Parametric Intelligent Elbow Structure Design Method Based on Tekla Software

Abstract

This invention discloses a parametric intelligent elbow structure design method based on Tekla software, belonging to the field of steel structure 3D design technology, and solving the problems of low efficiency and inaccurate geometric adaptation in traditional elbow design. Its key points are: constructing a parametric resource library containing elbow cross-sections and material properties; creating a 3D elbow model prototype and parametric components in Tekla; associating geometric and material parameters with the 3D model prototype through a dual binding engine to form target parametric nodes; and automatically generating a three-layer elbow model based on user input parameters and primary and secondary member models. This method can be used to efficiently and accurately generate 3D models and manufacturing data for multi-layer dissimilar material pipe elbows.

Description

Technical Field

[0001] This invention relates to the field of three-dimensional design technology for steel structures. More specifically, this invention relates to a parametric intelligent elbow structure design method based on Tekla software. Background Technology

[0002] In the field of steel structure and industrial equipment manufacturing, elbows are key connecting components, and their design accuracy and modeling efficiency directly affect project quality and construction progress. Traditional elbow modeling mainly relies on manual drawing using general-purpose 3D software (such as AutoCAD) or specialized tools (such as Tekla Structures), which has the following inherent drawbacks:

[0003] 1. Low modeling efficiency and insufficient accuracy: Elbow structures involve multiple geometric parameters such as bending radius, pipe diameter, wall thickness, and angle. Manual modeling requires repeated adjustments to the model to meet process requirements. Especially for three-layer composite structures (outer steel pipe, middle fiberboard, and inner partitioned lining), each layer's cross-section needs to be drawn independently and must meet spatial nesting relationships, making the operation steps complex and significantly increasing time consumption. Manual operation is prone to introducing dimensional errors, leading to deviations between the model and actual needs, requiring corrections in downstream processes and increasing engineering costs.

[0004] 2. Low level of parameterization and slow response to design changes: Existing methods mostly use static templates. When modifying a single parameter (such as elbow angle or number of segments), it is necessary to remodel or perform multiple steps, which cannot achieve parameter linkage updates. For non-standard elbows (such as unconventional angles or 1-4 segment combination structures), there is a lack of rapid adaptation capability, requiring a complete model reconstruction, which makes it difficult to meet the customized needs of engineering projects.

[0005] 3. Assembly compatibility relies on manual verification, leading to a high risk of interference: The assembly relationship between the elbow and adjacent pipes, as well as the three-layer structure inside the elbow, requires manual inspection for spatial compatibility. This can easily result in dimensional conflicts or incompatible connections (such as the inner lining not being adjusted synchronously with the outer pipe). When design changes occur (such as adding or removing inner structures), remodeling and manual verification of interference are required. This process is cumbersome and prone to omissions, and problems often surface only during the manufacturing stage, leading to a surge in rework costs.

[0006] 4. Limited functionality and high barrier to entry for professional software: Although Tekla Structures has the capability for detailed steel structure design and a relatively open API, its built-in elbow types and flexibility are insufficient, its applicability is limited, and it lacks a dedicated toolchain for parametric modeling of elbows. Users need to write highly professional and complex scripts, which are difficult for ordinary designers to master, resulting in a high technical barrier to entry.

[0007] The aforementioned defects make the design process of complex multi-layered non-material elbows lengthy, error-prone, and costly to modify, making it difficult to meet the requirements of modern pipeline engineering for design efficiency, accuracy, and flexibility. Summary of the Invention

[0008] The purpose of this invention is to provide a parametric intelligent elbow structure design method based on Tekla software, so as to at least solve the above-mentioned problems.

[0009] To achieve the objectives and other advantages of this invention, a parametric intelligent elbow structure design method based on Tekla software is provided, comprising:

[0010] Construct a parametric resource library for elbows, which includes a predefined library of parametric cross sections for elbows, material properties, and grade information;

[0011] Based on the aforementioned elbow parametric resource library, a prototype 3D model of the target elbow is created in the 3D model interface of Tekla software.

[0012] In Tekla software, a parametric modeling component for elbows is created: geometric and material parameters are bound to the 3D model prototype of the target elbow to obtain parametric nodes of the target elbow.

[0013] The system receives user-input design parameters, 3D models of main members and secondary members, and generates a 3D model of the target elbow based on the parameterized nodes of the target elbow; wherein,

[0014] The design parameters include: elbow angle, number of elbow sections, thickness of inner 1st layer section, thickness of inner 2nd layer section, angle of inner 2nd layer partition, whether the inner 1st layer is created as a whole, material of outer layer section, material of inner 1st layer section, material of upper section of inner 2nd layer, and material of lower section of inner 2nd layer.

[0015] The target elbow 3D model has a three-layer structure: the outermost layer is a steel pipe layer defined by the outer cross-sectional material, the main cross-sectional dimensions of the main members and / or secondary members 3D models; the middle layer is a continuous cladding layer defined by the thickness and material of the inner 1st layer cross-section; the inner layer is a liner defined by the thickness of the inner 2nd layer cross-section, and is divided into an upper region and a lower region according to the partition angle of the inner 2nd layer, wherein the upper region is associated with the upper cross-sectional material of the inner 2nd layer, and the lower region is associated with the lower cross-sectional material of the inner 2nd layer; the geometry of the target elbow 3D model is defined by the elbow angle and the number of elbow segments and is adapted to the main member 3D model and the secondary member 3D model. The number of elbow segments is the number of elbow segments plus 1, and the middle part of the elbow is a standard segment, and the two ends of the elbow are half of the standard segment. Each elbow segment is connected end to end along the central axis and associated through the elbow inflection point coordinates. The curvature of the interlayer contact surface of each elbow segment is continuous.

