Cellular erosion-based aviation metal braided wire point cloud data entity modeling method

Abstract

The application provides an aviation metal braided wire point cloud data entity modeling method based on cell erosion, relates to the technical field of metal corrosion numerical simulation analysis, and comprises the following steps: S1, a three-dimensional cell space simulating the corrosion environment of an aviation metal braided wire is established; S2, simulation modeling of the corrosion process of the aviation metal braided wire is performed; S3, an aviation metal braided wire cell three-dimensional space point cloud equation is constructed, and an aviation metal braided wire grid unit is generated; and S4, the aviation metal braided wire tetrahedral grid unit is spliced to generate a smooth curved surface, and the aviation metal braided wire point cloud data entity modeling is completed. The aviation metal braided wire three-dimensional discrete points generated in the cellular automaton can be converted into an entity in the finite element simulation software, the complex aviation metal braided wire surface topography is retained, and the simulation-to-physical model conversion process is optimized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of numerical simulation analysis of metal corrosion, and particularly relates to a point cloud data entity modeling method for aviation metal braided wires based on cellular corrosion. BACKGROUND

[0002] Traditional corrosion research mainly relies on experimental methods in simulated complex corrosion environments. However, it is difficult to accurately control all variables during the experiment, resulting in poor repeatability and controllability of the results. At the same time, the local or surface information provided by the experiment is difficult to fully and continuously reveal the dynamic evolution of the material corrosion in the long-term service process. In recent years, numerical simulation has been widely used in the field of metal corrosion and other related fields due to its efficiency and process observability. Compared with other numerical simulation methods such as finite element method and boundary element method, the cellular automata algorithm introduces randomness and is suitable for simulating the development law of small-scale irregular pitting corrosion. However, the calculation results of the cellular automata are three-dimensional discrete points, which cannot be imported into the finite element software for subsequent simulation analysis. At present, the related research on importing cellular automata into finite element software is mostly single-pit corrosion or multi-pit corrosion after simplification, which is difficult to reflect the real morphology of the pits.

[0003] However, the cellular automata method still has some limitations, especially when applied to actual engineering problems. The calculation results of the cellular automata are often discrete three-dimensional point clouds, which cannot be directly compatible and linked with the finite element analysis software. This is because the finite element software requires the input model to be a continuous and solid geometric body, while the cellular automata generate point cloud data composed of a large number of discrete points.

[0004] Therefore, based on the point cloud data, which is a data structure composed of a large number of discrete three-dimensional coordinate points, and the corrosion morphology generated by the cellular automata has strong randomness and complexity, it is an urgent problem to quickly convert it into a high-precision entity model that can be subsequently calculated by finite element. SUMMARY

[0005] In order to solve the above problems of the prior art, the present application provides a point cloud data entity modeling method for aviation metal braided wires based on cellular corrosion, which can convert the three-dimensional discrete points of aviation metal braided wires generated in the cellular automata into aviation metal braided wire entities calculated in the finite element simulation software, and can preserve the complex surface morphology of the aviation metal braided wires, optimize the conversion process from simulation to entity model, and be applicable to a variety of metal materials.

[0006] Specifically, the present application provides a point cloud data entity modeling method for aviation metal braided wires based on cellular corrosion, which comprises the following steps:

[0007] S1: Establish a three-dimensional cell space simulating the corrosion environment of aviation metal braided wire; convert the reaction elements involved in the corrosion process of the aviation metal braided wire into each cell in the three-dimensional cell space of the wire;

[0008] S2: Establish a wire corrosion process simulation model, set the wire corrosion step number N, and after N cycles, obtain the corroded metal cell R as the corrosion simulation result of the wire corrosion process simulation;

[0009] S3: Output the corrosion simulation result of the corroded metal cell R in step S2 as a three-dimensional discrete point to obtain the coordinate judgment equation of the wire cell in the three-dimensional space; determine whether the three-dimensional discrete point is a wire cell, extract the three-dimensional discrete point coordinates (x i ,y i ,z i ) of the wire cell, and construct a three-dimensional space point cloud equation; use an optimization algorithm to distinguish the three-dimensional point cloud corrosion range, obtain the target point triangular mesh according to the target point normal vector in the three-dimensional space point cloud, generate wire triangular mesh elements; and use a curvature minimization smoothing algorithm to convert the wire triangular mesh elements into wire tetrahedral mesh elements;

[0010] S4: Generate a smooth surface from the wire tetrahedral mesh elements in step S3 to complete the wire point cloud data solidification modeling.

