Arched truss modeling optimization method based on Grasshopper

Abstract

The invention discloses an arch truss modeling optimization method based on Grasshopper, and relates to the technical field of building steel structure engineering, and the method comprises the steps: inputting structure parameters of an arch truss; obtaining an arched reference curve according to the structural parameters; equally dividing along the arch reference curve to obtain a plurality of lower chord control points; based on the structure parameters and the plurality of lower chord control points, constructing an inverted triangular section at each lower chord control point by utilizing two lower chord control points corresponding to the lower chord control point, and connecting a lower chord, an upper chord and a web member system according to each control point to form a truss member center line model; and importing the truss rod piece center line model into structure analysis software to obtain a key structure performance index, and driving the truss rod piece center line model to automatically optimize the structure parameters according to the feedback of the key structure performance index. According to the method, parametric modeling and structural analysis can be seamlessly integrated, rapid design iteration and performance driving optimization are achieved, and the construction period is effectively shortened while the structural reliability is improved.

Description

Technical Field

[0001] This application generally relates to the field of building steel structure engineering technology, and specifically to a Grasshopper-based method for modeling and optimizing arch trusses. Background Technology

[0002] The external dimensions of the coal shed structure are affected by the site and the bucket wheel excavator. In order to ensure the economic rationality of the structure, it is necessary to continuously adjust the height, width, thickness and grid size of the truss. For example, the height, span, thickness and grid size of the arch truss have a certain reasonable ratio. When adjusting the span, it is necessary to modify the truss height, thickness and grid division. Manual adjustment requires manually correcting the spatial position of the chord and web members one by one. Traditional modeling methods rely on manual labor, and the adjustment of geometric parameters needs to be repeatedly modified, which is inefficient.

[0003] Meanwhile, traditional geometric modeling and structural analysis are often two separate processes. Design adjustments cannot obtain immediate feedback on mechanical performance, such as changes in deflection and stress, leading to long design iteration cycles and difficulty in quickly comparing and optimizing multiple parameter combinations. This often relies on experience, making it difficult to accurately find the optimal solution that balances safety and economy. Therefore, there is an urgent need for a method that can seamlessly integrate parametric modeling and structural analysis, enabling rapid design iteration and performance-driven optimization. Summary of the Invention

[0004] In view of the above-mentioned defects or deficiencies in the existing technology, it is desirable to provide a Grasshopper-based method for modeling and optimizing arch trusses.

[0005] This application provides a Grasshopper-based method for modeling and optimizing arched trusses, including: Input the structural parameters of the arch truss, which include at least the span parameter, arch height parameter, thickness parameter, width parameter, longitudinal grid number parameter, and landing angle parameter; Based on the span parameters, arch height parameters, and landing angle parameters, an arch reference curve is generated in the Grasshopper platform; Along the arched reference curve, the longitudinal grid is divided into equal parts according to the number of grid points to obtain multiple lower chord control points; Based on the thickness parameter, the width parameter, and multiple lower chord control points, two upper chord control points corresponding to the current lower chord control point are identified, so that an inverted triangular cross section is constructed at each lower chord control point, forming a control point set consisting of multiple sets of lower chord control points and upper chord control points corresponding to the inverted triangular cross sections; Based on the set of control points, the system automatically generates a lower chord connecting all lower chord control points, two upper chords connecting the corresponding upper chord control points, and a web member system connecting the upper chord control points and the lower chord control points, forming a complete truss member centerline model. The centerline model of the truss members is imported into the structural analysis software in real time to obtain key structural performance indicators. The feedback of the key structural performance indicators is used to guide the adjustment of the structural parameters and to automatically optimize the structural parameters by driving the centerline model of the truss members.

[0006] According to the technical solution provided in this application, based on the thickness parameter, the width parameter, and multiple lower chord control points, two upper chord control points corresponding to the current lower chord control point are identified, so that an inverted triangular cross-section is constructed at each lower chord control point, including: Obtain the current lower chord control point, the thickness parameter, and the width parameter; Based on the lower chord control point, construct a normal plane that is perpendicular to the tangent of the arched reference curve. Within the normal plane, based on the thickness and width parameters, two upper chord control points corresponding to the current lower chord control point are calculated; each lower chord control point and its two corresponding upper chord control points form an inverted triangular cross section.

[0007] According to the technical solution provided in this application, each lower chord control point and its corresponding two upper chord control points form an inverted triangular cross section that is an isosceles triangle; and the lower chord control point serves as the spatial coordinate point of the lower chord of the truss; the two upper chord control points serve as the spatial coordinate points of the two upper chords of the truss.

