Concrete structure printing method, apparatus, and computer readable storage medium

Abstract

The application discloses a concrete structure printing method and device and a computer readable storage medium, and belongs to the technical field of civil construction. The method comprises the following steps: acquiring a smooth concrete voxelization model of a target concrete structure; calculating a principal stress trajectory for the smooth concrete voxelization model, and determining a printing path of a 3D printing device based on the principal stress trajectory; and controlling the 3D printing device to print the target concrete structure according to the printing path. The application determines the printing path through the principal stress trajectory, and aims to improve construction efficiency.

Description

Technical Field

[0001] This invention relates to the field of civil engineering technology, and more particularly to a method, equipment, and computer-readable storage medium for printing concrete structures. Background Technology

[0002] Concrete is mainly composed of cement, sand, stone and other materials. Due to the weak bonding between the various materials, the overall tensile strength of concrete is weak, making it prone to cracking, which affects the safety and stability of the building structure.

[0003] In 3D concrete printing technology, prestressed tendons are installed in the tension zone of a concrete structure. By applying prestress, the originally tensile concrete material is compressed, thus ensuring that the concrete material will not break due to tension.

[0004] However, installing prestressing tendons in concrete structures requires the use of special equipment such as perforated jacks, and after the prestressing tendons are installed, grouting is required inside the cavity, making the construction process complicated and the construction period long.

[0005] The above content is only used to help understand the technical solution of the present invention and does not represent an admission that the above content is prior art. Summary of the Invention

[0006] The main objective of this invention is to provide a method, equipment, and computer-readable storage medium for printing concrete structures, aiming to solve the technical problem of low construction efficiency in existing concrete structures.

[0007] To achieve the above objectives, the present invention provides a method for printing concrete structures, the method comprising the following steps:

[0008] Obtain a smooth concrete voxelized model of the target concrete structure;

[0009] The principal stress trajectories are calculated for the smooth concrete voxel model, and the printing path of the 3D printing equipment is determined based on the principal stress trajectories.

[0010] The 3D printing equipment is controlled to print the target concrete structure according to the printing path.

[0011] Optionally, the principal stress trace includes the principal compressive stress line, and the step of calculating the principal stress trace for the smooth concrete voxel model and determining the printing path of the 3D printing equipment based on the principal stress trace includes:

[0012] Finite element analysis was performed on the smooth concrete voxel model, and the minimum principal stress of each element of the smooth concrete voxel model was determined based on the finite element analysis results.

[0013] Connect the directions of the minimum principal stress of each element to form a line, and obtain the principal compressive stress line of the smooth concrete voxel model;

[0014] The segmentation direction of the segmentation plane is determined based on the vertical direction of the principal compressive stress line.

[0015] The segmentation position of the segmentation plane is determined based on the preset number of segments corresponding to the target concrete structure.

[0016] Based on the segmentation direction and the segmentation position, the smooth concrete voxel model is segmented into concrete blocks;

[0017] Based on the principal compressive stress line, several printing paths are determined corresponding to the several concrete blocks.

[0018] Optionally, before the step of obtaining a smooth concrete voxel model of the target concrete structure, the following steps are included:

[0019] Obtain the original design domain, load, support, evolution rate, target volume, and preset convergence tolerance threshold of the target steel-concrete composite structure, wherein the target steel-concrete composite structure includes the target concrete structure;

[0020] The original design domain is discretized into several original elements using a finite element mesh, and the original volume is calculated based on all the original elements.

[0021] Based on the load and the support, calculate the element sensitivity number corresponding to each original element;

[0022] Calculate the optimized volume based on the original volume and the evolution rate;

[0023] The original cells are added or deleted according to the cell sensitivity number and the optimization volume to obtain optimized cells, and the convergence tolerance of the optimized cells is calculated.

[0024] If the optimized volume satisfies the target volume and the convergence tolerance satisfies the preset convergence tolerance threshold, then an initial mixed steel voxel model is generated based on the optimized unit.

[0025] Based on the initial concrete voxel model, the initial concrete voxel model of the target concrete structure is determined;

[0026] The initial concrete voxel model is then subjected to post-design processing to obtain the corresponding smooth concrete voxel model.

[0027] Optionally, after the steps of adding or deleting the original cells according to the cell sensitivity number and the optimized volume to obtain optimized cells, and calculating the convergence tolerance of the optimized cells, the method further includes:

[0028] If the optimized volume does not meet the target volume, and / or the convergence tolerance does not meet the preset convergence tolerance threshold, then the optimized unit is used as a new original unit, and the optimized volume is used as a new original volume.

[0029] The steps include calculating the element sensitivity number corresponding to each original element based on the load and the support, and performing post-design processing on the initial concrete voxel model to obtain the corresponding smooth concrete voxel model.

[0030] Optionally, the step of calculating the element sensitivity number corresponding to each original element based on the load and the support includes:

[0031] Based on the load and the support, and combined with historical data, calculate the element sensitivity number corresponding to each original element.

