A visual parametric modeling method for ultra-long span steel truss arch bridge based on Grasshopper

Abstract

The present invention relates to the technical field of bridge design, and in particular to a visual parametric modeling method for an ultra-long span steel truss arch bridge based on Grasshopper, which comprises the following steps: analyzing bridge structural characteristics and building an overall logical framework; writing geographic information and bridge basic information into a parametric C-level module; generating an arch axis curve and an arch structure three-dimensional model through a parametric arch structure C-1 level module; generating a truss structure three-dimensional model through a parametric truss structure C-2 level module; calculating the bridge deck position and establishing a bridge deck three-dimensional model based on data in the parametric arch structure C-1 level module, the parametric truss structure C-2 level module, and the parametric bridge deck position C-3 level module; calculating the camber angle and the inclination angle based on the parametric basket angle C-4 level module, and establishing an arch bridge three-dimensional model. The present invention can greatly shorten the modeling time of an ultra-long span steel truss arch bridge structure and greatly improve the modeling accuracy.

Description

Technical Field

[0001] The present invention relates to the technical field of bridge design, and in particular to a Grasshopper-based visual parametric modeling method for an ultra-long span steel truss arch bridge. Background Art

[0002] Steel truss arch bridges are widely used in ultra-long-span arch bridges due to their excellent structural performance, durability, and exceptional spanning capacity. However, due to their large spans (typically exceeding 300 meters), the risk of structural failure increases. To effectively control these structural risks, these bridges require more stringent accuracy in structural calculations. Furthermore, due to their large spans, the calculation model for these steel truss arch bridges requires a significant number of nodes and elements.

[0003] Currently, manual modeling is usually used when modeling such bridge structures. Modeling is based on a single node or a single unit. The modeling process is extremely cumbersome. Building a computational model can often take several days, and a large amount of time is consumed in highly repetitive but uninnovative operations such as connecting nodes and units one by one. At the same time, due to the large number of node units, errors are very easy to make when connecting units. This leads to many disadvantages, such as low efficiency of modeling calculations, long cycles, and high error rates.

[0004] In addition, scheme comparison is often required during the scheme design stage of such bridges. The scheme adjustment of such bridges will lead to an exponential increase in the workload of modeling and calculation. As a result, the scheme comparison of such bridges can only be determined by empirical estimation or analogical calculation, which greatly reduces the accuracy and feasibility of the scheme design of such bridges. Summary of the Invention

[0005] In order to solve the problem of difficulty in modeling super-long span steel truss arch bridge structures, the present invention provides a visual parametric modeling method for super-long span steel truss arch bridges based on Grasshopper.

[0006] The present invention provides a visual parametric modeling method for an ultra-long span steel truss arch bridge based on Grasshopper, which adopts the following technical solutions:

[0007] A visual parametric modeling method for a super-long span steel truss arch bridge based on Grasshopper includes the following steps:

[0008] Obtain geographic information and basic information and write them into the parameterized C-level module;

[0009] Generate arch axis curve and arch structure 3D model through parametric arch structure C-1 level module;

[0010] Generate a 3D model of the truss structure based on the data in the parametric truss structure C-2 level module and the parametric arch structure C-1 level module;

[0011] Based on the data in the parametric arch structure C-1 level module and the parametric truss structure C-2 level module, the bridge deck position is calculated through the parametric bridge deck position C-3 level module to establish a three-dimensional bridge deck model;

[0012] According to the data in the parametric arch structure C-1 level module, the parametric truss structure C-2 level module, and the parametric bridge deck position C-3 level module, the parametric basket angle C-4 level module is used to adjust the arch axis's outward and inward angles, calculate the spatial position relationship between the arch axis and the bridge deck, and establish a three-dimensional model of the arch bridge.

[0013] In a specific feasible implementation plan, the geographic information includes the geographical location and span range of the bridge site; the basic information includes the bridge coordinate system, elevation system, starting and ending positions, longitudinal slope, transverse slope, bridge site watershed information, and ground information under the bridge.

