Visual parametric modeling method for ultra-large-span steel truss arch bridge based on Grasshopper

Abstract

The invention relates to the technical field of bridge design, in particular to a Grasshopper-based super-large-span steel truss arch bridge visuality parameterization modeling method which comprises the following steps: analyzing bridge structure characteristics, and building an overall logic framework; geographic information and bridge basic information are written into the parameterized C-level module; generating an arch axis curve and an arch structure three-dimensional model through a parameterized arch structure C-1-level module; generating a three-dimensional model of the truss structure by parameterizing a C-2-level module of the truss structure; according to data in the parameterized arch structure C-1-level module, the parameterized truss structure C-2-level module and the parameterized bridge floor position C-3-level module, the bridge floor position is calculated, and a bridge floor three-dimensional model is established; and according to the parameterized lifting basket angle C-4-level module, calculating an outward inclination angle and an inward inclination angle, and establishing an arch bridge three-dimensional model. According to the method, the modeling time of the ultra-large-span steel truss arch bridge structure can be shortened to a great extent, and the modeling precision is greatly improved.

Description

Technical Field

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

[0002] Steel truss arch bridge structures are widely used in super-long span arch bridges due to their excellent structural performance, good durability and super spanning capacity. However, due to their large span (usually more than 300m), the risk of structural failure also increases. In order to effectively control structural risks, the accuracy requirements for structural calculations of such bridges are more stringent. In addition, due to the large span, the number of nodes and units required to build the calculation model for such steel truss arch bridge structures during structural calculations is huge.

[0003] At present, manual modeling is usually adopted 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 often takes several days, and a lot of time is consumed in highly repetitive but non-innovative operations such as connecting nodes and units one by one. At the same time, due to the large number of node units, it is very easy to make mistakes when connecting units. There are many disadvantages such as low efficiency of modeling calculations, long cycle and high error rate.

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

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

[0006] The present invention provides a visual parametric modeling method for a super-long span steel truss arch bridge based on Grasshopper, which adopts the following technical solutions: A visual parametric modeling method for a super-long span steel truss arch bridge based on Grasshopper includes the following steps: Obtain geographic information and basic information and write them into the parameterized C-level module; Generate the arch axis curve and arch structure 3D model through the 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; According to 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; 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.

[0007] 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.

[0008] In a specific implementation scheme, generating an arch axis curve and an arch structure three-dimensional model by parameterizing the arch structure C-1 level module includes the following steps: 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 is controlled by parameters; Based on the arch height, the position matrix of the key points of the arch foot is expanded to form the arch foot coordinate system; Logically associate the key points of arch height, arch span, arch top and arch foot; By adjusting the absolute value of the arch span, the arch span can be controlled parametrically; Obtain the arch width, build the logical relationship between the arch width and the key points of the arch top and arch foot, and realize the parameter control of the arch width; Generate multiple related key points, select the key points of the arch foot and the key points of the arch top, and randomly generate two intermediate key points at the 1 / 4 span position. Generate the arch axis curve using the key points of the arch foot, the arch top and the intermediate key points; Generate a 3D model of the arch structure.

[0009] In a specific possible implementation manner, the arch axis curve is generated by a non-uniform rational B-spline curve - nurbs curve.

[0010] In a specific possible implementation scheme, according to the data in the parameterized arch structure C-1 level module, establishing the truss structure three-dimensional model through the parameterized truss structure C-2 level module includes the following steps: Construct the logical association between the internode length and the arch axis curve, divide the arch axis curve according to the internode length, and obtain the curve segmentation; Get the endpoints of each curve segment to form an endpoint position matrix; Obtain the truss height, build a logical association between the truss height and the arch axis curve, and vertically copy the arch axis curve according to the truss height; The copied arch axis curve is divided according to the internode length to obtain curve segments of the copied arch axis curve; For the copied arch axis curve, the endpoint of each curve segment is obtained to form an endpoint position matrix of the copied arch axis curve; According to the arch width and the length of the internode, 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 dot matrix of the upper and lower parallel, and the logical relationship between the endpoint position dot matrix; The axis of the web member 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 chord axis and the lower chord axis. A three-dimensional model of the truss is generated according to the axis of the upper chord, the axis of the lower chord, the upper and lower parallel joints, and the axis of the web.

