Simulation optimization method and system for equivalent billet based on solidification path of large-size casting

Abstract

The application belongs to the technical field of die casting performance prediction, and relates to an equivalent billet simulation optimization method and system based on a large-size casting solidification path, specifically by analyzing key structural features of a large one-piece die casting, designing an equivalent solidification path simulation billet structure of an ultra-long size, making the metal liquid filling distance consistent with the key structure filling path of the large-size casting; and combining a mold flow analysis method, realizing high-precision simulation of the equivalent billet under the condition that the die casting pressure and other production process parameters are completely consistent with the actual production process parameters of the die casting, and optimizing the equivalent billet model through analysis of the simulation results; and then verifying the performance of the equivalent billet of the die casting based on a tensile test, optimizing the equivalent billet model and its processing technology by using the tensile test results, so that the mechanical property deviation of the equivalent billet from the actual large-size casting is controlled within a preset condition. The application solves the problems of large performance prediction error, high sampling cost and long processing technology optimization cycle of large-size castings.

Description

Technical Field

[0001] The present application belongs to the technical field of die casting performance prediction, and more specifically, relates to an equivalent sheet simulation optimization method and system based on the solidification path of large-scale castings. Background Art

[0002] Aluminum alloy one-piece die-castings are widely used in the automotive, aerospace, and other fields due to their lightweight, high strength, and efficient molding. With the increasing demand for large, complex structural parts in industrial manufacturing, die-casting parts are gradually moving towards integrated, larger sizes. In existing technologies, the injection distance of die-casting flat molds is generally short (usually no more than 2 meters), resulting in excessive temperature gradients in the molten metal during the filling process (the temperature difference can reach over 40°C at a flow distance of 2 meters). This leads to significant variations in grain size, precipitate distribution, and porosity along the flow direction of the molded sheet. This poor material uniformity directly affects the yield strength, tensile strength, and elongation during the subsequent FDS (Fused Deformed Screw) joining process. Measured mechanical property deviations often exceed 15%, and hardness fluctuations range as high as ±10HV, making it difficult to meet the design requirements for high-reliability connections. Furthermore, existing die-casting flat molds make it difficult to perform one-piece die-casting of complex structures (such as ribs, bosses, curved thin walls, etc.). Traditional blank design can only simulate simple geometric features and cannot reproduce the stress concentration areas or hot spots caused by structural mutations in actual castings. As a result, the test results of FDS and SPR (self-piercing riveting process) based on small-sized blanks cannot truly reflect the overall performance of large castings, and cannot accurately predict the risk of connection failure of large castings under complex stress, such as edge cracking, rivet cracking, and rivet penetration.

[0003] Conventional casting performance testing uses small-sized blanks to replace actual parts. However, there are significant differences in solidification paths, stress distribution, and other characteristics between small-sized blanks and large, one-piece die-castings (such as large-sized castings with a molten metal flow distance exceeding 2m). This makes it difficult for performance data to guide the design of connection processes and quality control in actual production. In addition, large-sized die-castings have complex structures and high sample preparation costs, making it difficult to prepare tensile specimens according to standard size requirements. Traditional experimental methods have difficulty reflecting true performance. Traditional mold flow analysis lacks accuracy when simulating ultra-long-distance filling (such as a filling distance exceeding 3m), making it difficult to reproduce key characteristics such as the temperature field and defect distribution in actual production. As a result, the simulation results are of limited guidance for process optimization. Summary of the Invention

[0004] In response to the defects of the existing technology, the purpose of this application is to provide an equivalent sheet simulation optimization method and system based on the solidification path of large-size castings, aiming to solve the problem that traditional casting sheet design methods and performance analysis methods cannot accurately reflect the overall true performance of large castings.