[0032] Optionally, before the step of obtaining the original design domain, load, support, evolution rate, target volume, and preset convergence tolerance threshold of the target steel-concrete composite structure, where the target steel-concrete composite structure includes the target concrete structure, the following steps are included:

[0033] Based on the specific structure of the target steel-concrete composite structure, a non-design domain is delineated from the original design domain;

[0034] The step of adding or deleting the original cells based on the cell sensitivity number and the optimized volume includes:

[0035] If the original unit belongs to the non-design domain, then the original unit will not be added or deleted;

[0036] If the original unit does not belong to the non-design domain, the original unit is added or deleted according to the unit sensitivity number and the optimized volume.

[0037] Optionally, the target steel-concrete structure includes a target steel structure. Before the step of performing post-design processing on the initial concrete voxel model to obtain the corresponding smooth concrete voxel model, the following steps are included:

[0038] Based on the initial mixed steel voxel model, the initial steel voxel model of the target steel structure is determined;

[0039] The step of performing post-design processing on the initial concrete voxel model to obtain the corresponding smooth concrete voxel model includes:

[0040] The network smoothing technology is used to transform the jagged contours in the initial steel voxel model and the initial concrete voxel model into curved contours, thereby obtaining the corresponding smooth steel voxel model and smooth concrete voxel model.

[0041] The simplification technique described above simplifies the steel in the smooth steel voxel model into a steel cable.

[0042] Optionally, after the step of controlling the 3D printing device to print the target concrete structure according to the printing path, the method further includes:

[0043] The target concrete structure and the steel cable are prefabricated and assembled to obtain the target steel-concrete structure.

[0044] Furthermore, to achieve the above objectives, the present invention also provides a concrete structure printing device, the device comprising: a memory, a processor, and a concrete structure printing program stored in the memory and executable on the processor, the concrete structure printing program being configured to implement the steps of the concrete structure printing method described above.

[0045] In addition, to achieve the above objectives, the present invention also provides a computer-readable storage medium storing a concrete structure printing program, which, when executed by a processor, implements the steps of the concrete structure printing method.

[0046] In one technical solution provided by this invention, a smooth concrete voxel model of the target concrete structure is obtained, and the principal stress trajectories are calculated for the smooth concrete voxel model to determine the printing path of the 3D printing equipment, thereby controlling the 3D printing equipment to print the target concrete structure. Unlike traditional concrete construction methods, the target concrete structure in this solution is printed in one piece, and no prestressing is required internally. Therefore, steps such as perforation and grouting are not necessary, shortening the construction cycle and improving overall construction efficiency. Attached Figure Description

[0047] Figure 1 This is a flowchart illustrating the first embodiment of the concrete structure printing method of the present invention;

[0048] Figure 2 This is a schematic diagram of the printing path in the first embodiment of the concrete structure printing method of the present invention;

[0049] Figure 3 This is a schematic diagram of 3D printing in the first embodiment of the concrete structure printing method of the present invention;

[0050] Figure 4 This is a flowchart illustrating the first embodiment of the concrete structure printing method of the present invention;

[0051] Figure 5 This is a schematic diagram of the principal compressive stress lines in the second embodiment of the concrete structure printing method of the present invention;

[0052] Figure 6This is a block diagram of the second embodiment of the concrete structure printing method of the present invention;

[0053] Figure 7 This is a flowchart illustrating the third embodiment of the concrete structure printing method of the present invention;

[0054] Figure 8 This is a schematic diagram of the load and support in the third embodiment of the concrete structure printing method of the present invention;

[0055] Figure 9 This is a schematic diagram of the initial concrete-steel voxel model in the third embodiment of the concrete structure printing method of the present invention;

[0056] Figure 10 This is a schematic diagram of a smooth steel-reinforced concrete voxel model in the third embodiment of the concrete structure printing method of the present invention;

[0057] Figure 11 This is a flowchart illustrating the fifth embodiment of the concrete structure printing method of the present invention;

[0058] Figure 12 This is a schematic diagram of the structure of a concrete structure printing device in the hardware operating environment of an embodiment of the present invention.

[0059] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0060] It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0061] Compared to traditional concrete construction methods, 3D concrete printing technology offers higher construction efficiency and enables the creation of free-form structures. However, compared to traditional concrete structures, the design of 3D printed concrete structures presents the following challenges:

[0062] First, due to the influence of material properties, concrete has excellent compressive properties but weak tensile properties. How to ensure that the designed concrete structure will not be subjected to tension is a difficult problem.

[0063] Secondly, there is currently no good solution for how to install steel bars inside a concrete printed structure.

[0064] To address the aforementioned issues, considering the stress state of 3D-printed concrete, the current mainstream design methods for 3D-printed concrete structures mainly include the following solutions:

[0065] 1. Design a purely compressive structural form, such as an arch bridge or a shell structure, to avoid tensile stress on the concrete. The general steps for this approach are:

[0066] (1) Design a reasonable arch axis based on the structural support, span, load and other conditions, determine the rise-span ratio, and try to ensure that the concrete material is in a pure compressive state.

[0067] (2) Determine the general shape of the structure based on the arch axis and carry out detailed design to obtain the form of an arch bridge or shell;

[0068] (3) Print, maintain and install the arch bridge or shell in separate panels.