[0011] Preferably, the determination method of the coordinate judgment equation of the wire cell in the three-dimensional space in step S3 is:

[0012] The corrosion simulation result of the corroded metal cell R in step S2 is output as a three-dimensional discrete point to obtain the coordinate judgment equation of the wire cell in the three-dimensional space as:

[0013]

[0014] Wherein, MetalSurface(i,j,k) is the coordinate of the wire cell in the three-dimensional space; is in contact with the passivation product cell P, the corroded metal cell R, and the corrosion-resistant coating cell D; i is the horizontal coordinate of the wire cell in space; j is the vertical coordinate of the wire cell in space; k is the vertical coordinate of the wire cell in space; if is a judgment function that meets the conditions; neighbor is a judgment function that meets the contact conditions; otherwise is a judgment function that does not meet the conditions.

[0015] Preferably, the determination method of the three-dimensional space point cloud equation in step S3 is: according to the coordinate judgment equation in step S31, determine whether the three-dimensional discrete point output in step S2 is a wire cell, and extract the coordinates (x i ,y i ,zi ), construct the three-dimensional spatial point cloud equation PoCl for the conductor.

[0016] Preferably, in step S3, an optimization algorithm is used to distinguish the erosion range of the three-dimensional point cloud and generate triangular mesh elements for the conductor. Specifically, for each point in the point cloud in the three-dimensional point cloud equation PoCl of the conductor, the normal vector is calculated using the points in the neighborhood; the target point in the point cloud is... Points within the neighborhood are {(Pa1,Pa2,……,Pa...} n Then, based on the normal vector of the target point in the point cloud, the triangular mesh of the target point is obtained; to accelerate the calculation of the normal vector, an optimization algorithm radius r is set to distinguish the relative range of the inner and outer parts of the point cloud, thus obtaining the triangular mesh n of the i-th target point in the point cloud. i .

[0017] Preferably, in step S3, the triangular mesh n of the i-th target point i for:

[0018]

[0019] Where, n i Pa is the triangular mesh for the i-th target point; i Pa is the i-th target point in the point cloud; j Let j be the j-th target point in the point cloud.

[0020] Preferably, in step S3, a curvature minimization smoothing algorithm is used to transform the wire triangular mesh elements into wire tetrahedral mesh elements, specifically:

[0021] The generated wire mesh is segmented, and each triangular facet △(v1,v2,v3) of the triangular mesh is divided into multiple secondary triangular faces. The midpoint of each edge of each triangular facet is taken and connected to the center point of the original triangle, thus generating multiple secondary triangular faces. The secondary vertex v4 is the centroid of the initial triangular facet. The tetrahedral mesh is smoothed using a curvature minimization-based smoothing algorithm. Based on the above mesh division, for each tetrahedral mesh, an initial position v is given. i The updated position is v' i .

[0022] Preferably, in step S3, position v' i It is a weighted average of the positions of its adjacent vertices, and the method for determining it is as follows:

[0023]

[0024] Among them, v' i The position of the updated tetrahedral mesh; v jN(i) is the initial position of the tetrahedral mesh; N(i) is the initial position of the tetrahedral mesh i The adjacent vertex set of the vertex is determined by the number of adjacent vertices of the vertex.

[0025] Preferably, the wire corrosion process simulation model in step S2 includes: when the wire contacts the hydrogen ion solution, an anodic reaction occurs, a quantitative conversion model and a corrosion probability are determined, and specifically:

[0026]

[0027] P2=mN H +nN W ;

[0028] Wherein, R is the metal cell corroded away; C is the ion cell generated by corrosion; P2 is the second probability of pit formation on the surface of the wire; m is the weight coefficient of the hydrogen ion cell H; n is the weight coefficient of the corrosive solution cell W; N H is the number of hydrogen ion cells H; N W is the number of corrosive solution cells W.