[0008] According to the technical solution provided in this application, the calculation of the two upper chord control points corresponding to the current lower chord control point includes: Obtain the curve tangent vector at the current lower chord control point; the curve tangent vector is used to construct a normal plane; The horizontal vector is calculated by performing a cross product between the global vertical vector and the tangent vector of the curve. Based on the horizontal vector and in combination with the width parameter, a first horizontal offset and a second horizontal offset, which are opposite in direction to the horizontal vector, are calculated. Calculate the vertical offset corresponding to the global vertical vector based on the thickness parameter and the global vertical vector; Add the first horizontal offset and the vertical offset to the spatial coordinates of the current lower chord control point to obtain the spatial coordinates of the first upper chord control point; add the second horizontal offset and the vertical offset to the spatial coordinates of the current lower chord control point to obtain the spatial coordinates of the second upper chord control point.

[0009] According to the technical solution provided in this application, the two upper chord control points are referred to as the first upper chord control point and the second upper chord control point; Based on the set of control points, the system automatically generates a lower chord connecting all lower chord control points, two upper chords connecting the corresponding upper chord control points, and a web member system connecting the upper and lower chord control points, forming a complete truss member centerline model, including: Connect all lower chord control points to generate the centerline of the lower chord. Connect all the first upper chord control points to generate the center line of the first upper chord bar; Connect all the second upper chord control points to generate the center line of the second upper chord. Based on the centerline of the lower chord, the centerline of the first upper chord, and the centerline of the second upper chord, a web member system is generated, and the web member system is used to form a K-shaped web member system by connecting the lower chord control point in each longitudinal grid with its two corresponding upper chord control points.

[0010] According to the technical solution provided in this application, the web member system includes: an upper chord plane web member and an oblique web member; The upper chord plane web member is a transverse web member connecting the first upper chord control point and the second upper chord control point within the same vertical grid, a longitudinal web member connecting different first upper chord control points within adjacent vertical grids, and a longitudinal web member connecting different second upper chord control points within adjacent vertical grids. The diagonal bracing is a bracing that connects the upper chord control point in each longitudinal grid with the next adjacent lower chord control point, such that in each longitudinal grid, the lower chord control point and the two upper chord control points form a K-shaped bracing system; and, between adjacent longitudinal grids, the diagonal bracing alternately connects to the lower chord control point starting from different upper chord control points.

[0011] According to the technical solution provided in this application, the centerline model of the truss member is imported into structural analysis software in real time to obtain key structural performance indicators, including: Preset load conditions and boundary conditions are applied in the structural analysis software; Perform structural analysis and feed back the key performance indicators of the current truss members to the Grasshopper platform interface in real time for visualization.

[0012] According to the technical solution provided in this application, after obtaining the key structural performance indicators, the following are also included: Use the structural parameters of the current arched truss as the global control slider; When the slider corresponding to any structural parameter is dragged, the structural parameters in the centerline model of the entire truss member are automatically updated, and the arch truss is reconstructed in real time. Based on the key structural performance indicators corresponding to the current arched truss displayed in real time, an arched truss construction scheme that meets the preset design requirements is obtained.

[0013] In summary, this technical solution specifically discloses a Grasshopper-based method for modeling and optimizing arched trusses, comprising: inputting the structural parameters of the arched truss, which include at least span parameters, arch height parameters, thickness parameters, width parameters, longitudinal grid number parameters, and landing angle parameters; generating an arched reference curve in the Grasshopper platform based on the span parameters, arch height parameters, and landing angle parameters; dividing the arched reference curve equally according to the longitudinal grid number to obtain multiple lower chord control points; and identifying two upper chord control points corresponding to the current lower chord control point based on the thickness parameters, width parameters, and the multiple lower chord control points. Chord control points are established by constructing an inverted triangular cross-section at each lower chord control point, forming a set of control points consisting of multiple sets of lower and upper chord control points corresponding to the inverted triangular cross-sections. Based on the control point set, lower chord members connecting all lower chord control points, two upper chord members connecting the corresponding upper chord control points, and a web member system connecting the upper and lower chord control points are automatically generated, forming a complete truss member centerline model. The truss member centerline model is imported into structural analysis software in real time to obtain key structural performance indicators. Feedback from the key structural performance indicators is used to guide the adjustment of structural parameters and automatically optimizes the structural parameters by driving the truss member centerline model.

[0014] Beneficial Effects: This invention defines the structural parameters of the arched truss as global driving variables, achieving fully automated generation from structural parameter input to a complete truss member centerline model. Therefore, after inputting the arched truss structural parameters, the system automatically generates the arch reference curve, equally divides the lower chord control points, constructs the inverted triangular cross-section based on precise vector operations, and automatically connects all chords and web members according to structural logic, generating an accurate member centerline model, effectively improving modeling efficiency and accuracy. Furthermore, this method imports the generated truss member centerline model into structural analysis software for real-time calculation and provides feedback on key structural performance indicators such as deflection and stress. This ensures that any adjustment to structural parameters is immediately verified by mechanical performance, thus constructing a real-time closed loop of adjustment-analysis-feedback. In this way, while ensuring structural safety, this method can quickly find the design scheme with the most economical material usage and optimal structural form, ultimately shortening the design cycle while improving the economy and reliability of the project. Attached Figure Description

[0015] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 This is a flowchart illustrating a Grasshopper-based method for modeling and optimizing arched trusses.

