High-volume-fraction fiber spatial distribution method and system for carbon fiber resin-based composite material

Abstract

The invention discloses a high-volume-fraction fiber spatial distribution method and system for a carbon fiber resin-based composite material. The method comprises the following steps: S1, acquiring a plurality of fiber coordinate points and fiber radiuses falling in a specified generation area; s2, determining a fiber center coordinate according to the fiber coordinate point and the fiber radius; s3, judging whether the fiber coordinate point falls into a dead zone or not, and if so, repositioning the single fiber; s4, judging whether a target fiber volume fraction is reached in the specified area or not, if not, continuing to place the fibers, executing S5, and if the target fiber volume fraction is reached, executing S6; s5, the spatial positions of the multiple fibers with the determined coordinate information in the designated area are repositioned; and S6, after the target fiber volume fraction is reached, generating a corresponding image to check whether the position relationship among the fibers meets the non-overlapping geometric constraint or not, and if not, carrying out secondary relocation on the fibers in the specified area.

Description

Technical Field

[0001] The present invention belongs to the field of resin-based composite materials, including carbon fiber, glass fiber and other special fiber resin-based composite materials, and specifically relates to a method and system for spatial distribution of high volume fraction fibers in carbon fiber resin-based composite materials. Background Art

[0002] The hierarchical structure of fiber-reinforced composites (FRCs) makes them ideal candidates for multiscale analysis. It is well known that their mechanical properties at the millimeter scale are determined by the compositional properties and spatial distribution of the reinforcing fibers, whose dimensions are on the micrometer scale. One of the most effective strategies is a bottom-up multiscale approach, which aims to predict the mechanical behavior of materials starting from the component material scale (fiber, matrix, and interface), that is, from the microscopic (component) to the mesoscopic (single layer) to the macroscopic (component) scale. This approach enables virtual testing of composites from microscopic components to macroscopic components within the finite element framework. Fiber spatial distribution is the core geometric modeling foundation for accurately predicting the mechanical properties of composites. To achieve this goal, numerous fiber spatial distribution algorithms have been developed, such as those based on pattern recognition, spatial descriptions based on statistical information, and random distribution algorithms. However, the maximum fiber volume fraction that these algorithms can generate is only 60%. For aerospace-grade CFRP, the fiber volume fraction is typically between 55% and 65%, while for braided or woven composites, the fiber volume fraction within the yarn is generally between 55% and 75%. Therefore, it is very important to study an algorithm that can generate fiber spatial distribution with high volume fraction. Summary of the Invention

[0003] In order to solve the technical problem that high volume fraction fiber spatial distribution cannot be generated in the existing technology, the present invention provides a method and system for high volume fraction fiber spatial distribution of carbon fiber resin-based composite materials. Its purpose is to provide a mathematical and physical basis for multi-scale virtual simulation of aviation-grade carbon fiber resin-based composite materials. Without losing the statistical distribution information of the fiber, the fiber volume fraction generated by this method based on the specified area is as high as 78%.

[0004] To achieve the above object, the present invention provides the following solutions:

[0005] A method for spatially distributing high volume fraction fibers in a carbon fiber resin-based composite material, the method comprising:

[0006] S1: Obtain several fiber coordinate points and fiber radius falling within the specified generation area;

[0007] S2: Determine the fiber center coordinates based on the fiber coordinate points and fiber radius;

[0008] S3: According to the fiber center coordinates, determine whether the fiber coordinate point falls into the dead zone area. If it falls into the dead zone area, reposition the single fiber;

[0009] S4: If the fiber does not fall into the dead zone, determine whether the target fiber volume fraction is reached in the designated area. If not, continue placing fibers and proceed to S5. If the target fiber volume fraction is reached, proceed to S6.

[0010] S5: relocating the spatial positions of multiple fibers with determined coordinate information within the designated area;

[0011] S6: After reaching the target fiber volume fraction, a corresponding image is generated to check whether the positional relationship between the fibers satisfies the non-overlapping geometric constraint. If not, the fibers in the specified area are repositioned a second time.