[0069] 2. Drawing on traditional concrete construction methods, prestressed tendons are installed in the tension zones of the concrete structure. By applying prestress, the concrete material, which was originally under tension, is subjected to compression, thus ensuring that the concrete material will not fracture due to tension. The steps of this approach are generally as follows:

[0070] (1) Determine the approximate shape of the preliminary structure based on the structural requirements;

[0071] (2) Perform finite element analysis on the preliminary structure to determine the tension zone of the structure;

[0072] (3) Design the location and orientation of prestressing tendons in the tension zone of the structure;

[0073] (4) Print the structural panels and cure them;

[0074] (5) Install prestressed tendons;

[0075] (6) Grouting inside the cavity of the 3D printed structure.

[0076] The disadvantages of the two existing solutions mentioned above are as follows:

[0077] 1. This approach has very limited application scenarios, only suitable for limited structural forms such as arch bridges or shell structures, and cannot be applied to structures with small spans and rises. For structures with large spans, this method is difficult to apply, as it is hard to guarantee that the structure is under pure compression with limited height. Furthermore, this approach relies heavily on traditional concrete structure design experience, and the structural rationality itself requires subsequent structural verification. Therefore, this method is difficult to widely promote and apply to various architectural scenarios.

[0078] 2. Installing prestressing tendons in concrete structures requires specialized equipment such as perforated jacks. Furthermore, grouting is necessary after installation, making the construction process cumbersome and time-consuming. The entire process is wet work, which is inconsistent with the principles of automated and intelligent construction.

[0079] To address the aforementioned issues, this invention calculates the principal stress trajectories based on a smooth concrete voxel model of the target concrete structure to determine the printing path of the 3D printing equipment. This setup ensures that the concrete layer remains perpendicular to the principal compressive stress lines during the printing process, guaranteeing that the printed target concrete structure is under overall compression. Therefore, there is no need to install prestressing tendons internally, thus improving construction efficiency.

[0080] To better understand the above technical solutions, exemplary embodiments of this application will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of this application are shown in the drawings, it should be understood that this application can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of this application and to fully convey the scope of this application to those skilled in the art.

[0081] This invention provides a method for printing concrete structures, referring to... Figure 1 , Figure 1 This is a flowchart illustrating the first embodiment of a concrete structure printing method according to the present invention.

[0082] In this embodiment, the concrete structure printing method includes:

[0083] Step S11: Obtain a smooth concrete voxel model of the target concrete structure;

[0084] It is understandable that the target concrete-steel structure consists of a target concrete structure and a target steel structure. The target concrete structure is the final 3D-printed concrete product and is a purely compressive structure. The tension portion is achieved by placing a target steel structure outside the concrete structure, making the steel structure a purely tensile structure. Based on this method, the designed structure can simultaneously contain tension and compression, thus enabling a wider range of applications. For structures with large span-to-rise ratios, the combination of tension and compression ensures sufficient bending stiffness to cope with complex stress requirements.

[0085] It is understandable that voxelization is the process of converting the geometric representation of an object into a voxel representation that is closest to the object. In the process of finite element analysis, the structure is usually represented in the form of a finite element mesh. Specifically, a smooth concrete voxelized model refers to a concrete structure that has been smoothed and represented by a finite element mesh.

[0086] Optionally, a smoothed concrete voxel model of the target concrete structure can be obtained. Specifically, this can be achieved by directly retrieving a pre-constructed smoothed concrete voxel model from a database, or by utilizing topology optimization techniques to automatically find the shape of the entire target steel-concrete structure and then smoothing it to obtain the smoothed concrete voxel model. This embodiment does not impose specific limitations. Topology optimization is a mathematical method that optimizes material distribution within a given region based on given load conditions, constraints, and performance indicators.

[0087] Step S12: Calculate the principal stress trajectories for the smooth concrete voxel model, and determine the printing path of the 3D printing equipment based on the principal stress trajectories;

[0088] Understandably, principal stress trajectories are a family of curves representing the directions of principal stresses, which can intuitively reflect the force flow transmission path and provide a mechanical basis for subsequent steps. Principal stress trajectories include principal tensile stress lines and principal compressive stress lines, and the tangents to these two lines at their intersection points are perpendicular to each other.

[0089] Optionally, a finite element analysis is performed on the smooth concrete voxel model, and the minimum principal stress σ of each element (i.e., each finite element mesh) is determined based on the finite element analysis results. 33 Finally, the minimum principal stress σ in each element is... 33 Connecting the directions of the stresses in the model yields the principal compressive stress lines of the smooth concrete matrix. Alternatively, the maximum principal stress σ of each element can be determined based on the finite element analysis results. 11 The maximum principal stress σ in each element 11 Connect the directions to form lines to obtain the principal tensile stress lines of the smooth concrete voxel model. Then, based on the principle of perpendicular tangents, determine the corresponding principal compressive stress lines. This embodiment does not impose specific limitations.

[0090] Furthermore, in the 3D printing of concrete, the slurry is layered and stacked to form a whole. Considering that the concrete layer has optimal compressive performance in the direction perpendicular to the contact surface of the printed layer, and that no shear force is generated between the layers at this point, the design process ensures that the concrete layer is always perpendicular to the principal compressive stress line in the principal stress trajectory, thus obtaining the printing path of the 3D printing equipment, such as... Figure 2 As shown, this ensures the stress performance of each concrete layer and that the pressure is always perpendicular to the printed layer, thus preventing shear force from being generated between adjacent concrete layers.