[0005] To achieve the above objectives, in a first aspect, the present application provides an equivalent sheet simulation optimization method based on the solidification path of a large-scale casting, comprising:

[0006] S1: Simulate the filling path of the molten metal according to the three-dimensional model of the target large-scale casting to obtain a blank model of the equivalent solidification path, wherein the filling path is multiple continuous S-shaped, and the blank model includes the key structure of the three-dimensional model and a preset shrinkage defect area; design a die-casting mold model based on the blank model, and design a conformal cooling water channel model according to the die-casting mold model;

[0007] S2 performs mold flow analysis using the blank model, the die-casting mold model, and the conformal cooling water channel model to obtain mold flow analysis results;

[0008] S3: based on the shrinkage defect area and the mold flow analysis result, determining whether the blank model satisfies a first preset condition; if so, die-casting an equivalent blank according to the blank model; if not, optimizing the blank model and repeating steps S2 to S3 until the blank model satisfies the first preset condition, die-casting an equivalent blank according to the optimized blank model;

[0009] S4: sampling the equivalent sheet according to the position of the key structure and performing a tensile test;

[0010] S5 determines whether the equivalent sheet satisfies the second preset condition based on the tensile test results and the actual performance of the corresponding position on the target large-size casting: if so, the process ends; if not, the sheet model is optimized and steps S2 to S5 are repeated until the optimized equivalent sheet satisfies the second preset condition.

[0011] Furthermore, in step S1, the change rate of the flow channel cross section of the filling path is not greater than 10%; and the wall thickness of the filling flow channel end of the sheet model gradually becomes thicker along the flow direction of the molten metal.

[0012] Furthermore, the parting surface of the die-casting mold model is perpendicular to the tablet filling path; and the gate of the die-casting mold model is a direct gate.

[0013] Furthermore, the conformal cooling water channel model includes multiple layers of conformal annular water channels arranged in a stacked manner.

[0014] Furthermore, the first preset condition is that the error between the solidification time difference at both ends of the sheet model and the actual solidification time difference at both ends of the target large-size casting is no more than 5%, the overlap error between the shrinkage defect area and the actual shrinkage area at the corresponding position of the target large-size casting is no more than 5%, and the error between the runner end temperature of the die-casting mold model and the actual runner end temperature of the target large-size casting is no more than 5%.

[0015] Furthermore, the key structure includes a bending structure, a reinforcing rib structure, a boss structure and a filling channel end structure.

[0016] Furthermore, the second preset condition is that the error between the tensile test results of all samples at each key structure and the performance parameters of the corresponding positions on the target large-size casting is no more than 5%.

[0017] In a second aspect, the present application further provides an equivalent sheet simulation optimization system based on the solidification path of a target large-size casting, for implementing the equivalent sheet simulation optimization method as described above, the equivalent sheet simulation optimization system comprising:

[0018] A model building module is used to build a three-dimensional model of a target large-scale casting; is also used to simulate the filling path of the molten metal based on the three-dimensional model to obtain a sheet model of an equivalent solidification path; is also used to design a die-casting mold model based on the sheet model, and to design a conformal cooling water channel model according to the die-casting mold model; and is also used to optimize the sheet model;

[0019] a mold flow analysis module, configured to perform mold flow analysis using the blank model, the die-casting mold model, and the conformal cooling water channel model to obtain mold flow analysis results; and further configured to re-perform mold flow analysis on the optimized blank model;

[0020] a mold flow analysis result verification module, configured to determine whether the blank model or the optimized blank model satisfies a first preset condition by using the shrinkage defect area and the mold flow analysis result;

[0021] a blank die-casting module, configured to die-cast an equivalent blank according to a blank model that meets a first preset condition;

[0022] A tensile testing module, used to take samples from equivalent sheets obtained by die casting according to the positions of the key structures and perform tensile testing;

[0023] The tensile test result verification module determines whether the performance error between the tensile test result and the corresponding position on the target large-size casting meets the second preset condition.

[0024] It can be understood that the beneficial effects of the second aspect mentioned above can be found in the relevant description of the first aspect mentioned above, and will not be repeated here.

[0025] In general, the above technical solutions conceived by this application have the following beneficial effects compared with the existing technologies:

[0026] (1) The complete technical chain of casting structure simulation design method, ultra-long-distance filling model design, mold flow analysis and verification, and in-situ sampling and stretching method provided in this application solves the problems of large performance prediction errors of large-sized castings, high sampling costs, and long processing technology optimization cycles in the existing technology, thereby improving the development efficiency of large-sized one-piece die castings and the quality stability of large-sized one-piece die castings.

