A random generation method for two-dimensional irregular-shaped concrete aggregates

Abstract

A method for randomly generating two-dimensional irregularly shaped concrete aggregates comprises the following steps: S1, determining the minimum circumscribed ellipse based on the size of the crushed stone aggregate to be generated; S2, randomly selecting several points on the ellipse as the vertices of a polygon; S3, calculating the area within the ellipse to obtain the randomly generated polygonal area; S4, obtaining the bonding interface of the aggregate and determining the distribution of the generated aggregate in the overall structure. The method for randomly generating two-dimensional irregularly shaped concrete aggregates provided by the present invention can obtain and adjust irregularly shaped aggregates of different shapes and sizes, improving production flexibility and adjustability, and achieving efficient random generation of irregularly shaped aggregates.

Description

Technical Field

[0001] The invention belongs to the technical field of concrete microscopic numerical simulation pre-processing, and particularly relates to a random generation method for two-dimensional irregular-shaped concrete aggregates. Background Art

[0002] Concrete is a heterogeneous composite material composed of aggregate and cement mortar. The shape and spatial distribution of the aggregate significantly influences the material's properties. With the continuous development of computer technology and the maturation of related numerical calculation techniques, random aggregate models for concrete, which consider internal mesostructures such as aggregate shape, gradation, and mortar interfaces, have begun to be adopted. Aggregate size, shape, and distribution directly influence multiple concrete properties, including mechanical properties, concrete ultrasonic field characteristics, and ground-penetrating radar wave field characteristics. Therefore, in-depth research on random generation models for two-dimensional irregularly shaped aggregates is particularly important.

[0003] Crushed stone aggregate is a commonly used type of aggregate in concrete. It is characterized by being produced from large stones that have been manually crushed. Its shape is irregular and angular, and particularly on a two-dimensional plane, the crushed stone aggregate and its bonding interface exhibit a unique "serrated" contour. However, existing methods for producing irregular aggregates make it difficult to obtain aggregates of varying shapes and sizes, and their adjustment is difficult, resulting in a lack of flexibility and adjustability. Therefore, to overcome these drawbacks, a method for producing irregular aggregates that can produce and adjust different shapes and sizes is needed. The present invention addresses this technical problem. Summary of the Invention

[0004] The present invention provides a random generation method for two-dimensional irregular-shaped concrete aggregates, which can obtain and adjust irregular-shaped aggregates of different shapes and sizes, improves production flexibility and adjustability, and realizes efficient random generation of irregular-shaped aggregates.

[0005] A random generation method for two-dimensional irregularly shaped concrete aggregates comprises the following steps:

[0006] S1. Determine the minimum circumscribed ellipse according to the size of the crushed stone aggregate to be generated;

[0007] S2. Randomly select several points on the ellipse as the vertices of the polygon;

[0008] S3. Calculate the area within the ellipse to obtain a randomly generated polygonal area;

[0009] S4. Obtain the bonding interface of the aggregate and determine the distribution of the generated aggregate in the overall structure.

[0010] Furthermore, the step S1 includes the following steps:

[0011] S11. Select the coordinates (h, k) of the ellipse center;

[0012] S12, selecting the major semi-axis a and the minor semi-axis b of the ellipse;

[0013] S13, randomly select the tilt angle of the ellipse within (0, 2π);

[0014] S14. The range of the grid area S where the ellipse is located in the x-direction is expressed as: ([ha], [h+a]), and the range in the y-direction is expressed as: ([ka], [k+a]), where the symbol [] indicates rounding up.

[0015] Furthermore, step S2 includes the following steps:

[0016] S21. Taking the center of the ellipse (h, k) as the origin, divide the ellipse into N parts evenly;

[0017] S22. On the arc of each part of the ellipse, randomly select a point as the vertex of the polygon;

[0018] S23. Calculate the equation of the straight line between adjacent vertices y=kx+b.

[0019] Furthermore, step S3 includes the following steps:

[0020] S31. Define a function: f(x,y)=y-kx-b

[0021] S32. Substitute the center of the ellipse (h, k) and the grid coordinates of the grid area S where the ellipse is located into f(x, y);

[0022] S33. Mark the grids in region S with the same sign as f(h, k) as Ai;

[0023] S34. Repeat the above process to obtain multiple regions Ai (i=1:N). The intersection of the regions Ai is the generated polygonal region.

[0024] Furthermore, the specific steps of step S4 are as follows:

[0025] S51, finding the position of the generated aggregate particles;

[0026] S52, judging the grid occupied by each aggregate particle, and assigning a value to the grid according to the presence of aggregate particles in four adjacent grids surrounding the grid;

[0027] S53. When at least one of the four grids adjacent to the grid is not an aggregate particle, the value of the grid is assigned to 1;

[0028] S54. When the values ​​assigned to the four grids adjacent to the grid are all aggregate particles, the value assigned to the grid is 0.