[0012] Preferably, said S2 includes:

[0013] The shape of the designated area is set to a square representative volume element, namely RVE, the area is set to dL×dL, and the fiber radius is r f , the minimum safety distance is d, and the center coordinate of the fiber is (x i ,y i );

[0014] If x i ≤r f +d, that is, close to the left boundary, then x i Adjusted to (dL-(r f +d));

[0015] If x i ≥dL-(r f +d), that is, close to the right boundary, then x i Adjust to r f +d;

[0016] If y i ≤r f +d, that is, close to the upper boundary, then y i Adjusted to (dL-(r f +d));

[0017] If y i ≥dL-(r f +d), that is, close to the lower boundary, then y i Adjust to r f +d;

[0018] Where dL is the side length of the square RVE.

[0019] Preferably, the S3 includes:

[0020] First calculate the direction of the offset, usually up, down, left or right.

[0021] Each time the offset is performed, a step size is set according to actual needs. After the offset is completed, check whether the fiber coordinate point is within the dead zone;

[0022] If the fiber coordinate point is no longer within the dead zone, the offset adjustment is successful and the repositioning process ends;

[0023] If the fiber coordinate point is still located in the dead zone, the offset is continued until the fiber coordinate point is no longer in the dead zone.

[0024] Preferably, the S5 includes:

[0025] Select the fiber to be relocated, calculate the free area near the current position, and generate multiple new position candidate points;

[0026] Determine whether the new position is within the target area and whether it overlaps with other fibers;

[0027] If a candidate position meets the preset requirements, the fiber is moved to the new position;

[0028] If all candidate locations do not meet the preset requirements, new locations are iterated until a point that meets the preset requirements is found or the maximum number of iterations is reached.

[0029] Preferably, the S6 includes:

[0030] After reaching the target fiber volume fraction, the coordinate and radius data of each fiber are extracted and imported into the finite element analysis software, namely FEA;

[0031] Draw the corresponding fiber positions and shapes within the RVE area in the sketch;

[0032] Based on the generated sketch, build an RVE shell model;

[0033] Using the detection tools provided by FEA, a test is run to verify whether the positional relationship between the fibers meets the geometric constraint of non-overlapping. If not, the fibers are repositioned again in the specified area.

[0034] The present invention also provides a carbon fiber resin matrix composite material high volume fraction fiber spatial distribution system, the system is used to implement the above method, the system includes: an acquisition module, a determination module, a first judgment module, a second judgment module, a first repositioning module, a second repositioning module;

[0035] The acquisition module is used to acquire a number of fiber coordinate points and fiber radius falling within a specified generation area;

[0036] The determination module is used to determine the fiber center coordinates based on the fiber coordinate points and the fiber radius;

[0037] The first judgment module is used to judge whether the fiber coordinate point falls into the dead zone area according to the fiber center coordinate, and if it falls into the dead zone area, reposition the single fiber;

[0038] The second judgment module is used to judge whether the target fiber volume fraction is reached in the specified area if the fiber does not fall into the dead zone area. If the fiber volume fraction is not reached, continue to place the fiber and perform the first repositioning module. If the target fiber volume fraction is reached, perform the second repositioning module;

[0039] The first repositioning module is used to reposition the spatial positions of multiple fibers with determined coordinate information within a specified area;

[0040] The second repositioning module is used to generate a corresponding image to check whether the positional relationship between fibers meets the non-overlapping geometric constraint after reaching the target fiber volume fraction. If not, the fibers in the specified area are repositioned a second time.

[0041] Preferably, the determining module includes: a setting unit, a first adjusting unit, a second adjusting unit, a third adjusting unit, and a fourth adjusting unit;

[0042] The setting unit is used to set the representative volume unit RVE of the specified area to be a square, the area is set to dL×dL, and the fiber radius is r f , the minimum safety distance is d, and the center coordinate of the fiber is (x i ,y i );

[0043] The first adjustment unit is used to adjust the i ≤r f +d, that is, close to the left boundary, then x i Adjusted to (dL-(r f +d));

[0044] The second adjustment unit is used for i ≥dL-(r f +d), that is, close to the right boundary, then x i Adjust to r f +d;

[0045] The third adjustment unit is used for i ≤r f +d, that is, close to the upper boundary, then y i Adjusted to (dL-(r f +d));

[0046] The fourth adjustment unit is used for i ≥dL-(r f +d), that is, close to the lower boundary, then y i Adjust to r f +d;

[0047] Where dL is the side length of the square RVE.