[0016] Preferably, the inflection point coordinates are located between adjacent bends, obtained through the following steps:

[0017] Obtain the user-inputted bend angle and number of bends, main section diameter value of the 3D model of the main and secondary members, and end face center point. The bend angle is greater than 0° and less than or equal to 90°, and the number of bends is greater than or equal to 1.

[0018] Based on the bend angle and the number of bends, calculate the average angle, where the average angle is the bend angle divided by the number of bends;

[0019] Based on the evenly divided angle, calculate the angle value corresponding to each inflection point of the bend. The angle of the first inflection point is half of the evenly divided angle, and the angles of subsequent inflection points are increased by the evenly divided angle on the previous inflection point angle. The number of inflection points is equal to the number of bends.

[0020] Set the radius of the inscribed circle of the line connecting the inflection points of the elbow to be equal to the diameter of the main section.

[0021] The center of the elbow is determined based on the center point of the main section end face and the radius of the inscribed circle.

[0022] Based on the diameter of the main section and the angle values ​​corresponding to each inflection point of the elbow, the temporary coordinates of each inflection point are calculated. The temporary coordinates are the coordinates of the intersection of the oblique line of the corresponding inflection point angle with the elbow center as the origin and the center line of the main section. The corresponding inflection point angle is the angle between the line connecting the elbow center and the center point of the main section end face and the corresponding oblique line.

[0023] Calculate the circumcircle radius at each bend of the elbow. The circumcircle radius is equal to the incircle radius divided by the cosine of the angle at the first bend.

[0024] Based on the temporary coordinates and the circumscribed circle radius, calculate the coordinate increment of each inflection point. The coordinate increment includes the X-axis increment and the Y-axis increment. The X-axis increment is the inflection line length increment multiplied by the sine of the corresponding inflection point angle. The Y-axis increment is the inflection line length increment multiplied by the cosine of the corresponding inflection point angle. The inflection line length increment is the distance between the temporary coordinates and the center of the bend minus the circumscribed circle radius.

[0025] Based on temporary coordinates and coordinate increments, the final coordinates of each inflection point are calculated. The absolute value of the final X-coordinate is the absolute value of the temporary X-coordinate minus the X-axis increment, and the absolute value of the final Y-coordinate is the Y-axis increment. Specifically, when the center point of the end face of the secondary member's 3D model is located to the upper right of the main member, both the final X-coordinate and the final Y-coordinate are positive; when the center point of the end face of the secondary member's 3D model is located to the lower right of the main member, the final X-coordinate is positive and the final Y-coordinate is negative; when the center point of the end face of the secondary member's 3D model is located to the upper left of the main member, the final X-coordinate is negative and the final Y-coordinate is positive; when the center point of the end face of the secondary member's 3D model is located to the lower left of the main member, both the final X-coordinate and the final Y-coordinate are negative.

[0026] Output the coordinates of each inflection point.

[0027] Preferably, the creation of the elbow parametric modeling component includes: defining a dynamic variable group in "Define Custom Component" in the "Component Directory". The dynamic variable group includes geometric variables and material variables. The geometric variables include elbow angle α, number of elbow sections N, inner layer 1 thickness T1, inner layer 2 thickness T2, and partition angle θ. The material variables include outer layer material M0, inner layer 1 material M1, and upper inner layer 2 material M 21 Inner 2 layers, lower material M 22 ;

[0028] The geometric and material variables are associated with the target elbow 3D model prototype through a dual binding engine. Specifically, α is bound to the angle between the central axes of the main member and the secondary member; N is bound to the number of segmented cutting surfaces; T1 and T2 are bound to the radial offset distances of their respective layers; θ is bound to the rotation angle of the virtual segmentation surface; and M0, M1, and M... 21 M 22 Bind to the material property field of the corresponding geometric entity.

[0029] Preferably, the generation of the inner two-layer partition structure includes: generating a partition surface based on the elbow centerline and the partition angle θ; and associating the upper region of the partition surface with the material variable M. 21 The lower region is associated with M 22 When θ is dynamically adjusted in the range of 0°-360°, the segmentation surface rotates in real time and reconstructs the material boundary.

[0030] Preferably, the dual-binding engine executes material variable M 21 M 22 When binding with the inner two-layer structure geometry, a material transition zone preprocessing module is integrated. This module, as a sub-functional unit of the elbow parametric modeling component, operates according to the following logic: During the initialization phase of the elbow parametric modeling component, a material transition zone is pre-generated within the complete annular region of the inner two-layer structure; a dynamic mask boundary controlled by the partition angle θ is defined for the material transition zone, the dynamic mask boundary consisting of two virtual boundary lines parallel to the partition surface and equidistant from the partition surface; when the θ value is updated, the dual binding engine drives the dynamic mask boundary to rotate synchronously around the central axis and executes: marking the upper region of the dynamic mask boundary as active, associating material M... 21 The region below the dynamic mask boundary is marked as active, and associated material M 22 The strip region between the boundaries of the dynamic mask is marked as a transition state, and its material properties inherit the logical association relationship of the adjacent active regions; the geometric topology of the material transition region remains static during the θ adjustment process.