[0014] In a specific implementation scheme, generating an arch axis curve and an arch structure three-dimensional model by using a parameterized arch structure C-1 level module includes the following steps:

[0015] Construct the position matrix of the key points of the vault to form the vault coordinate system;

[0016] Form a logical association between the arch height and the key point position of the arch top;

[0017] By obtaining the absolute value of the arch height, the arch height can be controlled by parameters;

[0018] Based on the arch height, the arch foot key point position matrix is ​​expanded to form the arch foot coordinate system;

[0019] Logically associate the key points of arch height, arch span, arch crown and arch foot;

[0020] By adjusting the absolute value of the arch span, the arch span can be controlled parametrically;

[0021] Obtain the arch width, establish the logical relationship between the arch width and the key points of the arch crown and arch foot, and realize the parameter control of the arch width;

[0022] Generate multiple related key points, select the arch foot key point and the arch top key point, and randomly generate two intermediate key points at the 1 / 4 span position. Generate the arch axis curve using the arch foot key point, arch top key point and intermediate key points;

[0023] Generate a 3D model of the arch structure.

[0024] In a specific embodiment, the arch axis curve is generated by a non-uniform rational B-spline curve - nurbs curve.

[0025] In a specific implementation scheme, based on the data in the parametric arch structure C-1 level module, establishing a truss structure three-dimensional model through the parametric truss structure C-2 level module includes the following steps:

[0026] Construct a logical relationship between internode length and arch axis curve, divide the arch axis curve according to the internode length, and obtain curve segments;

[0027] Get the endpoints of each curve segment to form an endpoint position matrix;

[0028] Obtain the truss height, establish a logical association between the truss height and the arch axis curve, and vertically copy the arch axis curve according to the truss height;

[0029] Dividing the copied arch axis curve according to the internode length to obtain curve segments of the copied arch axis curve;

[0030] Obtaining the endpoint of each curve segment of the copied arch axis curve to form an endpoint position matrix of the copied arch axis curve;

[0031] According to the arch width and internode length, the arch axis curve and the copied arch axis curve, as well as the end point position matrix are copied along the bridge width direction;

[0032] According to the positional relationship of the endpoints in the endpoint position lattice in space, the logical relationship between the endpoint position lattices is constructed;

[0033] Generate the upper and lower parallel axis according to the connection type and endpoint position matrix of the upper and lower parallels, as well as the logical relationship between the endpoint position matrixes;

[0034] The web member axis is generated according to the connection relationship of the web member and the end point position lattice, as well as the logical relationship between the end point position lattices;

[0035] The curve segments of the arch axis curve and the curve segments of the copied arch axis curve are the upper chord axis and the lower chord axis,

[0036] A three-dimensional truss model is generated based on the upper chord axis, lower chord axis, upper and lower parallel joint axes, and web axis.

[0037] In a specific possible implementation scheme, the logical relationship between the endpoint position lattices satisfies all connection types of the upper and lower parallel connections between the arch axis curves;

[0038] The connection types of upper and lower parallel connections include staggered connection, same frequency connection, and cross connection.

[0039] In a specific feasible implementation scheme, the logical relationship between the endpoint position lattices can satisfy the different connection modes of all web members between the arch axis curves;

[0040] The connection relationship of the web includes positive increasing staggered connection, positive decreasing staggered connection, reverse increasing staggered connection, reverse decreasing staggered connection and same frequency connection.

[0041] In a specific embodiment,

[0042] Based on the data from the parametric arch structure C-1 level module and the parametric truss structure C-2 level module, the bridge deck position is calculated using the parametric bridge deck position C-3 level module. The three-dimensional bridge deck model is established in the following steps:

[0043] The bridge deck position is associated with the bridge deck elevation, and the bridge deck elevation is associated with the arch crown key points, arch foot key points, and endpoint position lattice, to build a logical relationship between the bridge deck elevation and the arch crown key points, arch foot key points, and endpoint position lattice of the arch axis curve.

[0044] Obtain the projection of the arch axis curve at the same height on the horizontal plane where the bridge deck is located, take the projection center as the bridge deck center, take the line connecting the centers of the short sides of the projection as the bridge deck center axis, and construct the bridge deck plane axis network in combination with the bridge deck width.

[0045] Segment the projected edge line, obtain the endpoints of the edge line segments, and form the bridge deck edge line point matrix.

[0046] Construct the logical relationship between the spatial position of the bridge deck edge lattice, and the spatial logical relationship between the bridge deck edge lattice and the endpoint position lattice of the arch axis curve.