[0091] Step S13: Control the 3D printing equipment to print the target concrete structure according to the printing path.

[0092] Specifically, based on the printing path, the 3D printing equipment is controlled to print the target concrete structure. This includes controlling the printing layer height, printing speed, material output speed, and printing direction angle. The 3D printing equipment can employ a six-axis robotic arm; this embodiment does not impose specific limitations. During the printing process, non-horizontal printing methods can be used to ensure the printing of free-form structures, such as... Figure 3 As shown, the use of a non-horizontal base and partition (plastic film) in 3D printing ensures that the upper printed part remains vertical during the printing process and will not tip over.

[0093] Whether it's a conventional or custom-designed structure, intelligent equipment such as a six-axis robotic arm can be used to print and build this type of structure. Subsequent maintenance can be carried out in the factory to ensure the construction quality of the components.

[0094] Since the smooth concrete voxel model of the target concrete structure is a purely compressive structure, the final printed product is purely compressive and will not be under tension, thus making efficient use of the inherent properties of concrete materials and having a wide range of applications.

[0095] In one technical solution provided in this embodiment, a smooth concrete voxel model of the target concrete structure is obtained. Principal stress trajectories are calculated for the smooth concrete voxel model to determine the printing path of the 3D printing equipment, thereby controlling the 3D printing equipment to print the target concrete structure. Unlike traditional concrete construction methods, the target concrete structure in this solution is printed as a single piece, and no prestressing is required internally. Therefore, steps such as perforation and grouting are unnecessary, reducing construction costs and shortening the construction cycle, thus improving overall construction efficiency.

[0096] Furthermore, refer to Figure 4 A second embodiment of the concrete structure printing method of the present invention is proposed. Based on the above... Figure 1 In the illustrated embodiment, the principal stress trace includes the principal compressive stress line. The steps of calculating the principal stress trace for the smooth concrete voxel model and determining the printing path of the 3D printing equipment based on the principal stress trace include:

[0097] Step S21: Perform finite element analysis on the smooth concrete voxel model, and determine the minimum principal stress of each element of the smooth concrete voxel model based on the finite element analysis results;

[0098] Step S22: Connect the directions of the minimum principal stress of each element into a line to obtain the principal compressive stress line of the smooth concrete voxel model;

[0099] Step S23: Determine the segmentation direction of the segmentation plane based on the vertical direction of the principal compressive stress line;

[0100] It is understandable that for large-volume concrete structures, such as bridges and dams, it is necessary to use segmented processing to facilitate printing, transportation, and maintenance.

[0101] Optionally, a finite element analysis is performed on the smooth concrete voxel model, and the minimum principal stress σ of each element (i.e., each finite element mesh) is determined based on the finite element analysis results. 33 Finally, the minimum principal stress σ in each element is... 33 Connect the directions to form lines to obtain the principal compressive stress lines of the smooth concrete voxel model, such as... Figure 5 As shown, this provides a mechanical basis for the subsequent block division steps.

[0102] Furthermore, the smooth concrete voxel model of the concrete section is divided into blocks based on the principal compressive stress lines. During the block division process, it is necessary to ensure that the dividing plane is always perpendicular to the principal compressive stress lines, that is, parallel to the principal tensile stress lines. Figure 5 As shown, therefore, the dividing direction of the dividing plane is determined by referring to the vertical direction of the principal compressive stress line, or by referring to the parallel direction of the principal tensile stress line.

[0103] It is important to note that during the segmentation process, the dividing plane must always be perpendicular to the principal compressive stress line. This ensures that the pressure transfer between adjacent concrete blocks remains perpendicular to the contact surface (i.e., the dividing plane in this case). (Refer to...) Figure 2 This characteristic is a prerequisite for achieving the final structure without the need for internal prestressing.

[0104] Step S24: Determine the segmentation position of the segmentation plane based on the preset number of segments corresponding to the target concrete structure;

[0105] Understandably, technicians can pre-divide the target concrete structure into several segments, with each segment having the same length by default. Technicians can also adjust the length of each segment according to the actual situation.

[0106] Optionally, the target concrete structure is uniformly segmented based on a preset number of segments to determine the segmentation position of the segmentation plane.

[0107] Step S25: Based on the segmentation direction and the segmentation position, the smooth concrete voxel model is segmented into concrete blocks;

[0108] Step S26: Based on the principal compressive stress line, determine several printing paths corresponding to the several concrete blocks.

[0109] Optionally, the starting segmentation point is first determined based on the segmentation location. Then, using the starting segmentation point as a reference, segmentation is performed along the segmentation direction, ultimately dividing the smooth concrete voxel model into several concrete blocks, such as... Figure 6 As shown.

[0110] Furthermore, for each concrete block, the corresponding printing path is determined based on the principal compressive stress line. The specific process is the same as step S12, and will not be repeated here.

