification of design iterations. For example, after adjusting the right half-arch thickness at a certain elevation, the system automatically updates the subsequent modeling process, avoiding the inefficient operation of manually modifying multiple files in traditional methods.

[0031] In combination with the first aspect, in some implementation manners of the first aspect, the curvature parameters include the left crown curvature radius value and the right crown curvature radius value, the thickness parameters include the left half-arch thickness value and the right half-arch thickness value, and step S2 includes: S2-1: Based on the left crown curvature radius value, construct the central axis equation of the left half-arch ring, and the central axis equation of the left half-arch ring is a quadratic function equation of the longitudinal coordinate and the horizontal coordinate of the crown of the horizontal arch ring; S2-2: Based on the right crown curvature radius value, construct the central axis equation of the right half-arch ring, and the central axis equation of the right half-arch ring is also a quadratic function equation of the longitudinal coordinate and the horizontal coordinate of the crown of the horizontal arch ring; S2-3: According to the left half-arch thickness value, shift the central axis of the left half-arch ring constructed in step S2-1 upstream along its normal direction by half of the left half-arch thickness value to generate the discrete point coordinates of the upstream arch arc curve; S2-4: According to the right half-arch thickness value, shift the central axis of the right half-arch ring constructed in step S2-2 downstream along its normal direction by half of the right half-arch thickness value to generate the discrete point coordinates of the downstream arch arc curve.

[0032] In step S2, by constructing independent central axis equations for the left and right half-arches and generating discrete points through offset along the normal direction, the problem of geometric distortion of the left and right half-arches in the traditional symmetric model is solved. The traditional method uses a single parabolic equation, resulting in forced symmetry of the curvature and thickness of the left and right half-arches and being unable to reflect the actual terrain differences. This method constructs quadratic function equations based on the curvature radii of the left and right arch crowns respectively, allowing differences in the curvature radii of the left and right half-arches (such as 80m on the left and 120m on the right), so as to accurately express the shape of the asymmetric arch ring. Generating discrete points by offsetting the thickness parameter along the normal direction of the central axis, for example, the left half-arch is offset upstream by half of the thickness value (such as 1.25m), and the right half-arch is offset downstream by the other half (such as 1.5m), ensuring that the arch ring thickness is strictly consistent with the design value. This method also avoids the error in the normal offset direction during the traditional manual drawing of the arch ring. For example, in a complex curvature area, a calculation error in the normal direction will lead to distortion of the arch ring shape, while this method automatically calculates the normal direction through the equation, significantly improving the accuracy and reliability.

[0033] Combined with the first aspect, in some implementation manners of the first aspect, the quadratic function equations in steps S2-1 and S2-2 are: The equation of the central axis of the left half-arch ring is: (x ≤ 0), The equation of the central axis of the right half-arch ring is: (x ≥ 0), where B is the longitudinal coordinate of the arch crown of the horizontal arch ring, R L is the curvature radius value of the left arch crown, R R is the curvature radius value of the right arch crown, x is the horizontal coordinate, and y is the longitudinal coordinate of the central axis of the horizontal arch ring. Among them, with the arch crown as the origin, x of the left half-arch is negative, and x of the right half-arch is positive.

[0034] In the embodiment of the present invention, the central axes of the left half-arch ring and the right half-arch ring are defined by specific quadratic function equations, ensuring the mathematical rigor and engineering applicability of the asymmetric arch ring. The traditional method uses circular arc or symmetric parabolic equations and cannot flexibly adjust the curvature of the left and right half-arches. In this solution, with the arch crown as the origin, the horizontal coordinate x of the left half-arch is negative, and the horizontal coordinate of the right half-arch is positive. Quadratic function equations are constructed respectively, where the curvature radius value R L of the left arch crown and the curvature radius value R R of the right arch crown directly determine the opening width of the parabola.

