Method, device and equipment for constructing model of concrete-filled steel tube structure considering random corrosion

Abstract

The invention provides a model construction method, device and equipment for a concrete-filled steel tube structure considering random corrosion. The method comprises the steps that a first shell unit model of a steel tube is constructed according to size parameters of the steel tube; determining a target to-be-corroded surface of the first shell unit model based on the corrosion type; if the total volume of the existing original corrosion pits in the target to-be-corroded surface is smaller than the target corrosion volume, randomly determining size information and position information of new corrosion pits in a predetermined depth range, a coordinate range and a diameter range; the target corrosion volume is determined according to the corrosion rate; if it is judged that the new corrosion pit is not overlapped with the original corrosion pit according to the size information and the position information, generating the new corrosion pit on the target to-be-corroded surface according to the size information and the position information to obtain a second shell unit model; and constructing a concrete-filled steel tube model according to the second shell unit model and the solid model of the concrete component. According to the invention, the random corrosion state can be truly simulated to provide accurate data for researching the mechanical properties of the concrete-filled steel tube structure in an actual corrosion environment.

Description

Technical Field

[0001] The present invention relates to the technical field of construction engineering, and in particular to a method, device and equipment for constructing a model of a concrete-filled steel tubular structure considering random corrosion. Background Art

[0002] The concrete-filled steel tubular structure is widely used in various engineering construction fields such as building construction and bridge engineering. During its service life, it will inevitably be affected by various environmental factors such as wind and snow, rain, air temperature and humidity, resulting in corrosion damage. Long-term corrosion and excessive corrosion damage areas will change the mechanical properties and state of its structure. The stress concentration caused by a large number of corrosion pits seriously endangers the durability of the concrete-filled steel tubular structure, thus having an adverse impact on the safety performance and service life of the overall building. Aiming at the technical problem that the mechanical properties of the concrete-filled steel tubular structure will change in a corrosive environment, resulting in a reduction in the building safety performance and service life, it is necessary to use technical means such as finite element analysis to establish a model that can accurately predict the bearing capacity of the concrete-filled steel tubular structure at different corrosion stages. Through this model, study the degree and mechanism of the influence of corrosion on its mechanical properties, and predict the mechanical property changes of the concrete-filled steel tubular structure under different corrosion degrees and load conditions, such as the attenuation of bearing capacity and the increase of deformation, etc., to provide a basis for the safety assessment and remaining life prediction of the structure, so as to provide a reference for the design and later maintenance of the concrete-filled steel tubular structure, and effectively guide engineering design and maintenance.

[0003] In the related art, when establishing a model of a concrete-filled steel tubular structure, uniform corrosion modeling, semi-automatic corrosion modeling and finite element mesh modeling methods are usually used to simulate the corrosion state. Among them, uniform corrosion modeling assumes that corrosion is uniformly distributed on all parts of the steel pipe, and the corrosion effect is simulated by global thickness reduction (such as reducing the wall thickness of the steel pipe as a whole); semi-automatic corrosion modeling is to manually define the corrosion area and local corrosion pits using finite element software (such as Abaqus) to generate a finite number of corrosion areas; finite element mesh modeling is to divide the flat plate into geometric meshes and set cylindrical pits with the same shape and size at the mesh nodes to simulate corrosion pits.

[0004] However, in actual situations, the location where corrosion occurs is random and uncontrollable, and the sizes of the corrosion areas are also different. The above modeling methods for manually defining corrosion pits are not only inefficient, but also difficult to simulate the corrosion state where corrosion points are randomly distributed and corrosion pits randomly appear in actual situations, thus being unable to accurately and comprehensively analyze the mechanical property changes of the concrete-filled steel tubular structure in the actual corrosion environment, resulting in insufficient accuracy of the stress analysis of the building structure and being difficult to provide effective data for engineering design and maintenance. Summary of the Invention

[0005] An embodiment of the present invention provides a method, device and equipment for constructing a model of a concrete-filled steel tubular structure considering random corrosion, so as to solve the problem in the prior art that the mechanical property changes of the concrete-filled steel tubular structure in the actual corrosion environment cannot be accurately and comprehensively analyzed, resulting in insufficient accuracy of the stress analysis of the building structure and difficulty in providing effective data for engineering design and maintenance.

[0006] In a first aspect, an embodiment of the present invention provides a method for constructing a model of a concrete-filled steel tubular structure considering random corrosion, including: Construct a first shell element model of the steel pipe according to the size parameters of the steel pipe; Based on the corrosion type, determine the target surface to be corroded in the first shell element model; If the total volume of the existing original corrosion pits in the target surface to be corroded is less than the target corrosion volume, randomly determine the size information and position information of the new corrosion pits to be generated within a pre-determined depth range, coordinate range and diameter range; wherein, the target corrosion volume is determined according to a preset corrosion rate; According to the size information and position information of the new corrosion pits, determine whether the new corrosion pits overlap with the original corrosion pits. If it is determined that the new corrosion pits do not overlap with the original corrosion pits, generate new corrosion pits on the target surface to be corroded according to the size information and position information of the new corrosion pits, and obtain a second shell element model with corrosion pits; Construct a concrete-filled steel tubular structure model according to the second shell element model of the steel pipe and the entity model of the pre-constructed concrete component.

[0007] In a second aspect, an embodiment of the present invention provides a device for constructing a model of a concrete-filled steel tubular structure considering random corrosion, including: A first construction module for constructing a first shell element model of the steel pipe according to the size parameters of the steel pipe; A first processing module for determining the target surface to be corroded in the first shell element model based on the corrosion type; A second processing module for randomly determining the size information and position information of the new corrosion pits to be generated within a pre-determined depth range, coordinate range and diameter range when the total volume of the existing original corrosion pits in the target surface to be corroded is less than the target corrosion volume; wherein, the target corrosion volume is determined according to a preset corrosion rate; A corrosion pit generation module for determining whether the new corrosion pits overlap with the original corrosion pits according to the size information and position information of the new corrosion pits. If it is determined that the new corrosion pits do not overlap with the original corrosion pits, generate new corrosion pits on the target surface to be corroded according to the size information and position information of the new corrosion pits, and obtain a second shell element model with corrosion pits; A second construction module, configured to construct a concrete-filled steel tube structure model according to the second shell element model of the steel tube and the solid model of the pre-constructed concrete component.

[0008] In a third aspect, an embodiment of the present invention provides an electronic device, including a memory and a processor. The memory stores a computer program, and when the processor executes the computer program, the method in the first aspect or any possible implementation manner of the first aspect above is implemented.

[0009] In a fourth aspect, an embodiment of the present invention provides a computer-readable storage medium, which stores a computer program, and when the computer program is executed by a processor, the method in the first aspect or any possible implementation manner of the first aspect above is implemented.

[0010] In a fifth aspect, an embodiment of the present invention provides a computer program product, including a computer program, and when the computer program is executed by a processor, the method in the first aspect or any possible implementation manner of the first aspect above is implemented.

[0011] In the embodiment of the present invention, after establishing the first shell element model of the steel tube, the target surface to be corroded in the first shell element model is determined based on the corrosion type. When the total volume of the existing original corrosion pits in the target surface to be corroded is less than the target corrosion volume, the size information and position information of the new corrosion pits to be generated are randomly determined within a pre-determined depth range, coordinate range, and diameter range; and it is necessary to determine whether the new corrosion pits overlap with the original corrosion pits. When the new corrosion pits and the original corrosion pits do not overlap, corrosion pits are generated on the target surface to be corroded according to the size information and position information of the new corrosion pits. Finally, a concrete-filled steel tube structure model is constructed based on the obtained second shell element model with corrosion pits and the solid model of the pre-constructed concrete component. Constrained by the target corrosion volume determined according to the preset corrosion rate, it can ensure that the total volume of the corrosion pits simulated on the target surface to be corroded subsequently meets the corrosion requirements in the actual corrosion environment. The randomly determined size and position of the new corrosion pits can more realistically simulate the corrosion situation mainly in random distribution on the surface of steel in actual engineering, providing accurate data for studying the mechanical properties of concrete-filled steel tube structures in the actual corrosion environment, so that relevant personnel can obtain accurate and comprehensive data on the change of the mechanical properties of concrete-filled steel tube structures in the actual corrosion environment when performing finite element analysis on the concrete-filled steel tube structure model subsequently, providing effective data for building engineering design and maintenance. Description of the Drawings