[0031] Preferably, the curvature continuity of the interlayer contact surface is achieved by automatically detecting the local curvature deviation value of the contact surface of adjacent layers. If the deviation value exceeds the preset tolerance threshold, it is marked as a discontinuous region. Subsequently, a transition surface is dynamically inserted into the marked region. The bidirectional curvature feature of the transition surface matches the geometric properties of the upper and lower layer surfaces. The detection, marking, insertion and curvature matching process is executed iteratively, and the rate of change of curvature deviation value is monitored in real time. The iteration is terminated when any of the following conditions are met: the curvature deviation value of all contact surfaces is lower than the tolerance threshold; the rate of change of curvature deviation value is less than 5% for three consecutive iterations; or the number of iterations reaches the upper limit of 10.

[0032] Preferably, after generating the target elbow 3D model, based on the user-input outer layer cross-section material, inner 1st layer cross-section material, inner 2nd layer upper cross-section material, inner 2nd layer lower cross-section material, inner 1st layer cross-section thickness, and inner 2nd layer cross-section thickness, as well as the obtained main cross-section dimensions of the main members and / or secondary members 3D models, the material usage is calculated and a bill of materials is generated using the report templates and data files built into the Tekla software. The manufacturing data files associated with the target elbow 3D model are output, including DXF data files and NC numerical control files.

[0033] The present invention has at least the following beneficial effects:

[0034] First, by constructing a predefined parametric resource library and creating parametric nodes in Tekla, automated modeling of three-layer dissimilar material elbows was achieved. The structure of the outer steel pipe, the intermediate continuous cladding layer, and the partitioned liner can be directly generated by user-input geometric parameters (angle, number of sections, thickness), material parameters, and the obtained 3D models of the main and / or secondary members. The inner liner is automatically divided into upper and lower dissimilar material regions according to the partition angle, solving the tedious problem of manually modeling each layer of multi-layer structures in traditional methods and significantly reducing manual modeling steps. Segmented design (number of sections + 1 segment) combined with a fold point coordinate association mechanism ensures accurate geometric adaptation between the elbow and the main and secondary members. The continuity of curvature of the interlayer contact surface ensures the rationality of structural stress and manufacturability, significantly improving design efficiency and model accuracy.

[0035] Secondly, a coordinate calculation algorithm based on the inscribed circle radius and inflection point angle sequence is adopted to accurately locate the connection points of each segment. The inscribed circle radius is dynamically determined by the main section diameter, and an inflection point angle sequence is generated by combining the evenly divided angles. Then, through iterative calculations using temporary coordinates and coordinate increments, the final inflection point coordinates are output. This algorithm replaces the traditional manual calculation relying on experience, eliminating the risk of gaps or interference caused by segment misalignment. The introduction of the circumscribed circle radius ensures the geometric smoothness of the connection points between adjacent segments, making the overall shape of the elbow strictly conform to the design parameter requirements, and providing a core geometric benchmark for automated segment modeling.

[0036] Third, by defining geometric variables (α, N, T1, T2, θ) and material variables (M0, M1, M... 21 M 22 The system uses a dynamic variable group and a dual-binding engine to associate it with the geometric entities and attribute fields of the model prototype, achieving full parameter-driven operation. Geometric variables directly control key features such as axis rotation angle, number of segments, and layer thickness offset; material variables are bound to entity attribute fields to ensure that material changes are mapped to the corresponding areas in real time. This mechanism centralizes the management of scattered parameters, avoiding the chain of modifications and omissions caused by isolated parameters in traditional design, and significantly improving the consistency and reliability of design iterations.

[0037] Fourth, based on the partition angle θ, a segmentation surface around the centerline is dynamically generated, achieving precise partitioning of the inner lining material. The real-time rotation and reconstruction of the segmentation surface ensures that the upper and lower material boundaries are always strictly synchronized with the θ value, solving the problem of maintaining surface consistency when manually segmented. The dynamic adjustment range of θ is specifically limited to 0°-360°, covering engineering requirements from no partitioning to full coverage on one side, enhancing design flexibility. Deep integration of the partitioning logic and geometric model avoids compatibility risks introduced by external auxiliary tools.

[0038] Fifth, the material transition zone preprocessing module achieves conflict-free switching of material partitions through a dynamic mask boundary mechanism. During the initialization phase, a static transition zone is pre-generated, and the active region (M) is divided by a mask boundary controlled by θ. 21 / M 22 The transition region is defined as follows: During θ update, the mask boundary rotation drives the material label update, and the transition region automatically inherits adjacent logical relationships. This mechanism ensures that changes in material properties do not trigger model reconstruction while maintaining geometric topological stability, thus avoiding computational delays caused by regeneration.

[0039] Sixth, an iterative curvature continuity assurance mechanism is adopted, dynamically optimizing the contact surface through a closed-loop process of "detection, marking, insertion, and matching." Curvature deviation detection locates discontinuous areas, and the insertion of transition surfaces synchronously matches bidirectional curvature features. Combined with rate of change monitoring and iteration termination conditions (tolerance threshold, rate of change threshold, and maximum number of iterations), efficient convergence is achieved. This mechanism replaces manual surface tuning, resolving the potential for stress concentration or sealing failure caused by abrupt changes in curvature at interlayer contact surfaces, improving structural reliability, and reducing rework in later stages.