[0047] Calculate the length of the column or suspender according to the absolute distance between the bridge deck elevation and the key point of the arch foot.

[0048] Generate a three-dimensional model of the bridge deck based on the parameters of the bridge deck position, columns and hangers.

[0049] In a specific implementation scheme, calculating the length of the column or the hanger according to the absolute distance between the bridge deck elevation and the key point of the arch foot includes the following steps:

[0050] When the distance between the bridge deck elevation and the key point of the arch foot is 0, the hanger axis is generated according to the logical relationship between the bridge deck position and the arch axis curve. The length of the hanger axis is the length of the hanger.

[0051] When the distance between the bridge deck elevation and the key point of the arch foot is greater than 0 and less than or equal to the arch height, the column axis and the hanger axis are generated according to the logical relationship between the bridge deck position and the arch axis curve. The length of the column axis is the length of the column, and the length of the hanger axis is the length of the hanger.

[0052] When the distance between the bridge deck elevation and the key point of the arch foot is greater than the arch height, the column axis is generated according to the logical relationship between the bridge deck position and the arch axis curve, and the length of the column axis is the length of the column.

[0053] In a specific implementation plan, based on the data in the parametric arch structure C-1 module, the parametric truss structure C-2 module, and the parametric bridge deck position C-3 module, the camber and inclination angles of the arch axis curve are calculated by the parametric basket angle C-4 module to establish a three-dimensional model of the arch bridge, including the following steps:

[0054] Taking the bridge deck position plane as the rotation reference plane and the bridge deck elevation as the rotation center axis, a coordinate vector matrix of the arch axis endpoint position lattice is generated;

[0055] Construct the logical relationship between the arch axis curve, upper and lower chords, web members, upper and lower parallel joints and the coordinate vector matrix;

[0056] Obtain the camber angle, rotate the coordinate vector matrix of the arch axis and the arch axis endpoint position matrix by the camber angle, and simultaneously rotate all the upper and lower chords, upper and lower parallel joints, and web members in real time;

[0057] Obtain the inclination angle, rotate the arch axis and the coordinate vector matrix of the lattice by the inclination angle, and at the same time, all the upper and lower chords, upper and lower parallel joints, and web members rotate in real time.

[0058] In summary, the present invention has the following beneficial effects:

[0059] By inputting, grabbing, dragging, and changing the corresponding parameters, you can quickly and accurately model steel truss bridge structures of any span, width, angle, and deck position. This can greatly shorten the modeling time of ultra-long span steel truss arch bridge structures and greatly improve modeling accuracy. At the same time, it also provides new modeling ideas and methods for the bridge design field, enabling efficient, high-accuracy, and highly adaptable changes in ultra-long span steel truss arch bridge structures at any design stage. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Figure 1 It is the overall architecture diagram.

[0061] Figure 2 It is the architectural diagram of the structural parameter C-level module.

[0062] Figure 3 This is the architectural diagram of the parametric arch structure C-1 level module.

[0063] Figure 4 It is the image generated in step S200.

[0064] Figure 5 This is the architectural diagram of the parametric truss structure C-2 level module.

[0065] Figure 6 This is the image after the belly bar is generated.

[0066] Figure 7 It is an architectural diagram for implementing step S350.

[0067] Figure 8 It is the image generated in step S300.

[0068] Figure 9 This is the architectural diagram of the C-3 level module for the parametric bridge deck position.

[0069] Figure 10 This is the image of the half-through steel truss arch bridge generated in step S400.

[0070] Figure 11 This is the architectural diagram of the parameterized basket handle angle C-4 level module.

[0071] Figure 12 This is the image of the inward-inclined through steel truss arch bridge generated in step S500.

[0072] Figure 13 This is the generated image of a half-through steel truss arch bridge.

[0073] Figure 14 This is the generated image of a deck steel truss arch bridge.

[0074] Figure 15 This is the generated image of a through steel truss arch bridge.

[0075] Figure 16 This is the generated image of an inward-inclined through steel truss arch bridge.

[0076] Figure 17 This is the generated image of an outward-inclined through steel truss arch bridge. DETAILED DESCRIPTION

[0077] The following is combined with Figure 1 The present invention is described in further detail.