[0111] In one technical solution provided in this embodiment, on the one hand, the segmentation direction is determined based on the principal compressive stress line, and on the other hand, the segmentation position is determined based on the preset number of segments. Thus, the smooth concrete bulk model can be segmented into concrete blocks according to the segmentation direction and position, and the corresponding printing path can be determined. Through block segmentation, large-volume structures are refined into smaller-volume structures, meeting the size limitations of 3D printed structures. Furthermore, the smaller-volume structures are easier to transport, reducing the risk of breakage during transportation.

[0112] Furthermore, refer to Figure 7 A third embodiment of the concrete structure printing method of the present invention is proposed. Based on the above... Figure 1 In the illustrated embodiment, prior to the step of obtaining a smooth concrete voxel model of the target concrete structure, the following steps are included:

[0113] Step S31: Obtain the original design domain, load, support, evolution rate, target volume and preset convergence tolerance threshold of the target steel-concrete composite structure, wherein the target steel-concrete composite structure includes the target concrete structure;

[0114] It is understandable that the target concrete-steel structure is an overall structure to be put into practical application, specifically including the target concrete structure and the target steel structure. Since it needs to be put into use as a whole, topology optimization of the target concrete-steel structure is required.

[0115] The original design domain refers to the closed space where topology optimization is performed; it is the region where the structure is allowed to appear, and is generally set as a rectangular (2D) or cuboid (3D) block that can contain the optimized structure; such as Figure 8 As shown, load refers to the pressure that the target concrete structure needs to bear, such as a car on a bridge deck; support refers to the supporting force on the target concrete structure, such as the rolling bearings and hinged bearings of a bridge; evolution rate is used to characterize the speed of the iteration process; target volume refers to the ratio of the iteration result to the original volume, such as 0.5; preset convergence tolerance threshold refers to the acceptable difference between the current iteration result and the target result.

[0116] Step S32: Discretize the original design domain into several original elements using a finite element mesh, and calculate the original volume based on all the original elements;

[0117] Optionally, the original design domain is discretized into several original elements using a finite element mesh, and initial attribute values ​​xi (0 or 1) are assigned to the original elements, where xi = 0 indicates that the element is an empty element, and xi = 1 indicates that the element is a solid element, in order to construct the initial design.

[0118] Furthermore, the original volume is calculated based on all original elements. For example, the volume corresponding to empty elements and solid elements is set to 1. Finally, the sum of the volumes of all original elements is calculated, which is the original volume corresponding to the original design domain.

[0119] Step S33: Calculate the element sensitivity number corresponding to each original element based on the load and the support;

[0120] Step S34: Calculate the optimized volume based on the original volume and the evolution rate;

[0121] It is understandable that the element sensitivity number is a physical quantity obtained from finite element analysis for each element, used to represent the degree of impact of adding or removing each element on the overall performance of the structure.

[0122] Optionally, the element sensitivity number corresponding to each original element can be calculated based on the load and support through finite element analysis. Where i represents the i-th unit, and k is the current iteration number.

[0123] Furthermore, based on the original volume and evolution rate, the optimized volume is calculated, specifically using the formula V. k+1 =V k (1±ER), where V k+1 To optimize volume, V k Let represent the original volume, ER represent the evolution rate, and k represent the current iteration number, where k = 1, 2, 3, ...

[0124] For example, the original volume V k If the value is 100 and the evolution rate ER is 0.8, then the optimized volume V is... k+1 It is 80.

[0125] Step S35: Add or delete the original units according to the unit sensitivity number and the optimized volume to obtain optimized units, and calculate the convergence tolerance of the optimized units;

[0126] Optionally, all original cells are sorted according to the size of the cell sensitivity number, and original cells are added or deleted based on the optimization volume. Finally, the adjusted original cells are statistically analyzed and defined as optimized cells.

[0127] For example, 100 original cells are sorted according to their cell sensitivity number, and the optimized volume V is known. k+1If the value is 80, then for the first 80 original elements, if xi = 0, adjust it to xi = 1; if xi = 1, leave it unchanged. For the last 20 original elements, perform the opposite adjustment, ensuring that the elements before the volume optimization are solid elements, and the optimized volume V... k+1 The following cells are empty cells.

[0128] Furthermore, the convergence tolerance of the optimization unit is calculated using the following formula:

[0129]

[0130] Where τ is the convergence tolerance, N is the total number of optimization units, i represents the i-th unit, C is the structural strain energy, k is the current iteration number, and S is an integer representing the change in the objective function in the most recent few steps.

[0131] Step S36: If the optimized volume satisfies the target volume and the convergence tolerance satisfies the preset convergence tolerance threshold, then the initial mixed steel voxel model is generated according to the optimization unit.

[0132] Optionally, if the volume V is optimized k+1 If the target volume V* is satisfied and the convergence tolerance τ satisfies the preset convergence tolerance threshold τ*, then the iteration termination condition is satisfied, indicating that the current optimization unit as a whole has reached the requirement. Therefore, the initial mixed steel voxel model is generated based on the optimization unit.