[0048] Preferably, the first judgment module includes: a first calculation unit, a first checking unit, a third judgment unit, and a fourth judgment unit;

[0049] The first calculation unit is used to first calculate the direction of the offset, usually selecting the up, down, left or right direction for offset;

[0050] The first checking unit is used to shift a step size set according to actual needs each time, and after the shift is completed, check whether the fiber coordinate point is located in the dead zone;

[0051] The third judgment unit is configured to determine that if the fiber coordinate point is no longer within the dead zone, the offset adjustment is successful and the repositioning process ends;

[0052] The fourth judgment unit is configured to continue shifting if the fiber coordinate point is still located in the dead zone until the fiber coordinate point is no longer located in the dead zone.

[0053] Preferably, the first relocation module includes: a second calculation unit, a second checking unit, a fifth judgment unit, and a sixth judgment unit;

[0054] The second calculation unit is used to select the fiber to be relocated, calculate the free area near the current position, and generate a plurality of new position candidate points;

[0055] The second inspection unit is used to determine whether the new position is within the target area and whether it overlaps with other fibers;

[0056] The fifth judgment unit is configured to move the fiber to a new position if a candidate position meets a preset requirement;

[0057] The sixth judgment unit is configured to iterate new positions if all candidate positions do not meet the preset requirements until a point meeting the preset requirements is found or the maximum number of iterations is reached.

[0058] Preferably, the second relocation module includes: an extraction unit, a drawing unit, a construction unit, and a verification unit;

[0059] The extraction unit is used to extract the coordinate and radius data of each fiber after reaching the target fiber volume fraction, and import them into the finite element analysis software (FEA);

[0060] The drawing unit is used to draw the corresponding fiber position and shape in the RVE area in the sketch;

[0061] The construction unit is used to construct an RVE shell model according to the generated sketch;

[0062] The verification unit is used to run a test using the detection tool provided by FEA to verify whether the positional relationship between the fibers meets the non-overlapping geometric constraint. If not, the fibers are repositioned twice within a specified area.

[0063] Compared with the prior art, the present invention has the following beneficial effects:

[0064] This paper proposes a method and system for high-volume-fraction fiber spatial distribution in carbon fiber resin-based composites. This method comprehensively considers multiple factors, including fiber diameter, fiber geometry, and statistical distribution patterns, to achieve optimal fiber spatial distribution at high volume fractions. This method effectively addresses the difficulty of existing fiber volume fraction algorithms in achieving reasonable fiber spatial distribution at high volume fractions. It provides a critical geometric modeling foundation for accurately predicting the mechanical properties of composite materials. Without compromising fiber statistical distribution information, this method can generate fiber volume fractions as high as 78% within a specified region. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] In order to more clearly illustrate the technical solution of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0066] Figure 1 The fibers of the embodiment of the present invention are close to the left and right boundaries of the designated area;

[0067] Figure 2 The fiber of the embodiment of the present invention is close to the corner point of the designated area;

[0068] Figure 3 The deadzone area of ​​the fiber distribution in the embodiment of the present invention;

[0069] Figure 4 The spatial distribution of fibers of different sizes according to the embodiment of the present invention;

[0070] Figure 5 The RVE shell model constructed by the finite element software in the embodiment of the present invention;

[0071] Figure 6 The spatial distribution of high volume fraction fibers in the RVE according to an embodiment of the present invention;

[0072] Figure 7 This is a logic flow chart of the high volume fraction fiber spatial distribution algorithm according to an embodiment of the present invention;

[0073] Figure 8 The RVE spatial distribution arrangement of the embodiment of the present invention with a fiber volume fraction of 75%;

[0074] Figure 9 Figure 3 shows the spatial distribution of high volume fraction fibers in the RVE under the traditional algorithm; (a) is 52.6%, and (b) is 60.6%. DETAILED DESCRIPTION

[0075] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0076] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0077] Example 1

[0078] An embodiment of the present invention provides a method for spatially distributing fibers with a high volume fraction in a carbon fiber resin-based composite material. Without losing statistical fiber distribution information, the algorithm generates a fiber volume fraction of up to 78% based on a specified area. The method includes:

[0079] S1: Obtain several fiber coordinate points and fiber radius falling within the specified generation area;

[0080] S2: Determine the fiber center coordinates based on the fiber coordinate points and fiber radius;

[0081] S3: According to the fiber center coordinates, determine whether the fiber coordinate point falls into the dead zone area. If it falls into the dead zone area, reposition the single fiber;

[0082] S4: If the fiber does not fall into the dead zone, determine whether the target fiber volume fraction is reached in the designated area. If not, continue placing fibers and proceed to S5. If the target fiber volume fraction is reached, proceed to S6.