[0078] Reference Figure 1 The visual parametric modeling method of a super-long span steel truss arch bridge based on Grasshopper includes the following steps:

[0079] S100, obtaining geographic information and basic information, and writing them into the parameterized C-level module.

[0080] Geographic information includes the geographical location of the bridge site and the span range; basic information includes the bridge coordinate system, elevation system, starting and ending points, longitudinal slope, transverse slope, bridge site watershed information, ground information under the bridge, etc. Figure 2 .

[0081] S200, generates the arch axis curve and arch structure 3D model through the parametric arch structure C-1 level module.

[0082] The C-1 level module of the parametric arch structure includes four C-1-X level modules: arch height, arch span, arch width, and arch axis curve, which are used to perform parametric control of arch height, arch span, arch width, and arch axis curve. Figure 3 The specific steps include:

[0083] S210 constructs a matrix of key vault point positions, forming a vault coordinate system accessible from any location. The positions of key vault points are identified and stored in real time. A data structure parameterized interface is constructed between the vault height and the vault axis curve, logically associating the vault height with the key vault point positions. This logical association is parameterized. By obtaining the absolute value of the input vault height, mm-level parameter control of the vault height is achieved.

[0084] S220 expands the arch foot key point position matrix based on the arch height to form an arch foot coordinate system accessible from any location. The positions of the arch foot key points are identified and stored in real time. A data structure interface is constructed between the arch span and the arch axis curve. The arch height, arch span, and arch crown key points are logically associated with the arch foot key points, and this logical association is parameterized. By adjusting the absolute value of the arch span, parametric control of the arch span is achieved at the centimeter level.

[0085] S230, obtaining the arch width, establishing a logical relationship between the arch width and the key points of the arch crown and arch foot, and then building a data linkage interface between the arch width and the arch axis curve to achieve cm-level parametric control of the arch width.

[0086] S240 uses the data in the key point position matrix to generate multiple related key points, selects the arch foot key point and the arch crown key point, and randomly generates two intermediate key points at the 1 / 4 span position. Using the arch foot key point, the arch crown key point and the intermediate key points, the arch axis curve is generated through the non-uniform rational B-spline curve - NURBS curve to achieve parametric linkage between the arch axis curve and the arch height, arch span and arch width.

[0087] S250, based on the data in the parameterized arch structure C-1 level module, generate a three-dimensional model of the arch structure, and by adjusting the arch height, arch span and arch width, observe whether the three-dimensional model of the arch structure changes according to the logical relationship as the arch height, arch span and arch width are adjusted. If the three-dimensional model of the arch structure does not meet the logical relationship, repeat steps S210-S240, adjust the parameters of the logical relationship in steps S210-S240, and repeat until the three-dimensional model of the arch structure meets the logical relationship. Finally, generate Figure 4 The image shown.

[0088] S300: Generate a truss structure three-dimensional model based on data in the parameterized truss structure C-2 level module and the parameterized arch structure C-1 level module.

[0089] The C-2 level module of the parametric truss structure includes five C-2-X level modules: span length, truss height, upper and lower parallel joints, upper and lower chords, and web members. Figure 5 and Figure 7 The specific steps include:

[0090] S310: Establish a logical association between internode length and arch axis curve, divide the arch axis curve generated in step S200 according to the internode length to obtain curve segments, obtain the endpoints of each curve segment, form an endpoint position matrix, and number and store the endpoint position matrix.

[0091] S320 , obtaining the truss height, establishing a logical association between the truss height and the arch axis curve, vertically copying the arch axis curve generated in step S200 according to the truss height, and repeating step S310 for the copied arch axis curve.

[0092] According to the arch width and the length of the span, the arch axis curve and the copied arch axis curve, as well as the endpoint position point matrix are copied along the width of the bridge.

[0093] S330: Based on the spatial positional relationships of the endpoints in the endpoint position lattice, a logical relationship is constructed between the endpoint position lattices. This logical relationship can satisfy all vertical parallel connection methods between the arch axis curves. Vertical parallel connection methods include staggered connection, co-frequency connection, and cross connection. Based on the connection method, the endpoint position lattice, and the logical relationship between the endpoint position lattices, a vertical parallel connection axis is generated. The vertical parallel connection can be further generated based on the vertical parallel connection axis.