[0040] Seventh, after the parametric components automatically associate model material properties, the Tekla software automatically generates a Bill of Materials (BOM) and manufacturing documents (DXF / NC) using built-in report templates and data files. This significantly improves the overall efficiency from design to production and eliminates the risk of data omissions due to the complex modeling process traditionally performed manually. The DXF / NC files are strictly synchronized with the 3D model, ensuring the uniqueness of the manufacturing data source. This function connects the data link from design to manufacturing, reduces errors in information conversion, provides directly usable standardized data for downstream processing, and shortens the delivery cycle.

[0041] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Attached Figure Description

[0042] Figure 1 This is a top view of a 90-degree elbow model according to an embodiment of the present invention;

[0043] Figure 2 yes Figure 1 A 3D model of a mid-bend. Detailed Implementation

[0044] The present invention will now be described in further detail with reference to the embodiments and accompanying drawings, so that those skilled in the art can implement it based on the description.

[0045] It should be understood that terms such as “having,” “comprising,” and “including” as used herein do not exclude the presence or addition of one or more other elements or combinations thereof.

[0046] It should be noted that, unless otherwise specified, the experimental methods described in the following embodiments are all conventional methods, and the reagents and materials described are all commercially available unless otherwise specified. In the description of this invention, the terms "lateral", "longitudinal", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0047] According to one embodiment of the present invention, a parametric intelligent elbow structure design method based on Tekla software includes:

[0048] Step 1: Construct a parametric elbow resource library, which includes a predefined parametric cross-section library, material properties, and grade information. The cross-section library can contain circular, elliptical, or rectangular cross-sections, with dimensions covering nominal diameters from DN50 to DN1000. The material property database can integrate commonly used industrial pipeline materials such as Q235B carbon steel, 304 stainless steel, fluororubber, and ceramic composites. Grade information can include color. This resource library is integrated into the Tekla software environment as a database, and parameters are accessed through a standard interface. Cross-section parameters can be entered via the user interface or imported in batches from CSV files. Material properties are bound to the Tekla software's material library, and grade information is associated with model attribute fields. The resource library is stored on the local computer and accessed during modeling through built-in software functions.

[0049] Step 2: Based on the elbow parameterization resource library, create a 3D model prototype of the target elbow with a specific structural form in the 3D model interface of Tekla software, such as 30° elbow, 45° elbow, 60° elbow, 70° elbow, 80° elbow and 90° elbow 3D model prototype.

[0050] Step 3: Create a parametric modeling component for the elbow in Tekla software. Specifically, define a dynamic variable group in "Define Custom Components" within the "Components Catalog". This dynamic variable group includes geometric variables and material variables. Geometric variables include the elbow angle α, which can be selected between 0 degrees and 90 degrees or less; the number of elbow sections N, which is a positive integer, for example, a positive integer from 1 to 8; the thickness of the inner 1st layer section T1, which can range from 5 mm to 50 mm; the thickness of the inner 2nd layer section T2, which can range from 3 mm to 30 mm; and the partition angle θ, which can be adjusted from 0 degrees to 360 degrees (0 degrees means no inner 2nd layer is created, 360 degrees means the upper material of the inner 2nd layer is sprayed as a whole). Material variables include the outer layer material M0, which can be selected as carbon steel or stainless steel; the inner 1st layer material M1, which can be selected as rubber or polyurethane; and the upper material of the inner 2nd layer M... 21 and lower material M 22 Ceramic or polyethylene can be selected. These geometric and material variables are associated with the target elbow's 3D model prototype using a dual-binding engine, resulting in parametric nodes for the target elbow. Specifically, the elbow angle α is bound to the angle between the central axes of the main member and the secondary member; the number of segments N is bound to the number of segmented cut surfaces; the thicknesses T1 and T2 are bound to the radial offset distance parameters of the corresponding layers; and the partition angle θ is bound to the rotation angle parameter of the virtual partition surface. Material variables M0, M1, and M... 21 M 22 Then it is bound to the material property field of the corresponding geometric entity.

[0051] Step 4: Receive user-input design parameters, the 3D model of the main member, and the 3D model of the secondary member. Generate the 3D model of the target elbow based on the parameterized nodes of the target elbow. Design parameters include elbow angle, number of elbow sections, thickness of inner layer 1 section, thickness of inner layer 2 section, angle of inner layer 2 partition, whether the inner layer 1 is created as a whole, material of outer layer section, material of inner layer 1 section, material of upper section of inner layer 2, and material of lower section of inner layer 2.