[0016] Figure 2 This is an expanded flowchart of step S400 in a Grasshopper-based method for modeling and optimizing arched trusses.

[0017] Figure 3 This is an expanded flowchart of step S401 in a Grasshopper-based method for modeling and optimizing arched trusses.

[0018] Figure 4 This is a schematic diagram of the Grasshopper parameterization algorithm logic.

[0019] Figure 5 This is a schematic diagram of a typical arched coal shed truss. Detailed Implementation

[0020] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0021] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0022] To make the technical solutions of the embodiments of this application clearer and easier to understand, the application background of the embodiments of this application is introduced below.

[0023] The external dimensions of coal shed structures are influenced by the site and the bucket wheel excavator. Generally, large arched coal sheds typically employ inverted triangular cross-section space truss structures. Their design requires comprehensive consideration of various parameters such as span, arch height, cross-sectional dimensions, and grid division to meet the requirements of process layout, site constraints, structural safety, and economy. For example, since the height, span, thickness, and grid size of an arched truss have a certain reasonable proportion, adjusting the span requires revising the truss height, thickness, and grid division. In traditional design processes, engineers typically use general-purpose 3D modeling software to manually create truss models. When any structural parameter (such as span or arch height) needs to be adjusted, the spatial positions and connections of numerous chords and web members must be manually modified one by one, a tedious, inefficient, and error-prone process.

[0024] Furthermore, traditional geometric modeling and structural analysis are often two separate processes. Design adjustments cannot obtain immediate feedback on mechanical performance, such as changes in deflection and stress, resulting in long design iteration cycles. It is difficult to quickly compare and optimize multiple parameter combinations, often relying on experience and making it difficult to accurately find the optimal solution that combines both safety and economy.

[0025] In view of this, this application proposes a Grasshopper-based modeling and optimization method for arched coal shed trusses, including: inputting the structural parameters of the arched truss, which at least include span, arch height, thickness, width, longitudinal grid number, and landing angle; generating an arched reference curve in the Grasshopper platform based on the span, arch height, and landing angle; dividing the arched reference curve equally according to the longitudinal grid number to obtain multiple lower chord control points; and, based on the thickness parameter, width parameter, and multiple lower chord control points, at each lower chord control point... An inverted triangular cross-section is constructed to form a set of control points consisting of multiple sets of inverted triangular cross-section control points. Based on the control point set, a lower chord connecting all lower chord control points, two upper chords connecting the corresponding upper chord control points, and a web member system connecting the upper and lower chord control points are automatically generated, forming a complete truss member centerline model. The truss member centerline model is imported into structural analysis software in real time to obtain key structural performance indicators. Feedback from the key structural performance indicators is used to guide the adjustment of structural parameters and automatically optimizes the structural parameters by driving the truss member centerline model.

[0026] To address the aforementioned traditional methods, the Grasshopper-based parametric method uses algorithms to associate structural parameters, defining span, arch height, thickness, width, longitudinal grid number, and landing angle as variables. By modifying these variables, automatic modeling of arched trusses is achieved. Modifying any structural parameter updates the established associated geometry, significantly improving modeling efficiency. Furthermore, this method integrates a parametric truss member centerline model with structural analysis software. While adjusting any structural parameter, the system calculates deflection changes, realizing an adjustment-verification closed loop and accelerating the confirmation of the final construction scheme for arched trusses.

[0027] Please refer to Figure 1 The flowchart shown in this embodiment illustrates the Grasshopper-based arched truss modeling and optimization method. The executing entity of this embodiment can be a modeling system for arched coal shed trusses. The modeling and optimization method includes the following steps: S100. Input the structural parameters of the arch truss. The structural parameters include at least the span parameter, arch height parameter, thickness parameter, width parameter, longitudinal grid number parameter, and landing angle parameter. This step is the starting point for driving the entire automated design process. Designers need to define and input a set of core structural parameters in the Grasshopper platform interface by creating number sliders, numerical panels, or connecting to external data tables. These structural parameters need to be set according to the actual design requirements.

[0028] Among them, the structural parameters include at least: the span and arch height that determine the outline of the arched coal shed truss structure; the thickness (vertical spacing between the upper and lower chords) and width (horizontal spacing between the two upper chords) of the inverted triangle cross-section, the number of longitudinal grids that control the longitudinal division density, and the landing angle that affects the connection state between the landing section and the foundation. It should be noted that all these structural parameters are set as global variables and become the input source for all subsequent algorithms.