[0094] S340: In steps S310-S320, a total of four arch axis curves (two upper and two lower) are generated. The two upper arch axis curves correspond to the upper chord axis, with each segment corresponding to the upper chord axis. The two lower arch axis curves correspond to the lower chord axis, with each segment corresponding to the lower chord axis. The upper and lower chord axes can be adjusted by adjusting the number, length, and position of the arch axis curve segments.

[0095] S350: Based on the spatial positional relationships of the endpoints in the endpoint position lattice, a logical relationship is constructed between the endpoint position lattices. This logical relationship can satisfy the different connection methods of all web members between the arch axes. Based on the web member connection relationship, the endpoint position lattice, and the logical relationship between the constructed endpoint position lattices, a web member axis is generated. The web member can be further generated based on the web member axis.

[0096] The connection methods of the web bars include positive increasing staggered connection, positive decreasing staggered connection, reverse increasing staggered connection, reverse decreasing staggered connection and same frequency connection.

[0097] It is easy to understand that steps S330-350 are different calculations for the upper and lower chords, upper and lower parallel joints, and web members. There is no necessary order between steps S330-350, and the step numbers are only used to distinguish them. The image generated after executing step S350 first is as follows: Figure 6 shown.

[0098] S360, based on the data in the C-2 level module of the parametric truss structure, a 3D model of the truss structure is generated by adjusting the automatic creation and real-time adjustment of the span length, truss height, upper and lower parallel joints, upper and lower chords, and webs. Observe whether the 3D model of the truss structure changes according to the logical relationship as the span length, truss height, upper and lower parallel joints, upper and lower chords, and webs are adjusted. If the 3D model of the truss structure does not satisfy the logical relationship, repeat steps S310-S350, adjust the parameters of the logical relationship in steps S310-S350, and loop until the 3D model of the truss structure satisfies the logical relationship. After completing the calculation of the upper and lower chords, upper and lower parallel joints, and webs, the following is finally generated. Figure 8 Images displayed.

[0099] S400, calculating the bridge deck position and establishing a three-dimensional bridge deck model based on the data in the parameterized arch structure C-1 level module, the parameterized truss structure C-2 level module, and the parameterized bridge deck position C-3 level module.

[0100] The parametric bridge deck position C-3 level module includes three C-3-X level modules: top-deck, mid-deck, and bottom-deck. Figure 9 The specific steps include:

[0101] S410: Associate the bridge deck position with the bridge deck elevation, and establish a logical relationship between the bridge deck elevation and the arch crown key points, the arch foot key points, and the endpoint position matrix of the arch axis curve. When the distance between the bridge deck elevation and the arch foot key points is greater than or equal to the arch height, a projection of the arch axis curve on the horizontal plane of the bridge deck is generated. The projection has an approximately rectangular outline, with the center of the projection being the bridge deck center and the line connecting the centers of the short sides of the projection being the bridge deck centerline. Combined with the preset bridge deck width, a bridge deck plane axis network is constructed.

[0102] The projected edge is segmented to form edge segments. The endpoints of the edge segments are obtained to form a bridge deck edge lattice. The bridge deck edge lattice is sorted along the width of the bridge, and a spatial logical relationship is established between the bridge deck edge lattice and the endpoint position lattice of the arch axis curve.

[0103] S420: When the distance between the bridge deck elevation and the arch foot key point is zero, the boom axis is automatically generated based on the input number and spacing of the booms, as well as the logical relationship between the bridge deck position and the arch axis curve. The boom axis length is the boom length. The absolute vertical distance between the bridge deck center and the arch crown key point is adjusted, and the distance between the bridge deck and the arch axis curve is calculated in real time. The boom length is then adjusted in real time, enabling parametric setup of the deck and booms for through-arch bridges.

[0104] S430: When the distance between the bridge deck elevation and the arch foot key point is greater than 0 and less than the arch height, the hanger and column axes are automatically generated based on the input number and spacing of hangers, the input number and spacing of columns, and the logical relationship between the bridge deck position and the arch axis curve. The column axis is located below the bridge deck and between the bridge deck and the arch axis curve; the hanger axis is located above the bridge deck and between the bridge deck and the arch axis curve.