[0035] In combination with the first aspect, in some implementation manners of the first aspect, step S4 includes: S4-1: Using the crown longitudinal coordinates, thickness parameters, and curvature parameters of each elevation horizontal arch ring input in step S1 as endpoint constraint conditions; S4-2: Based on the cubic spline interpolation algorithm, generating a parameter set of the encrypted arch ring in the elevation direction between adjacent elevation horizontal arch rings. The parameter set of the encrypted arch ring includes the crown longitudinal coordinates of the encrypted arch ring, the thickness distribution gradient, and the curvature change parameters; S4-3: Based on the crown longitudinal coordinates, thickness distribution gradient, and curvature change parameters of the encrypted arch ring, generating the discrete point coordinates of the encrypted arch ring; S4-4: Invoking a curve generation tool to generate the upstream arch arc curve and the downstream arch arc curve of the encrypted arch ring based on the discrete point coordinates of the encrypted arch ring.

[0036] Step S4 generates a parameter set of the encrypted arch ring through cubic spline interpolation, solving the problem of non-smooth surfaces caused by traditional linear interpolation. The traditional method directly evenly distributes parameters (such as curvature and thickness) between elevations, resulting in sudden changes in the curvature of adjacent arch rings and affecting the accuracy of mechanical analysis. This method uses the parameters of the horizontal arch ring as endpoint constraints and adopts cubic spline interpolation to generate the crown longitudinal coordinates, thickness distribution gradient, and curvature change parameters of the encrypted arch ring, ensuring that the parameters are continuous and second-order differentiable in the elevation direction. This interpolation method not only ensures parameter continuity but also keeps the curvature change rate (i.e., the second derivative of curvature) of the encrypted arch ring consistent, eliminating the stress concentration caused by sudden curvature changes in the traditional method.

[0037] In combination with the first aspect, in some implementation manners of the first aspect, step S4-2 includes: S4-2-1: Based on the cubic spline interpolation algorithm, establishing a first-order derivative continuous constraint equation for the crown longitudinal coordinates of the encrypted arch ring between adjacent elevation horizontal arch rings; S4-2-2: Based on the cubic spline interpolation algorithm, establishing a second-order derivative continuous constraint equation for the thickness distribution gradient of the encrypted arch ring between adjacent elevation horizontal arch rings; S4-2-3: Based on the cubic spline interpolation algorithm, establishing a second-order derivative continuous constraint equation for the curvature change parameters of the encrypted arch ring between adjacent elevation horizontal arch rings; S4-2-4: Simultaneously solving the constraint equations in steps S4-2-1 to S4-2-3 to generate the parameter set of the encrypted arch ring.

[0038] The embodiment of the present invention further ensures the smoothness and physical rationality of the encrypted arch ring parameters through the derivative continuity constraint of cubic spline interpolation. The traditional interpolation method only ensures the continuity of the function, ignores the continuity of the derivative, and causes a sudden change in the parameter change rate. The method establishes the first-order derivative continuity constraint of the longitudinal coordinates of the crown between adjacent elevations, the second-order derivative continuity constraint of the thickness distribution gradient and the curvature change parameter, and solves the parameter set through simultaneous equations. For example, the longitudinal coordinate B values ​​of the crown of a certain arch dam at the elevation of 950m-970m are 45m, 47m, and 49m respectively, and the B value at the elevation of 965m generated by cubic spline interpolation is 48.2m. Its first-order derivative is consistent with the adjacent segment, and the second-order derivative is zero, ensuring the smoothness of the change rate of the longitudinal coordinates of the crown. The continuity constraint of the second-order derivative of the thickness distribution gradient and the curvature change parameter ensures that the acceleration of thickness and curvature change is consistent, making the mechanical properties of the dense arch ring closer to the real dam body. For example, when the thickness gradient changes from 0.1m / m to 0.15m / m, the change rate is uniform, avoiding local strength mutations.