[0133] Step S37: Determine the initial concrete voxel model of the target concrete structure based on the initial steel-reinforced concrete voxel model;

[0134] It is understandable that the target concrete-steel structure includes both the target concrete structure and the target steel structure. After topology optimization, the initial concrete-steel voxel model correspondingly includes an initial concrete voxel model and an initial steel voxel model, such as... Figure 9 As shown, the overall model is the initial voxel model of the steel structure, the top model is the initial voxel model of the concrete, and the bottom model is the initial voxel model of the steel structure.

[0135] Optionally, an initial concrete voxel model can be selected from these models for 3D printing.

[0136] Step S38: Perform post-design processing on the initial concrete voxel model to obtain the corresponding smooth concrete voxel model.

[0137] Understandably, during topology optimization, the structure is generally represented using finite element meshes. Therefore, after topology optimization, the resulting structural layout is also represented in the form of voxels. Consequently, the surface of the initial concrete voxel model will have many jagged steps, which cannot be directly used for subsequent concrete printing. Therefore, post-design processing, i.e., smoothing, is required.

[0138] Optionally, the initial concrete voxel model of the target concrete structure can be post-designed using mesh smoothing techniques to adjust the jagged edges into curves, resulting in a smooth concrete voxel model, such as... Figure 10 As shown.

[0139] Step S38: If the optimized volume does not meet the target volume, and / or the convergence tolerance does not meet the preset convergence tolerance threshold, then the optimized unit is used as a new original unit, and the optimized volume is used as a new original volume;

[0140] Step S39: Based on the load and the support, and combined with historical data, calculate the element sensitivity number corresponding to each original element;

[0141] The steps include calculating the optimized volume based on the original volume and the evolution rate, and performing post-design processing on the initial concrete voxel model to obtain the corresponding smooth concrete voxel model.

[0142] Optionally, if the volume V is optimized k+1 If the target volume V* is not met, and / or the convergence tolerance τ does not meet the preset convergence tolerance threshold τ*, then the iteration termination condition is not met, indicating that the current optimization unit as a whole has not met the requirements. Therefore, the next topology optimization needs to be performed. Thus, the optimization unit is taken as the new original unit, and the optimization volume is taken as the new original volume.

[0143] Furthermore, during the subsequent iterations, when calculating the element sensitivity number, it can be calculated not only based on loads and supports, but also by referring to historical data, i.e., previous element sensitivity numbers, to reduce the error caused by a single calculation and make the data more accurate. The specific formula is as follows:

[0144]

[0145] in, This is the cell sensitivity number calculated during the previous iteration. This is the currently calculated unit sensitivity number.

[0146] Furthermore, a new round of topology optimization is performed, including the step of calculating the optimized volume based on the original volume and the evolution rate, and the step of post-designing the initial concrete voxel model to obtain the corresponding smooth concrete voxel model.

[0147] In one technical solution provided in this embodiment, the original design domain of the target steel-concrete composite structure is topologically optimized using pre-set parameters until the optimized volume and convergence tolerance meet the requirements. An initial steel-concrete composite voxel model is then output. After partitioning and post-design processing, a corresponding smooth concrete voxel model is obtained. Through topology optimization techniques and iterative steps, the overall volume of the structure is gradually reduced, ensuring that the structural layout formed by each topology optimization is the most efficient.

[0148] Furthermore, a fourth embodiment of the concrete structure printing method of the present invention is proposed. Based on the above... Figure 7 In the illustrated embodiment, prior to the steps of obtaining the original design domain, load, support, evolution rate, target volume, and preset convergence tolerance threshold of the target concrete structure, the following steps are included:

[0149] Step S41: Based on the specific structure of the target steel-concrete composite structure, divide the non-design domain from the original design domain;

[0150] It is understandable that topology optimization optimizes the material distribution within the original design domain. Considering practical factors, it is necessary to divide the non-design domain from the original design domain according to the specific structure of the target steel-concrete composite structure, so as to ensure that the material in this region is always preserved during the topology optimization process.

[0151] For example, such as Figure 8 As shown, the original design domain is a simply supported beam. A certain thickness of its upper surface is set as the bridge deck and divided into non-design domains to ensure that the complete bridge deck still exists in the final output structure.

[0152] The step of adding or deleting the original cells based on the cell sensitivity number and the optimized volume includes:

[0153] Step S42: If the original unit belongs to the non-design domain, then the original unit is not added or deleted;

[0154] Step S43: If the original unit does not belong to the non-design domain, then add or delete the original unit according to the unit sensitivity number and the optimized volume.

[0155] Optionally, based on the principle of always retaining elements outside the design domain, there is no need to adjust the original elements within the non-design domain. Therefore, if an original element belongs to the non-design domain, it will not be added or deleted. Conversely, if an original element belongs to the non-design domain, topology optimization is required, i.e., adding or deleting elements based on the element sensitivity number and optimization volume.

[0156] In one technical solution provided in this embodiment, a non-design domain is divided from the original design domain according to the specific structure of the target concrete structure. This non-design domain serves as a prerequisite for whether to add or delete original elements. By setting the non-design domain, it is ensured that the material in this region is always preserved during the topology optimization process, that is, the necessary parts of the structure are retained, avoiding the situation where the structure after multiple topology optimizations is not practical and cannot be put into practical application.