[0012] Figure 1 is an application scenario diagram of the model construction method of the concrete-filled steel tube structure provided by the embodiment of the present invention; Figure 2It is the implementation flowchart of the method for constructing a model of a concrete-filled steel tubular structure considering random corrosion provided by an embodiment of the present invention; Figure 3a It is the implementation flowchart of the method for constructing a model of a concrete-filled steel tubular structure considering random corrosion provided by another embodiment of the present invention; Figure 3b It is the implementation flowchart of the method for iteratively generating corrosion pits provided by an embodiment of the present invention; Figure 4 It is the structural schematic diagram of the shell element model of the steel pipe provided by an embodiment of the present invention Figure 1 ; Figure 5 It is the structural schematic diagram of the shell element model of the steel pipe provided by an embodiment of the present invention Figure 2 ; Figure 6 It is the third structural schematic diagram of the shell element model of the steel pipe provided by an embodiment of the present invention; Figure 7 It is the structural schematic diagram of the shell element model of the corrosion pit provided by an embodiment of the present invention; Figure 8 It is the structural schematic diagram of the shell element model of the steel pipe provided by an embodiment of the present invention Figure 4 ; Figure 9 It is the structural schematic diagram of the device for constructing a model of a concrete-filled steel tubular structure considering random corrosion provided by an embodiment of the present invention; Figure 10 It is the schematic diagram of an electronic device provided by an embodiment of the present invention. Detailed implementation manners

[0013] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in this disclosure without creative efforts shall fall within the protection scope of the present invention.

[0014] The corrosion modeling of concrete-filled steel tube structures refers to simulating and analyzing the state, mechanical property changes, etc. of concrete-filled steel tube structures in a corrosive environment through technical means such as finite element analysis, establishing a model that can reflect the true corrosion state and the influence of the corrosion state on the mechanical properties of concrete-filled steel tube structures. Further finite element analysis of this model can better study the action mechanism of corrosion on concrete-filled steel tube structures, predict their mechanical property changes, etc. Through finite element analysis, understand the influence law of corrosion on the structural performance, and provide accurate reference data for engineering design and maintenance. In the process of modeling, accurately describing the randomness of corrosion damage is a prerequisite for evaluating the true bearing capacity of corroded structures. However, the modeling methods in the existing technologies are difficult to simulate the corrosion state where corrosion points are randomly distributed and the sizes of corrosion pits randomly appear in actual situations, thus unable to accurately and comprehensively analyze the mechanical property changes of concrete-filled steel tube structures in the actual corrosion environment, resulting in insufficient accuracy in the stress analysis of building structures and difficulty in providing effective data for engineering design and maintenance.

[0015] Aiming at the defects of the existing technologies, the technical concept of the present invention mainly includes: after establishing the first shell element model of the steel tube, determining the target surface to be corroded in the first shell element model according to the required corrosion type, and taking the total volume of the original corrosion pits already existing in the target surface to be corroded being less than the target corrosion volume as a constraint premise, randomly generating new corrosion pits on the target corrosion surface. Since the target corrosion volume is determined by a preset corrosion rate, it can ensure that the simulated corrosion pits meet the corrosion rate requirements in the actual corrosion environment. The size and position of the new corrosion pits are randomly determined within a pre-determined depth range, coordinate range, and diameter range, and it is necessary to judge whether the new corrosion pits overlap with the original corrosion pits. Finally, the corrosion pits generated on the target surface to be corroded according to the size information and position information of the new corrosion pits can more realistically simulate the corrosion situation mainly with random distribution on the steel surface in actual engineering, providing accurate data for studying the mechanical properties of concrete-filled steel tube structures in the actual corrosion environment, and these data can effectively guide the design and maintenance of building engineering.

[0016] Next, the embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0017] Figure 1 It is an application scenario diagram of the model construction method for the concrete-filled steel tube structure provided by the embodiment of the present invention.

[0018] As Figure 1 shown, the application scenario provided by this embodiment includes: an operation platform 101, a server 102, and a building facility 103.

[0019] In this embodiment, the display interface of the operation platform 101 includes the operation interface of finite element analysis software (such as Abaqus). The operation interface for finite element analysis of the concrete-filled steel tube structure model includes: a part module, a property module, an assembly module, an analysis step module, an interaction module, a load module, a mesh module, and a job module. The server 102 is used to process various data in the background.

[0020] Among them, the part module, the property module, and the assembly module are used to construct the concrete-filled steel tube structure model. The analysis step module, the interaction module, the load module, the mesh module, and the job module are used to perform a series of analyses on the concrete-filled steel tube structure model by using various finite element analysis techniques to simulate the mechanical behavior changes of the concrete-filled steel tube structure under different actual corrosion conditions, and finally obtain analysis results such as the stress nephogram and deformation diagram of the concrete-filled steel tube structure. These analysis results can guide relevant personnel to design and maintain the building facility 103.

[0021] It can be understood that the application scenario provided in this embodiment is only for exemplary use to facilitate relevant personnel to understand the method provided by the present invention, and does not constitute any limitation to the present invention.

[0022] Figure 2 It is a flowchart of the implementation of the method for constructing a model of a concrete-filled steel tube structure considering random corrosion provided by an embodiment of the present invention. As Figure 2 shown, the method provided by the embodiment of the present invention includes the following steps: S201, construct a first shell element model of the steel tube according to the size parameters of the steel tube.

[0023] In this step, before creating a specific model, it is necessary to first define the size parameters of the steel tube, including the inner side length, outer side length, and height of the steel tube. The specific values of the size parameters are determined according to the size of the steel tube required for actual engineering construction. These size parameters will be used as inputs in the subsequent modeling process to determine the specific geometric shape and size of the shell element model of the steel tube.

[0024] In a possible implementation manner, taking a concrete-filled steel tube structure in the shape of a quadrangular prism as an example, in the operation section of the finite element software, referring to Figure 4 , first create a sketch. In the sketch, draw a rectangle 41, and the coordinates of the two diagonal points of the rectangle are calculated according to the inner side length of the steel tube to ensure that the size of the rectangle matches the inner cross-sectional size of the steel tube. Then, stretch the drawn rectangle in the height direction in the created sketch, and the stretching depth is determined by the height of the steel tube (denoted as ), forming a three-dimensional shell element model, which is the first shell element model 42 of the steel tube.

[0025] In this step, by creating a first shell element model that can accurately describe the geometry and dimensions of the steel pipe, it is convenient to accurately analyze the stress changes of the steel pipe after corrosion in actual application scenarios.

[0026] S202. Based on the corrosion type, determine the target surface to be corroded in the first shell element model of the steel pipe.

[0027] In this step, the first shell element model of the steel pipe can be, but is not limited to, in the shape of a quadrangular prism. In actual application scenarios, the mechanical behavior of the steel pipe will change differently when it corrodes in different regions. Therefore, in order to analyze the changes in the mechanical behavior of the steel pipe under various regional corrosion conditions, various corrosion types need to be considered when establishing the model, and the target surface to be corroded is determined based on the specific corrosion type.

[0028] S203. If the total volume of the existing original corrosion pits in the target surface to be corroded is less than the target corrosion volume, randomly determine the size information and position information of the new corrosion pits to be generated within a pre-determined depth range, coordinate range, and diameter range; where the target corrosion volume is determined according to a preset corrosion rate.

[0029] In this step, the target corrosion volume is determined according to a preset corrosion rate. The corrosion rate refers to the ratio of the total volume of the corrosion pits to the total volume of the steel pipe. In actual application scenarios, the magnitude of the corrosion rate reflects the corrosion degree of the steel pipe at different times. Therefore, in order to realistically simulate the corrosion state of the steel pipe at different time periods during service, in specific implementation, the value of the corrosion rate can be determined according to the corrosion degree of the steel pipe at different time periods in the actual corrosion environment, and thus the target corrosion volume determined by the corrosion rate can better reflect the actual corrosion state of the steel pipe.

[0030] Specifically, before generating new corrosion pits on the target surface to be corroded, it is necessary to determine whether the total volume of the existing original corrosion pits on the target surface to be corroded is less than the target corrosion volume. If the total volume of the original corrosion pits is greater than or equal to the target corrosion volume, it means that the corrosion situation of the target surface to be corroded has met the corrosion rate requirements of the actual steel pipe, and there is no need to generate new corrosion pits; if the total volume of the original corrosion pits is less than the target corrosion volume, it means that the current corrosion state on the target surface to be corroded is not sufficient to accurately reflect the true corrosion state of the steel pipe, and it is necessary to continue to simulate the generation of new corrosion pits.