[0011] In a specific feasible implementation scheme, the logical relationship between the end point position lattices satisfies all connection types of the vertical parallel connection between the arch axis curves; The connection types of upper and lower parallel connections include staggered connection, same frequency connection, and cross connection.

[0012] In a specific feasible implementation scheme, the logical relationship between the end point position lattices can satisfy the different connection modes of all the web members between the arch axis curves; The connection relationship of the belly rod includes positive increasing staggered connection, positive decreasing staggered connection, reverse increasing staggered connection, reverse decreasing staggered connection and same frequency connection.

[0013] In a specific embodiment, According to 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, and the three-dimensional model of the bridge deck is established, including the following steps: The bridge deck position is associated with the bridge deck elevation, and the bridge deck elevation is associated with the key points of the arch crown, the key points of the arch foot, and the end point position lattice, and the logical relationship between the bridge deck elevation and the key points of the arch crown, the key points of the arch foot, and the end point position lattice of the arch axis curve is constructed. Get 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 build the bridge deck plane axis network in combination with the bridge deck width. Segment the projected edge line, obtain the endpoints of the edge line segments, and form a bridge deck edge line dot matrix. Construct the logical relationship between the spatial position of the bridge deck edge line lattice, and construct the spatial logical relationship between the bridge deck edge line lattice and the end point 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. A three-dimensional model of the bridge deck is generated based on the parameters of the bridge deck position, columns and hangers.

[0014] In a specific possible implementation scheme, the length of the column or the hanger is calculated according to the absolute distance between the bridge deck elevation and the key point of the arch foot, including 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, 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 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 length of the column.

[0015] In a specific feasible implementation plan, 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, the camber angle and inclination angle of the arch axis curve are calculated by the parameterized basket angle C-4 level module, and the three-dimensional model of the arch bridge is established, including 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 dot matrix by the camber angle, and at the same time, all the upper and lower chords, upper and lower parallel joints, and web members rotate in real time; Get the inclination angle, rotate the arch axis and the coordinate vector matrix of the dot matrix by the inclination angle, and all the upper and lower chords, upper and lower parallel joints, and web members rotate in real time.

[0016] In summary, the present invention has the following beneficial effects: By inputting, grabbing, dragging and changing the corresponding parameters, it is possible to achieve fast and accurate modeling of steel truss bridge structures with any span, width, angle and deck position, which can greatly shorten the modeling time of super-long span steel truss arch bridge structures and greatly improve the modeling accuracy. At the same time, it also provides a new modeling idea and method for the field of bridge design, which can achieve efficient, high-accuracy and high-adaptability changes in any design stage of super-long span steel truss arch bridge structures. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is the overall architecture diagram.

[0018] Figure 2 It is the architecture diagram of the structural parameter C-level module.

[0019] Figure 3 It is the architectural diagram of the parametric arch structure C-1 level module.

[0020] Figure 4 It is the image generated in step S200.

[0021] Figure 5 It is the architectural diagram of the parametric truss structure C-2 level module.

[0022] Figure 6 This is the image after the belly bar is generated.

[0023] Figure 7 It is an architectural diagram for implementing step S350.

[0024] Figure 8 It is the image generated in step S300.

[0025] Fig. 9 It is the architectural diagram of the C-3 level module for the parametric bridge deck position.

[0026] Fig.10 It is an image of the half-through steel truss arch bridge generated in step S400.

[0027] Fig.11 It is the architectural diagram of the C-4 level module of parameterized basket angle.

[0028] Fig.12 This is the image of the inward-inclined through-type steel truss arch bridge generated in step S500.