[0027] (2) This application obtains the complex structural features of an actual large die-casting through a three-dimensional model, and constructs a simulation sheet model according to a continuous S-shaped filling path that can truly restore the equivalent filling and solidification characteristics of the large die-casting. This solves the problem of poor material uniformity and mechanical property fluctuations caused by insufficient injection distance of the die-casting flat mold in the prior art (usually <2m), breaks through the limitation that traditional sheets cannot reflect complex structural features, provides a reliable basis for the performance prediction of die-casting parts, and significantly improves the consistency of mechanical properties in the FDS connection area.

[0028] (3) This application effectively solves the problem that existing technologies are difficult to quantitatively predict the performance gradient of large castings by performing high-simulation mold flow analysis on simulated casting pieces with innovative designs and long filling distances (at least greater than 3m). It can restore the temperature and defect distribution at the end of the casting and ensure that there is a basis for optimizing process parameters.

[0029] (4) This application can directly obtain tensile and connection test specimens that meet the standard size of GB / T 228.1 by sampling from key parts of the equivalent sheet. Compared with sampling from production castings, tensile and connection specimens can be directly cut from key features such as the body, reinforcement, and boss of the equivalent sheet, eliminating the time of splitting the original casting, reducing overall working hours, significantly improving inspection efficiency, reducing sample preparation costs, and ensuring stable test sample performance, which can ensure the representativeness and effectiveness of the test results. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is one of the flow diagrams of the equivalent sheet simulation optimization method based on the solidification path of a large-size casting provided in an embodiment of the present application;

[0031] Figure 2 This is a schematic diagram of the equivalent sheet model structure provided in the embodiment of the present application;

[0032] Figure 3 This is a schematic diagram of the left side view of the equivalent sheet model structure provided in an embodiment of the present application;

[0033] Figure 4 This is a schematic diagram of the front side view of the equivalent sheet model structure provided in an embodiment of the present application;

[0034] Figure 5 This is a schematic diagram of the rear end side view of the equivalent sheet model structure provided in an embodiment of the present application;

[0035] Figure 6 It is a schematic diagram of the three-dimensional structure of the equivalent sheet model provided in the embodiment of the present application.

[0036] Throughout the drawings, the same reference numerals are used to denote the same elements or structures, wherein:

[0037] 1-sheet body, 2-bending section, 3-boss structure, 4-reinforcement rib, 5-shrinkage defect area, 6-filling channel end. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0039] The term "and / or" as used herein describes an association between related objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A exists alone, A and B exist simultaneously, or B exists alone. The symbol " / " as used herein indicates that the related objects are in an "or" relationship, for example, A / B means either A or B.

[0040] The terms "first" and "second" in this specification and claims are used to distinguish different objects rather than to describe a specific order of objects. For example, "first response message" and "second response message" are used to distinguish different response messages rather than to describe a specific order of response messages.

[0041] In the embodiments of this application, words such as "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of this application should not be interpreted as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0042] In the description of the embodiments of the present application, unless otherwise specified, "multiple" means two or more, for example, multiple processing units means two or more processing units, etc.; multiple elements means two or more elements, etc.

[0043] This application provides an equivalent sheet simulation optimization method based on the solidification path of large-scale castings, specifically for large-scale castings with a die-casting flat die with an injection-filling distance exceeding 2 meters. This equivalent sheet simulation optimization method places no particular restrictions on the composition of the materials used in die-casting production. The following describes the embodiments of this application using an integrated die-cast rear floor panel as an example, in conjunction with the accompanying drawings.

[0044] This embodiment provides an equivalent sheet simulation optimization method based on the solidification path of a large-scale casting, such as Figure 1 As shown, it mainly includes the following steps:

[0045] S1 simulates the filling path of the molten metal according to the 3D model of the target large-scale casting to obtain a blank model of the equivalent solidification path. The filling path is multiple continuous S-shaped. The blank model includes the key structures of the 3D model and the preset shrinkage defect area. The die-casting mold model is designed based on the blank model, and the conformal cooling water channel model is designed according to the die-casting mold model. The aforementioned key structures include the bending structure, the reinforcing rib structure, the boss structure and the filling channel end structure.