[0083] S5: relocating the spatial positions of multiple fibers with determined coordinate information within the designated area;

[0084] S6: After reaching the target fiber volume fraction, a corresponding image is generated to check whether the positional relationship between the fibers satisfies the non-overlapping geometric constraint. If not, the fibers in the specified area are repositioned a second time.

[0085] The detailed implementation steps are as follows:

[0086] 1. According to the microscopic geometric statistical information of the actual composite material, such as the fiber volume fraction V f , fiber number N f and the fiber radius r f Based on the above parameters, the size of the RVE model can be determined by the following formula. Figure 1 As shown, the shape of the specified area is set to a square RVE, and the side length of the area is set to dL.

[0087]

[0088] The range of the RVE region can be set to: 0≤x≤dL; 0≤y≤dL. In order to simulate the distribution of fibers in this region, the fiber coordinate points are generated based on the pseudo-random number generator: x i =rand()×dL;y i = rand() × dL, where rand() represents a random number generated in the range [0,1]. The coordinates of the generated point: 0≤x i ≤dL;0≤y i ≤dL, ensure that the center coordinate point (x i ,y i ) is located within the specified generation area; when each fiber is placed in the specified area, the difference in its diameter is controlled by statistical parameters such as the mean and standard deviation.

[0089] During the curing process, carbon fiber resin-based composites are squeezed by internal fibers due to factors such as temperature and pressure. This results in varying fiber diameters within the final composite. Therefore, accounting for these differences in fiber diameters can improve the realism and accuracy of the model.

[0090] The fiber radius is derived from the microscopic geometric statistics of the actual composite material.

[0091] 2. Combined fiber radius r f And the center coordinate information (x i ,y i) to determine whether the two randomly generated fibers overlap; if they do not overlap, the fiber is checked to see if it is close to the boundary of the specified area. If so, the fiber center coordinates must be determined at the opposite boundary of the specified area. By setting the minimum safety distance to d, the fiber position can be optimized in the following ways to ensure a reasonable distribution and avoid being too close to the boundary:

[0092] If x i ≤r f +d, that is, close to the left boundary, then x i Adjusted to (dL-(r f +d));

[0093] If x i ≥dL-(r f +d), that is, close to the right boundary, then x i Adjust to r f +d;

[0094] If y i ≤r f +d, that is, close to the upper boundary, then y i Adjusted to (dL-(r f +d));

[0095] If y i ≥dL-(r f +d), that is, close to the lower boundary, then y i Adjust to r f +d.

[0096] Where dL is the side length of the square RVE.

[0097] If the fiber is located at any corner point of the specified boundary, the coordinates of the fiber center at the other three corner points must be determined, such as Figure 2 The purpose is to achieve periodic boundary conditions in the RVE model, ensuring geometric symmetry and mechanical consistency. This effectively avoids boundary effects and ensures that the microscopic behavior of the composite accurately represents the overall structure. If a fiber is not near the boundary of a designated region or any corner of the region, the center coordinate is recorded.

[0098] 3. Determine whether the fiber coordinate point falls into the dead zone area. If it falls into the area, perform the repositioning operation of the single fiber, such as Figure 3As shown. First calculate the direction of the offset, usually up, down, left or right. Each offset is a small step (such as 10% of the fiber radius or a value set according to actual needs). After the offset is completed, check whether the fiber coordinate point is within the dead zone. If the fiber coordinate point is no longer within the dead zone, the offset adjustment is successful and the repositioning process is completed. If the fiber coordinate point is still within the dead zone, continue to offset until the fiber coordinate point is no longer within the dead zone.