[0105] Adjust the absolute vertical distance between the center of the bridge deck and the key points of the arch crown, calculate the distance between the suspension points of the bridge deck and the arch axis curve in real time, and adjust the hanger length and column length in real time, so as to achieve the cm-level interval adjustment of the bridge deck of the half-through arch bridge and the automatic creation and adjustment of all hangers and columns.

[0106] S440: When the distance between the bridge deck elevation and the arch foot key point is greater than the arch height, the column axis is automatically generated based on the input number and spacing of columns, as well as the logical relationship between the bridge deck position and the arch axis curve. The absolute vertical distance between the bridge deck center and the arch crown key point is calculated, and then the spatial distance between the bridge deck center and the arch crown key point is calculated. The column height is adjusted in real time based on the spatial and absolute distances, enabling arbitrary adjustment of the deck of a deck arch bridge at the centimeter level and the automatic creation and adjustment of all columns.

[0107] It can be understood that steps S420-S440 are for calculating the columns and hangers in three types of arch bridges: top-supported arch bridge, mid-supported arch bridge and bottom-supported arch bridge. There is no necessary order between steps S420-S440, and the step numbers are only used for distinction.

[0108] S450, based on the data in the parameterized bridge deck position C-3 level module, generate a three-dimensional bridge deck model. By adjusting the bridge deck position, columns, and hangers, observe whether the three-dimensional bridge deck model changes according to the logical relationship as the bridge deck position, columns, and hangers are adjusted. If the three-dimensional bridge deck model does not meet the logical relationship, repeat steps S410-S430, adjust the parameters of the logical relationship in steps S410-S430, and repeat until the three-dimensional bridge deck model meets the logical relationship. Finally, generate Figure 10 It is understandable that Figure 10Only the generated image of the half-through steel truss arch bridge structure is shown. The difference between the through steel truss arch bridge and the top-decker steel truss arch bridge and the half-through steel truss arch bridge is only the position of the bridge deck.

[0109] S500: Calculate the basket lift angle based on data in the parameterized arch structure C-1 level module, the parameterized truss structure C-2 level module, the parameterized bridge deck position C-3 level module, and the parameterized basket lift angle C-4 level module.

[0110] The parameterized basket angle C-4 level module includes three C-4-X level modules: outward, inward, and median. Figure 11 The specific steps include:

[0111] S510 generates a coordinate vector matrix for the arch axis lattice, using the bridge deck plane as the rotation reference plane and the bridge deck elevation as the rotation center axis. The arch axis and the lattice coordinate vector matrix are rotated to the camber angle. Simultaneously, all upper and lower chords, upper and lower crossbars, and web members rotate in real time, enabling parametric adjustment of any outward camber angle within 60 degrees of the arch axis. The camber angle range is [0°, 60°].

[0112] S520: Rotate the arch axis and the coordinate vector matrix of the lattice by an inward inclination angle. Simultaneously, all upper and lower chords, upper and lower crossbars, and web members rotate in real time, enabling parametric adjustment of any inward inclination angle within 40 degrees of the arch axis. The inclination angle range is [0°, 40°].

[0113] It is understandable that there is no necessary order between steps S510 and S520, and the step numbers are only used for distinction.

[0114] S530, based on the data in the parameterized basket handle angle C-4 level module, generate a three-dimensional model of the arch bridge, and by adjusting the inclination angle and the outclination angle, observe whether the three-dimensional model of the arch bridge changes according to the logical relationship with the adjustment of the inclination angle and the outclination angle. If the three-dimensional model of the arch bridge does not meet the logical relationship, repeat steps S510 and S520, adjust the parameters of the logical relationship in steps S510-S520, and repeat until the three-dimensional model of the arch bridge meets the logical relationship. Finally, generate Figure 12 It is understandable that the inward and outward inclined structures are more common in the through steel truss arch bridge, and are not common in the other two types of arch bridges. Figure 12 Only the generated inward-inclined through steel truss arch bridge is shown.

[0115] Figure 13-17The models generated are, in order, a half-through steel truss arch bridge, a top-decker steel truss arch bridge, a through-the-wall steel truss arch bridge, an inward-inclined through-the-wall steel truss arch bridge, and an outward-inclined through-the-wall steel truss arch bridge. In other words, by implementing the aforementioned Grasshopper-based visual parametric modeling method for ultra-long-span steel truss arch bridges and adjusting the input parameters, it is possible to satisfy the computational design requirements for all types of steel truss arch bridges, achieving efficient, accurate, and adaptable changes to ultra-long-span steel truss arch bridge structures at any stage of design.