[0046] S2 uses the blank model, die-casting mold model and conformal cooling water channel model to perform mold flow analysis and obtain mold flow analysis results;

[0047] S3 determines whether the blank model meets the first preset condition based on the shrinkage defect area and the mold flow analysis results: if so, die-cast an equivalent blank according to the blank model; if not, optimize the blank model and repeat steps S2 to S3 until the blank model meets the first preset condition, and die-cast an equivalent blank according to the optimized blank model;

[0048] S4 takes samples from equivalent sheets according to the locations of critical structures and performs tensile tests;

[0049] S5 determines whether the equivalent sheet meets the second preset condition based on the tensile test results and the actual performance of the corresponding position on the target large-size casting: if it does, the process ends; if it does not, the sheet model is optimized and steps S2 to S5 are repeated until the optimized equivalent sheet meets the second preset condition.

[0050] The target large-size casting of this embodiment is an integrated die-casting of the rear floor of an automobile. The die-casting adopts cast magnesium alloy AZ91D as a production material, and its alloy composition is as follows in percentage by mass: 9% Al, 1% Zn, 0.15% Mn, and the balance is Mg.

[0051] The aforementioned step S1 specifically includes the following steps:

[0052] Structural feature extraction and analysis of the integrated die-casting part of the rear floor of the S101 automobile

[0053] First, a high-precision 3D scanner (such as ATOS Q, with an accuracy of 0.05mm) is used to scan a large-scale casting (an integrated die-cast part of the rear floor of the car) to obtain its point cloud data.

[0054] The CAD 3D model was then reconstructed using reverse modeling software (such as Geomagic Design X) and key structural features were extracted. Specifically, these key features included: two 90°±5° bends in the curved structure; a 5mm transition fillet radius (R); 10 ribs with a thickness of 2.5±0.2mm, a spacing of 150mm between adjacent ribs; a 100mm-long and 30mm-high boss protruding from the large-scale casting, located in the middle of the large-scale casting; and a wall thickness of 3mm at its thinnest point and 8mm at its thickest point.

[0055] Based on experience and mold flow analysis preview, high-risk areas at the end of the runner where air holes and shrinkage are likely to occur are marked in the CAD model.

[0056] S102 simulates and designs the blank model according to the CAD model

[0057] According to the CAD model data of large-scale castings, the filling path of molten metal is simulated to obtain Figures 2-5 The equivalent solidification path of the blank model is shown. Figure 3 This is a schematic diagram of its left side view. Figure 4 and Figure 5 They are the upper side view and the lower side view respectively, as shown in Figure 6 As shown in the figure, the curved section in the filling path is a 90° bend; the change rate of the flow channel cross-section of the filling path is no more than 10%. The change rate of the flow channel cross-section of the filling path is the degree of change of the flow channel cross-section area along the flow direction of the fluid (such as molten metal or polymer melt) during the filling process. Its core function is to control flow stability and avoid defects. The change rate of the flow channel cross-section of the filling path is a key parameter for balancing flow efficiency and defect control. It needs to be dynamically adjusted in combination with material properties (such as viscosity and shrinkage) and process goals (such as filling speed); the wall thickness of the filling flow channel end of the sheet model gradually becomes thicker.

[0058] Specifically, a continuous S-shaped filling path is used to simulate the ultra-long distance filling path of the molten metal (the total length of the filling path in this embodiment exceeds 3.2m). The obtained sheet model also contains all the key structures of the three-dimensional model, such as Figure 6 As shown: the bending section 2 reproduces a 90° bend and ensures that the change rate of the flow channel cross section is ≤10%; the reinforcing rib 4 is replicated at a 1:1 ratio; a thickness gradient zone is set at the end 6 of the filling flow channel, with the thickness gradually increasing from 2.5mm to 3.0mm; and a boss structure 3 identical to the three-dimensional model is set in the middle of the sheet model.

[0059] In addition, after the metal liquid is filled, air will be discharged to the end of the flow channel, so the end of the flow channel has the most air content and the most defects, so the pre-set shrinkage defect area at the end of the flow channel can best represent the characteristics of the high-risk area of the large-size casting. Specifically, a shrinkage defect area 5 with a diameter of 40 mm and a depth of 10 mm is set at the distal end of the strip model (about 2.8 m away from the gate position) for subsequent verification of the accuracy of the mold flow analysis.