[0029] Preferably, the wire corrosion process simulation model in step S2 includes: when the wire contacts the metal ion solution, a passivation reaction occurs, a quantitative conversion model and a corrosion probability are determined, and specifically:

[0030]

[0031] Wherein, C is the ion cell generated by corrosion; W n is a random corrosive solution cell; P3 is the third probability of pit formation on the surface of the wire; P is the passivation product cell; H n is a random hydrogen ion cell; C n is a random ion cell generated by corrosion; P4 is the fourth probability of pit formation on the surface of the wire; P n is a random passivation product cell.

[0032] Preferably, the hydrogen ion cell H generated by the passivation reaction in step S2 will cause the hydrolysis reaction to have reversibility, and the corresponding quantitative conversion model is:

[0033]

[0034] Wherein, P5 is the fifth probability of pit formation on the surface of the wire.

[0035] Compared with the prior art, the beneficial effects of the present application are as follows:

[0036] (1) The present application realizes accurate point cloud generation and surface extraction through a cellular corrosion simulation algorithm, truly reflects the surface morphology of the corroded aviation metal braided wire, and introduces randomness compared to other numerical simulation methods, suitable for simulating the development law of small-scale irregular pitting corrosion.

[0037] (2) The present application converts the three-dimensional point cloud of the aviation metal braided wire into a grid, and processes it through point cloud Cloud Compare, optimizes the conversion process from simulation to solid model, simplifies the cumbersome steps in the traditional modeling method, and improves the conversion efficiency.

[0038] (3) The present application can be adjusted for different metals and different corrosion conditions, is suitable for a variety of metal materials, provides accurate model data for subsequent finite element analysis, and thus promotes engineering design, optimization and safety evaluation. BRIEF DESCRIPTION OF DRAWINGS

[0039] Figure 1 The flowchart of the aviation metal braided wire point cloud data solid modeling method based on cellular corrosion of the present application;

[0040] Figure 2 The aviation metal braided wire cellular space schematic diagram of the CA model of the corrosion process in the embodiment of the present application;

[0041] Figure 3 The pit morphology schematic diagram of the aviation metal braided wire simulated in the embodiment of the present application;

[0042] Figure 4 The point cloud schematic diagram of the aviation metal braided wire in the embodiment of the present application;

[0043] Figure 5 The grid schematic diagram of the aviation metal braided wire in the embodiment of the present application;

[0044] Figure 6 The curved surface schematic diagram of the aviation metal braided wire in the embodiment of the present application;

[0045] Figure 7 The physical diagram of the copper braided wire after immersion corrosion in the embodiment of the present application;

[0046] Figure 8 The solid schematic diagram of the aviation metal braided wire in the embodiment of the present application. DETAILED DESCRIPTION

[0047] Hereinafter, the embodiments of the present application will be described with reference to the accompanying drawings.

[0048] The embodiment of the present application uses an aviation metal braided wire model of an aviation product as a specific research and analysis object, and provides a method for modeling aviation metal braided wire point cloud data entities based on cellular corrosion, as shown in Figure 1 A three-dimensional cellular space simulating the corrosion environment of the aviation metal braided wire is established; aviation metal braided wire corrosion process simulation modeling is performed according to the three-dimensional cellular space, aviation metal braided wire cellular transformation, probability diffusion model and corresponding corrosion and diffusion probability are determined; an aviation metal braided wire cellular three-dimensional space point cloud equation is constructed to generate an aviation metal braided wire grid unit; the aviation metal braided wire tetrahedral grid unit is spliced to generate a smooth surface, and the aviation metal braided wire point cloud data entity modeling is completed; which includes:

[0049] Step S1: a three-dimensional cellular space simulating the corrosion environment of the aviation metal braided wire is established, which is represented by three-dimensional coordinates, as shown in Figure 2 The CA model of the corrosion process in the embodiment of the present application is shown in the aviation metal braided wire cellular space diagram, Figure 2 1 is an aviation metal braided wire; the reaction conversion elements involved in the pitting process of the aviation metal braided wire are converted into each cell in the aviation metal braided wire three-dimensional cellular space; the reaction conversion elements refer to the metal, solution and corrosion products generated in the corrosion reaction, and specifically include: aviation metal braided wire cell M, corroded metal cell R, anticorrosion coating cell D, passivation product cell P, corrosive solution cell W, hydrogen ion cell H and corrosion generated ion cell C.

[0050] Step S2: according to the three-dimensional cellular space in step S1, aviation metal braided wire corrosion process simulation modeling is performed, aviation metal braided wire cellular transformation, probability diffusion model and corresponding corrosion and diffusion probability are determined.

[0051] Step S21: determine the cellular quantitative transformation model of the aviation metal braided wire and the corrosion probability; based on the small anode and large cathode corrosion model, the inside of the etch pit is an anode reaction, no cathode reaction occurs, and in the reaction process, the anticorrosion coating surface randomly generates a damage point with a probability P1, and a hemispherical etch pit is generated with the damage point as the center, the inside of the etch pit is the hydrogen ion cell H, and the first probability P1 of the aviation metal braided wire surface generating the etch pit is:

[0052]

[0053] Wherein, P1 is the first probability of the aviation metal braided wire surface generating the etch pit; k is the corrosion parameter of the aviation metal braided wire; N is the corrosion step number of the aviation metal braided wire.

[0054] Step S22: When the aviation metal braided wire contacts the hydrogen ion solution, an anodic reaction can occur, specifically, the corroded metal cell R is converted into the corrosion generated ion cell C, wherein the second probability P2 of the aviation metal braided wire surface producing pits is positively correlated with the number N of the hydrogen ion cell H adjacent to the corroded metal cell R H and the number N of the corrosive solution cell W W , and the weight coefficient m of the hydrogen ion cell H and the weight coefficient n of the corrosive solution cell W; compared with the corrosive solution cell W, the hydrogen ion cell H can directly react with the metal matrix. Therefore, the weight coefficient m of the hydrogen ion cell H is greater than the weight coefficient n of the corrosive solution cell W. The corresponding quantitative conversion model and the corrosion probability are:

[0055]

[0056] P2=mN H +nN W ;

[0057] wherein R is a corroded metal cell; C is a corrosion generated ion cell; P2 is the second probability of the aviation metal braided wire surface producing pits; m is the weight coefficient of the hydrogen ion cell H; n is the weight coefficient of the corrosive solution cell W; N H is the number of the hydrogen ion cell H; N W is the number of the corrosive solution cell W.

[0058] Step S23: When the aviation metal braided wire contacts the metal ion solution, a passivation reaction can occur, specifically, the corrosion generated ion cell C randomly selects a contact cell, if the selected contact cell is the corrosive solution cell W, the corrosion generated ion cell C is converted into the passivation product cell P, and the corrosive solution cell W is converted into the hydrogen ion cell H, and the probability value is the third probability P3 of the aviation metal braided wire surface producing pits, which is related to the concentration, temperature and reactivity of the solution and the metal surface, and needs to be determined by experiment fitting; when two corrosion generated ion cells C meet, that is, the selected contact cell of the corrosion generated ion cell C is the corrosion generated ion cell C, the fourth probability P4 of the aviation metal braided wire surface producing pits of the passivation reaction will increase, which is related to the passivation product, hydrogen ion concentration and corrosion generated ion cell, and needs to be determined by experiment fitting, and the corrosion generated ion cell C is all converted into the passivation product cell P; the fourth probability P4 of the aviation metal braided wire surface producing pits is greater than the third probability P3 of the aviation metal braided wire surface producing pits. The corresponding quantitative conversion model is:

[0059]

[0060] wherein C is a corrosion generated ion cell; W n is a random corrosive solution cell; P3 is a third probability of pitting on the surface of the aviation metal braided wire; P is a passivation product cell; H n is a random S hydrogen ion cell; C n is a random corrosion generated ion cell; P4 is a fourth probability of pitting on the surface of the aviation metal braided wire; P n is a random passivation product cell.