[0116] The above are all preferred embodiments of the present invention, and are not intended to limit the scope of protection of the present invention. Therefore, any equivalent changes made based on the structure, shape, and principle of the present invention should be included in the scope of protection of the present invention.

Claims

1. A visual parametric modeling method for a super-long span steel truss arch bridge based on Grasshopper, characterized by: The steps include: Obtain geographic information and basic information and write them into the parameterized C-level module; Generate arch axis curve and arch structure 3D model through parametric arch structure C-1 level module; Generate a 3D model of the truss structure based on the data in the parametric truss structure C-2 level module and the parametric arch structure C-1 level module; Based on the data in the parametric arch structure C-1 level module and the parametric truss structure C-2 level module, the bridge deck position is calculated through the parametric bridge deck position C-3 level module to establish a three-dimensional bridge deck model; Based on the data in the parametric arch structure C-1 module, the parametric truss structure C-2 module, and the parametric bridge deck position C-3 module, the parametric basket angle C-4 module is used to adjust the arch axis's outward and inward angles, calculate the spatial position relationship between the arch axis and the bridge deck, and establish a three-dimensional model of the arch bridge. The steps of generating the arch axis curve and the arch structure 3D model through the parametric arch structure C-1 level module include the following: Construct the position matrix of the key points of the vault to form the vault coordinate system; Form a logical association between the arch height and the key point position of the arch top; By obtaining the absolute value of the arch height, the arch height can be controlled by parameters; Based on the arch height, the arch foot key point position matrix is ​​expanded to form the arch foot coordinate system; Logically associate the key points of arch height, arch span, arch crown and arch foot; By adjusting the absolute value of the arch span, the arch span can be controlled parametrically; Obtain the arch width, establish the logical relationship between the arch width and the key points of the arch crown and arch foot, and realize the parameter control of the arch width; Generate multiple related key points, select the arch foot key point and the arch top key point, and randomly generate two intermediate key points at the 1 / 4 span position. Generate the arch axis curve using the arch foot key point, arch top key point and intermediate key points; Generate a 3D model of the arch structure.

2. The Grasshopper-based visual parametric modeling method for a super-long span steel truss arch bridge according to claim 1 is characterized by: Geographic information includes the geographical location and span of the bridge site; basic information includes the bridge coordinate system, elevation system, starting and ending points, longitudinal slope, transverse slope, bridge site watershed information, and ground information under the bridge.

3. The Grasshopper-based visual parametric modeling method for a super-long span steel truss arch bridge according to claim 1 is characterized by: The arch axis curve is generated by non-uniform rational B-spline curve - NURBS curve.

4. The Grasshopper-based visual parametric modeling method for a super-long span steel truss arch bridge according to claim 1 is characterized by: Based on the data in the parametric arch structure C-1 level module, the three-dimensional model of the truss structure is established through the parametric truss structure C-2 level module, including the following steps: Construct a logical relationship between internode length and arch axis curve, divide the arch axis curve according to the internode length, and obtain curve segments; Get the endpoints of each curve segment to form an endpoint position matrix; Obtain the truss height, establish a logical association between the truss height and the arch axis curve, and vertically copy the arch axis curve according to the truss height; Dividing the copied arch axis curve according to the internode length to obtain curve segments of the copied arch axis curve; Obtaining the endpoint of each curve segment of the copied arch axis curve to form an endpoint position matrix of the copied arch axis curve; According to the arch width and internode length, the arch axis curve and the copied arch axis curve, as well as the end point position matrix are copied along the bridge width direction; According to the positional relationship of the endpoints in the endpoint position lattice in space, the logical relationship between the endpoint position lattices is constructed; Generate the upper and lower parallel axis according to the connection type and endpoint position matrix of the upper and lower parallels, as well as the logical relationship between the endpoint position matrixes; The web member axis is generated according to the connection relationship of the web member and the end point position lattice, as well as the logical relationship between the end point position lattices; The curve segments of the arch axis curve and the curve segments of the copied arch axis curve are the upper and lower chord axes. Generate a 3D truss model based on the upper and lower chord axes, the upper and lower parallel joint axes, and the web axis.