[0060] S103 Pre-setting sampling points for subsequent tensile test on the strip model

[0061] Eleven sampling points are pre-set on the strip model, that is, sampling is taken at key structures such as bending structure, reinforcing rib structure, boss structure, and filling flow channel end structure. The sampling positions include: the strip body area 3, the reinforcing rib structure 4, the boss area 2 (i.e. the boss structure), the filling flow channel end 1, the bending structure 1, the sampling positions correspond to the key structure positions on the large-size casting, and the subsequent cutting sampling cuts the test sample according to the pre-set eleven sampling points.

[0062] S104 Designing the die casting mold model based on the strip model

[0063] The die casting mold model is designed based on the strip model. When designing, it is necessary to ensure that the parting surface is perpendicular to the strip filling path, the gate is located at the starting end of the strip, and the direct gate is used to match the metal liquid flow direction.

[0064] S105 Designing the conformal water cooling system according to the die casting mold model

[0065] A multi-layer conformal water cooling system is designed, which is formed by stacking four groups of annular water channels with a diameter of 12 mm. The conformal water cooling system can ensure that the temperature difference of each part of the mold is less than 5℃, and the conformal water cooling system focuses on strengthening the cooling of the distal end of the strip.

[0066] Through the above steps, the strip model, the die casting mold model, and the conformal cooling water channel model are designed.

[0067] In step S2, the strip model, the die casting mold model, and the conformal cooling water channel model designed in step S1 are used for mold flow analysis.

[0068] Specifically, mold flow analysis software (such as Flow 3D Cast 2023) is used for mold flow analysis. The process parameters during mold flow analysis are the same as the actual production process parameters of the die casting equipment and the large-size casting.

[0069] Specifically, the die-casting machine model selected was J1120H (clamping force 1200T). The pouring speed was set to 0.1 m / s for the first 0.1 seconds, switching to 2.5 m / s at 0.11 seconds, and then pouring at 2.5 m / s until the mold was filled. The die-casting pressure was 70 MPa, and the holding time was 15 seconds.

[0070] The material of the die-casting mold is H13 steel, whose thermal conductivity is 30W / (m·K). The temperature of the die-casting mold is 200±10℃, the pouring temperature is set to 630℃, and the metal liquid used for filling and pouring is magnesium alloy AZ91D.

[0071] The four groups of annular water channels of the conformal cooling water channel model are simulated. The water channel pipe diameter is 12 mm, the flow rate is 2 L / min, the inlet temperature of the cooling water is 25 °C, and the turbulence model adopts the VOF+RNG k-ε model.

[0072] In step S3, the first preset condition is that the error between the solidification time difference at both ends of the sheet model and the actual solidification time difference at both ends of the large-size casting is no more than 5%, the overlap error between the preset shrinkage defect area and the actual shrinkage area at the corresponding position of the large-size casting is no more than 5%, and the error between the runner end temperature of the die-casting mold model and the actual runner end temperature of the target large-size casting is no more than 5%.

[0073] Specifically, by comparing the mold flow analysis results with the actual performance test data of large-scale castings, die-casting molds and other physical objects, the following conclusions were obtained: the runner end temperature in the mold flow analysis results was 590±5℃, and the error compared with the actual thermocouple measured data of the large-scale casting was ≤3%. The solidification time difference at both ends of the sheet model along the filling direction was ≤8s, and the error between the solidification time difference at both ends of the large-scale casting was less than 5%. The sheet model met the design requirements and did not need to be re-optimized. The overlap between the preset shrinkage defect area and the shrinkage defect area on the large-scale casting detected by X-ray was ≥90%.

[0074] Based on the above data comparison results, it is necessary to optimize the die-casting mold model, specifically its gate size, so that the gate size is adjusted from a diameter of 30 mm to a diameter of 35 mm to reduce air entrapment defects, so that the overlap error between the preset shrinkage defect area and the actual shrinkage defect area on the large-size casting is no more than 5%, and the temperature difference at both ends of the sheet model along the filling direction is ≤10°C, and the solidification time difference is ≤5s; the injection speed also needs to be optimized to adjust the shrinkage defect area.