[0061] The hydrogen ion cell H generated by the passivation reaction causes the hydrolysis reaction to have reversibility, that is, the contact cell selected by the passivation product cell P is the hydrogen ion cell H, and the passivation product cell P and the hydrogen ion cell H are converted into the corrosion generated ion cell C, and the probability is a fifth probability P5 of pitting on the surface of the aviation metal braided wire, and the corresponding quantitative conversion model is:

[0062]

[0063] wherein P5 is the fifth probability of pitting on the surface of the aviation metal braided wire.

[0064] Step S24: determining a probability diffusion model of the corrosion process of the aviation metal braided wire; the corrosion generated ion cell C and the hydrogen ion cell H occur N diff diffusions in each corrosion reaction step, the passivation product cell P occurs N diff_I diffusions, and the probabilities of exchange between cells are the same; since the corrosion generated ion cell C and the hydrogen ion cell H exist in the form of ions in the solution, the passivation product cell P is suspended in the form of colloid in the electrolyte solution, and it can be concluded that N diff >N diff_I ; the probability diffusion model of the corrosion process of the aviation metal braided wire is obtained: the corrosion generated ion cell C and the hydrogen ion cell H randomly move to one of the nearby solution cells in the diffusion process, if the corrosion generated ion cell C and the hydrogen ion cell H move to the same state cell position, no position exchange occurs, if they move to a different state cell position, the position is exchanged; if the passivation product cell P exists around the solid cell, it does not move, otherwise, it exchanges the position with one of the randomly encountered solution cells. The solution cells include: the corrosion generated ion cell C, the hydrogen ion cell H and the corrosive solution cell W. The solid cells include: the corroded metal cell R, the anti-corrosion coating cell D and the aviation metal braided wire cell M.

[0065] Step S25: setting the corrosion step number N of the aviation metal braided wire, and ending after repeating steps S21-S24 for N times, obtaining the corroded metal cell R as the corrosion simulation result simulated by the corrosion process of the aviation metal braided wire, representing the simulated pitting morphology, such asFigure 3 Figure 1 shows a schematic diagram of the etch pit morphology of an aviation metal braided wire simulated in an embodiment of the present application, accurately and in detail depicting the etch pit morphology and position of the embodiment in a spatial coordinate system.

[0066] Step S3: constructing a three-dimensional spatial point cloud equation of the aviation metal braided wire cell, and generating an aviation metal braided wire grid unit.

[0067] Step S31: outputting the corrosion simulation result of the corroded metal cell R in step S2 as a three-dimensional discrete point, and obtaining the coordinate judgment equation of the aviation metal braided wire cell in three-dimensional space as:

[0068]

[0069] wherein MetalSurface(i,j,k) is the coordinate of the aviation metal braided wire cell in three-dimensional space; to contact the passivation product cell P, the corroded metal cell R and the anti-corrosion coating cell D; i is the horizontal coordinate of the aviation metal braided wire cell in space; j is the vertical coordinate of the aviation metal braided wire cell in space; k is the vertical coordinate of the aviation metal braided wire cell in space; if is a judgment function that meets the condition; otherwise is a judgment function that does not meet the condition.

[0070] Step S32: determining whether the three-dimensional discrete point output in step S2 is an aviation metal braided wire cell according to the coordinate judgment equation in step S31, and extracting the coordinates (x i ,y i ,z i ) as shown in Figure 2. Figure 4 Figure 2 shows a point cloud diagram of an aviation metal braided wire in an embodiment of the present application; and a three-dimensional spatial point cloud equation PoCl of the aviation metal braided wire is constructed as:

[0071] PoCl = {(x1,y1,z1),(x2,y2,z2),…,(x n ,y n ,z n )};

[0072] wherein PoCl is the three-dimensional spatial point cloud equation of the aviation metal braided wire; x1 is the horizontal coordinate of the first point in three-dimensional space; y1 is the vertical coordinate of the first point in three-dimensional space; z1 is the vertical coordinate of the first point in three-dimensional space; x2 is the horizontal coordinate of the second point in three-dimensional space; y2 is the vertical coordinate of the second point in three-dimensional space; z2 is the vertical coordinate of the second point in three-dimensional space; x n is the horizontal coordinate of the n-th point in three-dimensional space; y n is the vertical coordinate of the n-th point in three-dimensional space; z n is the vertical coordinate of the n-th point in three-dimensional space.