[0052] When the inner layer 1 is defined as "Create Overall", the generated target elbow 3D model is a three-layer structure: the outermost layer is a steel pipe layer defined by the main cross-sectional dimensions of the outer layer cross-section material, main members, and / or secondary members 3D models; the middle layer is a continuous cladding layer defined by the inner layer 1 cross-sectional thickness and inner layer 1 cross-sectional material, such as a 15 mm thick rubber layer, generated through a radial offset operation; the inner layer is a liner defined by the inner layer 2 cross-sectional thickness, such as a 10 mm thick layer, and is divided into upper and lower dissimilar material regions according to the inner layer 2 partition angle θ (the upper part is associated with the upper cross-sectional material M of the inner layer 2). 21 The lower part is associated with the inner two layers of cross-sectional material M. 22 When the creation status of the inner layer is not specified, the system automatically skips the intermediate layer generation logic, and the target elbow 3D model is simplified to a two-layer structure: the outer layer is a steel pipe layer defined by the outer cross-sectional material (geometric properties are consistent with the three-layer structure); the inner layer is a liner defined by the thickness of the inner two cross-sections, directly nested on the inner surface of the outer steel pipe, and divided into upper and lower dissimilar material regions according to the partition angle θ (the upper part is associated with M). 21 The lower part is related to M. 22 At this point, the inner layer section thickness parameter T1 is ignored, and the inner layer section material parameter M1 is invalid. The geometry of the target elbow 3D model is defined by the elbow angle and the number of elbow segments, and is adapted to the 3D models of the main members and secondary members. The number of elbow segments is the number of elbow segments plus 1, with the middle of the elbow being the standard segment and both ends of the elbow being half of the standard segment. Each elbow segment is connected end-to-end along the central axis and associated through the elbow inflection point coordinates, and the interlayer contact surfaces of each elbow segment maintain curvature continuity. When the user inputs parameters such as: elbow angle 90 degrees, number of sections 4, inner layer 1 section thickness 20mm, inner layer 2 section thickness 60mm, inner layer 2 partition angle 120 degrees, whether the inner layer 1 is created as a whole (yes), outer layer section material Q235B, inner layer 1 section material 1260 type fiberboard, inner layer 2 upper section material Gunar40 spray coating, and inner layer 2 lower section material PC40 wear-resistant plastic, the system automatically generates a target elbow 3D model that matches the main member 3D model and the secondary member 3D model and their main section dimensions. Figure 1 , Figure 2 As shown.

[0053] In existing methods, when engineers design a 90-degree three-layer elbow using Tekla's basic functions, they first need to independently create a solid model of the outer steel pipe. Then, based on the existence of the primary and secondary members, a copy of the outer steel pipe is made at the same location, and the cross-sectional specifications of the copy are changed to create the intermediate layer. Next, the inner liner is divided: manually laying out the lines, drawing the positions of the 120-degree lines, and then using the cut command to cut off the unwanted parts to achieve a semi-circular cross-section effect. The upper area after cutting is assigned ceramic material, and the lower area is assigned polyethylene material. Subsequently, the segmented structure is processed. Based on the calculation of 4 segments, it is determined that it needs to be divided into 5 segments. Through lofting, the positions of each bend point are found, and then the members are placed end-to-end at each bend point. Finally, the segments are connected together using the "Fit to Part End" command. Final checks include: ① manually checking whether the working points of all members are uniformly at the bend point positions, whether there are collisions between layers (collisions indicate errors in the cross-sectional specifications of the members), whether the ends of each member have been properly integrated, and the material, grade, and other attribute information of each member. ② Collision issues can also be checked using the "Collision Check" command to examine interference. Problems discovered during the check can be manually adjusted manually to address specific issues related to values ​​and positional relationships. If the bend angle needs to be changed to 60 degrees or the partition angle to 150 degrees, all modeling steps must be re-executed.

[0054] A comparison of this solution with existing methods reveals that the implementation of this invention achieves a fundamental improvement in efficiency and accuracy in elbow structure design. Existing methods rely on engineers manually performing each step of modeling, cutting, segmentation, and material assignment, a process that is cumbersome, error-prone, and difficult to modify (e.g., adjusting angles or partitions requires starting from scratch). In contrast, this invention automates the design process through a pre-built parametric resource library and intelligent components: users only need to input key parameters (such as angle, number of sections, thickness, and material), and the system automatically generates a geometrically accurate, layer-to-layer, and collision-free 3D model. This not only reduces time consumption but also completely avoids errors caused by manual intervention, greatly improving design quality and repeatability.

[0055] According to another embodiment of the present invention, such as Figure 1 The elbow shown has its inflection point coordinates obtained through the following steps: Step 1: Obtain user input parameters, the main section diameter value of the three-dimensional model of the main and secondary members, and the center point of the end face (input parameters such as elbow angle 90 degrees, number of sections 4).

[0056] Step 2: The system automatically calculates the bisector angle as 90 / 4 = 22.5 degrees;

[0057] Step 3: Generate the inflection point angle sequence: First inflection point 11.25 degrees (22.5 / 2), second inflection point 33.75 degrees (11.25+22.5), third inflection point 56.25 degrees (33.75+22.5), fourth inflection point 78.75 degrees (56.25+22.5);

[0058] Step 4: Set the radius of the inscribed circle to be equal to the diameter of the main member, such as 300 mm;

[0059] Step 5: Set the center point of the main member end face to (0,0,0) and determine the center position of the elbow (0,-300,0);

[0060] Step 6: Calculate the temporary coordinates. First inflection point: the intersection of the 11.25-degree oblique line and the center line of the main section, temporary X = 300 × tan(11.25°); Second inflection point: the intersection of the 33.75-degree oblique line and the center line of the main section, temporary X = 300 × tan(33.75°); Third inflection point: the intersection of the 56.25-degree oblique line and the center line of the main section, temporary X = 300 × tan(56.25°); Fourth inflection point: the intersection of the 78.75-degree oblique line and the center line of the main section, temporary X = 300 × tan(78.75°).