[0039] In combination with the first aspect, in some implementations of the first aspect, step S3 includes: S3-1: Calling the B-spline curve generation module of the building information modeling software; S3-2: Using the B-spline curve generation module, the coordinates of the discrete points of the upstream arch curve and the coordinates of the discrete points of the downstream arch curve are fitted respectively, and the continuous upstream arch curve and the continuous downstream arch curve of each elevation level arch ring are generated accordingly.

[0040] Step S3 fits discrete points through the B-spline curve generation module of the BIM software, solving the geometric error problem caused by traditional polyline splicing. The traditional method uses straight lines or arcs to splice discrete points, resulting in an uneven arch curve and too many control points. This solution calls the B-spline tool of the BIM software (such as Revit) to fit the discrete points into a third-order B-spline curve. For example, 50 discrete points are optimized to 12 control points, which not only reduces the amount of data, but also ensures that the curve strictly passes through the discrete points, and the maximum fitting error is small. The local controllability of the B-spline also allows the shape of a certain section of the curve to be adjusted individually without affecting the overall shape. For example, after modifying the coordinates of a discrete point on the left half of the arch, only the adjacent control points need to be adjusted, while the traditional method requires the entire arch to be redrawn, which improves the fitting efficiency.

[0041] In combination with the first aspect, in some implementations of the first aspect, step S7 includes: S7-1: extracting the top edge line, bottom edge line, left boundary line and right boundary line of the upstream camber surface generated in step S6; S7-2: extracting the top edge line, bottom edge line, left boundary line and right boundary line of the downstream arc surface generated in step S6; S7-3: Call the boundary surface generation tool of the building information model software to connect the top edge line of the upstream arc surface and the top edge line of the downstream arc surface to generate the dam top surface, connect the bottom edge line of the upstream arc surface and the bottom edge line of the downstream arc surface to generate the dam base surface, connect the left boundary line of the upstream arc surface and the left boundary line of the downstream arc surface to generate the left bank surface, connect the right boundary line of the upstream arc surface and the right boundary line of the downstream arc surface to generate the right bank surface. The upstream arc surface, the downstream arc surface, the dam top surface, the dam base surface, the left bank surface and the right bank surface constitute the three-dimensional model body of the arch dam.

[0042] In step S7, the upstream and downstream arc surface boundary lines are connected through four-way skinning, which solves the geometric crack problem of the traditional BIM lofting model. This solution extracts the top edge line, bottom edge line and left and right boundary lines of the upstream and downstream arc surfaces, and calls the BIM boundary surface generation tool to automatically connect the corresponding boundary lines to generate the dam top surface, dam base surface and left and right bank surfaces. For example, the top edge line of the upstream arc surface and the top edge line of the downstream arc surface generate the dam top surface through skinning, and its width gradually changes from the crown to both sides, strictly fitting the design value. Four-way skinning forcibly constrains the boundary alignment to ensure the geometric closure of the model, which can be directly exported in STL or STEP format for finite element analysis, avoiding the mesh generation failure caused by model cracks in the traditional method and reducing the post-processing time.