[0031] Since in actual application scenarios, the corrosion points on the steel pipe surface are randomly distributed, and the depth and size of the corrosion points are not fixed. Therefore, in order to more realistically simulate the distribution of corrosion points on the steel pipe surface, it is necessary to first determine the possible depth range, coordinate range, and diameter range of the corrosion pits in the actual environment. Under the constraints of the depth range, coordinate range, and diameter range, the size information and position information of the newly generated corrosion pits determined randomly can better simulate the random distribution state of the corrosion pits.

[0032] S204. According to the size information and position information of the new corrosion pit, determine whether the new corrosion pit overlaps with the original corrosion pit. If it is determined that the new corrosion pit does not overlap with the original corrosion pit, then generate a new corrosion pit on the target surface to be corroded according to the size information and position information of the new corrosion pit, and obtain a second shell element model with corrosion pits.

[0033] In this step, in order not to generate the same corrosion pit repeatedly at the same position, it is necessary to determine whether there is an overlap between the new corrosion pit and the original corrosion pit according to the size information and position information of the new corrosion pit. If there is an overlap, then the size information and position information of the new corrosion pit need to be re-determined; if the new corrosion pit and the original corrosion pit do not overlap, then create a new hole, that is, a new corrosion pit, on the target surface to be corroded of the first shell element model of the steel pipe according to the size information and position information of the new corrosion pit.

[0034] S205. Construct a concrete-filled steel tubular structure model according to the second shell element model of the steel pipe and the pre-constructed solid model of the concrete component.

[0035] In this step, the actual model of the concrete component is constructed in advance.

[0036] In a possible implementation manner, the construction method of the solid model of the concrete component is the same as that of the shell element model of the steel pipe, that is, first determine the size parameters of the concrete component, including the side length and height of the concrete component. The specific values of the size parameters are determined according to the size of the concrete component required for the actual engineering construction. The size parameters of the concrete component will be used as the input in the subsequent modeling process to determine the specific geometric shape and size of the solid model of the concrete component; then, taking the concrete-filled steel tubular structure in the shape of a quadrangular prism as an example, create a sketch on the operation interface of the finite element software, draw a rectangle in the sketch, and the size of the rectangle is determined by the side length of the concrete component. Then, stretch the drawn rectangle in the created sketch along the height direction, and the stretching depth is determined by the height of the concrete component to form a three-dimensional solid model of the concrete component.

[0037] In this step, through the above steps, a second shell element model with corrosion pit cavities can be obtained. By combining the second shell element model of the steel pipe and the actual model of the concrete component, a concrete-filled steel tube structure model that can accurately predict the bearing capacity of the concrete-filled steel tube structure at different corrosion stages can be obtained.

[0038] In actual application scenarios, after the modeling is completed, through finite element analysis of the concrete-filled steel tube structure model, the corrosion mechanism of the concrete-filled steel tube structure under different environmental conditions can be deeply studied, such as the corrosion effects of chloride ion erosion, carbonation, etc. on the steel pipe and concrete, understanding the occurrence and development process of corrosion, as well as the variation law of the interaction between the steel pipe and the concrete during the corrosion process; according to this model, the influence degree of various factors on corrosion can be systematically analyzed, such as how environmental humidity, temperature, pH value and other factors accelerate or slow down the corrosion process, and the differences in the corrosion resistance of steel pipes and concretes with different materials and different mix ratios, so as to guide relevant technicians to select appropriate materials and construction means to resist environmental corrosion during engineering design according to the analysis results of the model. Moreover, the change of the bearing capacity, deformation degree and stability of the concrete-filled steel tube structure can be predicted based on this model, and the durability life of the building structure can be evaluated. For example, predict the attenuation of the bearing capacity (including mechanical properties such as compressive, flexural and shear resistance) of the concrete-filled steel tube structure under the action of corrosion, determine the load size that can be borne at different corrosion stages, provide a basis for the safety assessment of the structure, and guide the design of the building engineering structure; study the influence of corrosion on the deformation and stability of the concrete-filled steel tube structure, understand whether excessive deformation will occur in the column after corrosion and whether stability will be lost in advance, so as to judge whether there are potential safety hazards in the structure; evaluate the durability life of the concrete-filled steel tube structure based on the model analysis results, predict the service life that the structure can safely use in the corrosive environment, and provide a time basis for the maintenance, reinforcement or replacement of the structure to guide engineering maintenance.

[0039] In this embodiment, after establishing the first shell element model of the steel pipe, the target surface to be corroded in the first shell element model is determined based on the corrosion type. When the total volume of the existing original corrosion pits in the target surface to be corroded is less than the target corrosion volume, the size information and position information of the new corrosion pits to be generated are randomly determined within a pre-determined depth range, coordinate range, and diameter range. And it is necessary to determine whether the new corrosion pits overlap with the original corrosion pits. When the new corrosion pits and the original corrosion pits do not overlap, corrosion pits are generated on the target surface to be corroded according to the size information and position information of the new corrosion pits. Finally, a concrete-filled steel tube structure model is constructed based on the obtained second shell element model with corrosion pits and the solid model of the pre-constructed concrete component. Constrained by the target corrosion volume determined according to the preset corrosion rate, it can ensure that the total volume of the corrosion pits subsequently simulated and generated on the target surface to be corroded meets the corrosion requirements in the actual corrosion environment. The randomly determined size and position of the new corrosion pits can more realistically simulate the corrosion situation mainly distributed randomly on the surface of the steel in actual engineering, providing accurate data for studying the mechanical properties of the concrete-filled steel tube structure in the actual corrosion environment, so that relevant personnel can obtain accurate and comprehensive data on the change of the mechanical properties of the concrete-filled steel tube structure in the actual corrosion environment when performing finite element analysis on the concrete-filled steel tube structure model subsequently, providing effective data for building engineering design and maintenance.

[0040] In a possible embodiment, the corrosion type includes single-sided corrosion and multi-sided corrosion; the determining of the target surface to be corroded in the first shell element model based on the corrosion type includes: obtaining the surface information of the first shell element model; the surface information includes the number of surfaces to be corroded in the first shell element model and the unit normal vector corresponding to each surface to be corroded; if single-sided corrosion is performed on the first shell element model, the surface to be corroded indicated by the unit normal vector is determined as the target surface to be corroded; if multi-sided corrosion is performed on the first shell element model, according to the unit normal vector corresponding to each surface to be corroded, the surface to be corroded indicated by each unit normal vector is sequentially determined as the target surface to be corroded.

[0041] In this embodiment, the first shell element model of the steel pipe contains multiple surfaces. Specifically, whether to select single-sided corrosion or multi-sided corrosion needs to be related to the factors to be considered in the actual engineering building design. In a specific application scenario, for a concrete-filled steel tube column in the shape of a quadrangular prism, it is usually necessary to consider the influence of partial concentrated area corrosion on the mechanical properties of the concrete-filled steel tube column structure, as well as the influence of comprehensive random corrosion on the mechanical properties of the concrete-filled steel tube column structure. Therefore, when constructing the model, the two corrosion types of single-sided corrosion and multi-sided corrosion need to be included.

[0042] In a possible implementation, for the surfaces of the steel pipe that need to be corroded among its four surfaces, a set of surfaces is created. If it is single-sided corrosion, the single surface to be corroded is created as a set; if it is four-sided corrosion, the four surfaces are created as a set. The number of surfaces to be corroded is recorded in the set. For each surface to be corroded in the set of surfaces, its centroid coordinates and unit normal vector are calculated, and the centroid coordinates and unit normal vector of each surface to be corroded are marked in the set of surfaces. The centroid coordinates are for determining the specific generation position of the corrosion pit subsequently, and the unit normal vector is for judging the direction of the surface to be corroded.

[0043] It should be noted that the calculation method of the centroid coordinates of the surface to be corroded can refer to the related technology and will not be elaborated here.

[0044] In specific implementation, traverse the set of surfaces. According to the number of surfaces to be corroded recorded in the set, judge whether it is single-sided corrosion or multi-sided corrosion. If it is single-sided corrosion, only one unit normal vector is recorded in the set, and the surface to be corroded corresponding to the direction indicated by this unit normal vector is used as the target surface to be corroded. If it is multi-sided corrosion, the surfaces to be corroded corresponding to the directions indicated by each unit normal vector are used as the target surfaces to be corroded in sequence.