[0157] Furthermore, refer to Figure 11 This invention proposes a fifth embodiment of the concrete structure printing method. The target concrete-steel structure includes a target steel structure. Before the step of performing post-design processing on the initial concrete voxel model to obtain a corresponding smooth concrete voxel model, the method includes:

[0158] Step S51: Determine the initial steel voxel model of the target steel structure based on the initial mixed steel voxel model;

[0159] The step of performing post-design processing on the initial concrete voxel model to obtain the corresponding smooth concrete voxel model includes:

[0160] Step S52: Using the network smoothing technology, the jagged contours in the initial steel voxel model and the initial concrete voxel model are transformed into curved contours to obtain the corresponding smooth steel voxel model and smooth concrete voxel model.

[0161] Step S53: Using the simplification technique, the steel in the smooth steel voxel model is simplified to a steel cable.

[0162] After the step of controlling the 3D printing equipment to print the target concrete structure according to the printing path, the following steps are included:

[0163] Step S54: The target concrete structure and the steel cable are prefabricated and assembled to obtain the target steel-concrete structure.

[0164] It is understandable that the target concrete-steel structure includes the target concrete structure and the target steel structure. After topology optimization, the initial concrete-steel voxel model includes the initial concrete voxel model and the initial steel voxel model. Optionally, the initial steel voxel model can be selected from these models for post-design processing.

[0165] Furthermore, by first using mesh smoothing technology, the jagged contours in the initial steel voxel model and the initial concrete voxel model are transformed into curved contours, respectively, to obtain smooth steel voxel models and smooth concrete voxel models.

[0166] Furthermore, for the voxelized model of smooth steel, since there are already mature steel products on the market, the steel part in the voxelized model of smooth steel is directly simplified to steel cable through simplification technology; for the voxelized model of smooth concrete, the target concrete structure is obtained through 3D printing.

[0167] Finally, after the steel cables and the target concrete structure are transported to the construction site, since prestressing is not required, the steel cables and the target concrete structure are directly prefabricated and assembled to obtain the target steel-concrete structure.

[0168] It is important to note that, such as Figure 10 As shown, in the post-processing stage, concrete pouring sections can be set at both ends of the concrete, and the junction between the steel and concrete can be treated as a metal node to ensure good force transmission. Accordingly, in the prefabricated assembly stage, the above settings are optimized.

[0169] In one technical solution provided in this embodiment, after optimizing the topology of the target steel-concrete structure, network smoothing technology is used to process the concrete and steel parts. Then, simplification technology is used to directly simplify the steel parts into steel cables so that they can be prefabricated and assembled later. This is convenient and fast, and the whole process is dry operation, which is in line with the concept of automated intelligent construction.

[0170] Reference Figure 12 , Figure 12 This is a schematic diagram of the concrete structure printing equipment in the hardware operating environment of the embodiment of the present invention.

[0171] like Figure 12 As shown, the concrete structure printing equipment may include: a processor 1001, such as a central processing unit (CPU), a communication bus 1002, a user interface 1003, a network interface 1004, and a memory 1005. The communication bus 1002 is used to enable communication between these components. The user interface 1003 may include a display screen and an input unit such as a keyboard; optionally, the user interface 1003 may also include a standard wired interface or a wireless interface. The network interface 1004 may optionally include a standard wired interface or a wireless interface (such as a Wi-Fi interface). The memory 1005 may be a high-speed random access memory (RAM) or a stable non-volatile memory (NVM), such as a disk drive. The memory 1005 may also optionally be a storage device independent of the aforementioned processor 1001.

[0172] Those skilled in the art will understand that Figure 12 The structures shown do not constitute a limitation on the concrete structure printing equipment and may include more or fewer parts than shown, or combine certain parts, or have different arrangements of parts.

[0173] like Figure 12 As shown, the memory 1005, which serves as a storage medium, may include an operating system, a data storage module, a network communication module, a user interface module, and a concrete structure printing program.

[0174] exist Figure 12 In the concrete structure printing device shown, the network interface 1004 is mainly used for data communication with other devices; the user interface 1003 is mainly used for data interaction with the user; the processor 1001 and the memory 1005 in the concrete structure printing device of the present invention can be set in the concrete structure printing device. The concrete structure printing device calls the concrete structure printing program stored in the memory 1005 through the processor 1001 and executes the concrete structure printing method provided in the embodiment of the present invention.

[0175] This invention provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of any of the above embodiments of the concrete structure printing method.

[0176] Since the embodiments of the computer-readable storage medium portion correspond to the embodiments of the method portion, the embodiments of the computer-readable storage medium portion are described in the description of the embodiments of the method portion, and will not be repeated here.

[0177] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or system that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or system. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or system that includes that element.

[0178] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0179] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) as described above, and includes several instructions to cause a terminal device (which may be a mobile phone, computer, server, or network device, etc.) to execute the methods described in the various embodiments of the present invention.