[0029] Fig.13 This is the generated image of a half-through steel truss arch bridge.

[0030] Fig.14 This is the generated image of a deck steel truss arch bridge.

[0031] Fig.15 This is the generated image of a through steel truss arch bridge.

[0032] Fig.16 This is the generated image of the inward-inclined through-type steel truss arch bridge.

[0033] Fig.17 This is the generated image of the outward-inclined through-steel truss arch bridge. DETAILED DESCRIPTION

[0034] The following is combined with Figure 1 The present invention is described in further detail.

[0035] Reference Figure 1 The visual parametric modeling method of the super-long span steel truss arch bridge based on Grasshopper includes the following steps: S100, obtaining geographic information and basic information, and writing them into a parameterized C-level module.

[0036] Geographic information includes the geographical location of the bridge site and the span range, etc. 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. For details, see Figure 2 .

[0037] S200, generates arch axis curve and arch structure 3D model through parameterized arch structure C-1 level module.

[0038] 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: S210, constructing a matrix of the key points of the vault, forming a vault coordinate system that can be reached at any position, and identifying and storing the key points of the vault in real time. Constructing a data structure parameterization interface between the vault height and the vault axis curve, forming a logical association between the vault height and the key points of the vault, and parameterizing the logical association. By obtaining the absolute value of the input vault height, the parameter control of the vault height in mm units is realized.

[0039] S220, based on the arch height, expand the arch foot key point position matrix to form an arch foot coordinate system that can be reached at any position, and identify and store the arch foot key point position in real time. Construct a data structure interface between the arch span and the arch axis curve, form a logical association between the arch height, arch span, arch top key points and arch foot key points, and parameterize the logical association. By adjusting the absolute value of the arch span, the cm unit level of the arch span can be achieved.

[0040] S230, obtaining the arch width, constructing a logical relationship between the arch width and the key points of the arch top and the arch foot, and then constructing a data linkage interface between the arch width and the arch axis curve, so as to achieve cm-level parametric control of the arch width.

[0041] S240, using the data in the key point position matrix to 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, and use the arch foot key point, arch top key point and intermediate key point to generate the arch axis curve 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.

[0042] S250, generate a three-dimensional model of the arch structure according to the data in the parameterized arch structure C-1 level module, and observe whether the three-dimensional model of the arch structure changes according to the logical relationship with the adjustment of the arch height, arch span and arch width by adjusting the arch height, arch span and arch width. If the three-dimensional model of the arch structure does not satisfy 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 satisfies the logical relationship. Finally, generate Figure 4 Image shown.

[0043] S300, generating a truss structure three-dimensional model according to data in the parameterized truss structure C-2 level module and the parameterized arch structure C-1 level module.

[0044] The parametric truss structure C-2 level module includes five C-2-X level modules: span length, truss height, upper and lower parallel links, upper and lower chords, and web members. Figure 5 and Figure 7 The specific steps include: S310, constructing a logical association between the internode length and the arch axis curve, dividing the arch axis curve generated in step S200 according to the internode length to obtain curve segments, obtaining the endpoints of each curve segment, forming an endpoint position matrix, and numbering and storing the endpoint position matrix.

[0045] S320, obtaining the truss height, constructing 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.

[0046] 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 dot matrix are copied along the bridge width direction.

[0047] S330, based on the positional relationship of the endpoints in the endpoint position lattice in space, construct a logical relationship between the endpoint position lattices, and the logical relationship can satisfy all the connection modes of the upper and lower parallel connection between the arch axis curves. The upper and lower parallel connection connection modes include staggered connection, same frequency connection, cross connection, etc. Based on the connection mode and the endpoint position lattice, and the logical relationship between the endpoint position lattices, generate the upper and lower parallel connection axis. The upper and lower parallel connection can be further generated through the upper and lower parallel connection axis.