[0045] Exemplarily, as Figure 5 shown in a of [reference], a three-dimensional coordinate system is established in the first shell element model of the steel pipe in the direction indicated by the lower left corner. The unit normal vectors of each surface are (1, 0, 0), (-1, 0, 0), (0, 1, 0), and (0, -1, 0) respectively, and the indicated directions are the positive X direction, the negative X direction, the positive Y direction, and the negative Y direction, corresponding to the four surfaces of the first shell element model respectively. Suppose the number of surfaces to be corroded recorded in the set of surfaces is 1 and the unit normal vector is (1, 0, 0). Then, when traversing the set, it can be known that the corrosion type is single-sided corrosion, and the surface in the positive X direction indicated by the unit normal vector (1, 0, 0) is used as the target surface to be corroded. Suppose the number of surfaces to be corroded recorded in the set of surfaces is 4 and the unit normal vectors are (1, 0, 0), (-1, 0, 0), (0, 1, 0), and (0, -1, 0). Then, the surfaces to be corroded in the positive X direction, the negative X direction, the positive Y direction, and the negative Y direction indicated by these four unit normal vectors are used as the target surfaces to be corroded.

[0046] It should be noted that in this embodiment, when the corrosion type is multi-sided corrosion, it can also be two-sided corrosion or three-sided corrosion, and no specific requirements are made for the corrosion sequence of each surface to be corroded.

[0047] In this embodiment, through the design of the unit normal vector, the corrosion area can be automatically judged by the unit normal vector without artificially defining the corrosion area, improving the processing efficiency. Moreover, single-sided corrosion and multi-sided corrosion can be automatically realized, and the influence of local concentrated random corrosion and overall random corrosion on the mechanical properties of the concrete-filled steel tube structure in the actual application scenario can be truly simulated.

[0048] In a possible embodiment, the dimensional parameters of the steel pipe include the inner side length of the steel pipe , the outer side length and the height . The method further includes: determining the target corrosion volume corresponding to each face in the first shell element model according to the dimensional parameters of the steel pipe, the first formula and the preset corrosion rate ; the first formula is , where represents the corrosion rate, and n represents the number of faces in the first shell element model; when a new corrosion pit is generated on the target surface to be corroded, recalculate the total volume of the original corrosion pits existing on the target surface to be corroded ; when the total volume of the original corrosion pits existing on the target surface to be corroded satisfies the preset corrosion rate condition, stop generating new corrosion pits on the target surface to be corroded; where the preset corrosion rate condition is: , represents the volume error

[0049] It should be noted that in this first formula, the corrosion rate means the ratio of the total volume of corrosion pits to the total volume of the steel pipe. In actual application scenarios, the magnitude of the corrosion rate C reflects the corrosion degree of the steel pipe at different times. Therefore, in order to truly simulate the corrosion state of the steel pipe at different time periods during service, in specific implementation, the value of the corrosion rate C can be determined according to the corrosion degree of the steel pipe at different time periods in the actual corrosion environment. In this first formula, the result is the total volume of the steel pipe, and the product of the total volume of the steel pipe and the corrosion rate C (i.e., the numerator part in the first formula) is the total volume of corrosion pits that may appear on the overall steel pipe in the actual corrosion environment. In order to simulate the corrosion state where corrosion pits randomly appear on each surface of the steel pipe in the actual corrosion environment, divide the total volume of corrosion pits that may appear on the steel pipe in the actual corrosion environment (i.e., the calculation result of the numerator part in the first formula) by the number n of faces of the steel pipe, and the single-sided corrosion volume V (i.e., the target corrosion volume) can be obtained. Therefore, the target corrosion volume of the single side of the steel pipe calculated by this first formula can better reflect the actual uniform corrosion state of the steel pipe

[0050] In this embodiment, the target corrosion volume that the target surface to be corroded needs to reach can be calculated according to the first formula. In actual application scenarios, the magnitude of the corrosion rate reflects the corrosion degree of the steel pipe at different times. Therefore, in order to truly simulate the corrosion state of the steel pipe at different time periods during service, in specific implementation, the value of the corrosion rate can be determined according to the corrosion degree of the steel pipe at different time periods in the actual corrosion environment, and thus the target corrosion volume determined by the corrosion rate can also better reflect the actual corrosion state of the steel pipe

[0051] Specifically, every time a new corrosion pit is generated on the target surface to be corroded, the volume of the new corrosion pit is calculated based on the size information of the new corrosion pit, and the volume of the new corrosion pit is added to the volumes of all the original corrosion pits to obtain the total volume. , where i represents the number of original corrosion pits already existing on the target surface to be corroded. Moreover, every time a new corrosion pit is generated on the target surface to be corroded, it is determined once whether the target surface to be corroded meets the actual corrosion rate requirement. The specific determination method is to calculate the total volume of all the original corrosion pits. and the target corrosion volume the absolute value of the difference between them and the volume error . When , it indicates that the total volume of the original corrosion pits already existing on the target surface to be corroded has reached or is close to the target corrosion volume, meaning that the corrosion requirements under the actual corrosion environment can be met, and thus the generation of new corrosion pits is stopped. Among them, the volume error can take a value of 1% of the target corrosion volume V.

[0052] In this embodiment, by calculating the target corrosion volume according to the corrosion rate, then generating corrosion pits on the target surface to be corroded with the target corrosion volume as a constraint, and using the volume error as the condition for stopping the generation of corrosion pits, it is ensured that the finally constructed model conforms to the corrosion rate, can more realistically simulate the corrosion states of the steel pipe at different time periods during service, and can meet the corrosion requirements under the actual corrosion environment, laying a foundation for the subsequent finite element analysis of the overall model. In a possible embodiment, the size information of the new corrosion pit includes the depth, diameter, and radius of the new corrosion pit, and the position information includes the local coordinates of the center point of the new corrosion pit relative to the target surface to be corroded; randomly determining the size information and position information of the new corrosion pit to be generated within a pre-determined depth range, coordinate range, and diameter range includes: randomly taking a value within the depth range as the depth of the new corrosion pit; determining the diameter and radius of the new corrosion pit according to the depth of the new corrosion pit and the diameter range; the diameter range is used to constrain that the diameter is m times the depth, and m is randomly taken within the diameter range; within the coordinate range, randomly selecting a set of point coordinates as the local coordinates of the center point of the new corrosion pit relative to the target surface to be corroded; the coordinate range is determined according to the radius of the new corrosion pit and is used to constrain the area covered by the new corrosion pit to be within the target surface to be corroded.

[0053] In this embodiment, the determination of the depth range needs to be based on the possible depths of the corrosion pits in the actual corrosion environment. According to the depths of a large number of actual corrosion pits, the depth range is determined to be [1.2, 3] millimeters. Within this range, the specific depth value of each new corrosion pit is dynamically generated by a random number generator. Further, after determining the depth of the new corrosion pit according to the depth range, the diameter range is determined based on the depth of the new corrosion pit, that is, the diameter range is 8 to 15 times the depth. The diameter of the new corrosion pit is a random value between 8 and 15 times its depth. For example, if the randomly determined depth of the new corrosion pit is 1.5 millimeters, then the diameter range is [1.5 * 8, 1.5 * 15], that is, [12, 22.5]. Then the diameter of the new corrosion pit is randomly selected within the range of [12, 22.5]. The radius of the new corrosion pit is half of the diameter, and then the coordinate range is determined based on the radius. To ensure that the coverage area of the new corrosion pit does not exceed the target surface to be corroded, the coordinate range should be within the range obtained by subtracting the radius of the new corrosion pit from the boundary of the target surface to be corroded. Exemplarily, as shown in Figure 5 b in [reference], assuming that the target surface to be corroded is the surface in the positive Y direction indicated by the normal vector (0, 1, 0), the range within the dashed line after subtracting the radius (denoted as r) from the boundary of the target surface to be corroded is the value range of the coordinates. A point is randomly selected within the dashed line as the center point of the new corrosion pit, and the local coordinates of this center point relative to the target surface to be corroded are calculated.

[0054] Exemplarily, as shown in Figure 5 b in [reference], a two-dimensional coordinate system O(x, y) can be established with any one of the four vertices of the target surface to be corroded (such as the upper left vertex) as the origin O. The coordinates of the center point generated in the two-dimensional coordinate system are the local coordinates of the center point of the new corrosion pit.