[0029] The technical effects of the present invention are as follows:

[0030] (1) This scheme first establishes a circumscribed ellipse of an irregular polygon and then determines the polygonal area within the ellipse to obtain a randomly generated polygonal area, thereby producing crushed stone aggregate of the corresponding shape. In addition, by adjusting various parameters of the ellipse and selecting the number of sides of the polygonal area, polygonal areas of different shapes and sizes can be obtained, and then polygonal aggregates can be obtained to adapt to different types of crushed stone aggregates. This makes the adjustment method of the aggregate more flexible and improves the flexibility and adjustability of obtaining irregular-shaped aggregates.

[0031] (2) Since the vertices of the polygons in this scheme are located on the arc of the ellipse, the polygonal area obtained in this scheme is approximately a convex polygon, which can effectively capture the complex geometric characteristics of the crushed stone aggregate and provide a reasonable basis for subsequent simulation and analysis;

[0032] (3) The method for determining the bonding interface provided by this scheme can obtain the generated aggregate bonding interface by assigning values ​​to the grid. Since the generated interface can reflect the adhesion relationship between aggregate particles and mortar, bonding interfaces of different shapes, sizes and distribution patterns will lead to different material properties, so that the accurate simulation of the bonding interface can lay the foundation for subsequent performance prediction. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 Random distribution diagram of polygonal irregular aggregates of different shapes and sizes.

[0034] Figure 2 Schematic diagram of quadrilateral aggregate.

[0035] Figure 3 Schematic diagram of decagonal aggregate.

[0036] Figure 4 Schematic diagram of tetragonal aggregate.

[0037] Figure 5 It is a single elliptical aggregate particle.

[0038] Figure 6 It is the bonding interface of a single elliptical aggregate particle.

[0039] Figure 7 Schematic diagram of a four-connected region.

[0040] Figure 8 The bonding interface of randomly generated elliptical aggregates of different sizes. DETAILED DESCRIPTION

[0041] The technical solution of the present invention will be clearly and completely described below in conjunction with specific embodiments and drawings.

[0042] A random generation method for two-dimensional irregularly shaped concrete aggregates comprises the following steps:

[0043] S1. Determine the minimum circumscribed ellipse according to the size of the crushed stone aggregate to be generated;

[0044] S2. Randomly select several points on the ellipse as the vertices of the polygon;

[0045] S3. Calculate the area within the ellipse to obtain a randomly generated polygonal area;

[0046] S4. Obtain the bonding interface of the aggregate and determine the distribution of the generated aggregate in the overall structure.

[0047] Furthermore, step S1 includes the following steps:

[0048] S11. Select the coordinates (h, k) of the ellipse center;

[0049] S12, selecting the major semi-axis a and the minor semi-axis b of the ellipse;

[0050] S13, randomly select the tilt angle of the ellipse within (0, 2π);

[0051] S14. The range of the grid area S where the ellipse is located in the x-direction is expressed as: ([ha], [h+a]), and the range in the y-direction is expressed as: ([ka], [k+a]), where the symbol [] indicates rounding up.

[0052] Furthermore, step S2 includes the following steps:

[0053] S21. Taking the center of the ellipse (h, k) as the origin, divide the ellipse into N parts evenly;

[0054] S22. On the arc of each part of the ellipse, randomly select a point as the vertex of the polygon;

[0055] S23. Calculate the equation of the straight line between adjacent vertices y=kx+b.

[0056] Furthermore, step S3 includes the following steps:

[0057] S31. Define a function: f(x,y)=y-kx-b

[0058] S32. Substitute the center of the ellipse (h, k) and the grid coordinates of the grid area S where the ellipse is located into f(x, y);

[0059] S33. Mark the grids in region S with the same sign as f(h, k) as Ai;

[0060] S34. Repeat the above process to obtain multiple regions Ai (i=1:N). The intersection of the regions Ai is the generated polygonal region.

[0061] Furthermore, the specific steps of step S4 are as follows:

[0062] S51, finding the position of the generated aggregate particles;

[0063] S52, judging the grid occupied by each aggregate particle, and assigning a value to the grid according to the presence of aggregate particles in four adjacent grids surrounding the grid;

[0064] S53. When at least one of the four grids adjacent to the grid is not an aggregate particle, the value of the grid is assigned to 1;

[0065] S54. When the values ​​assigned to the four grids adjacent to the grid are all aggregate particles, the value assigned to the grid is 0.

[0066] See also Figure 2-Figure 4 In order to illustrate the method of this solution more specifically, a specific example is shown here: in a 100×100 grid area, the center of the ellipse is set to (50, 50), the major axis is 40 grids, and the minor axis is 20 grids. The three pictures represent the generated quadrilateral, decagonal and tetragonal aggregates respectively. It can be clearly seen from the figure that as the number of sides increases, the final aggregate shape is closer to an ellipse. The generation of quadrilateral aggregate can be used to simulate crushed stone aggregate with poor roundness, while the decagonal aggregate is closer to the shape of pebbles.