[0075] According to the aforementioned blank model and the optimized die-casting mold model, equivalent blanks are produced by die casting.

[0076] In step S4, tensile specimens are cut from the actual equivalent sheet at pre-set sampling locations. The specimens conform to the GB / T 228.1-2021 standard, with a gauge length of 50 mm, a width of 12.5 mm, and a thickness of 3 mm. Specimens for the equivalent sheet body area are taken from the front and rear sections of the sheet body 1 along the filling direction, corresponding to the rear floor mounting bracket area. Rib specimens are taken from the thickness gradient area at the end of the filling channel, corresponding to the rear floor longitudinal beam reinforcement structure. Boss specimens are taken from the edge of boss structure 3 in the middle of the equivalent sheet, corresponding to the rear floor assembly hole area. Specimens at the end of the channel are taken near the simulated shrinkage defect area 5, corresponding to the edge of the rear floor. Bend specimens are taken from the middle area of ​​the front section of the equivalent sheet filling channel, corresponding to the height variation area at the front section of the rear floor.

[0077] Specifically, such as Figure 6 As shown, samples were taken from three locations on the blank body 1: four samples each on the left and right sides of the front section (near the gate) of the blank body 1, and four samples from the rear section (away from the gate). Samples were taken from four locations on the rib 4: one sample each from two locations in the middle section, and two samples from each transition area on either side of the rib 4. Samples were taken from two locations on the boss structure 3: one sample each from the left and right sides, and one sample from each transition area on either side of the boss structure 3. One sample was taken at the end of the filling channel, for a total of four samples. One sample was taken from the curved section 2 of the blank, for a total of four samples. This yielded a total of 34 tensile specimens, all of which corresponded to key structural features of large-scale castings.

[0078] In step S5, the second preset condition is that the error between the tensile test results of all samples at each key structure and the performance parameters of the corresponding position on the large-scale casting is no more than 5%.

[0079] Specifically, an MTS universal testing machine was used to perform tensile tests on all samples taken from the equivalent sheet, and the loading rate was set to 1 mm / min. An HV5 hardness tester was used to detect the hardness distribution at different positions of the sheet. The tensile test showed that: the average yield strength of all samples of the sheet body 1 was 265 MPa, and the elongation was 6.1%; the average yield strength of all samples at the rib 4 was 285 MPa, and the elongation was 4.9%; the average yield strength of all samples at the boss structure 3 was 272 MPa, and the elongation was 4.2%; the average yield strength of all samples at the filling channel end 6 was 253 MPa, and the elongation was 3.1%; the average yield strength of all samples at the bending section 2 was 258 MPa, and the elongation was 4.7%.

[0080] All tensile specimens obtained from the areas on the large-size casting corresponding to the above-mentioned equivalent sheets were subjected to tensile tests under the same conditions as the above-mentioned tensile tests. The performance parameters obtained from the tests were as follows: the average yield strength of the specimens in the casting body area was 258 MPa, and the elongation was 5.8%; the average yield strength of all specimens in the rib area was 280 MPa, and the elongation was 4.5%; the average yield strength of all specimens in the boss area was 270 MPa, and the elongation was 3.8%; the average yield strength of all specimens at the end of the filling channel was 245 MPa, and the elongation was 2.6%; the average yield strength of all specimens in the bending section was 258 MPa, and the elongation was 4.7%.

[0081] Specimens from the body area, taken at the preset locations of the equivalent sheet, were subjected to the same FDS connections as those used at the original rear floor panel. FDS connection testing demonstrated that the joint strength was ≥85% of the body strength. Comparing the tensile test results, the performance of the equivalent sheet with that of the corresponding locations on the large-scale casting was within 5%, meeting engineering design requirements.