[0073] Step S33: For the aerial metal braided wire three-dimensional space point cloud equation PoCl in step S32, an octree optimization algorithm is used to distinguish the corrosion range of the aerial metal braided wire three-dimensional point cloud, and an aerial metal braided wire triangular mesh element is generated, specifically:

[0074] For each point in the aerial metal braided wire three-dimensional space point cloud, the points in the neighborhood are used to calculate the normal vector; the target point in the point cloud is The points in the neighborhood are {(Pa1, Pa2, …, Pa n}, and the triangular mesh of the target point is obtained according to the normal vector of the target point in the point cloud:

[0075]

[0076] Where n i is the triangular mesh of the i-th target point in the point cloud; Pa i is the i-th target point normal vector in the point cloud; Pa j is the j-th target point normal vector in the point cloud; i is the first number of the target point in the point cloud; j is the second number of the target point in the point cloud; and m is the total number of target points in the point cloud.

[0077] To speed up the calculation of the normal vector, an octree radius r is set to distinguish the relative range of the inside and outside of the point cloud, as shown in Figure 5 The grid diagram of the aerial metal braided wire in the embodiment of the application is shown in the figure; the triangular mesh n i of the i-th target point in the point cloud is:

[0078]

[0079] Step S34: The aerial metal braided wire triangular mesh element generated in step S33 is segmented, and a curvature minimization smoothing algorithm is used to convert the aerial metal braided wire triangular mesh element into an aerial metal braided wire tetrahedral mesh element, specifically:

[0080] Each triangular face △(v1, v2, v3) of the triangular mesh element is divided into four secondary triangular faces; the midpoint of each edge corresponding to each triangular face is connected to the center point of the original triangle, thereby generating four secondary triangular faces, and the secondary vertex v4 is the centroid of the initial triangular face; each triangular face will be continuously refined until the triangular mesh element contains enough tetrahedral mesh elements, and the tetrahedral mesh secondary vertex v4 is:

[0081]

[0082] Where v4 is the second-level vertex of the tetrahedral mesh; v1 is the first vertex of the triangular facet; v2 is the second vertex of the triangular facet; and v3 is the third vertex of the triangular facet.

[0083] like Figure 6 This is a schematic diagram of the curved surface of the aerospace metal braided wire in an embodiment of the present invention; the complex triangular mesh is transformed into a tetrahedral mesh, and then a smooth multisurface is generated by continuously splicing G1 layers. A curvature-minimizing smoothing algorithm is used to smooth the tetrahedral mesh. Based on the above mesh division, an initial position v is given for each tetrahedral mesh. i Its updated position v' i It is a weighted average of the positions of its adjacent vertices, and the method for determining it is as follows:

[0084]

[0085] Among them, v' i The position of the updated tetrahedral mesh; v j The initial position is given for the tetrahedral mesh; N(i) is the initial position v of the tetrahedral mesh. i The set of adjacent vertices of a vertex is determined by the number of adjacent vertices of that vertex.

[0086] Step S4: Combine the tetrahedral mesh units of the aerospace metal braided wire in step S3 to generate a smooth surface, and complete the solid modeling of the point cloud data of the aerospace metal braided wire.