[0029] S200. Based on the span parameters, arch height parameters, and landing angle parameters, an arch reference curve is generated in the Grasshopper platform. This step transforms the structural parameters input in S100 into specific spatial geometric references. Specifically, in Grasshopper, mathematical functions are used to precisely generate a curve in the form of a circular arc or parabola, using the span, arch height, and landing angle as input. This curve is not the final member, but rather the spine of the entire truss space, explicitly defined as the centerline of the lower chord. The Grasshopper parametric algorithm logic is as follows: Figure 4 This figure shows the local connections between the parameter variables and the arithmetic unit (the overall connections are not shown).

[0030] As can be seen, using a mathematically precise curve as the sole benchmark for the overall shape ensures the smoothness and accuracy of the arched coal shed truss. All subsequent cross-sectional constructions and point generation are based on this curve, giving the final model a high degree of geometric consistency and logic, and avoiding the misalignment or discontinuity problems that may occur with manual segmented modeling.

[0031] S300, along the arched reference curve, divide the longitudinal grid equally to obtain multiple lower chord control points; This step aims to determine the critical node locations of the longitudinal members of the truss (especially the lower chord) along the reference curve. Using Grasshopper's Divide Curve component, the previously generated arched reference curve is used as input, with the longitudinal grid number defined in S100 as the number of equal segments (N). The calculator automatically generates N+1 equal division points on the arched reference curve.

[0032] It should be noted that these points are the lower chord control points (Point_lower[i]), which are essentially a series of precise spatial coordinates on the centerline through which the lower chord will pass; and each lower chord control point is the bottom vertex of the inverted triangle cross-section. In this way, by parametrically dividing the structure, the continuous curve is discretized into a controllable set of points. The longitudinal grid number directly controls the number of truss sections and the density of the web members. During subsequent structural parameter adjustments, modifying this parameter can adjust the mesh division of the entire bridge without manually adding or deleting nodes, enabling rapid changes in the structural topology and facilitating the discovery of the impact of different mesh densities on steel consumption and load-bearing performance.

[0033] S400. Based on the thickness parameter, the width parameter, and multiple lower chord control points, identify two upper chord control points corresponding to the current lower chord control point, so as to construct an inverted triangular cross section at each lower chord control point, forming a control point set composed of multiple sets of lower chord control points and upper chord control points corresponding to the inverted triangular cross sections. First, it needs to be clarified that the inverted triangular cross-section design is a truss form with excellent spatial stress performance and high torsional stiffness. Therefore, the goal of this step is to construct an inverted triangular cross-section perpendicular to the curve's direction, based on each lower chord control point and its two corresponding upper chord control points. Specifically, for each generated lower chord control point, a set of vector operations is performed to determine the spatial coordinates of the remaining two upper chord control points that form the inverted triangular cross-section with that lower chord control point.

[0034] Specifically, see Figure 2 Step S400 includes the following steps: S401. Obtain the current lower chord control point, thickness parameters, and width parameters; S402. Based on the lower chord control point, construct a normal plane that is perpendicular to the tangent of the arched reference curve. S403. In the normal plane, calculate the two upper chord control points corresponding to the current lower chord control point based on the thickness and width parameters. Each lower chord control point and its two corresponding upper chord control points form an inverted triangular cross-section.

[0035] First, the previously generated lower chord control points, as well as the thickness and width parameters, are needed as input structural parameters. Then, the tangent vector of the arched reference curve at the lower chord control point is calculated to determine the cross-section orientation (normal plane). Next, within this normal plane, the horizontal positions of the two upper chord points are obtained by horizontal offset to both sides based on the width parameter; the height positions of the upper chord points are obtained by vertical offset upwards based on the thickness parameter. Finally, each cross-section is uniquely determined by one lower chord control point (Point_lower[i]) and two upper chord control points (Point_upper1[i], Point_upper2[i]).

[0036] It is evident that the calculations for obtaining the upper chord control points corresponding to each lower chord control point are performed in the normal plane perpendicular to the tangent of the arch reference curve. This is crucial to ensuring that the cross-section always maintains the correct orthogonal relationship with the longitudinal axis of the truss. Only by offsetting within this plane can the generated inverted triangular cross-section be correctly twisted as the curve bends, ensuring that all members are located in the correct structural stress plane and providing a qualified geometric basis for subsequent accurate structural analysis.

[0037] It should be noted that the inverted triangular cross-section formed by each lower chord control point and its two corresponding upper chord control points is an isosceles triangle; and the lower chord control point serves as the spatial coordinate point of the lower chord member of the truss; the two upper chord control points serve as the spatial coordinate points of the two upper chord members of the truss. Preferably, the inverted triangular cross-section constructed in this embodiment is an isosceles triangle, which means that the upper chord members corresponding to the two upper chord control points are symmetrical about the vertical central axis, thereby optimizing the force path of the entire arched coal shed truss and ensuring the accurate mapping relationship from the geometric model to the structural model.