[0099] 4. Determine whether the preset fiber volume fraction has been reached. If not, continue placing fibers. If there is no more space for fiber placement within the designated area and the target fiber volume fraction has not yet been reached, proceed to step 5. If the target fiber volume fraction has been reached, proceed to step 6.

[0100] 5. Relocate the spatial positions of multiple fibers with determined coordinate information within the specified area, such as Figure 4 As shown. Select the fiber to be relocated, based on the coordinates and radius of the current fiber, by calculating the distance between each fiber and the surrounding fibers, if the distance between two fibers is greater than the sum of their radii, there is a vacant area near the current position, and multiple new position candidate points can be generated. Determine whether the new position is within the target area and whether it overlaps with other fibers. If a candidate position is valid, move the fiber to the new position. If all candidate positions are not feasible, iterate the new position until a suitable point is found or the maximum number of iterations is reached. It should be noted here that fibers located at the boundaries and corners of the specified area do not participate in the relocation. If multiple fibers in the specified area are relocated for 30 iterations and there is still no extra space to place new fibers, delete all recorded fiber coordinate information in the specified area and repeat steps 1 to 4.

[0101] After reaching the target fiber volume fraction, the coordinates and radius data of each fiber are extracted and imported into the finite element analysis (FEA) software. The corresponding fiber positions and shapes within the RVE area are drawn in the sketch. Based on the generated sketch, the RVE shell model is constructed, as shown in the following example. Figure 5 As shown. The RVE shell model has a square shape with a side length of dL, and the geometric range of the model is: Ω RVE =[0,dL]×[0,dL]. In the model, each fiber can be represented as: Where i = 1, 2, ..., N represents the i-th fiber; (x, y) is an arbitrary point, and whether it is within the range of the i-th fiber is determined. For finite element analysis, the RVE area will be divided into several small finite element units, and the dimensions of each unit are set to Δx and Δy. The entire area can be represented by several units: where Ω jis the jth unit, and M is the total number of units. Through the detection tool provided by the FEA software, a test is run to verify whether the positional relationship between the fibers meets the geometric constraint of non-overlapping. If not, the fibers are repositioned twice in the specified area. The positions of the fibers with overlapping marks are randomly adjusted within a small range until all fibers are ensured to no longer overlap. Thus, the spatial distribution of high volume fraction fibers in the RVE area is achieved, such as Figure 6 shown.

[0102] Example 2

[0103] In this embodiment, the carbon fiber resin-based composite material is T700 / EH301, which specifically includes the following contents:

[0104] 1. An optical microscope was used to observe the unidirectional T700 / EH301 composite material (16 layers) with a thickness of 3 mm and a size of 15 mm × 10 mm. The diameter distribution of 3000 carbon fibers was statistically analyzed using ImageJ open source image analysis software. The fiber diameter in the sample was found to be 6.78 μm, the standard deviation was 0.184, and the fiber volume content was 0.75.

[0105] 2. Based on the multi-scale virtual simulation characteristics, the shape of the designated area is set to square RVE, and the area is set to dL×dL, which can be obtained by the fiber volume fraction V f The function of dL is used to find dL.

[0106]

[0107] 3. Generate fiber coordinate points (x i ,y i ) so that the coordinate point lies within the RVE area. If the fiber is near a boundary, the fiber center coordinates must be determined at the opposite RVE boundary. If the fiber is located at any corner of the RVE boundary, the fiber center coordinates must be determined at the other three corner locations. If the fiber is neither near the RVE boundary nor at any RVE corner, record the coordinates.

[0108] 4. Determine whether the fiber coordinate point falls into the deadzone area. If it falls into the area, reposition the fiber.

[0109] 5. Determine whether the preset fiber volume fraction V is reached f , if the fiber volume fraction V is not reached f , then continue to place fibers. If there is no extra space for fiber placement in the RVE area and the target fiber volume fraction V is still not reached f , then continue to generate random fiber center positions and continue to place fibers. If the target fiber volume fraction is reached, then check for overlap.

[0110] 6. Reposition the multiple fibers with confirmed coordinates within the RVE region to increase the volume fraction of the fibers within the RVE region. If, after 30 iterations of repositioning multiple fibers within the RVE region, no space is left for new fibers, delete all recorded fiber coordinates within the RVE region and repeat steps 2-6.