[0061] Step 7: Calculate the circumcircle radius = 300 / cos(11.25°);

[0062] Step 8: Derive the coordinate increments. For the first inflection point, the X increment = 11.25° slope length increment × sin(11.25°), and the Y increment = 11.25° slope length increment × cos(11.25°). The 11.25° slope length increment is the distance between the temporary coordinates of the first inflection point and the center of the bend minus the circumscribed circle radius. For the second inflection point, the X increment = 33.75° slope length increment × sin(33.75°), and the Y increment = 33.75° slope length increment × cos(33.75°). The 33.75° slope length increment is the distance between the temporary coordinates of the second inflection point and the center of the bend minus the circumscribed circle radius. The radius of the circumscribed circle is calculated as follows: X increment of the third inflection point = 56.25° diagonal length increment × sin(56.25°), Y increment = 56.25° diagonal length increment × cos(56.25°), where the 56.25° diagonal length increment is the distance between the temporary coordinates of the third inflection point and the center of the bend minus the radius of the circumscribed circle; X increment of the fourth inflection point = 78.75° diagonal length increment × sin(78.75°), Y increment = 78.75° diagonal length increment × cos(78.75°), where the 78.75° diagonal length increment is the distance between the temporary coordinates of the fourth inflection point and the center of the bend minus the radius of the circumscribed circle.

[0063] Step 9: Output the final vertex coordinates: First vertex (temporary X of first vertex - X increment of first vertex, 0, 0); Second vertex (temporary X of second vertex - X increment of second vertex, - Y increment of second vertex, 0); Third vertex (temporary X of third vertex - X increment of third vertex, - Y increment of third vertex, 0); Fourth vertex (temporary X of fourth vertex - X increment of fourth vertex, - Y increment of fourth vertex, 0);

[0064] Step 10: Automatically associate 5 bends based on the inflection point coordinates, and precisely connect the half-sections at both ends of the bends with the main and secondary members.

[0065] In this embodiment, a coordinate calculation algorithm based on the inscribed circle radius and the inflection point angle sequence is used to accurately locate the connection points of each segment. The inscribed circle radius is dynamically determined by the main section diameter, and the inflection point angle sequence is generated by combining the evenly divided angles. After iterative calculations using temporary coordinates and coordinate increments, the inflection point coordinates are finally output. This algorithm replaces the traditional manual calculations that rely on experience, eliminating the risk of gaps or interference caused by segment misalignment. The introduction of the circumscribed circle radius ensures the geometric smoothness of the connection points between adjacent segments, making the overall shape of the elbow strictly conform to the design parameter requirements, and providing a core geometric benchmark for automated segment modeling.

[0066] According to another embodiment of the invention, the dual-binding engine executes material variable M 21 M 22 When binding with the inner two-layer structural geometry, an integrated material transition zone preprocessing module is used. This module runs during the initialization phase of the elbow parametric modeling component, pre-generating a material transition zone within the complete annular area of ​​the inner two-layer structure. The width of this material transition zone can be set to 3 mm, 5 mm, or 7 mm. The geometric topology of the material transition zone remains statically unchanged during parameter adjustments.

[0067] A dynamic mask boundary, controlled by the partition angle θ, is defined for the material transition zone. This dynamic mask boundary consists of two virtual boundary lines parallel to the partition surface, with equal spacing between them. The virtual boundary lines are generated using a parametric surface algorithm, and their spatial coordinates are associated with a rotation matrix of the θ angle. When the user inputs a new partition angle (e.g., θ updates from 90 degrees to 120 degrees), the dual-binding engine drives the dynamic mask boundary to rotate synchronously around the elbow's central axis. During the rotation, the two virtual boundary lines remain parallel and their spacing remains constant.

[0068] After the dynamic mask boundary is rotated, material state marking is performed: the area above the dynamic mask boundary is marked as active and associated with the material variable M. 21 (e.g., ceramics), the lower region is marked as active and associated with the material variable M. 22(e.g., polyethylene). The strip-shaped region between two virtual boundary lines is marked as a transition state, and its material properties inherit the logical association between adjacent active regions. The material property update process does not trigger geometry reconstruction, but only modifies the entity attribute fields. This method achieves conflict-free switching of material partitions while maintaining geometric topological stability through the cooperation of static transition regions and dynamic mask boundaries, avoiding computational delays caused by model reconstruction.

[0069] According to another embodiment of the present invention, the curvature continuity of the interlayer contact surface is achieved by automatically detecting the local curvature deviation value of the contact surface of adjacent layers, and the preset tolerance threshold can be 0.05 mm. The detection process uses a surface analysis algorithm to scan the contact area between the outer steel pipe layer and the intermediate cladding layer, and between the intermediate cladding layer and the inner liner layer. When the system detects that the curvature deviation value of a certain contact point exceeds the 0.05 mm threshold, it automatically marks the area as a discontinuous area and highlights it in semi-transparent red in the three-dimensional model.

[0070] For marked discontinuous regions, the system dynamically inserts transition surfaces for repair. The bidirectional curvature features of the transition surface simultaneously adapt to the geometric properties of the upper and lower surface layers. The specific working process is as follows: First, the normal vectors (accuracy 0.01°) and principal curvature radii (accuracy 0.1 mm) of the upper and lower surface layers at the boundary of the discontinuous region are extracted, and then a transition surface with continuous curvature change is generated.