[0043] Embodiment 2 As Figure 3 shown, in the second aspect, the present invention provides a parabolic arch dam model creation system. The creation system is applied to the creation method provided in any of the above embodiments. The creation system includes: An input module 10 for inputting a basic parameter set of the arch dam. The basic parameter set includes the longitudinal coordinates of the crown of each elevation horizontal arch ring, the thickness parameter and the curvature parameter; A construction module 20 connected to the input module 10 for constructing the central axis equation of each elevation horizontal arch ring based on the longitudinal coordinates of the crown of the horizontal arch ring and the curvature parameter, and calculating the discrete point coordinates of the upstream arch curve and the discrete point coordinates of the downstream arch curve according to the offset of the thickness parameter of the horizontal arch ring in the normal direction of the central axis; A first generation module 30 connected to the construction module 20 for calling the curve generation tool of the building information model software to generate the continuous upstream arch curve and the continuous downstream arch curve of each elevation horizontal arch ring based on the discrete point coordinates of the upstream arch curve and the discrete point coordinates of the downstream arch curve; A second generation module 40 connected to the construction module 20 for inserting encrypted arch rings between adjacent elevation horizontal arch rings, generating a parameter set of the encrypted arch rings based on the cubic spline interpolation algorithm, and generating the upstream arch curve and the downstream arch curve of the encrypted arch rings based on the parameter set of the encrypted arch rings; The merging module 50, connected to the first generation module 30 and the second generation module 40, is used to call the geometric merging tool of the building information model software to merge the continuous upstream arch curve of each elevation horizontal arch ring and the upstream arch curve of the encrypted arch ring into an upstream contour line set, and merge the continuous downstream arch curve of each elevation horizontal arch ring and the downstream arch curve of the encrypted arch ring into a downstream contour line set; The third generation module 60, connected to the construction module 20 and the merging module 50, is used to perform spatial lofting along the central axis with the upstream contour line set and the downstream contour line set as inputs respectively, and generate an upstream arc surface and a downstream arc surface correspondingly; The fourth generation module 70, connected to the third generation module 60, is used to extract the boundary lines of the upstream arc surface and the downstream arc surface, and perform four-way skinning processing by connecting the corresponding boundary lines to generate a three-dimensional model body of the arch dam.

[0044] This creation system corresponds to the creation method provided in Embodiment 1. Through the continuous technical chain of "parameter-driven asymmetric modeling, then cubic spline interpolation encryption, and finally BIM automated lofting and skinning", the modeling accuracy and the smoothness of the model are improved, and the three core problems of arch ring shape distortion, poor surface continuity, and low modeling efficiency in the traditional method are solved.

[0045] The present invention also provides an electronic device, which includes: A processor; A memory for storing processor-executable instructions; Wherein, the processor is used to execute the creation method provided in any one of the above embodiments.

[0046] The present invention also provides a computer-readable storage medium, which stores a computer program for executing the creation method provided in any one of the above embodiments.

[0047] The computer-readable storage medium may adopt any combination of one or more readable media. The readable medium may be a readable signal medium or a readable storage medium. The readable storage medium may include, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination of the above. More specific examples (non-exhaustive list) of the readable storage medium include: an electrical connection having one or more wires, a portable disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above.

[0048] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the technical solutions of the embodiments of the present invention.

Claims

1. A method for creating a parabolic arch dam model, characterized in that: include: S1: Input the basic parameter set of the arch dam, which includes the longitudinal coordinates, thickness parameters and curvature parameters of the arch crown of each horizontal arch ring at each elevation; S2: Based on the longitudinal coordinates and curvature parameters of the crown of the horizontal arch ring, the central axis equation of each elevation horizontal arch ring is constructed, and the coordinates of the discrete points of the upstream arch curve and the downstream arch curve are calculated according to the offset of the thickness parameter of the horizontal arch ring along the normal direction of the central axis; S3: calling a curve generation tool of the building information model software to generate a continuous upstream arch curve and a continuous downstream arch curve of each elevation level arch ring based on the coordinates of the discrete points of the upstream arch curve and the coordinates of the discrete points of the downstream arch curve; S4: inserting an infilled arch ring between adjacent horizontal arch rings at the elevation, generating a parameter set of the infilled arch ring based on a cubic spline interpolation algorithm, and generating an upstream arch curve and a downstream arch curve of the infilled arch ring based on the parameter set of the infilled arch ring; S5: calling the geometry merging tool of the building information model software, merging the continuous upstream arch curves of each elevation horizontal arch ring generated in step S3 and the upstream arch curves of the encrypted arch ring generated in step S4 into an upstream contour line set, and merging the continuous downstream arch curves of each elevation horizontal arch ring generated in step S3 and the downstream arch curves of the encrypted arch ring generated in step S4 into a downstream contour line set; S6: taking the upstream contour line set and the downstream contour line set as input respectively, performing spatial lofting along the central axis constructed in step S2, and generating an upstream camber surface and a downstream camber surface accordingly; S7: extracting the boundary lines of the upstream camber surface and the downstream camber surface, and performing four-way skinning processing by connecting the corresponding boundary lines to generate a three-dimensional model of the arch dam.