[0055] In the actual application scenario, the size and position of the corrosion pits are randomly determined. Therefore, when modeling, the characteristics of the random distribution of corrosion need to be considered. In this embodiment, the size and position of the new corrosion pit are randomly determined within the depth range, diameter range, and coordinate range, and these ranges are all determined according to the laws of the appearance of corrosion pits in the actual corrosion environment, which can accurately simulate the random distribution state of the corrosion pits. Further, by dynamically associating the depth and the diameter, it is ensured that the size of the corrosion pit changes within a certain range, while maintaining a reasonable ratio between the diameter and the depth, making the simulated corrosion pits more in line with the corrosion laws of steel pipes in the actual corrosion environment, so that more accurate mechanical property data can be obtained when performing finite element analysis on the finally built steel tube concrete structure model in the subsequent process.

[0056] In a possible embodiment, determining whether the new corrosion pit overlaps with the original corrosion pit according to the size information and position information of the new corrosion pit includes: determining a first distance between the center point of the new corrosion pit and the center point of the original corrosion pit according to the local coordinates of the center point of the new corrosion pit and the local coordinates of the center point of the original corrosion pit; if the first distance is less than the sum of the radius of the new corrosion pit and the radius of the original corrosion pit, it is determined that the new corrosion pit overlaps with the original corrosion pit, and the size information and position information of the new corrosion pit are re-determined; otherwise, it is determined that the new corrosion pit does not overlap with the original corrosion pit.

[0057] In this embodiment, since the size information and position information of the new corrosion pit are randomly determined, it is possible that different corrosion pits may take repeated values. Therefore, in order to ensure that the corrosion pits do not overlap, it is necessary to determine whether the new corrosion pit overlaps with the original corrosion pit. If they overlap, the size information and position information of the new corrosion pit need to be re-determined.

[0058] In a possible implementation manner, the first distance between the center point of the new corrosion pit and the center point of the original corrosion pit is calculated according to the second formula, and the second formula is: , where and represent the local coordinates of the center point of the new corrosion pit, and represent the local coordinates of the center point of the original corrosion pit. If r + r1, it is determined that the new corrosion pit overlaps with the original corrosion pit, r represents the radius of the new corrosion pit, and r1 represents the radius of the original corrosion pit.

[0059] In a possible implementation manner, it is also necessary to calculate a second distance from the center point of the new corrosion pit to the boundary of the target surface to be corroded according to the third formula, and the third formula is: , h represents the height of the steel pipe. If r, it is determined that the coverage range of the new corrosion pit is on the target surface to be corroded.

[0060] In this embodiment, by calculating the distance between the center points of the corrosion pits, it is ensured that the corrosion pits do not overlap, while truly simulating the random distribution of the corrosion pits and improving the efficiency of model construction.

[0061] In a possible embodiment, generating a new corrosion pit on the target surface to be corroded according to the size information and position information of the new corrosion pit includes: determining the global coordinates of the center point of the new corrosion pit relative to the first shell element model of the steel pipe according to the local coordinates of the center point of the new corrosion pit and the pre-determined centroid coordinates of the target surface to be corroded; generating a new corrosion pit on the target surface to be corroded according to the global coordinates, depth and diameter of the new corrosion pit.

[0062] It should be noted that the method for obtaining the centroid coordinates of the target surface to be corroded can refer to the description in the above relevant method embodiments and will not be repeated here.

[0063] In this embodiment, the local coordinates of the center point of the new corrosion pit are first converted into relative coordinates relative to the centroid of the surface to be corroded, and then rotation and translation operations are performed on the relative coordinates to obtain the global coordinates of the center point of the new corrosion pit.

[0064] In this embodiment, by converting the local coordinates of the center point of the new corrosion pit into global coordinates, the new corrosion pit is more adapted to the second shell element model of the steel pipe, improving the accuracy of the finally constructed concrete-filled steel tube structure model and also obtaining more accurate analysis results when performing finite element analysis on the concrete-filled steel tube structure model subsequently.

[0065] In a possible embodiment, constructing a concrete-filled steel tube structure model according to the second shell element model of the steel pipe and the pre-constructed solid model of the concrete component includes: copying the first shell element model of the steel pipe to obtain a copied shell element model of the steel pipe; using the second shell element model as a cutting tool to perform cutting processing on the copied shell element model of the steel pipe to obtain the shell element models of all corrosion pits on the second shell element model; performing a merging process on the shell element models of all corrosion pits and the second shell element model to obtain a third shell element model of the steel pipe; performing a merging process on the third shell element model of the steel pipe and the solid model of the concrete component to obtain the concrete-filled steel tube structure model.

[0066] In this embodiment, the Boolean operation function of finite element analysis software is used to further process the shell element model of the steel pipe. By performing a cutting operation on the copied shell element model of the steel pipe and the second shell element model with corrosion pits, the shell element models of all corrosion pits can be obtained; then the Boolean operation is continued to merge the models, and the shell element models of all corrosion pits are merged with the second shell element model of the steel pipe to finally generate a complete corroded steel pipe model (i.e., the third shell element model).

[0067] Exemplarily, when corrosion is completed on all four surfaces of the first shell element model of the steel pipe according to the set corrosion rate, the second shell element model with corrosion pits is asFigure 6 As shown, after using Boolean operations to complete the cutting operation of the corrosion pits, the shell element models of all the corrosion pits obtained are as follows Figure 7 As shown, after merging the shell element models of all the corrosion pits with the second shell element model of the steel pipe, the third shell element model obtained is as follows Figure 8 As shown.

[0068] In the modeling process, accurately describing the geometric characteristics of the building structure in the actual application scenario is a prerequisite for ensuring the accuracy of the mechanical property analysis results. In order to provide accurate mechanical property data for actual engineering design and maintenance, in this embodiment, through a series of processes such as cutting and merging the shell element model using the Boolean operation function, seamless cutting and merging of the corrosion area are realized, avoiding topological errors caused by manual intervention. The finally obtained third shell element model of the steel pipe not only includes the geometric shape of the original steel pipe but also incorporates the characteristics of the corrosion pits, providing an accurate geometric basis for subsequent finite element analysis.

[0069] In a possible embodiment, the method further includes: creating a corresponding first shell element cross-section for each corrosion pit in the third shell element model, and establishing a mapping relationship between each first shell element cross-section and the preset steel pipe material property information; the thickness of the first shell element cross-section is randomly determined according to the depth of the corresponding corrosion pit, and the steel pipe material property information includes the elastic property information and plastic property information of the steel pipe; for the uncorroded part in the third shell element model, creating a second shell element cross-section; the thickness of the second shell element cross-section is determined according to the thickness of the steel pipe; for the solid model of the concrete component, creating a homogeneous solid cross-section, and establishing a mapping relationship between the homogeneous solid cross-section and the preset concrete material property information; the concrete material property information includes the elastic property information and plastic property information of the concrete material.

[0070] In actual building engineering design, it is necessary to consider environmental corrosion factors when selecting the materials of steel pipes and concrete. Different material properties have different anti-corrosion capabilities, and their mechanical behaviors also change differently after environmental corrosion. Therefore, when establishing a steel-concrete structure model, it is necessary to consider the relationship between the material properties of steel pipes and concrete and corrosion.

[0071] In this embodiment, the material properties of the steel pipe and concrete are first defined, and then the cross-section properties are defined for different parts in the model of the steel pipe.

[0072] Specifically, for the part with corrosion pits in the third shell element model of the steel pipe, an independent shell element section is created for each corrosion pit. The thickness of the section is dynamically generated according to the depth of the corrosion pit to ensure that the shell element section of each corrosion pit can accurately reflect its actual geometric characteristics. After creating the sections, these sections are assigned to the corresponding corrosion pit areas, and a mapping relationship is established between the sections and the steel pipe material property information. In this way, each corrosion pit will have a shell element section that matches its depth. By combining the steel pipe material properties with the shell element sections of the corrosion pits, a complete mechanical behavior description is defined for the steel pipe model, so that the influence of the corrosion pits on the structural performance can be accurately simulated in subsequent finite element analyses.

[0073] For the uncorroded part of the third shell element model of the steel pipe, a unified shell element section (i.e., the second shell element section) is created. The thickness of this section is set to a fixed value according to the actual thickness of the steel pipe. Subsequently, this section is assigned to the uncorroded part of the steel pipe model, and a mapping relationship is established between the section and the steel pipe material property information, thereby defining a complete section property for the entire steel pipe model. For the solid model of the concrete component, a homogeneous solid section is created and assigned to the concrete model, and a mapping relationship is established between the homogeneous solid section and the concrete material properties. In finite element analysis, the solid section is used to describe the material properties and geometric characteristics of the solid elements (i.e., the concrete structure). By combining the concrete material properties with the solid section, a complete mechanical behavior description is defined for the concrete model.