[0048] S340, in steps S310-S320, a total of four arch axis curves, two upper and two lower, are generated, wherein the two upper arch axis curves correspond to the axis of the upper chord, and each segment is the corresponding axis of the upper chord; the two lower arch axis curves correspond to the axis of the lower chord, and each segment is the corresponding axis of the lower chord. The upper and lower chord axes can be adjusted by adjusting the number of segments, segment lengths, and segment positions of the arch axis curve segments.

[0049] S350, constructing a logical relationship between the endpoint position lattices according to the position relationship of the endpoints in the endpoint position lattice in space, wherein the logical relationship can satisfy the different connection modes of all the web members between the arch axes. Generate a web member axis according to the connection relationship of the web member, the endpoint position lattice, and the logical relationship between the constructed endpoint position lattices. The web member can be further generated through the web member axis.

[0050] The connection modes of the belly bars include positive increasing staggered connection, positive decreasing staggered connection, reverse increasing staggered connection, reverse decreasing staggered connection and same frequency connection.

[0051] It is easy to understand that steps S330-350 are different calculations for the upper and lower chords, the upper and lower parallel joints, and the 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.

[0052] S360, based on the data in the C-2 level module of the parametric truss structure, generate a three-dimensional model of the truss structure by adjusting the automatic creation and real-time adjustment of the internode length, truss height, upper and lower parallel connections, upper and lower chords, and web members. Observe whether the three-dimensional model of the truss structure changes according to the logical relationship as the internode length, truss height, upper and lower parallel connections, upper and lower chords, and web members are adjusted. If the three-dimensional 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 three-dimensional model of the truss structure satisfies the logical relationship. After completing the calculation of the upper and lower chords, upper and lower parallel connections, and web members, finally generate the following Figure 8 The images shown.

[0053] S400, calculating the bridge deck position and establishing a three-dimensional model of the bridge deck according to 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.

[0054] The parametric bridge deck position C-3 level module includes three C-3-X level modules: top-bearing, mid-bearing, and bottom-bearing. Fig. 9 The specific steps include: S410, the bridge deck position is associated with the bridge deck elevation, and a logical relationship is constructed between the bridge deck elevation and the key points of the arch crown, the key points of the arch foot, and the end point position dot matrix of the arch axis curve. When the distance between the bridge deck elevation and the key points of the arch foot is greater than or equal to the arch height, a projection of the arch axis curve on the horizontal plane where the bridge deck is located is generated, and the outline of the projection is approximately rectangular, the center of the projection is the center of the bridge deck, and the line connecting the centers of the short sides of the projection is the central axis of the bridge deck. Combined with the preset bridge deck width, a bridge deck plane axis network is constructed.

[0055] The projected edge is segmented to form edge segments. The endpoints of the edge segments are obtained to form a bridge deck edge dot matrix. The bridge deck edge dot matrix is ​​sorted along the bridge width direction to construct a spatial logical relationship between the bridge deck edge dot matrix and the endpoint position dot matrix of the arch axis curve.

[0056] S420, when the distance between the bridge deck elevation and the key point of the arch foot is 0, the axis of the hanger is automatically generated according to the number and spacing of the input hangers, and the logical relationship between the bridge deck position and the arch axis curve. The length of the hanger axis is the hanger length. Adjust the vertical absolute distance between the center of the bridge deck and the key point of the arch top, calculate the distance between the bridge deck and the arch axis curve in real time, adjust the hanger length in real time, and realize the parametric setting of the bridge deck and hangers of the bottom-through arch bridge.

[0057] S430, when the distance between the bridge deck elevation and the key point of the arch foot is greater than 0 and less than the arch height, the hanger rod axis and the column axis are automatically generated according to the input number and spacing of the hangers, the input number and spacing of the 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 rod axis is located on the bridge deck and between the bridge deck and the arch axis curve.

[0058] 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 length of the hanger and the column in real time, so as to realize 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.