[0082] Through this application, it is possible to quantitatively evaluate the performance gradient and connection failure risk of large die castings during the design phase, provide data support for process optimization, and effectively solve the bottlenecks of existing technologies in performance prediction and quality control. By analyzing the complex structural characteristics of large-scale castings and constructing a simulation sheet model of an equivalent solidification path, the performance distribution of the castings can be accurately restored, solving the problem that traditional sheets cannot reflect actual performance differences; using an S-shaped structure to innovatively design a simulation sheet with a filling distance of more than 3 meters, combined with mold flow analysis to accurately predict the temperature gradient and defects at the end of the filling channel, and quantify the performance gradient distribution of large castings; pre-set sampling areas at key locations of the simulation sheet to directly obtain test samples that meet the standards, reduce sample preparation costs and improve test representativeness; quantitatively evaluate the impact of process parameters through high-simulation mold flow analysis, achieve "simulation-design-verification" closed-loop optimization, and break through the limitations of existing experience-based process design.

[0083] The equivalent sheet simulation optimization system provided in the present application is described below. The equivalent sheet simulation optimization system described below and the equivalent sheet simulation optimization method described above can be referenced to each other.

[0084] This embodiment provides an equivalent blank simulation optimization system based on the solidification path of a large-scale casting, which is used to implement the equivalent blank simulation optimization method as described above. The equivalent blank simulation optimization system includes:

[0085] The model building module is used to construct a 3D model of a large-scale casting. It is also used to simulate the filling path of the molten metal based on the 3D model to obtain a blank model of the equivalent solidification path. The filling path is a continuous S-shape, and the blank model includes the key structures of the 3D model and a preset shrinkage defect area. It is also used to design a die-casting mold model based on the blank model and a conformal cooling water channel model according to the die-casting mold model. It is also used to optimize the blank model.

[0086] The mold flow analysis module is used to perform mold flow analysis using the blank model, die-casting mold model, and conformal cooling water channel model to obtain mold flow analysis results; it is also used to re-perform mold flow analysis on the optimized blank model;

[0087] A mold flow analysis result verification module is used to determine whether the blank model or the optimized blank model meets the first preset condition by using the shrinkage defect area and the mold flow analysis result;

[0088] a blank die-casting module, configured to die-cast an equivalent blank according to a blank model that meets a first preset condition;

[0089] Tensile test module, used to take samples from equivalent sheets obtained by die casting according to the location of key structures and perform tensile tests;

[0090] The tensile test result verification module determines whether the performance error between the tensile test result and the corresponding position on the large-size casting meets the second preset condition.

[0091] It is understandable that the detailed functional implementation of each of the above units / modules can be found in the introduction of the aforementioned method embodiment, and will not be repeated here.

[0092] It should be understood that the above-mentioned device is used to execute the method in the above-mentioned embodiment. The implementation principle and technical effect of the corresponding program module in the device are similar to those described in the above-mentioned method. The working process of the device can refer to the corresponding process in the above-mentioned method and will not be repeated here.

[0093] The method steps in the embodiments of the present application can be implemented by hardware or by a processor executing software instructions. The software instructions can be composed of corresponding software modules, which can be stored in random access memory (RAM), flash memory, read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), registers, hard disks, mobile hard disks, CD-ROMs, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor so that the processor can read information from the storage medium and write information to the storage medium. Of course, the storage medium can also be an integral part of the processor. The processor and storage medium can be located in an ASIC.

[0094] The above embodiments can be implemented in whole or in part using software, hardware, firmware, or any combination thereof. When implemented using software, they can be implemented in whole or in part in the form of a computer program product. The computer program product comprises one or more computer instructions. When loaded and executed on a computer, the computer program instructions fully or partially produce the processes or functions described in the embodiments of this application. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted via the computer-readable storage medium. The computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium accessible by a computer or a data storage device such as a server or data center that integrates one or more available media. The available medium can be magnetic media (e.g., floppy disk, hard disk, tape), optical media (e.g., DVD), or semiconductor media (e.g., solid-state drive (SSD)).

[0095] It will be understood that the various numerical numbers involved in the embodiments of the present application are merely distinctions for the convenience of description and are not intended to limit the scope of the embodiments of the present application.

[0096] It is easy for those skilled in the art to understand that the above is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the scope of protection of the present application.

[0097] In addition, in the embodiments of the present application, the mathematical concepts mentioned include symmetry, equality, parallelism, and perpendicularity. These limitations are all for the current state of the art, rather than being absolutely strict definitions in a mathematical sense. A small amount of deviation is allowed, and it is possible to be approximately symmetric, approximately equal, approximately parallel, or approximately perpendicular. For example, A and B are parallel, which means that A and B are parallel or approximately parallel, and the angle between A and B can be between 0 and 10 degrees. A and B are perpendicular, which means that A and B are perpendicular or approximately perpendicular, and the angle between A and B can be between 80 and 100 degrees.