[0038] Specifically, see Figure 3 The aforementioned step of "calculating the two upper chord control points corresponding to the current lower chord control point" includes: S4011. Obtain the curve tangent vector at the current lower chord control point; the curve tangent vector is used to construct a normal plane. First, find the tangent vector of the reference curve at that point to determine the orientation of the cross section (normal plane).

[0039] In practical applications, at each Point_lower[i] point, the Evaluate Curve component is used to calculate the curve tangent vector T of that point on the arch reference curve; then, a normal plane is constructed through vector operations, and the normal of this plane is the curve tangent vector T, which means that this plane is always perpendicular to the extension direction of the arch line at the current point.

[0040] S4012. Calculate the horizontal vector by performing a cross product between the global vertical vector and the curve tangent vector. Create a vertical vector, usually the global Z-axis vector (0,0,1). Here, we can directly use the cross product of the global vertical vector V and the curve tangent vector (T) to obtain the horizontal vector B. This vector B is located in the horizontal plane and is perpendicular to the curve tangent vector T. This value represents the width direction of the arch truss section.

[0041] S4013. Based on the horizontal vector and in combination with the width parameter, calculate the first horizontal offset and the second horizontal offset, which are opposite to the two directions corresponding to the horizontal vector. Next, based on the width parameter input by the user, the horizontal vector B is normalized and multiplied by the first adjustment factor (the first adjustment factor is the input width parameter / 2), to calculate two horizontal offset vectors + B in opposite directions. offset and -B offset And the first horizontal offset is recorded as +B offset The second horizontal offset is denoted as -B. offset It should be noted that the plus sign and the symbol here represent direction. For example, the plus sign here can represent a horizontal offset to the right, while the minus sign represents a horizontal offset to the left.

[0042] S4014. Calculate the vertical offset corresponding to the global vertical vector based on the thickness parameter and the global vertical vector. Similarly, based on the thickness parameter input by the user, the global vertical vector V is normalized and multiplied by the second adjustment factor (the second adjustment factor is +thickness parameter, where the positive sign indicates upward in the vertical direction) to obtain the vertical offset vector V. offset .

[0043] S4015. Add the first horizontal offset and the vertical offset to the spatial coordinates of the current lower chord control point to obtain the spatial coordinates of the first upper chord control point; add the second horizontal offset and the vertical offset to the spatial coordinates of the current lower chord control point to obtain the spatial coordinates of the second upper chord control point.

[0044] Finally, after obtaining all the data, the spatial coordinates of the first upper chord control point Point_upper1[i] are calculated using the following formula: The x-coordinate of the first upper chord control point: x-coordinate of the lower chord control point (Point_lower[i]) + first horizontal offset + B offset Its ordinate: the ordinate of the lower chord control point (Point_lower[i]) + vertical offset V offset .

[0045] The spatial coordinates of the second upper chord control point Point_upper2[i] are calculated using the following formula: The x-coordinate of the second upper chord control point: x-coordinate of the lower chord control point (Point_lower[i]) + second horizontal offset - B offset Its ordinate: the ordinate of the lower chord control point (Point_lower[i]) + vertical offset V offset .

[0046] Thus, each vertical grid has obtained an inverted isosceles triangle section defined by three points (Point_lower[i], Point_upper1[i], Point_upper2[i]), and the three control points of all sections constitute the control point set of the entire arched coal shed truss.

[0047] S500: Based on the set of control points, automatically generate the lower chord members connecting all lower chord control points, the two upper chord members connecting the corresponding upper chord control points, and the web member system connecting the upper chord control points and the lower chord control points, forming a complete truss member centerline model. This step constructs a complete structural skeleton from the spatial coordinates generated by S400. The algorithm automatically identifies the connection rules between point sets, connecting all lower chord points sequentially to generate the lower chord centerline; connecting all first upper chord points to generate the first upper chord centerline; and connecting all second upper chord points to generate the second upper chord centerline. Subsequently, according to the predetermined topological rules of the web system structure (such as a K-shape), the web system (including diagonal web members and upper chord planar web members) is automatically generated between the upper and lower chord points, thus forming a complete spatial truss wireframe model composed of numerous straight line segments.

[0048] As can be seen, this application realizes the automated assembly from discrete points to continuous arched trusses. It uses a centerline model to replace the work of manually drawing hundreds or even thousands of line segments in traditional software, which greatly shortens the modeling time of several days or even weeks.

[0049] Specifically, for ease of explanation, the two upper chord control points are denoted as the first upper chord control point Point_upper1[i] and the second upper chord control point Point_upper2[i]. The specific expansion of the aforementioned step S500 includes the following: (1) Connect all lower chord control points to generate the lower chord centerline; Connect all Point_lower[i] points directly, using the Interpolate Curve or directly using the arch baseline as the center line of the lower chord.