[0059] S440, 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 automatically generated according to the number and spacing of the input columns, and the logical relationship between the bridge deck position and the arch axis curve. The vertical absolute distance between the bridge deck center and the key point of the arch top is calculated, and then the spatial distance between the bridge deck center and the key point of the arch top is calculated. The column height is adjusted in real time according to the spatial distance and absolute distance, realizing arbitrary adjustment of the cm unit level of the bridge deck of the top-bearing arch bridge and automatic creation and adjustment of all columns.

[0060] It can be understood that steps S420-S440 are for calculating the columns and hangers in three types of arch bridges, namely, top-supported arch bridges, mid-supported arch bridges and bottom-supported arch bridges. There is no necessary sequence between steps S420-S440, and the step numbers are only used for distinction.

[0061] S450, generate a three-dimensional model of the bridge deck according to the data in the parameterized bridge deck position C-3 level module, and observe whether the three-dimensional model of the bridge deck changes according to the logical relationship with the adjustment of the bridge deck position, columns, and hangers by adjusting the bridge deck position, columns, and hangers. If the three-dimensional model of the bridge deck does not satisfy the logical relationship, repeat steps S410-S430, adjust the parameters of the logical relationship in steps S410-S430, and repeat until the three-dimensional model of the bridge deck satisfies the logical relationship. Finally, generate Fig.10 It is understandable that Fig.10 Only the generated image of the structure of the half-through steel truss arch bridge is shown. The difference between the bottom-through steel truss arch bridge and the top-through steel truss arch bridge and the half-through steel truss arch bridge is only the difference in the position of the bridge deck.

[0062] S500, calculating the basket lifting angle according to the 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 lifting angle C-4 level module.

[0063] The C-4 level module of parameterized basket angle includes three C-4-X level modules: outward, inward, and median. Fig.11 The specific steps include: S510, using the bridge deck position plane as the rotation reference plane and the bridge deck elevation as the rotation center axis, generates the coordinate vector matrix of the arch axis lattice. The arch axis and the coordinate vector matrix of the lattice are rotated to the camber angle, and all the upper and lower chords, upper and lower parallel joints, and web members are rotated in real time to achieve parametric adjustment of any outward inclination angle within 60 degrees of the arch axis. The camber angle change range is [0°, 60°].

[0064] S520, the coordinate vector matrix of the arch axis and the dot matrix is ​​rotated inwardly by an angle, and all the upper and lower chords, upper and lower parallel links, and web members are rotated in real time in a linked manner to achieve parametric adjustment of any inward inclination angle within 40 degrees of the arch axis. The inclination angle variation range is [0°, 40°].

[0065] It is understandable that there is no necessary sequence between steps S510 and S520, and the step numbers are only used for distinction.

[0066] S530, generate a three-dimensional model of the arch bridge according to the data in the parameterized basket handle angle C-4 level module, and 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 by adjusting 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 Fig.12 It is understandable that the inward and outward inclined structures are more common in the bottom-through steel truss arch bridge, and are not common in the other two arch bridges. Fig.12 Only the generated inward-inclined through-type steel truss arch bridge is shown.

[0067] Figure 13-Figure 17 The models of the generated mid-span steel truss arch bridge, top-span steel truss arch bridge, bottom-span steel truss arch bridge, inward-inclined bottom-span steel truss arch bridge, and outward-inclined bottom-span steel truss arch bridge are shown in sequence. In other words, by executing the above-mentioned visual parametric modeling method of super-long-span steel truss arch bridge based on Grasshopper and adjusting the input parameters, the calculation design of all types of steel truss arch bridges can be met, and the changes of super-long-span steel truss arch bridge structure at any design stage with high efficiency, high accuracy, and high adaptability can be achieved.

[0068] The above are all preferred embodiments of the present invention, and are not intended to limit the protection scope 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 protection scope 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 the arch axis curve and arch structure 3D model through the 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; According to 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; 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.