2. The creation method according to claim 1, characterized in that: The step S1 comprises: S1-1: Import the horizontal arch elevation sequence using a parametric table; S1-2: Reading the longitudinal coordinates of the crown of each elevation horizontal arch ring in the elevation sequence; S1-3: Loading thickness parameters of each elevation horizontal arch ring in the elevation sequence, wherein the thickness parameters include a left half arch thickness value and a right half arch thickness value; S1-4: Loading curvature parameters of each elevation horizontal arch ring in the elevation sequence, wherein the curvature parameters include a left arch crown curvature radius value, a right arch crown curvature radius value, a left half arch width value, and a right half arch width value.

3. The creation method according to claim 1, characterized in that: The curvature parameter includes a left crown curvature radius value and a right crown curvature radius value, and the thickness parameter includes a left half-arch thickness value and a right half-arch thickness value. Step S2 includes: S2-1: constructing a central axis equation of the left half arch ring based on the curvature radius of the left arch crown, wherein the central axis equation of the left half arch ring is a quadratic function equation of the longitudinal coordinates and the horizontal coordinates of the arch crown of the horizontal arch ring; S2-2: constructing a central axis equation of the right half arch ring based on the curvature radius of the right arch crown, wherein the central axis equation of the right half arch ring is also a quadratic function equation of the longitudinal coordinate and the horizontal coordinate of the arch crown of the horizontal arch ring; S2-3: According to the left half arch thickness value, the center axis of the left half arch circle constructed in step S2-1 is shifted upstream along its normal direction by half of the left half arch thickness value to generate the coordinates of the discrete points of the upstream arch curve; S2-4: According to the right half arch thickness value, the center axis of the right half arch circle constructed in step S2-2 is offset downstream along its normal direction by half of the right half arch thickness value to generate the coordinates of the discrete points of the downstream arch curve.

4. The creation method according to claim 3, characterized in that: The quadratic function equation in steps S2-1 and S2-2 is: The equation of the center axis of the left half arch is: (x≤0), The equation of the center axis of the right half arch is: (x ≥ 0), Wherein, B is the longitudinal coordinate of the crown of the horizontal arch ring, R L is the radius of curvature of the left crown, R R is the curvature radius of the right arch crown, x is the horizontal coordinate, y is the longitudinal coordinate of the central axis of the horizontal arch ring, wherein, with the arch crown as the origin, the left half arch x is a negative value, and the right half arch x is a positive value.

5. The creation method according to claim 1, characterized in that: The step S4 comprises: S4-1: taking the longitudinal coordinates of the crowns of the horizontal arch rings at each elevation input in step S1, the thickness parameter and the curvature parameter as endpoint constraints; S4-2: Based on the cubic spline interpolation algorithm, a parameter set of the encrypted arch ring is generated in the elevation direction between adjacent horizontal arch rings, wherein the parameter set of the encrypted arch ring includes the longitudinal coordinates of the crown of the encrypted arch ring, the thickness distribution gradient and the curvature change parameter; S4-3: generating the coordinates of discrete points of the dense arch ring based on the longitudinal coordinates of the crown of the dense arch ring, the thickness distribution gradient and the curvature variation parameters; S4-4: Call the curve generation tool to generate an upstream arch curve and a downstream arch curve of the encrypted arch based on the discrete point coordinates of the encrypted arch.