[0111] 7. To explain the above algorithm framework more clearly and intuitively, Figure 7 The logic flow chart of the fiber space distribution algorithm is given. Based on the fact that the present invention proposes a fiber space distribution algorithm for high volume fraction of carbon fiber resin matrix composite materials, this example gives the fiber space distribution arrangement in RVE with a final fiber volume fraction of 75%, see Figure 8 .

[0112] Compared with the spatial distribution of fibers in RVE under traditional algorithms, Figure 9 As shown, the fiber volume fractions achieved by traditional algorithms are relatively small. This paper proposes an algorithm for high-volume-fraction fiber spatial distribution in carbon fiber resin-based composites. This algorithm comprehensively considers multiple factors, including fiber diameter, fiber geometry, and statistical distribution patterns, to achieve optimal fiber spatial distribution at high volume fractions. This method effectively addresses the difficulty of existing fiber volume fraction algorithms in achieving reasonable fiber spatial distribution at high volume fractions, providing a critical geometric modeling foundation for accurately predicting the mechanical properties of composite materials.

[0113] Example 3

[0114] An embodiment of the present invention provides a high volume fraction fiber spatial distribution system for carbon fiber resin-based composite materials, the system being used to implement the method of embodiment 1, the system comprising: an acquisition module, a determination module, a first judgment module, a second judgment module, a first repositioning module, and a second repositioning module;

[0115] An acquisition module is used to obtain a number of fiber coordinate points and fiber radiuses falling within a specified generation area;

[0116] A determination module is used to determine the fiber center coordinates based on the fiber coordinate points and the fiber radius;

[0117] The first judgment module is used to judge whether the fiber coordinate point falls into the dead zone area according to the fiber center coordinate, and if it falls into the dead zone area, reposition the single fiber;

[0118] The second judgment module is used to judge whether the target fiber volume fraction is reached in the designated area if the fiber does not fall into the dead zone area. If the fiber volume fraction is not reached, the fiber is placed and the first repositioning module is performed. If the target fiber volume fraction is reached, the second repositioning module is performed.

[0119] A first repositioning module is used to reposition the spatial positions of multiple fibers with determined coordinate information within a specified area;

[0120] The second repositioning module is used to generate corresponding images to check whether the positional relationship between fibers meets the non-overlapping geometric constraint after reaching the target fiber volume fraction. If not, the fibers in the specified area are repositioned twice.

[0121] In this embodiment, the determination module includes: a setting unit, a first adjustment unit, a second adjustment unit, a third adjustment unit, and a fourth adjustment unit;

[0122] Set the unit to set the representative volume unit (RVE) of the specified area to a square shape. The area is set to dL×dL, and the fiber radius is r. f , the minimum safety distance is d, and the center coordinate of the fiber is (x i ,y i );

[0123] The first adjustment unit is used if x i ≤r f +d, that is, close to the left boundary, then x i Adjusted to (dL-(r f +d));

[0124] The second adjustment unit is used if x i ≥dL-(r f +d), that is, close to the right boundary, then x i Adjust to r f +d;

[0125] The third adjustment unit is used if y i ≤r f +d, that is, close to the upper boundary, then y i Adjusted to (dL-(r f +d));

[0126] The fourth adjustment unit is used for i ≥dL-(r f +d), that is, close to the lower boundary, then y i Adjust to r f +d;

[0127] Where dL is the side length of the square RVE.

[0128] In this embodiment, the first judgment module includes: a first calculation unit, a first checking unit, a third judgment unit, and a fourth judgment unit;

[0129] The first calculation unit is used to calculate the direction of the offset, usually selecting the up, down, left or right direction for offset;

[0130] The first checking unit is used to offset a step size set according to actual needs each time, and after the offset is completed, check whether the fiber coordinate point is within the dead zone;

[0131] A third judgment unit is used to determine that if the fiber coordinate point is no longer located in the dead zone, the offset adjustment is successful and the repositioning process ends;

[0132] The fourth judgment unit is configured to continue shifting if the fiber coordinate point is still located in the dead zone until the fiber coordinate point is no longer in the dead zone.