[0087] The copper braided wire after immersion corrosion in the embodiment of the present invention is as follows: Figure 7 As shown, this is a copper braided wire after being soaked in a 3.5% NaCl solution for 16 days, with visible corrosion products on the surface. After treatment to remove corrosion products, the corrosion weight loss was measured to be 0.0431 g, a relative corrosion weight loss of 1.47%. The resistance before and after corrosion was measured using the four-wire method to be 596.3 μΩ and 621 μΩ, respectively, with a relative increase in resistance of 4.14%. The corrosion morphology after 160 steps of corrosion simulation using the cellular automata algorithm in this invention is shown below. Figure 3 As shown in Table 1, the main parameters of the model are as follows.

[0088] Table 1 Model Parameter Table

[0089]

[0090]

[0091] In this example, every 10 corrosion steps roughly correspond to 1 day of immersion corrosion. The corresponding corrosion weight loss rate, calculated from the number of cells, is 1.52%. Using the solid modeling method of this invention, the corresponding three-dimensional solid morphology is obtained as follows: Figure 8 As shown, Figure 8For the embodiment of the application, the schematic diagram of the aviation metal braided wire entity is introduced into the COMSOL software to calculate the resistances before and after corrosion, which are 588.2 mu omega and 611.4 mu omega respectively, and the relative growth rate of the resistance is 3.95%. Compared with the experimental results, the corrosion weight loss rate and the relative growth rate of the resistance have small errors, which proves the feasibility of the method in the application.

[0092] The application has the beneficial effects that the application provides an aviation metal braided wire point cloud data entity modeling method based on cellular corrosion, the corrosion simulation in the embodiment of the application can be used to guide the accelerated corrosion test, the simulation software can simulate the corrosion condition of the equipment or the component under the accelerated corrosion condition by setting specific environmental parameters. It is helpful to identify the potential corrosion risk point in the design stage, so as to optimize the anti-corrosion design. And the corrosion simulation result entity model can be widely applied in the finite element analysis (FEA), including the fields of building, machinery, aviation and the like. The entity is introduced into the finite element analysis to simulate the stress, deformation and heat conduction and the like structural analysis of different materials and structures. In the field of fluid mechanics, the fluid mechanics performance of the equipment or the structure is evaluated by simulating the fluid flow. In the field of electronic products, engines and the like, the finite element analysis is used for heat conduction analysis to evaluate the temperature distribution and thermal expansion effect and the like.

[0093] The above-described embodiments are only used to describe the preferred embodiments of the application, and do not limit the scope of the application. Without departing from the design spirit of the application, various modifications and improvements of the technical solutions of the application made by those skilled in the art should fall within the protection scope of the claims of the application.

Claims

1. A method for modeling the entity of aviation metal braided wire point cloud data based on cellular corrosion, characterized in that: S1: a three-dimensional cellular space simulating the corrosion environment of aviation metal braided wire is established; the reaction conversion elements participating in the corrosion process during the wire point corrosion process are converted into each cell in the wire three-dimensional cellular space; S2: Establish a wire corrosion process simulation model, set the wire corrosion step number , after 6 cycles, the corroded metal cells are obtained as the corrosion simulation results of the wire corrosion process simulation S3: Remove the metal cells that were corroded in step S2. The corrosion simulation results are output as three-dimensional discrete points, and the coordinate judgment equation of the conductor cell in three-dimensional space is obtained; to determine whether the three-dimensional discrete point is a conductor cell, the coordinates of the three-dimensional discrete point of the conductor cell are extracted. A three-dimensional spatial point cloud equation is constructed; an optimization algorithm is used to distinguish the erosion range of the three-dimensional point cloud; the triangular mesh of the target point is obtained based on the normal vector of the target point in the three-dimensional spatial point cloud, and the wire triangular mesh element is generated. a smoothing algorithm with minimum curvature is used to convert the wire triangular mesh element into a wire tetrahedral mesh element; an optimization algorithm is used to distinguish the corrosion range of the three-dimensional point cloud to generate the wire triangular mesh element, specifically: Equation for three-dimensional space point cloud of lead wire The point in each point cloud is calculated by using the points in the neighborhood; the target point in the point cloud is , the points in the neighborhood are , and the triangular mesh of the target point is obtained according to the normal vector of the target point in the point cloud; in order to accelerate the calculation of the normal vector, the optimization algorithm radius is set to distinguish the relative range of the inner and outer parts of the point cloud, and the triangular mesh of the th target point in the point cloud is obtained . Wherein, the triangle mesh of the first target point is: :​ ； wherein, is a triangle mesh for the th target point; is a point cloud for the th target point; is a point cloud for the th target point, is a total number of target points in the point cloud; S4: the wire tetrahedral mesh element in step S3 is generated into a smooth surface to complete the entity modeling of the wire point cloud data.