[0098] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. An equivalent sheet simulation optimization method based on the solidification path of large-scale castings, characterized in that: include: S1 simulates the filling path of the molten metal according to the three-dimensional model of the target large-scale casting to obtain a sheet model of the equivalent solidification path, wherein the filling path is a plurality of continuous S-shaped shapes, and the sheet model includes the key structure of the three-dimensional model and a preset shrinkage defect area; Designing a die-casting mold model based on the blank model, and designing a conformal cooling water channel model according to the die-casting mold model; S2 performs mold flow analysis using the blank model, the die-casting mold model, and the conformal cooling water channel model to obtain mold flow analysis results; S3 determines whether the blank model satisfies a first preset condition based on the shrinkage defect area and the mold flow analysis result: if so, die-casting an equivalent blank according to the blank model; if not, optimizing the blank model and repeating steps S2 to S3 until the blank model satisfies the first preset condition, and die-casting an equivalent blank according to the optimized blank model; the first preset condition is that the error between the solidification time difference at both ends of the blank model and the actual solidification time difference at both ends of the target large-scale casting is no more than 5%, the overlap error between the shrinkage defect area and the actual shrinkage area at the corresponding position of the target large-scale casting is no more than 5%, and the error between the runner end temperature of the die-casting mold model and the actual runner end temperature of the target large-scale casting is no more than 5%. S4: sampling the equivalent sheet according to the position of the key structure and performing a tensile test; S5 determines whether the equivalent sheet satisfies a second preset condition based on the tensile test results and the actual performance of the corresponding position on the target large-size casting: if so, the optimization is terminated; if not, the sheet model is optimized, and steps S2 to S5 are repeated until the optimized equivalent sheet satisfies the second preset condition; the second preset condition is that the error between the tensile test results of all samples at each key structure and the performance parameters of the corresponding position on the target large-size casting is no more than 5%.

2. The equivalent sheet simulation optimization method according to claim 1, wherein: In step S1, the change rate of the cross-sectional area of ​​the flow channel of the filling path is not greater than 10%; and the wall thickness of the filling flow channel end of the sheet model gradually becomes thicker along the flow direction of the molten metal.

3. The equivalent sheet simulation optimization method according to claim 1, wherein: In step S1, the parting surface of the die-casting mold model is perpendicular to the blank filling path; and the gate of the die-casting mold model is a direct gate.

4. The equivalent sheet simulation optimization method according to claim 1, wherein: In step S1, the conformal cooling water channel model includes multiple layers of conformal annular water channels stacked together.

5. The equivalent sheet simulation optimization method according to claim 1, wherein: In step S1, the key structures include a bending structure, a reinforcing rib structure, a boss structure and a filling channel end structure.

6. An equivalent sheet simulation optimization system for implementing the equivalent sheet simulation optimization method according to any one of claims 1 to 5, characterized in that: include: Model building module, used to build a three-dimensional model of the target large-scale casting; It is also used to simulate the filling path of the molten metal based on the three-dimensional model to obtain a sheet model of the equivalent solidification path; it is also used to design a die-casting mold model based on the sheet model, and design a conformal cooling water channel model according to the die-casting mold model; and it is also used to optimize the sheet model; a mold flow analysis module, configured to perform mold flow analysis using the blank model, the die-casting mold model, and the conformal cooling water channel model to obtain mold flow analysis results; and further configured to re-perform mold flow analysis on the optimized blank model; a mold flow analysis result verification module, configured to determine whether the blank model or the optimized blank model satisfies a first preset condition by using the shrinkage defect area and the mold flow analysis result; a blank die-casting module, configured to die-cast an equivalent blank according to a blank model that meets a first preset condition; A tensile testing module, used to take samples from equivalent sheets obtained by die casting according to the positions of the key structures and perform tensile testing; The tensile test result verification module determines whether the performance error between the tensile test result and the corresponding position on the target large-size casting meets the second preset condition.

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