[0074] In a possible implementation, in finite element analysis, after the section properties of the third shell element model of the steel pipe and the solid model of the concrete component are defined respectively, the combined steel pipe-concrete structure model is instantiated into the assembly to prepare for subsequent finite element analysis of the steel pipe-concrete structure model.

[0075] In this embodiment, by creating the shell element section corresponding to each corrosion pit according to the depth of each corrosion pit and establishing the mapping relationship between the steel pipe material properties and the shell element section, the precise adaptation of the local thickness and material properties is realized. Further, by defining a complete section property for the entire steel pipe model and combining the concrete material properties with the solid section, the finally obtained steel pipe-concrete structure model can accurately simulate the influence of the corrosion pits on the structural performance in subsequent finite element analyses, so as to provide effective and accurate reference data for engineering design according to the finite element analysis results.

[0076] To understand this application more clearly, the following will be combined with Figure 3a and Figure 3b to describe in detail the entire implementation process of the method provided by this application.

[0077] Figure 3a It is the implementation flowchart of the model construction method for a concrete-filled steel tubular structure considering random corrosion provided by another embodiment of the present invention. As Figure 3a shown, the method provided in this embodiment includes the following steps: S301, Determine the size parameters of the steel pipe and the size parameters of the concrete component.

[0078] S302, Construct the first shell element model of the steel pipe according to the size parameters of the steel pipe, and construct the solid model of the concrete component according to the size parameters of the concrete component.

[0079] S303, Copy the first shell element model of the steel pipe to obtain a replicated shell element model of the steel pipe.

[0080] In this step, in order to perform subsequent Boolean operation operations, a copy of the already created first shell element model of the steel pipe is made. In finite element analysis, Boolean operations usually require two or more instances to participate. Therefore, by replicating the steel pipe component, preparations are made for subsequent cutting and merging operations.

[0081] S304, Create the surface to be corroded in the first shell element model as a set of surfaces.

[0082] S305, Determine the relevant parameters of the corrosion pit, including: corrosion rate, depth range of the corrosion pit, diameter range, and coordinate range.

[0083] S306, Traverse the set of surfaces, and calculate the centroid coordinates and unit normal vectors of each surface to be corroded.

[0084] In this step, in specific implementation, first initialize a list to store the information of each surface to be corroded, and a counter to record the number of surfaces, and then traverse all the surfaces in the set of surfaces, calculate the centroid coordinates and unit normal vectors of each surface to be corroded, and store the number of surfaces to be corroded, centroid coordinates, and unit normal vectors in the list. Subsequently, when selecting the target surface to be corroded, directly read the information from the list.

[0085] S307, Determine the target corrosion volume according to the corrosion rate.

[0086] S308, Generate corrosion pits on the surface to be corroded in the first shell element model, so that the total volume of all the corrosion pits already generated on the surface to be corroded reaches the preset corrosion rate requirement, and obtain a second shell element model with corrosion pits.

[0087] For each surface to be corroded, the generation of corrosion pits is an iterative process. The goal is to generate a sufficient number of corrosion pits on each surface to be corroded so that their total volume reaches the set corrosion rate. As Figure 3bAs shown, the process of iteratively generating corrosion pits includes the following steps: S3081, initialize the total volume variable of the corrosion pits .

[0088] In this step, it is used to record the total volume of the corrosion pits that have been generated on the surface to be corroded. At the same time, initialize four lists existing_circles_X1, existing_circles_X2, existing_circles_Y1, and existing_circles_Y2, which are used to store the information (coordinates of the center point, radius, and depth) of the corrosion pits that have been generated on the surfaces to be corroded in the positive X direction, negative X direction, positive Y direction, and negative Y direction, respectively.

[0089] It should be noted that if the steel pipe has four surfaces, then initialize four lists. If there are more surfaces, then initialize a list for each surface to store the information of the corrosion pits that have been generated on each surface.

[0090] S3082, select the target surface to be corroded from the set of surfaces.

[0091] S3083, judge whether the total volume of the original corrosion pits that already exist in the target surface to be corroded is less than the target corrosion volume; if the judgment result is yes, then continue to execute step S3084; if the judgment result is no, then end the process.

[0092] S3084, randomly determine the size information and position information of the new corrosion pit to be generated according to the depth range, diameter range, and coordinate range.

[0093] S3085, judge whether the new corrosion pit and the original corrosion pit overlap according to the size information and position information of the new corrosion pit; if the judgment result is yes, then return to execute step S3084; if the judgment result is no, then continue to execute step S3086.

[0094] S3086, generate a new corrosion pit on the target surface to be corroded according to the size information and position information of the new corrosion pit.

[0095] S3087, calculate the volume of the new corrosion pit, and update the total volume of the original corrosion pits that already exist in the target surface to be corroded according to the volume of the new corrosion pit .

[0096] In specific implementation, every time a new corrosion pit is generated, the coordinates of the center point, radius, and depth of the new corrosion pit are stored in the corresponding list. For example, if the target surface to be corroded is the surface corresponding to the positive X direction, then the information of the generated new corrosion pit is stored in the list existing_circles_X1.

[0097] S3088, determine the total volume of the original corrosion pits after update Check whether the absolute value of the difference between the total volume of the original corrosion pits after update and the target corrosion volume is less than a preset volume error; if the judgment result is yes, end the process; if the judgment result is no, return to step S3084 for execution.

[0098] It should be noted that if four surfaces need to be corroded, assuming that the target corrosion volume to be achieved for each surface is the same, then the four surfaces are sequentially used as the target surfaces to be corroded and processed in a loop according to the steps of S3081 - S3088, and corrosion pits that meet the requirements of the preset corrosion rate are generated on each surface.

[0099] S309, based on the Boolean operation method, perform a cutting operation on the replicated shell element model of the steel pipe and the second shell element model to obtain the shell element model of all corrosion pits on the second shell element model, and merge the shell element models of all corrosion pits with the second shell element model to obtain the third shell element model of the steel pipe. Then merge the third shell element model and the solid model of the concrete component to obtain the steel - concrete structure model.

[0100] S310, define the material property information of the steel pipe and the material property information of the concrete component.

[0101] In this step, for the steel pipe, first define its elastic properties, including the elastic modulus and Poisson's ratio. Subsequently, define the plastic properties of the steel pipe. The plastic properties are described by a series of stress - strain data points to represent the deformation behavior of the material after exceeding the yield strength. These data points include information such as the yield strength and hardening curve, which can accurately simulate the mechanical behavior of the steel in the plastic stage. Finally, define the cyclic hardening property of the steel. Cyclic hardening refers to the phenomenon that the yield strength of the material gradually increases with the increase in the number of loading cycles during cyclic loading. By defining the cyclic hardening parameters, the mechanical properties of the steel under cyclic loading conditions can be more accurately simulated. Similar to defining the material properties of the steel pipe, define the elastic properties of the concrete, including the elastic modulus and Poisson's ratio. These parameters are similar to the elastic properties of the steel pipe and are used to describe the mechanical behavior of the concrete in the elastic stage. Subsequently, use the concrete damage plasticity model to define the plastic behavior of the concrete. This model describes the hardening curve and damage characteristics of the concrete under compression and tension states through a series of parameters, including the compressive hardening curve, tensile hardening curve, compressive damage curve, and tensile damage curve, etc. These curves are defined by a series of data points, and each data point contains stress and strain information, thus being able to describe in detail the mechanical behavior of the concrete under different loading conditions.

[0102] S311, for each corrosion pit, the uncorroded part in the third shell element model, and the solid model of the concrete component, create corresponding cross - sections respectively and perform an assignment operation on the cross - sections.

[0103] S312, instantiate the concrete-filled steel tube structure model into the assembly.

[0104] S313, perform finite element analysis on the concrete-filled steel tube structure model to obtain the finite element analysis results.

[0105] It should be noted that the steps not detailed in this embodiment can refer to the descriptions in the above-mentioned method embodiments. The specific implementation manners of each embodiment can be referred to each other, and will not be elaborated here.

[0106] It can be understood that the structures in the shape of a quadrangular prism in all the above embodiments and the accompanying drawings are for explaining the present invention, and do not specifically limit the shape of the concrete-filled steel tube structure. Modeling methods for any shape of concrete-filled steel tube structure, such as cylindrical, cuboid, triangular pyramid, quadrangular pyramid, hexagonal prism, etc., can adopt the method provided by the present invention and are within the protection scope of the present invention.