[0180] The above are merely preferred embodiments of the present invention and do not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A method of printing a concrete structure, characterized by, The concrete structure printing method includes the following steps: Obtain a smooth concrete voxelized model of the target concrete structure; The principal stress trajectories are calculated for the smooth concrete voxel model, and the printing path of the 3D printing equipment is determined based on the principal stress trajectories. According to the printing path, the 3D printing equipment is controlled to print the target concrete structure; The principal stress trajectories include principal compressive stress trajectories. The steps of calculating the principal stress trajectories for the smooth concrete voxel model and determining the printing path of the 3D printing equipment based on the principal stress trajectories include: Finite element analysis was performed on the smooth concrete voxel model, and the minimum principal stress of each element of the smooth concrete voxel model was determined based on the finite element analysis results. Connect the directions of the minimum principal stress of each element to form a line, and obtain the principal compressive stress line of the smooth concrete voxel model; Based on the vertical direction of the principal compressive stress line, the dividing direction of the dividing plane is determined, and it is necessary to ensure that the dividing plane is always perpendicular to the principal compressive stress line. The segmentation position of the segmentation plane is determined based on the preset number of segments corresponding to the target concrete structure. Based on the segmentation direction and the segmentation position, the smooth concrete voxel model is segmented into concrete blocks; Based on the principal compressive stress line, several printing paths are determined for several concrete blocks, ensuring that the concrete layer is always perpendicular to the principal compressive stress line in the principal stress trace, thus obtaining the printing path of the 3D printing equipment.

2. The method of printing a concrete structure of claim 1, wherein, Before the step of obtaining a smooth concrete voxel model of the target concrete structure, the following steps are included: Obtain the original design domain, load, support, evolution rate, target volume, and preset convergence tolerance threshold of the target steel-concrete composite structure, wherein the target steel-concrete composite structure includes the target concrete structure; The original design domain is discretized into several original elements using a finite element mesh, and the original volume is calculated based on all the original elements. Based on the load and the support, calculate the element sensitivity number corresponding to each original element; Calculate the optimized volume based on the original volume and the evolution rate; The original cells are added or deleted according to the cell sensitivity number and the optimization volume to obtain optimized cells, and the convergence tolerance of the optimized cells is calculated. If the optimized volume satisfies the target volume and the convergence tolerance satisfies the preset convergence tolerance threshold, then an initial mixed steel voxel model is generated based on the optimized unit. Based on the initial concrete voxel model, the initial concrete voxel model of the target concrete structure is determined; The initial concrete voxel model is then subjected to post-design processing to obtain the corresponding smooth concrete voxel model.

3. The concrete structure printing method as described in claim 2, characterized in that, After the steps of adding or deleting the original cells according to the cell sensitivity number and the optimization volume to obtain optimized cells, and calculating the convergence tolerance of the optimized cells, the method includes: If the optimized volume does not meet the target volume, and / or the convergence tolerance does not meet the preset convergence tolerance threshold, then the optimized unit is used as a new original unit, and the optimized volume is used as a new original volume. The steps include calculating the element sensitivity number corresponding to each original element based on the load and the support, and performing post-design processing on the initial concrete voxel model to obtain the corresponding smooth concrete voxel model.

4. The concrete structure printing method as described in claim 3, characterized in that, The step of calculating the element sensitivity number corresponding to each original element based on the load and the support includes: Based on the load and the support, and combined with historical data, calculate the element sensitivity number corresponding to each original element.

5. The concrete structure printing method as described in claim 4, characterized in that, Prior to the step of obtaining the original design domain, load, support, evolution rate, target volume, and preset convergence tolerance threshold of the target steel-concrete composite structure, where the target steel-concrete composite structure includes the target concrete structure: Based on the specific structure of the target steel-concrete composite structure, a non-design domain is delineated from the original design domain; The step of adding or deleting the original cells based on the cell sensitivity number and the optimized volume includes: If the original unit belongs to the non-design domain, then the original unit will not be added or deleted; If the original unit does not belong to the non-design domain, the original unit is added or deleted according to the unit sensitivity number and the optimized volume.

6. The concrete structure printing method as described in claim 2, characterized in that, The target steel-concrete structure includes a target steel structure. Before the step of performing post-design processing on the initial concrete voxel model to obtain the corresponding smooth concrete voxel model, the following steps are included: Based on the initial mixed steel voxel model, the initial steel voxel model of the target steel structure is determined; The step of performing post-design processing on the initial concrete voxel model to obtain the corresponding smooth concrete voxel model includes: By using network smoothing technology, the jagged contours in the initial steel voxel model and the initial concrete voxel model are transformed into curved contours, resulting in the corresponding smooth steel voxel model and smooth concrete voxel model. By using simplification techniques, the steel in the smooth steel voxel model is simplified to a steel cable.

7. The concrete structure printing method as described in claim 6, characterized in that, After the step of controlling the 3D printing equipment to print the target concrete structure according to the printing path, the following steps are included: The target concrete structure and the steel cable are prefabricated and assembled to obtain the target steel-concrete structure.

8. A concrete structure printing device, characterized in that, The device includes: a memory, a processor, and a concrete structure printing program stored in the memory and executable on the processor, the concrete structure printing program being configured to implement the steps of the concrete structure printing method as described in any one of claims 1 to 7.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a concrete structure printing program, which, when executed by a processor, implements the steps of the concrete structure printing method as described in any one of claims 1 to 7.

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