[0133] In this embodiment, the first relocation module includes: a second calculation unit, a second checking unit, a fifth judgment unit, and a sixth judgment unit;

[0134] a second calculation unit, configured to select a fiber to be relocated, calculate a free area near a current position, and generate a plurality of new position candidate points;

[0135] a second checking unit for determining whether the new position is within the target area and whether it overlaps with other fibers;

[0136] a fifth judgment unit, configured to move the fiber to a new position if a candidate position meets a preset requirement;

[0137] The sixth judgment unit is configured to iterate new positions if all candidate positions do not meet the preset requirements until a point meeting the preset requirements is found or the maximum number of iterations is reached.

[0138] In this embodiment, the second relocation module includes: an extraction unit, a drawing unit, a construction unit, and a verification unit;

[0139] The extraction unit is used to extract the coordinate and radius data of each fiber after the target fiber volume fraction is achieved, and import them into the finite element analysis software (FEA);

[0140] A drawing unit, used to draw the corresponding fiber position and shape in the RVE area in the sketch;

[0141] A construction unit, used to construct an RVE shell model based on the generated sketch;

[0142] The verification unit is used to run a test using the detection tools provided by FEA to verify whether the positional relationship between fibers meets the non-overlapping geometric constraint. If not, the fibers are repositioned again within the specified area.

[0143] The embodiments described above are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by persons skilled in the art should fall within the scope of protection defined by the claims of the present invention.

Claims

1. A method for spatial distribution of high volume fraction fibers in carbon fiber resin-based composite materials, characterized in that: The method comprises: S1: Obtain several fiber coordinate points and fiber radius falling within the specified generation area; S2: Determine the fiber center coordinates based on the fiber coordinate points and fiber radius; S3: According to the fiber center coordinates, determine whether the fiber coordinate point falls into the dead zone area. If it falls into the dead zone area, reposition the single fiber; S4: If the fiber does not fall into the dead zone, determine whether the target fiber volume fraction is reached in the designated area. If not, continue placing fibers and proceed to S5. If the target fiber volume fraction is reached, proceed to S6. S5: relocating the spatial positions of multiple fibers with determined coordinate information within the designated area; S6: After reaching the target fiber volume fraction, a corresponding image is generated to check whether the positional relationship between the fibers satisfies the non-overlapping geometric constraint. If not, the fibers in the specified area are repositioned a second time.

2. The method according to claim 1, characterized in that Said S2 comprises: The shape of the designated area is set to a square representative volume element, namely RVE, the area is set to dL×dL, and the fiber radius is r f , the minimum safety distance is d, and the center coordinate of the fiber is (x i ,y i ); If x i ≤r f +d, that is, close to the left boundary, then x i Adjusted to (dL-(r f +d)); If x i ≥dL-(r f +d), that is, close to the right boundary, then x i Adjust to r f +d; If y i ≤r f +d, that is, close to the upper boundary, then y i Adjusted to (dL-(r f +d)); If y i ≥dL-(r f +d), that is, close to the lower boundary, then y i Adjust to r f +d; Where dL is the side length of the square RVE.

3. The method according to claim 1, characterized in that Said S3 comprises: First calculate the direction of the offset, usually up, down, left or right. Each time the offset is performed, a step size is set according to actual needs. After the offset is completed, check whether the fiber coordinate point is within the dead zone; If the fiber coordinate point is no longer within the dead zone, the offset adjustment is successful and the repositioning process ends; If the fiber coordinate point is still located in the dead zone, the offset is continued until the fiber coordinate point is no longer in the dead zone.

4. The method according to claim 1, wherein Said S5 comprises: Select the fiber to be relocated, calculate the free area near the current position, and generate multiple new position candidate points; Determine whether the new position is within the target area and whether it overlaps with other fibers; If a candidate position meets the preset requirements, the fiber is moved to the new position; If all candidate locations do not meet the preset requirements, new locations are iterated until a point that meets the preset requirements is found or the maximum number of iterations is reached.

5. The method according to claim 2, characterized in that Said S6 comprises: After reaching the target fiber volume fraction, the coordinate and radius data of each fiber are extracted and imported into the finite element analysis software, namely FEA; Draw the corresponding fiber positions and shapes within the RVE area in the sketch; Based on the generated sketch, build an RVE shell model; Using the detection tools provided by FEA, a test is run to verify whether the positional relationship between the fibers meets the geometric constraint of non-overlapping. If not, the fibers are repositioned again in the specified area.