[0067] See also Figure 1 , Figure 1 The simulation area is [0, 20] × [0, 20] (unit: cm), which is divided into a grid of 200 × 200. The particles are divided into four levels, and the major semi-axes of the particles are: 1.5-2, 1-1.5, 0.5-1, and 0.2-0.5. The simulation results are: the number of four types of aggregates are 16, 10, 22, and 42, respectively, with a total of 90. The randomly generated irregular aggregates and bonding interfaces are shown in the figure. The edge of the aggregate is the bonding interface. The total area of ​​the aggregate is 112.39, accounting for 28.10% of the total area of ​​the specimen. The total area of ​​the bonding interface is 38.14, accounting for 0.0954 of the total area of ​​the specimen.

[0068] In actual engineering applications, it is often necessary to simulate and analyze the various properties of concrete materials. Accurately modeling irregularly shaped materials like crushed stone aggregate is extremely challenging. The simulation method proposed in this solution can more realistically reflect the shape characteristics of crushed stone aggregate, providing a more accurate basis for subsequent performance simulations. This has important practical significance for a deeper understanding of the role of crushed stone aggregate in concrete and for predicting the various properties of concrete structures. It provides strong support for subsequent concrete material performance simulations and engineering applications. This solution is highly versatile and can adjust parameters according to specific needs to adapt to different types of crushed stone aggregate, providing new ideas and methods for research and practical applications in the field of concrete engineering.

[0069] See also Figure 5-Figure 8 , the gray part is the generated aggregate particles, assigned a value of 1, and the black part is the mortar, assigned a value of 0. In order to obtain the bonding interface of random aggregates, the following steps need to be performed:

[0070] ① Finding the location of aggregate particles: By locating the red part in the image, we can clearly see the distribution of the generated aggregate particles in the overall structure. This lays the foundation for the subsequent generation of the bonding interface.

[0071] ② Determine the grid occupied by each aggregate particle: if the values ​​of the four adjacent grids are all 1, then the value of the grid is 0; conversely, if at least one of the four adjacent grids (i.e., the four-connected region) is not an aggregate particle (value is 0), then the value of the grid is 1. The key to this step is to determine the adhesion state between the aggregate particles and the mortar by judging the neighboring relationship.

[0072] Figure 7 A schematic diagram of a four-connected region is given in . Assume that grid A is an aggregate. If the four adjacent grids BCDE are all aggregates, then grid A is assigned a value of 0, otherwise the value of grid A is 1.

[0073] See also Figure 8 Taking the randomly generated elliptical aggregate bonding interface as an example, the generated interface reflects the adhesion relationship between aggregate particles and mortar. Bonding interfaces of different shapes, sizes and distribution patterns will lead to different material properties. Accurate simulation of the bonding interface lays the foundation for subsequent performance prediction.

[0074] The above embodiments are only preferred embodiments of the present invention. Those skilled in the art can derive other embodiments from the above embodiments without creative work. Therefore, the embodiments in this solution are only one of the implementation methods of this solution. Therefore, this solution protects not only the above embodiments, but also the widest range consistent with the principles and features of the solution of the present invention.

Claims

1. A method for randomly generating two-dimensional irregular-shaped concrete aggregates, characterized in that: The following steps are involved: S1. Determine the minimum circumscribed ellipse according to the size of the crushed stone aggregate to be generated; S2. Randomly select several points on the ellipse as the vertices of the polygon; S3. Calculate the area within the ellipse to obtain a randomly generated polygonal area; S4, obtaining the bonding interface of the randomly generated aggregate and determining the distribution of the generated aggregate in the overall structure; The step S1 includes the following steps: S11. Select the coordinates (h, k) of the ellipse center; S12, selecting the major semi-axis a and the minor semi-axis b of the ellipse; S13, randomly select the tilt angle of the ellipse within (0, 2π); S14. The range of the grid area S where the ellipse is located in the x-direction is expressed as: ([ha], [h+a]), and the range in the y-direction is expressed as: ([ka], [k+a]), where the symbol [] indicates rounding up; The step S2 includes the following steps: S21. Taking the center of the ellipse (h, k) as the origin, divide the ellipse into N parts evenly; S22. In each part of the arc, randomly select a point as the vertex of the polygon; S23, calculating the equation of the line between adjacent vertices y=kx+b; The step S3 includes the following steps: S31. Define a function: f(x,y)=y-kx-b S32. Substitute the center of the ellipse (h, k) and the grid coordinates of the grid area S where the ellipse is located into f(x, y); S33. Mark the grids in region S with the same sign as f(h, k) as Ai; S34, repeat the above process to obtain multiple regions Ai (i=1:N), and the intersection of the regions Ai is the generated polygonal region; The specific steps of step S4 are as follows: S51, finding the position of the generated aggregate particles; S52, judging the grid occupied by each aggregate particle, and assigning a value to the grid according to the presence of aggregate particles in four adjacent grids surrounding the grid; S53. When at least one of the four grids adjacent to the grid is not an aggregate particle, the value of the grid is assigned to 1; S54. When the values ​​assigned to the four grids adjacent to the grid are all aggregate particles, the value assigned to the grid is 0.

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