6. The creation method according to claim 5, characterized in that: The step S4-2 comprises: S4-2-1: Based on the cubic spline interpolation algorithm, a first-order derivative continuity constraint equation of the longitudinal coordinates of the crown of the encrypted arch ring is established between adjacent horizontal arch rings; S4-2-2: Based on the cubic spline interpolation algorithm, a second-order derivative continuity constraint equation of the thickness distribution gradient of the dense arch ring is established between adjacent horizontal arch rings; S4-2-3: Based on the cubic spline interpolation algorithm, a second-order derivative continuity constraint equation of the curvature change parameter of the encrypted arch ring is established between adjacent horizontal arch rings; S4-2-4: Solve the constraint equations of steps S4-2-1 to S4-2-3 jointly to generate a parameter set of the encrypted arch ring.

7. The creation method according to claim 1, characterized in that: The step S3 comprises: S3-1: calling the B-spline curve generation module of the building information model software; S3-2: Using the B-spline curve generation module, respectively fit the coordinates of the discrete points of the upstream arch curve and the coordinates of the discrete points of the downstream arch curve, and correspondingly generate continuous upstream arch curves and continuous downstream arch curves for each elevation level arch ring.

8. The creation method according to claim 1, characterized in that: The step S7 comprises: S7-1: extracting the top edge line, bottom edge line, left boundary line and right boundary line of the upstream cambered surface generated in step S6; S7-2: extracting the top edge line, bottom edge line, left boundary line and right boundary line of the downstream cambered surface generated in step S6; S7-3: Call the boundary surface generation tool of the building information model software, connect the top edge line of the upstream arc surface and the top edge line of the downstream arc surface to generate the dam top surface, connect the bottom edge line of the upstream arc surface and the bottom edge line of the downstream arc surface to generate the dam base surface, connect the left boundary line of the upstream arc surface and the left boundary line of the downstream arc surface to generate the left bank surface, connect the right boundary line of the upstream arc surface and the right boundary line of the downstream arc surface to generate the right bank surface, the upstream arc surface, the downstream arc surface, the dam top surface, the dam base surface, the left bank surface and the right bank surface constitute the three-dimensional model of the arch dam.

9. A parabolic arch dam model creation system, characterized in that: The creation system is applied to the creation method described in any one of claims 1 to 8, and the creation system comprises: An input module is used to input a basic parameter set of the arch dam, wherein the basic parameter set includes the longitudinal coordinates of the crown of each horizontal arch ring at each elevation, a thickness parameter and a curvature parameter; A construction module connected to the input module, for constructing the central axis equation of each elevation horizontal arch ring based on the longitudinal coordinates of the crown of the horizontal arch ring and the curvature parameter, and calculating the coordinates of the discrete points of the upstream arch curve and the downstream arch curve according to the offset of the thickness parameter of the horizontal arch ring along the normal direction of the central axis; A first generating module is connected to the building module and is used to call a curve generating tool of a building information model software to generate a continuous upstream arch curve and a continuous downstream arch curve of each elevation level arch ring based on the coordinates of the discrete points of the upstream arch curve and the coordinates of the discrete points of the downstream arch curve; A second generating module, connected to the building module, is used to insert an encrypted arch ring between adjacent horizontal arch rings, generate a parameter set of the encrypted arch ring based on a cubic spline interpolation algorithm, and generate an upstream arch curve and a downstream arch curve of the encrypted arch ring based on the parameter set of the encrypted arch ring; A merging module, connected to the first generating module and the second generating module, for calling a geometric merging tool of the building information model software, merging the continuous upstream arch curves of each elevation level arch ring with the upstream arch curves of the encrypted arch ring into an upstream contour line set, and merging the continuous downstream arch curves of each elevation level arch ring with the downstream arch curves of the encrypted arch ring into a downstream contour line set; A third generating module, connected to the building module and the merging module, is used to take the upstream contour line set and the downstream contour line set as inputs respectively, perform spatial lofting along the central axis, and generate an upstream camber and a downstream camber accordingly; The fourth generation module is connected to the third generation module and is used to extract the boundary lines of the upstream curved surface and the downstream curved surface, and generate a three-dimensional model of the arch dam by connecting the corresponding boundary lines and performing four-way skinning.

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