[0107] The model constructed in this embodiment can accurately simulate the real corrosion distribution automatically while ensuring compliance with the actual corrosion rate requirements. Finite element analysis of it can accurately predict the mechanical property changes of the concrete-filled steel tube structure under different corrosion degrees and load conditions, such as the attenuation of bearing capacity, the increase of deformation, etc., providing a basis for the safety assessment and remaining life prediction of the structure. Through finite element analysis, understand the influence law of corrosion on the structural performance, and provide a reference for the design and maintenance of the concrete-filled steel tube structure. For example, corresponding anti-corrosion measures can be taken in the design stage to improve the corrosion resistance of the structure; in the maintenance stage, a reasonable detection period and maintenance plan can be determined according to the analysis results. Deeply study the interaction mechanism between corrosion and structural mechanical properties, and provide support for the development of corrosion protection technologies and the improvement of related theories. It should be understood that the magnitudes of the sequence numbers of the steps in the above embodiments do not mean the order of execution. The execution order of each process should be determined according to its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present invention.

[0108] The following is the device embodiment of the present invention. For the details not described in detail, reference can be made to the corresponding method embodiments above.

[0109] Figure 9 The structural schematic diagram of the model construction device for the concrete-filled steel tube structure considering random corrosion provided by the embodiment of the present invention is shown. For the convenience of description, only the parts related to the embodiment of the present invention are shown and are described in detail as follows: As Figure 9As shown in the figure, the device includes: a first construction module 901, configured to construct a first shell element model of the steel pipe according to the dimensional parameters of the steel pipe; a first processing module 902, configured to determine a target surface to be corroded in the first shell element model based on the corrosion type; a second processing module 903, configured to, when the total volume of the original corrosion pits existing in the target surface to be corroded is less than the target corrosion volume, randomly determine the dimensional information and position information of the new corrosion pits to be generated within a pre-determined depth range, coordinate range, and diameter range; wherein, the target corrosion volume is determined according to a preset corrosion rate; a corrosion pit generation module 904, configured to determine whether the new corrosion pits overlap with the original corrosion pits according to the dimensional information and position information of the new corrosion pits, and if it is determined that the new corrosion pits do not overlap with the original corrosion pits, generate new corrosion pits on the target surface to be corroded according to the dimensional information and position information of the new corrosion pits, to obtain a second shell element model with corrosion pits; a second construction module 905, configured to construct a concrete-filled steel tube structure model according to the second shell element model of the steel pipe and the solid model of the pre-constructed concrete component.

[0110] In a possible implementation manner, the corrosion type includes single-sided corrosion and multi-sided corrosion; the first processing module 902 is specifically configured to: obtain the surface information of the first shell element model; the surface information includes the number of surfaces to be corroded in the first shell element model and the unit normal vector corresponding to each surface to be corroded; if single-sided corrosion is performed on the first shell element model, the surface to be corroded indicated by the unit normal vector is determined as the target surface to be corroded; if multi-sided corrosion is performed on the first shell element model, according to the unit normal vector corresponding to each surface to be corroded, the surface to be corroded indicated by each unit normal vector is sequentially determined as the target surface to be corroded.

[0111] In a possible implementation manner, the dimensional parameters of the steel pipe include the inner side length 、outer side length and height of the steel pipe, and the second processing module 903 is further configured to: determine the target corrosion volume corresponding to each surface in the first shell element model according to the dimensional parameters of the steel pipe, a first formula, and the preset corrosion rate ; the first formula is , where represents the corrosion rate, and n represents the number of surfaces in the first shell element model; when generating each new corrosion pit on the target surface to be corroded, recalculate the total volume of the original corrosion pits existing on the target surface to be corroded ; when the total volume of the original corrosion pits existing on the target surface to be corroded meets the preset corrosion rate condition, stop generating new corrosion pits on the target surface to be corroded; wherein, the preset corrosion rate condition is: , Indicates the volume error.

[0112] In a possible implementation, the size information of the new corrosion pit includes the depth, diameter, and radius of the new corrosion pit, and the position information includes the local coordinates of the center point of the new corrosion pit relative to the target surface to be corroded. The second processing module 903 is specifically configured to: randomly take a value within the depth range as the depth of the new corrosion pit; determine the diameter and radius of the new corrosion pit according to the depth of the new corrosion pit and the diameter range; the diameter range is used to constrain that the diameter is m times the depth, and m is randomly taken within the diameter range; within the coordinate range, randomly select a set of point coordinates as the local coordinates of the center point of the new corrosion pit relative to the target surface to be corroded; the coordinate range is determined according to the radius of the new corrosion pit and is used to constrain that the area covered by the new corrosion pit is within the target surface to be corroded.

[0113] In a possible implementation, the corrosion pit generation module 904 is specifically configured to: determine the first distance between the center point of the new corrosion pit and the center point of the original corrosion pit according to the local coordinates of the center point of the new corrosion pit and the local coordinates of the center point of the original corrosion pit; if the first distance is less than the sum of the radius of the new corrosion pit and the radius of the original corrosion pit, it is determined that the new corrosion pit overlaps with the original corrosion pit, and the size information and position information of the new corrosion pit are re-determined; otherwise, it is determined that the new corrosion pit does not overlap with the original corrosion pit.

[0114] In a possible implementation, the corrosion pit generation module 904 is specifically configured to: determine the global coordinates of the center point of the new corrosion pit relative to the first shell element model of the steel pipe according to the local coordinates of the center point of the new corrosion pit and the pre-determined centroid coordinates of the target surface to be corroded; generate a new corrosion pit on the target surface to be corroded according to the global coordinates, depth, and diameter of the new corrosion pit.

[0115] In a possible implementation, the second construction module 905 is specifically configured to: copy the first shell element model of the steel pipe to obtain a replicated shell element model of the steel pipe; use the second shell element model as a cutting tool to perform cutting processing on the replicated shell element model of the steel pipe to obtain the shell element models of all corrosion pits on the second shell element model; perform a merging process on the shell element models of all corrosion pits and the second shell element model to obtain the third shell element model of the steel pipe; perform a merging process on the third shell element model of the steel pipe and the solid model of the concrete component to obtain the steel pipe concrete structure model.

[0116] In a possible implementation, the second building block 905 is further configured to: create a corresponding first shell element cross-section for each corrosion pit in the third shell element model, and establish a mapping relationship between each first shell element cross-section and preset steel pipe material property information; the thickness of the first shell element cross-section is randomly determined according to the depth of the corresponding corrosion pit, and the steel pipe material property information includes the elastic property information and plastic property information of the steel pipe; for the uncorroded part in the third shell element model, create a second shell element cross-section; the thickness of the second shell element cross-section is determined according to the thickness of the steel pipe; for the solid model of the concrete component, create a homogeneous solid cross-section, and establish a mapping relationship between the homogeneous solid cross-section and preset concrete material property information; the concrete material property information includes the elastic property information and plastic property information of the concrete material.

[0117] Figure 10 is a schematic diagram of an electronic device provided by an embodiment of the present invention. As Figure 10 shown, the electronic device 10 of this embodiment includes: a processor 100 and a memory 1001. The memory 1001 stores a computer program 1002. When the processor 100 executes the computer program 1002, the steps in the above-mentioned method embodiments are implemented. Alternatively, when the processor 100 executes the computer program 1002, the functions of each module / unit in the above-mentioned device embodiments are implemented.

[0118] Exemplarily, the computer program 1002 can be divided into one or more modules / units, and the one or more modules / units are stored in the memory 1001 and executed by the processor 100 to complete the present invention. The one or more modules / units can be a series of computer program instruction segments capable of performing specific functions, and the instruction segments are used to describe the execution process of the computer program 1002 in the electronic device 10.

[0119] The electronic device 10 may include, but is not limited to, a processor 100 and a memory 1001. Those skilled in the art can understand that Figure 10 this is only an example of the electronic device 10 and does not constitute a limitation on the electronic device 10. It may include more or fewer components than shown in the figure, or combine some components, or different components. For example, the electronic device 10 may further include input / output devices, network access devices, a bus, etc.