[0050] (2) Connect all the first upper chord control points Point_upper1[i] to generate the center line of the first upper chord; (3) Connect all the second upper chord control points Point_upper2[i] to generate the center line of the second upper chord; (4) Based on the center line of the lower chord, the center line of the first upper chord and the center line of the second upper chord, generate the web bar system, and use the web bar system to form a K-shaped web bar system with the lower chord control point in each longitudinal grid and its two corresponding upper chord control points.

[0051] As can be seen, the above content explains the generation method of the upper and lower chords as specified in the embodiments of this application, and also clarifies the core structural feature of the web member system adopting a K-shaped web member system. The K-shaped web member system can be understood as a stable structural system resembling the letter "K" formed by two diagonal web members and corresponding chord members within two adjacent longitudinal grids; that is, the two diagonal web members intersect at a lower chord node. This system has a clear shear force transmission path and relatively simple node construction, making it a commonly used and efficient form in large trusses.

[0052] Furthermore, the web member system includes: upper chord plane web members and diagonal web members; The upper chord plane web members are transverse web members connecting the first upper chord control point and the second upper chord control point within the same longitudinal grid, longitudinal web members connecting different first upper chord control points within adjacent longitudinal grids, and longitudinal web members connecting different second upper chord control points within adjacent longitudinal grids.

[0053] Understandably, the upper chord plane web member includes the member connecting Point_upper1[i] and Point_upper2[i]. This member, together with the two upper chord members, constitutes the horizontal triangular stability system of the upper chord member, which is crucial for preventing lateral instability of the upper chord member; where i represents the i-th longitudinal grid.

[0054] In addition, the upper chord plane web members also include members connecting Point_upper1[i]--Point_upper1[i+1] and Point_upper2[i]--Point_upper2[i+1]. These members together with the upper chord members form a truss in the upper chord plane.

[0055] The diagonal web member is a diagonal web member that connects the upper chord control point in each longitudinal grid with the next adjacent lower chord control point, so that in each longitudinal grid, the lower chord control point and the two upper chord control points form a K-shaped web member system; and, between adjacent longitudinal grids, the diagonal web members alternately connect to the lower chord control point with different upper chord control points as the starting point. The diagonal web member is the main member that transmits shear force, and it alternately connects to Point_upper1[i] or Point_upper2[i]. That is, the diagonal web system is as follows: Connect Point_upper1[i]--Point_lower[i+1] and Point_upper2[i]--Point_lower[i+1], so that in each vertical grid, the lower chord control point and the two upper chord control points form a K-shape.

[0056] S600: Import the centerline model of the truss members into the structural analysis software in real time to obtain key structural performance indicators; the feedback of key structural performance indicators is used to guide the adjustment of structural parameters, and the structural parameters are automatically optimized by driving the centerline model of the truss members.

[0057] After obtaining the centerline model of the truss members, this step deeply integrates the parametric geometry of the truss member centerline model with engineering verification. Using dedicated Grasshopper plugins (such as Karamba, SAP2000, and midas), the truss member centerline model generated in step S500, along with preset section properties and material properties, is converted in real-time into a finite element model recognizable by structural analysis software. This yields key performance indicators (such as maximum deflection, member stress, and steel consumption) analyzed by the structural analysis software. These key performance indicators are parameters for evaluating the current performance of the arched truss and also serve as the basis for parametric adjustments.

[0058] Specifically, the process of importing the centerline model of the truss members into the structural analysis software in real time to obtain key structural performance indicators is as follows: apply preset load conditions and boundary conditions in the structural analysis software; perform structural analysis and feed back the current key performance indicators of the truss members to the Grasshopper platform interface in real time for visualization.

[0059] In practical applications, structural analysis software automatically applies the set loads (self-weight, wind, snow, etc.) and set boundary conditions (supports), then calls the solver to perform calculations. The calculation results (maximum deflection, stress ratio, steel consumption, etc.) are extracted in real time and fed back to the Grasshopper interface for visualization. This breaks down the barriers between design and analysis, enabling real-time analysis or immediate verification. When operators adjust the structural parameters of the arch truss, they can immediately see its impact on structural safety and economy, shortening the analysis cycle that originally took hours or even days to within seconds.

[0060] In a preferred embodiment, the truss member centerline model is imported into the structural analysis software in real time. After obtaining the key structural performance indicators, the method further includes: using the structural parameters input for the current arched truss as global control sliders; automatically updating the structural parameters within the entire truss member centerline model when the slider corresponding to any structural parameter is dragged, thus reconstructing the arched truss in real time; and adjusting the construction scheme of the arched truss to meet the preset design requirements based on the key structural performance indicators corresponding to the current arched truss member displayed in real time.

[0061] See below Figures 1-5 Take the design of a coal shed truss with a span of 138 meters and an arch height of 52 meters as an example.