[0071] By iteratively executing the detection, marking, insertion, and curvature matching processes, the system monitors the rate of change of curvature deviation values ​​in real time. The iteration termination condition is set to one of the following three: the curvature deviation values ​​of all contact surfaces are below the 0.05 mm tolerance threshold; or the rate of change of curvature deviation values ​​is less than 5% for three consecutive iterations; or the number of iterations reaches the upper limit of 10. In the example, for a 90-degree elbow with a diameter of 300 mm, the system can meet the tolerance requirements with an average of 4.3 iterations. This method, through an automated curvature optimization mechanism, ensures the mechanical performance and sealing reliability of multi-layer elbow structures.

[0072] According to another embodiment of the present invention, after generating the three-dimensional model of the target elbow, based on the user-input outer layer cross-section material, inner 1st layer cross-section material, inner 2nd layer upper cross-section material, inner 2nd layer lower cross-section material, inner 1st layer cross-section thickness, and inner 2nd layer cross-section thickness, as well as the main cross-sectional dimensions of the obtained main members and / or secondary members three-dimensional models, the material usage is calculated and a bill of materials is generated through the report templates and data files built into the Tekla software. The manufacturing data file associated with the three-dimensional model of the target elbow is output, including a DXF data file and an NC numerical control file.

[0073] During operation, the system first accesses the report template, then automatically fills the specified fields of the template with the acquired outer layer cross-section material, inner layer 1 cross-section material, inner layer 2 upper cross-section material, inner layer 2 lower cross-section material, inner layer 1 cross-section thickness, and inner layer 2 cross-section thickness, as well as the main cross-section dimensions of the acquired main members and / or secondary members' 3D models. This ultimately generates a complete bill of materials (BOM) statistical table. Simultaneously, the system uses built-in data files to convert the model's geometric data into DXF data files and NC numerical control files that meet the requirements of the workshop equipment. The DXF data file contains the segmented outlines of the bent pipes, while the NC numerical control file defines the machining and manufacturing data parameters.

[0074] The number of devices and processing scale described herein are for simplification of the invention. Applications, modifications, and variations of the parametric intelligent elbow structure design method based on Tekla software of this invention will be readily apparent to those skilled in the art.

[0075] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A parametric intelligent elbow structure design method based on Tekla software, characterized in that, include: Construct a parametric resource library for elbows, which includes a predefined library of parametric cross sections for elbows, material properties, and grade information; Based on the aforementioned elbow parametric resource library, a prototype 3D model of the target elbow is created in the 3D model interface of Tekla software. In Tekla software, a parametric modeling component for elbows is created: geometric and material parameters are bound to the 3D model prototype of the target elbow to obtain parametric nodes of the target elbow. The system receives user-input design parameters, 3D models of main members and secondary members, and generates a 3D model of the target elbow based on the parameterized nodes of the target elbow; wherein, The design parameters include: elbow angle, number of elbow sections, thickness of inner 1st layer section, thickness of inner 2nd layer section, angle of inner 2nd layer partition, whether the inner 1st layer is created as a whole, material of outer layer section, material of inner 1st layer section, material of upper section of inner 2nd layer, and material of lower section of inner 2nd layer. The target elbow 3D model has a three-layer structure: the outermost layer is a steel pipe layer defined by the main cross-sectional dimensions of the outer cross-sectional material, the main members, and / or secondary members; the middle layer is a continuous cladding layer defined by the thickness and material of the inner 1st layer; and the inner layer is a liner defined by the thickness of the inner 2nd layer, which is divided into an upper region and a lower region according to the partition angle of the inner 2nd layer. The upper region is associated with the upper cross-sectional material of the inner 2nd layer, and the lower region is associated with the lower cross-sectional material of the inner 2nd layer. The geometry of the target elbow 3D model is defined by the elbow angle and the number of elbow segments and is adapted to the main member 3D model and the secondary member 3D model. The number of elbow segments is the number of elbow segments plus 1, and the middle part of the elbow is a standard segment, and the two ends of the elbow are half of the standard segment. Each elbow segment is connected end to end along the central axis and associated through the elbow inflection point coordinates. The curvature of the interlayer contact surface of each elbow segment is continuous. The creation of the parametric modeling component for the elbow includes: defining a dynamic variable group in "Define Custom Component" within the "Component Directory". This dynamic variable group includes geometric variables and material variables. The geometric variables include the elbow angle α, the number of elbow sections N, the inner layer thickness T1, the inner layer thickness T2, and the partition angle θ. The material variables include the outer layer material M0, the inner layer material M1, and the upper inner layer material M... 21 Inner 2 layers, lower material M 22 ; The geometric and material variables are associated with the target elbow 3D model prototype through a dual binding engine. Specifically, α is bound to the angle between the central axes of the main member and the secondary member; N is bound to the number of segmented cutting surfaces; T1 and T2 are bound to the radial offset distances of their respective layers; θ is bound to the rotation angle of the virtual segmentation surface; and M0, M1, and M... 21 M 22 Bind to the material property field of the corresponding geometric entity; The generation of the inner two-layer partition structure includes: generating a partition surface based on the elbow centerline and the partition angle θ; and associating the upper region of the partition surface with the material variable M. 21 The lower region is associated with M 22 When θ is dynamically adjusted in the range of 0°-360°, the segmentation surface rotates in real time and reconstructs the material boundary.