[0120] The processor 100 may be a Central Processing Unit (CPU), or may also be other general-purpose processors, Digital Signal Processors (DSPs), Application Specific Integrated Circuits (ASICs), Field-Programmable Gate Arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0121] The memory 1001 may be an internal storage unit of the electronic device 10, such as the hard disk or memory of the electronic device 10. The memory 1001 may also be an external storage device of the electronic device 10, such as a plug-in hard disk, Smart Media Card (SMC), Secure Digital (SD) card, FlashCard, etc. equipped on the electronic device 10. Further, the memory 1001 may also include both the internal storage unit and the external storage device of the electronic device 10. The memory 1001 is used to store the computer program 1002 and other programs and data required by the electronic device 10. The memory 1001 may also be used to temporarily store the data that has been output or is to be output.

[0122] For the convenience and simplicity of description, only the above division of each functional module / unit is used as an example. In actual applications, the above functions may be assigned to different functional modules / units according to needs. The above modules / units may be implemented in the form of hardware, or in the form of software, or in the form of a combination of hardware and software.

[0123] The embodiment of the present invention also provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, the methods in the above method embodiments are implemented.

[0124] The embodiment of the present invention also provides a computer program product, including a computer program. When the computer program is executed by a processor, the methods in the above method embodiments are implemented.

[0125] Among them, the computer program includes computer program code, and the computer program code can be in the form of source code, object code, executable file or some intermediate form, etc. The computer-readable medium can include: any entity or device capable of carrying the computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disc, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signal, telecommunication signal, and software distribution medium, etc.

[0126] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them. The descriptions of each embodiment have their own emphases. For the parts not detailed or recorded in a certain embodiment, reference can be made to the relevant descriptions of other embodiments. If there is no special explanation and logical conflict, the terms and / or descriptions between different embodiments are consistent and can be mutually referred to. The technical features in different embodiments can be combined to form new embodiments according to their inherent logical relationships.

Claims

1. A method for constructing a model of a steel tube concrete structure considering random corrosion, characterized in that: include: Constructing a first shell unit model of the steel pipe according to the size parameters of the steel pipe; Based on the corrosion type, determining a target surface to be corroded in the first shell element model; If the total volume of the existing original corrosion pits in the target surface to be corroded is smaller than the target corrosion volume, the size information and position information of the new corrosion pits to be generated are randomly determined within a predetermined depth range, coordinate range and diameter range; wherein the target corrosion volume is determined according to a preset corrosion rate; According to the size information and position information of the new corrosion pit, it is determined whether the new corrosion pit overlaps with the original corrosion pit; if it is determined that the new corrosion pit does not overlap with the original corrosion pit, a new corrosion pit is generated on the target surface to be corroded according to the size information and position information of the new corrosion pit, so as to obtain a second shell element model with the corrosion pit; A steel tube concrete structure model is constructed according to the second shell element model of the steel tube and the pre-constructed solid model of the concrete component.

2. The method according to claim 1, characterized in that The corrosion types include single-sided corrosion and multi-sided corrosion; The step of determining the target surface to be corroded in the first shell element model based on the corrosion type includes: Acquire surface information of the first shell unit model; the surface information includes the number of surfaces to be corroded in the first shell unit model and the unit normal vector corresponding to each surface to be corroded; If the first shell element model is subjected to single-sided corrosion, the surface to be corroded indicated by the unit normal vector is determined as the target surface to be corroded; If the first shell element model is subjected to multi-faceted erosion, then according to the unit normal vector corresponding to each surface to be eroded, the surface to be eroded indicated by each unit normal vector is determined as the target surface to be eroded in turn.

3. The method according to claim 1, characterized in that The size parameters of the steel pipe include the inner side length of the steel pipe , outer length and height , the method further comprises: Determine the target corrosion volume corresponding to each surface in the first shell unit model according to the size parameters of the steel pipe, the first formula and the preset corrosion rate ; The first formula is ,in, represents the corrosion rate, n represents the number of faces in the first shell element model; When a new corrosion pit is generated on the target surface to be etched, the total volume of the original corrosion pits on the target surface to be etched is recalculated. ; When the total volume of the original corrosion pits on the target surface to be corroded meets the preset corrosion rate condition, stop generating new corrosion pits on the target surface to be corroded; Wherein, the preset corrosion rate condition is: , Indicates volume error.

4. The method according to claim 1, characterized in that: The size information of the new corrosion pit includes the depth, diameter and radius of the new corrosion pit, and the position information includes the local coordinates of the center point of the new corrosion pit relative to the target surface to be etched; The step of randomly determining the size information and position information of the new corrosion pit to be generated within a predetermined depth range, coordinate range, and diameter range includes: Randomly select a value within the depth range as the depth of the new corrosion pit; Determine the diameter and radius of the new corrosion pit according to the depth of the new corrosion pit and the diameter range; the diameter range is used to constrain the diameter to be m times the depth, and m is randomly selected within the diameter range; Within the coordinate range, a set of point coordinates are randomly selected as the local coordinates of the center point of the new corrosion pit relative to the target surface to be corroded; the coordinate range is determined according to the radius of the new corrosion pit and is used to constrain the area covered by the new corrosion pit to be within the target surface to be corroded.

5. The method according to claim 4, characterized in that The step of judging whether the new corrosion pit overlaps with the original corrosion pit according to the size information and the position information of the new corrosion pit comprises: Determine a first spacing distance between the center point of the new corrosion pit and the center point of the original corrosion pit according to the local coordinates of the center point of the new corrosion pit and the local coordinates of the center point of the original corrosion pit; If the first spacing distance is smaller than the sum of the radius of the new corrosion pit and the radius of the original corrosion pit, it is determined that the new corrosion pit overlaps with the original corrosion pit, and the size information and position information of the new corrosion pit are re-determined; otherwise, it is determined that the new corrosion pit does not overlap with the original corrosion pit.

6. The method according to claim 4, characterized in that Generating a new corrosion pit on the target surface to be etched according to the size information and position information of the new corrosion pit comprises: Determine the global coordinates of the center point of the new corrosion pit relative to the first shell element model of the steel pipe according to the local coordinates of the center point of the new corrosion pit and the predetermined coordinates of the center of gravity of the target surface to be corroded; A new corrosion pit is generated on the target surface to be etched according to the global coordinates, depth and diameter of the new corrosion pit.

7. The method according to any one of claims 1 to 6, characterized in that: The step of constructing a steel tube concrete structure model based on the second shell unit model of the steel tube and the pre-constructed entity model of the concrete component includes: Copying the first shell element model of the steel pipe to obtain a copied shell element model of the steel pipe; Using the second shell element model as a cutting tool, cutting the replicated shell element model of the steel pipe to obtain shell element models of all corrosion pits on the second shell element model; Merging the shell element models of all the corrosion pits with the second shell element model to obtain a third shell element model of the steel pipe; The third shell unit model of the steel tube and the solid model of the concrete component are combined to obtain the steel tube concrete structure model.

8. The method according to claim 7, characterized in that Also includes: A corresponding first shell unit section is created for each corrosion pit in the third shell unit model, and a mapping relationship between each first shell unit section and preset steel pipe material property information is established; the thickness of the first shell unit section is randomly determined according to the depth of the corresponding corrosion pit, and the steel pipe material property information includes elastic property information and plastic property information of the steel pipe; For the uncorroded portion of the third shell element model, a second shell element section is created; the thickness of the second shell element section is determined according to the thickness of the steel pipe; A homogeneous solid section is created for the solid model of the concrete component, and a mapping relationship between the homogeneous solid section and preset concrete material property information is established; the concrete material property information includes elastic property information and plastic property information of the concrete material.

9. A model building device for a steel tube concrete structure considering random corrosion, characterized in that: include: A first construction module, used to construct a first shell unit model of the steel pipe according to the size parameters of the steel pipe; A first processing module, configured to determine a target surface to be corroded in the first shell element model based on the corrosion type; The second processing module is used to randomly determine the size information and position information of the new corrosion pits to be generated within a predetermined depth range, coordinate range and diameter range when the total volume of the original corrosion pits in the target corrosion surface is smaller than the target corrosion volume; wherein the target corrosion volume is determined according to a preset corrosion rate; An erosion pit generating module is used to determine whether the new erosion pit overlaps with the original erosion pit according to the size information and position information of the new erosion pit; if it is determined that the new erosion pit does not overlap with the original erosion pit, a new erosion pit is generated on the target erosion surface according to the size information and position information of the new erosion pit to obtain a second shell element model with the erosion pit; The second construction module is used to construct a steel tube concrete structure model according to the second shell unit model of the steel tube and the pre-constructed solid model of the concrete component.

10. An electronic device, characterized in that: The method comprises a memory and a processor, wherein the memory stores a computer program, and the processor implements the method according to any one of claims 1 to 8 when executing the computer program.

Images