[0062] Implement this invention in the Grasshopper plugin of Rhinoceros software: First, create six digital sliders and set them as follows: span = 138, arch height = 52, thickness = 4.0, width = 4.0, vertical grid number = 36, and landing angle = 70°.

[0063] Using the ArcSED (start, end, direction arc) calculator, with span, arch height, and landing angle as input, a reference arc is generated.

[0064] A logical entity measuring 138 meters long, 4 meters wide, and 4 meters high is constructed using Brep-related components. This entity is then associated with an arched reference curve using commands such as Split Brep to achieve spatial positioning.

[0065] Divide the arched reference curve into 36 equal segments using Divide Curve, resulting in 37 equal division points. OffsetCurve is used to offset the curve upwards and downwards by 2 meters (half the thickness) to generate the spatial coordinate points of the upper and lower chords. Then, the Line component is used to connect the spatial coordinate points of the upper and lower chords according to the preset logic, generating the corresponding web member system and obtaining the truss member centerline model.

[0066] Next, specify a pipe diameter of 300mm for all chord centerlines and 180mm for the web centerlines. Using the Grasshopper Karamba plugin, the generated member line model is automatically converted into a finite element analysis model, fixed supports and standard loads are applied, and real-time structural analysis is performed.

[0067] Create a panel in the Grasshopper interface to display the maximum deflection of the truss at the current structural parameters, which is 185mm. If the operator feels the deflection is too large, they can slowly drag the arch thickness slider from 4.0 to 6.0. This change in slider value instantly triggers the entire algorithm chain to re-execute from step S200, performing real-time reconstruction of the truss members. The centerline model of the entire truss member will immediately become thicker, and Karamba will complete the recalculation within seconds, updating the maximum deflection on the panel to 140mm. Based on the improvement in the maximum deflection, the operator judges that the adjustment is effective and can continue to fine-tune other parameters (such as arch height and width) until all indicators such as deflection and stress meet the preset design requirements and the steel usage is economical, thus determining the final truss member construction scheme.

[0068] Based on the Grasshopper-based arch truss modeling and optimization method described above, this method constructs a complete closed-loop optimization process from parameter-driven to geometry generation and real-time analysis. Its core lies in: first, defining key structural parameters of the arch truss (such as span, arch height, cross-sectional dimensions, and mesh count) as global input variables; then, through a rigorous algorithmic logic (including arch baseline generation, vector-based inverted isosceles triangle cross-section construction, and automatic connection of web members following a K-shaped system), automatically converting these parameters into accurate 3D truss member centerline models; subsequently, through deep integration, transmitting this truss member centerline model to the structural analysis software kernel in real time for calculation and providing immediate feedback on key performance indicators; finally, by associating the input structural parameters with key structural performance indicators, an interactive closed loop is formed, enabling designers to intuitively and instantly understand the impact of changes in various structural parameters on structural performance and economy by adjusting the corresponding sliders, until the optimal truss member construction scheme is found.

[0069] The advantages of the embodiments of the present invention are as follows: (1) Extremely high modeling and modification efficiency: It transforms the tedious manual modeling work into a parameter-driven automated process. Modifying any core parameter can achieve rapid updates of the entire complex truss model, improving design efficiency by tens or even hundreds of times.

[0070] (2) Strong repeatability and adaptability: The established standard algorithm can be used in different stages of the same project or new projects of different scales. New truss member centerline models can be generated simply by inputting new parameters, which effectively enhances the reuse value of the technology.

[0071] (3) A closed loop of integrated design and analysis has been realized: By deeply integrating the parametric geometric model with the structural analysis software, a modern design process of adjustment and verification has been realized, which shortens the design cycle and improves the scientificity and reliability of the design results.

[0072] (4) Facilitates comparison and optimization of multiple solutions: Designers can easily explore countless possible solutions in a variety of parameter spaces and make objective comparisons through real-time feedback performance data, providing a powerful tool to support the search for the optimal solution.

[0073] (5) Enhance the economic and social benefits of the project: Through rapid optimization, the most economical material usage scheme can be found while ensuring structural safety, thereby reducing the project cost. At the same time, an efficient design process helps to shorten the overall project duration, bringing significant social and economic benefits.

[0074] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. A Grasshopper-based method for modeling and optimizing arched trusses, characterized in that, include: Input the structural parameters of the arch truss, which include at least the span parameter, arch height parameter, thickness parameter, width parameter, longitudinal grid number parameter, and landing angle parameter; Based on the span parameters, arch height parameters, and landing angle parameters, an arch reference curve is generated in the Grasshopper platform; Along the arched reference curve, the longitudinal grid number parameter is used to divide the area into equal parts to obtain multiple lower chord control points; Based on the thickness parameter, the width parameter, and multiple lower chord control points, two upper chord control points corresponding to the current lower chord control point are identified, so that an inverted triangular cross section is constructed at each lower chord control point, forming a control point set consisting of multiple sets of lower chord control points and upper chord control points corresponding to the inverted triangular cross sections; Based on the set of control points, the system automatically generates a lower chord connecting all lower chord control points, two upper chords connecting the corresponding upper chord control points, and a web member system connecting the upper chord control points and the lower chord control points, forming a complete truss member centerline model. The centerline model of the truss members is imported into the structural analysis software in real time to obtain key structural performance indicators. The feedback of the key structural performance indicators is used to guide the adjustment of the structural parameters, so as to drive the centerline model of the truss members to automatically optimize its structural parameters.