6. A high volume fraction fiber spatial distribution system for carbon fiber resin-based composite materials, the system being used to implement the method according to any one of claims 1 to 5, characterized in that: The system includes: an acquisition module, a determination module, a first judgment module, a second judgment module, a first relocation module, and a second relocation module; The acquisition module is used to acquire a number of fiber coordinate points and fiber radius falling within a specified generation area; The determination module is used to determine the fiber center coordinates based on the fiber coordinate points and the fiber radius; The first judgment module is used to judge whether the fiber coordinate point falls into the dead zone area according to the fiber center coordinate, and if it falls into the dead zone area, reposition the single fiber; The second judgment module is used to judge whether the target fiber volume fraction is reached in the specified area if the fiber does not fall into the dead zone area. If the fiber volume fraction is not reached, continue to place the fiber and perform the first repositioning module. If the target fiber volume fraction is reached, perform the second repositioning module; The first repositioning module is used to reposition the spatial positions of multiple fibers with determined coordinate information within a specified area; The second repositioning module is used to generate a corresponding image to check whether the positional relationship between fibers meets the non-overlapping geometric constraint after reaching the target fiber volume fraction. If not, the fibers in the specified area are repositioned a second time.

7. The system according to claim 6, characterized in that The determining module includes: a setting unit, a first adjusting unit, a second adjusting unit, a third adjusting unit, and a fourth adjusting unit; The setting unit is used to set the representative volume unit RVE of the specified area to be a square, the area is set to dL×dL, and the fiber radius is r f , the minimum safety distance is d, and the center coordinate of the fiber is (x i ,y i ); The first adjustment unit is used to adjust the i ≤r f +d, that is, close to the left boundary, then x i Adjusted to (dL-(r f +d)); The second adjustment unit is used for i ≥dL-(r f +d), that is, close to the right boundary, then x i Adjust to r f +d; The third adjustment unit is used for i ≤r f +d, that is, close to the upper boundary, then y i Adjusted to (dL-(r f +d)); The fourth adjustment unit is used for i ≥dL-(r f +d), that is, close to the lower boundary, then y i Adjust to r f +d; Where dL is the side length of the square RVE.

8. The system according to claim 6, wherein: The first judgment module includes: a first calculation unit, a first checking unit, a third judgment unit, and a fourth judgment unit; The first calculation unit is used to first calculate the direction of the offset, usually selecting the up, down, left or right direction for offset; The first checking unit is used to shift a step size set according to actual needs each time, and after the shift is completed, check whether the fiber coordinate point is located in the dead zone; The third judgment unit is configured to determine that if the fiber coordinate point is no longer within the dead zone, the offset adjustment is successful and the repositioning process ends; The fourth judgment unit is configured to continue shifting if the fiber coordinate point is still located in the dead zone until the fiber coordinate point is no longer located in the dead zone.

9. The system according to claim 6, wherein: The first relocation module includes: a second calculation unit, a second checking unit, a fifth judgment unit, and a sixth judgment unit; The second calculation unit is used to select the fiber to be relocated, calculate the free area near the current position, and generate a plurality of new position candidate points; The second inspection unit is used to determine whether the new position is within the target area and whether it overlaps with other fibers; The fifth judgment unit is configured to move the fiber to a new position if a candidate position meets a preset requirement; The sixth judgment unit is configured to iterate new positions if all candidate positions do not meet the preset requirements until a point meeting the preset requirements is found or the maximum number of iterations is reached.

10. The system according to claim 7, wherein: The second relocation module includes: an extraction unit, a drawing unit, a construction unit, and a verification unit; The extraction unit is used to extract the coordinate and radius data of each fiber after reaching the target fiber volume fraction, and import them into the finite element analysis software (FEA); The drawing unit is used to draw the corresponding fiber position and shape in the RVE area in the sketch; The construction unit is used to construct an RVE shell model according to the generated sketch; The verification unit is used to run a test using the detection tool provided by FEA to verify whether the positional relationship between the fibers meets the non-overlapping geometric constraint. If not, the fibers are repositioned twice within a specified area.

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