2. The visual parametric modeling method for a super-long span steel truss arch bridge based on Grasshopper according to claim 1 is characterized in that: 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 visual parametric modeling method for a super-long span steel truss arch bridge based on Grasshopper according to claim 1 is characterized in that: The following steps are involved in generating the arch axis curve and the arch structure 3D model through the parametric arch structure C-1 level module: 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 is controlled by parameters; Based on the arch height, the position matrix of the key points of the arch foot is expanded to form the arch foot coordinate system; Logically associate the key points of arch height, arch span, arch top and arch foot; By adjusting the absolute value of the arch span, the arch span can be controlled parametrically; Obtain the arch width, build the logical relationship between the arch width and the key points of the arch top and arch foot, and realize the parameter control of the arch width; Generate multiple related key points, select the key points of the arch foot and the key points of the arch top, and randomly generate two intermediate key points at the 1 / 4 span position. Generate the arch axis curve using the key points of the arch foot, the arch top and the intermediate key points; Generate a 3D model of the arch structure.

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

5. The visual parametric modeling method for a super-long span steel truss arch bridge based on Grasshopper according to claim 1 is characterized in that: According to 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 the logical association between the internode length and the arch axis curve, divide the arch axis curve according to the internode length, and obtain the curve segmentation; Get the endpoints of each curve segment to form an endpoint position matrix; Obtain the truss height, build a logical association between the truss height and the arch axis curve, and vertically copy the arch axis curve according to the truss height; The copied arch axis curve is divided according to the internode length to obtain curve segments of the copied arch axis curve; For the copied arch axis curve, the endpoint of each curve segment is obtained to form an endpoint position matrix of the copied arch axis curve; According to the arch width and the length of the internode, 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 dot matrix of the upper and lower parallel, and the logical relationship between the endpoint position dot matrix; The axis of the web member 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. A three-dimensional model of the truss is generated based on the upper and lower chord axes, the upper and lower parallel joint axes, and the web axis.

6. The visual parametric modeling method for a super-long span steel truss arch bridge based on Grasshopper according to claim 5 is characterized in that: 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.

7. The visual parametric modeling method for a super-long span steel truss arch bridge based on Grasshopper according to claim 5 is characterized in that: The logical relationship between the endpoint position lattices can satisfy the different connection modes of all the web members between the arch axis curves; The connection relationship of the belly rod includes positive increasing staggered connection, positive decreasing staggered connection, reverse increasing staggered connection, reverse decreasing staggered connection and same frequency connection.

8. The visual parametric modeling method for a super-long span steel truss arch bridge based on Grasshopper according to claim 5 is characterized in that: According to 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, and the three-dimensional model of the bridge deck is established, including the following steps: The bridge deck position is associated with the bridge deck elevation, and the bridge deck elevation is associated with the key points of the arch crown, the key points of the arch foot, and the end point position lattice, and the logical relationship between the bridge deck elevation and the key points of the arch crown, the key points of the arch foot, and the end point position lattice of the arch axis curve is constructed. Get 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 build 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 a bridge deck edge dot matrix. Construct the logical relationship between the spatial position of the bridge deck edge line lattice, and construct the spatial logical relationship between the bridge deck edge line lattice and the end point 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. A three-dimensional model of the bridge deck is generated based on the parameters of the bridge deck position, columns and hangers.

9. The Grasshopper-based visual parametric modeling method for a super-long span steel truss arch bridge according to claim 8 is characterized in that: Based on the absolute distance between the bridge deck elevation and the key point of the arch foot, the length of the column or hanger is calculated by 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, 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 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.

10. The visual parametric modeling method for a super-long span steel truss arch bridge based on Grasshopper according to claim 5 is characterized in that: According to 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, the camber angle and inclination angle of the arch axis curve are calculated through the parameterized basket angle C-4 level module, and the three-dimensional model of the arch bridge is established, which includes 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 dot matrix by the camber angle, and at the same time, all the upper and lower chords, upper and lower parallel joints, and web members rotate in real time; Get the inclination angle, rotate the arch axis and the coordinate vector matrix of the dot matrix 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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