2. The method for modeling and optimizing arched trusses based on Grasshopper according to claim 1, characterized in that, Based on the thickness parameter, the width parameter, and multiple lower chord control points, two upper chord control points corresponding to the current lower chord control point are identified, so that an inverted triangular cross-section is constructed at each lower chord control point, including: Obtain the current lower chord control point, the thickness parameter, and the width parameter; Based on the lower chord control point, construct a normal plane that is perpendicular to the tangent of the arched reference curve. Within the normal plane, based on the thickness and width parameters, two upper chord control points corresponding to the current lower chord control point are calculated; each lower chord control point and its two corresponding upper chord control points form an inverted triangular cross section.

3. The method for modeling and optimizing arched trusses based on Grasshopper according to claim 2, characterized in that, Each lower chord control point and its corresponding two upper chord control points form an inverted triangular cross-section that is an isosceles triangle; and the lower chord control point serves as the spatial coordinate point of the lower chord of the truss; the two upper chord control points serve as the spatial coordinate points of the two upper chords of the truss.

4. The method for modeling and optimizing arched trusses based on Grasshopper according to claim 2, characterized in that, The calculation yields two upper chord control points corresponding to the current lower chord control point, including: Obtain the curve tangent vector at the current lower chord control point; the curve tangent vector is used to construct a normal plane; The horizontal vector is calculated by performing a cross product between the global vertical vector and the tangent vector of the curve. Based on the horizontal vector and in combination with the width parameter, a first horizontal offset and a second horizontal offset, which are opposite in direction to the horizontal vector, are calculated. Calculate the vertical offset corresponding to the global vertical vector based on the thickness parameter and the global vertical vector; Add the first horizontal offset and the vertical offset to the spatial coordinates of the current lower chord control point to obtain the spatial coordinates of the first upper chord control point; add the second horizontal offset and the vertical offset to the spatial coordinates of the current lower chord control point to obtain the spatial coordinates of the second upper chord control point.

5. The method for modeling and optimizing arched trusses based on Grasshopper according to claim 4, characterized in that, Based on the set of control points, the system automatically generates a lower chord connecting all lower chord control points, two upper chords connecting the corresponding upper chord control points, and a web member system connecting the upper and lower chord control points, forming a complete truss member centerline model, including: Connect all lower chord control points to generate the centerline of the lower chord. Connect all the first upper chord control points to generate the center line of the first upper chord bar; Connect all the second upper chord control points to generate the center line of the second upper chord. Based on the centerline of the lower chord, the centerline of the first upper chord, and the centerline of the second upper chord, a web member system is generated, and the web member system is used to form a K-shaped web member system by connecting the lower chord control point in each longitudinal grid with its two corresponding upper chord control points.

6. The method for modeling and optimizing arched trusses based on Grasshopper according to claim 5, characterized in that, The web member system includes: an upper chord plane web member and an oblique web member; The upper chord plane web member is a transverse web member connecting the first upper chord control point and the second upper chord control point within the same vertical grid, a longitudinal web member connecting different first upper chord control points within adjacent vertical grids, and a longitudinal web member connecting different second upper chord control points within adjacent vertical grids. The diagonal bracing is a bracing that connects the upper chord control point in each longitudinal grid with the next adjacent lower chord control point, such that in each longitudinal grid, the lower chord control point and the two upper chord control points form a K-shaped bracing system; and, between adjacent longitudinal grids, the diagonal bracing alternately connects to the lower chord control point starting from different upper chord control points.

7. The method for modeling and optimizing arched trusses based on Grasshopper according to claim 1, characterized in that, The centerline model of the truss members is imported into the structural analysis software in real time to obtain key structural performance indicators, including: Preset load conditions and boundary conditions are applied in the structural analysis software; Perform structural analysis and feed back the key performance indicators of the current truss members to the Grasshopper platform interface in real time for visualization.

8. The method for modeling and optimizing arched trusses based on Grasshopper according to claim 7, characterized in that, After obtaining the key structural performance indicators, the following are also included: Use the structural parameters of the current arched truss as the global control slider; When the slider corresponding to any structural parameter is dragged, the structural parameters in the centerline model of the entire truss member are automatically updated, and the arch truss is reconstructed in real time. Based on the key structural performance indicators corresponding to the current arched truss component displayed in real time, an arched truss construction scheme that meets the preset design requirements is obtained.

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