5. The Grasshopper-based visual parametric modeling method for a super-long span steel truss arch bridge according to claim 4 is characterized by: The logical relationship between the endpoint position lattices satisfies all the connection types of the upper and lower parallel connections between the arch axis curves; The connection types of upper and lower parallel connections include staggered connection, same frequency connection, and cross connection.

6. The Grasshopper-based visual parametric modeling method for a super-long span steel truss arch bridge according to claim 4 is characterized by: The logical relationship between the endpoint position lattices can satisfy the different connection methods of all web members between the arch axis curves; The connection relationship of the web includes positive increasing staggered connection, positive decreasing staggered connection, reverse increasing staggered connection, reverse decreasing staggered connection and same frequency connection.

7. The Grasshopper-based visual parametric modeling method for a super-long span steel truss arch bridge according to claim 4 is characterized by: Based on the data from the parametric arch structure C-1 level module and the parametric truss structure C-2 level module, the bridge deck position is calculated using the parametric bridge deck position C-3 level module. The three-dimensional bridge deck model is established in the following steps: The bridge deck position is associated with the bridge deck elevation, and the bridge deck elevation is associated with the arch crown key points, arch foot key points, and endpoint position lattice, to build a logical relationship between the bridge deck elevation and the arch crown key points, arch foot key points, and endpoint position lattice of the arch axis curve. Obtain the projection of the arch axis curve at the same height on the horizontal plane where the bridge deck is located, take the projection center as the bridge deck center, take the line connecting the centers of the short sides of the projection as the bridge deck center axis, and construct the bridge deck plane axis network in combination with the bridge deck width. Segment the projected edge to form edge segments, obtain the endpoints of the edge segments, and form the bridge deck edge lattice. Construct the logical relationship between the spatial position of the bridge deck edge lattice, and the spatial logical relationship between the bridge deck edge lattice and the endpoint position lattice of the arch axis curve. Calculate the length of the column or suspender according to the absolute distance between the bridge deck elevation and the key point of the arch foot. Generate a three-dimensional model of the bridge deck based on the parameters of the bridge deck position, columns and hangers.

8. The Grasshopper-based visual parametric modeling method for a super-long span steel truss arch bridge according to claim 7 is characterized by: Calculating the length of columns or hangers based on the absolute distance between the bridge deck elevation and the key points of the arch foot includes the following steps: When the distance between the bridge deck elevation and the key point of the arch foot is 0, the hanger axis is generated according to the logical relationship between the bridge deck position and the arch axis curve. The length of the hanger axis is the length of the hanger. When the distance between the bridge deck elevation and the key point of the arch foot is greater than 0 and less than or equal to the arch height, the column axis and the hanger axis are generated according to the logical relationship between the bridge deck position and the arch axis curve. The length of the column axis is the length of the column, and the length of the hanger axis is the length of the hanger. When the distance between the bridge deck elevation and the key point of the arch foot is greater than the arch height, the column axis is generated according to the logical relationship between the bridge deck position and the arch axis curve, and the length of the column axis is the column length.

9. The Grasshopper-based visual parametric modeling method for a super-long span steel truss arch bridge according to claim 4 is characterized by: Based on the data from the parametric arch structure C-1 module, the parametric truss structure C-2 module, and the parametric bridge deck position C-3 module, the camber and inclination angles of the arch axis curve are calculated using the parametric basket angle C-4 module. The three-dimensional model of the arch bridge is established in the following steps: Taking the bridge deck position plane as the rotation reference plane and the bridge deck elevation as the rotation center axis, a coordinate vector matrix of the arch axis endpoint position lattice is generated; Construct the logical relationship between the arch axis curve, upper and lower chords, web members, upper and lower parallel joints and the coordinate vector matrix; Obtain the camber angle, rotate the coordinate vector matrix of the arch axis and the arch axis endpoint position matrix by the camber angle, and simultaneously rotate all the upper and lower chords, upper and lower parallel joints, and web members in real time; Obtain the inclination angle, rotate the arch axis and the coordinate vector matrix of the lattice by the inclination angle, and at the same time, all the upper and lower chords, upper and lower parallel joints, and web members rotate in real time.

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