2. The parametric intelligent elbow structure design method based on Tekla software as described in claim 1, characterized in that, The coordinates of the inflection point are located between adjacent bends and are obtained through the following steps: Obtain the user-inputted bend angle and number of bends, main section diameter value of the 3D model of the main and secondary members, and end face center point. The bend angle is greater than 0° and less than or equal to 90°, and the number of bends is greater than or equal to 1. Based on the bend angle and the number of bends, calculate the average angle, where the average angle is the bend angle divided by the number of bends; Based on the evenly divided angle, calculate the angle value corresponding to each inflection point of the bend. The angle of the first inflection point is half of the evenly divided angle, and the angles of subsequent inflection points are increased by the evenly divided angle on the previous inflection point angle. The number of inflection points is equal to the number of bends. Set the radius of the inscribed circle of the line connecting the inflection points of the elbow to be equal to the diameter of the main section. The center of the elbow is determined based on the center point of the main section end face and the radius of the inscribed circle. Based on the diameter of the main section and the angle values ​​corresponding to each inflection point of the elbow, the temporary coordinates of each inflection point are calculated. The temporary coordinates are the coordinates of the intersection of the oblique line of the corresponding inflection point angle with the elbow center as the origin and the center line of the main section. The corresponding inflection point angle is the angle between the line connecting the elbow center and the center point of the main section end face and the corresponding oblique line. Calculate the circumcircle radius at each bend of the elbow. The circumcircle radius is equal to the incircle radius divided by the cosine of the angle at the first bend. Based on the temporary coordinates and the circumscribed circle radius, calculate the coordinate increment of each inflection point. The coordinate increment includes the X-axis increment and the Y-axis increment. The X-axis increment is the inflection line length increment multiplied by the sine of the corresponding inflection point angle. The Y-axis increment is the inflection line length increment multiplied by the cosine of the corresponding inflection point angle. The inflection line length increment is the distance between the temporary coordinates and the center of the bend minus the circumscribed circle radius. Based on temporary coordinates and coordinate increments, the final coordinates of each inflection point are calculated. The absolute value of the final X-coordinate is the absolute value of the temporary X-coordinate minus the X-axis increment, and the absolute value of the final Y-coordinate is the Y-axis increment. Specifically, when the center point of the end face of the secondary member's 3D model is located to the upper right of the main member, both the final X-coordinate and the final Y-coordinate are positive; when the center point of the end face of the secondary member's 3D model is located to the lower right of the main member, the final X-coordinate is positive and the final Y-coordinate is negative; when the center point of the end face of the secondary member's 3D model is located to the upper left of the main member, the final X-coordinate is negative and the final Y-coordinate is positive; when the center point of the end face of the secondary member's 3D model is located to the lower left of the main member, both the final X-coordinate and the final Y-coordinate are negative. Output the coordinates of each inflection point.

3. The parametric intelligent elbow structure design method based on Tekla software as described in claim 1, characterized in that, The dual-binding engine executes material variable M 21 M 22 When binding with the inner two-layer structure geometry, a material transition zone preprocessing module is integrated. This module, as a sub-functional unit of the elbow parametric modeling component, operates according to the following logic: During the initialization phase of the elbow parametric modeling component, a material transition zone is pre-generated within the complete annular region of the inner two-layer structure; a dynamic mask boundary controlled by the partition angle θ is defined for the material transition zone, the dynamic mask boundary consisting of two virtual boundary lines parallel to the partition surface and equidistant from the partition surface; when the θ value is updated, the dual binding engine drives the dynamic mask boundary to rotate synchronously around the central axis and executes: marking the upper region of the dynamic mask boundary as active, associating material M... 21 The region below the dynamic mask boundary is marked as active, and associated material M 22 The strip region between the boundaries of the dynamic mask is marked as a transition state, and its material properties inherit the logical association relationship of the adjacent active regions; the geometric topology of the material transition region remains static during the θ adjustment process.

4. The parametric intelligent elbow structure design method based on Tekla software as described in claim 1, characterized in that, The curvature continuity of the interlayer contact surface is achieved by automatically detecting the local curvature deviation value of the contact surface of adjacent layers. If the deviation value exceeds the preset tolerance threshold, it is marked as a discontinuous region. Then, a transition surface is dynamically inserted into the marked region. The bidirectional curvature feature of the transition surface matches the geometric properties of the upper and lower layer surfaces. The detection, marking, insertion and curvature matching process is executed iteratively, and the rate of change of curvature deviation value is monitored in real time. The iteration is terminated when any of the following conditions are met: the curvature deviation value of all contact surfaces is lower than the tolerance threshold; the rate of change of curvature deviation value is less than 5% for three consecutive iterations; or the number of iterations reaches the upper limit of 10.

5. The parametric intelligent elbow structure design method based on Tekla software as described in claim 1, characterized in that, After generating the target elbow 3D model, based on the user-input outer layer section material, inner 1st layer section material, inner 2nd layer upper section material, inner 2nd layer lower section material, inner 1st layer section thickness, and inner 2nd layer section thickness, as well as the main section dimensions of the obtained main members and / or secondary members 3D models, the material usage is calculated and a bill of materials is generated using the report templates and data files built into the Tekla software. The manufacturing data files associated with the target elbow 3D model are output, including DXF data files and NC numerical control files.

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