2. The method of claim 1, wherein the method is based on cellular erosion. The determination method of the coordinate judgment equation of the wire cell in step S3 in the three-dimensional space is: the metal cells that are etched away in step S2 The output of the etching simulation result is three-dimensional discrete points, and the coordinate determination equation of the wire cells in three-dimensional space is: ； wherein is the coordinate of the wire cell in three-dimensional space; is the coordinate of the wire cell in three-dimensional space; is the coordinate of the wire cell in three-dimensional space; is the coordinate of the wire cell in three-dimensional space; is the coordinate of the wire cell in three-dimensional space; is the coordinate of the wire cell in three-dimensional space; is the coordinate of the wire cell in three-dimensional space; is the coordinate of the wire cell in three-dimensional space; is the coordinate of the wire cell in three-dimensional space; is the coordinate of the wire cell in three-dimensional space; 3. The method of claim 1, wherein the method is based on cellular erosion. The method for determining the three-dimensional space point cloud equation in step S3 is: determining whether the three-dimensional discrete points output in step S2 are wire cells according to the coordinate judgment equation in step S31, extracting the coordinates , and constructing a wire three-dimensional space point cloud equation .

4. The method of claim 1, wherein: Step S3 uses a curvature minimization smoothing algorithm to transform the wire triangular mesh elements into wire tetrahedral mesh elements. Specifically, this involves dividing the generated wire triangular mesh elements and dividing each triangular facet of the triangular mesh element into its constituent triangular facets. The process involves dividing the triangle into multiple secondary triangular facets; the midpoint of each edge of each facet is then connected to the center point of the original triangle, thus generating multiple secondary triangular facets and secondary vertices. It is the centroid of the initial triangular facet; The tetrahedral mesh is smoothed using a smoothing algorithm based on curvature minimization, based on the mesh partitioning described above, for each tetrahedral mesh a initial position is given and the updated position is .

5. The method of claim 4, wherein: The position in step S3 is a weighted average of the positions of its adjacent vertices, determined by the method: ； wherein, is the updated position of the tetrahedral mesh; is the given initial position of the tetrahedral mesh is the given initial position of the tetrahedral mesh is the set of adjacent vertices of the tetrahedron, determined by the number of adjacent vertices of the vertex.

6. The method of claim 1, wherein: The wire corrosion process simulation model in step S2 includes: when the wire contacts the hydrogen ion solution, an anodic reaction occurs, a quantitative conversion model and a corrosion probability are determined, specifically: ； ； wherein, is the metal cell being etched away; is the ion cell generated by the etching; is the second probability of creating an etch pit on the wire surface; is the weight coefficient of the hydrogen ion cell ; is the weight coefficient of the corrosive solution cell ; is the number of hydrogen ion cells ; is the number of corrosive solution cells .

7. The method of claim 1, wherein: The wire corrosion process simulation model in step S2 includes: when the wire contacts the metal ion solution, a passivation reaction occurs, a quantitative conversion model and a corrosion probability are determined, specifically: ； ； wherein, is a randomly generated ion cell; is a randomly etching solution cell; is a third probability of creating pits on the wire surface; is a passivation product cell; is a randomly hydrogen ion cell; is a randomly generated ion cell; is a fourth probability of creating pits on the wire surface; is a randomly passivation product cell.

8. The method of claim 7, wherein the method further comprises: Hydrogen ion cell generated by passivation reaction in step S2 This will lead to the presence of reversibility of the hydrolysis reaction, the corresponding quantitative conversion model is: ； wherein a fifth probability of creating an etch pit on the surface of the wire.

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