Thin-wall cover plate design method and system based on topology simulation

Abstract

The invention belongs to the technical field of controller design, and provides a thin-wall cover plate design method and system based on topology simulation, and the method comprises the steps: constructing a topology simulation model which comprises a super-unit model and a thin-wall cover plate model, carrying out the continuous optimization through simulation solving, obtaining a structural density cloud chart of the thin-wall cover plate model, and obtaining a structural density cloud chart of the thin-wall cover plate model; modeling is conducted again through the density cloud atlas, verification is conducted, and finally a design model meeting the requirements is obtained. According to the method, a traditional empirical design method is changed, vibration and noise reduction topological optimization is conducted on the thin-walled parts such as the cover plate through simulation design, the optimal positions of the reinforcing ribs on the surface of the thin-walled plate and height and width distribution of the reinforcing ribs are obtained, structural design is conducted according to the topological optimization result, the design period of the thin-walled plate is shortened, and the design efficiency is improved. The lightweight design is realized, and the structural vibration response and noise radiation characteristics are reduced at the same time.

Description

Technical Field

[0001] The present invention belongs to the technical field of controller design, and in particular relates to a thin-wall cover plate design method and system based on topological simulation. Background Art

[0002] The noise of the electric drive system mainly comes from the electromagnetic noise caused by electromagnetic excitation and the howling caused by gear shaft excitation. The structure of the controller cover is a thin-walled plate with a large area, and its structural stiffness and low-order modal frequency are low. Under the action of the noise excitation source, it is easy to resonate at its first-order drum modal frequency to amplify the radiation noise of the electric drive to the external environment.

[0003] At present, thin-walled cover plates are designed based on experience. In order to meet the modal frequency avoidance requirements of thin-walled cover plates, dense radial or ring-shaped stiffeners are designed on the inner and outer surfaces of thin-walled cover plates to improve the structural stiffness and thus the natural frequency. However, the current empirical design method makes it difficult for thin-walled cover plate structures to meet the design requirements at one time. The solution needs to be iterated many times, and the design cycle is long. The optimal layout of the stiffeners cannot be identified, resulting in insufficient local stiffness performance or redundant weight of the thin-walled cover plates. At present, thin-walled cover plates mostly use modal as the design evaluation standard, and cannot control the vibration response and noise radiation performance of the cover plates. Summary of the invention

[0004] In view of the problems in the background technology, the present invention proposes a thin-walled cover plate design method and system based on topological simulation.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A thin-walled cover plate design method based on topological simulation includes the following steps:

[0007] Construct topological simulation models, including super-element models and thin-walled cover plate models;

[0008] Set the excitation source of the super unit model;

[0009] Set constraints and optimization objectives for the thin-walled cover model;

[0010] Cycle steps: Based on the constraints, the thin-walled cover plate model is simulated and solved through the excitation source to determine whether the simulation solution meets the optimization goal. If not, the constraints are adjusted and the simulation solution is performed again until the result meets the optimization goal;

[0011] After the optimization target is met, the structural density cloud map of the thin-walled cover plate model is obtained;

[0012] Reconstruct the thin-wall cover plate model based on the structural density cloud map, perform equivalent radiation power simulation, obtain the simulated equivalent radiation power curve, and obtain the equivalent radiation power curve of the existing empirical design;

[0013] Determine whether the reconstructed thin-walled cover plate model meets the constraints of the last adjustment and whether the value of the equivalent radiation power curve is lower than the value of the equivalent radiation power curve of the existing empirical design. If both are yes, the reconstructed thin-walled cover plate model will be used as the final design model. Otherwise, modify the constraints and return to the loop step.

[0014] Furthermore, constructing a topology simulation model includes the following steps:

[0015] Construct thin-walled cover plate model;

[0016] Build a motor model;

[0017] Construct a gearbox model that is transmission-connected to the motor model;

[0018] Construct a controller housing model located on the surface of the motor model and connected to the thin-walled cover model;

[0019] The motor model, gearbox model and controller housing model are condensed into a super unit model.

[0020] Further, setting the excitation source of the super unit model includes the following steps:

[0021] The central nodes are coupled out in the stator tooth surface of the motor model and the bearing chamber of the gearbox model respectively, and the unconstrained substructure interface degree of freedom set is established based on the central nodes;

[0022] Electromagnetic excitation is set as the first excitation source and applied to the unconstrained substructure interface degree of freedom set corresponding to the stator tooth surface of the motor model;

[0023] The gear shaft excitation is set as the second excitation source and applied to the unconstrained substructure interface degree of freedom set corresponding to the bearing chamber of the gearbox model.

[0024] Furthermore, setting the constraint conditions of the thin-walled cover plate model includes the following steps:

[0025] Set the optimization target, set the thin-walled cover plate model as the equivalent sound radiation power response output component, and set the equivalent sound radiation power value to the minimum peak value in the full frequency range;

[0026] Set the first constraint condition to set the first-order drum mode frequency of the thin-walled cover model to ≥700Hz;

[0027] The second constraint condition is set to set the volume percentage of the design area of ​​the thin-walled cover plate model to ≤0.35, and the design area is located inside the non-design area, and the non-design area is the area where the thin-walled cover plate model is connected to the controller housing model.

[0028] Furthermore, the thin-walled cover plate model is simulated and solved by the excitation source to determine whether the simulation solution results meet the optimization goal. If not, the constraint conditions are adjusted and the simulation solution is performed again until the result meets the optimization goal, including the following steps:

[0029] Applying gear shaft excitation to the bearing chamber of the gearbox model, and applying electromagnetic excitation to the stator tooth surface of the motor model;

[0030] Obtain the equivalent acoustic radiation power of the thin-walled cover model under the influence of gear excitation and electromagnetic excitation;

[0031] Determine whether the equivalent sound radiation power meets the optimization target. If not, adjust the constraints and test again until the equivalent sound radiation power meets the optimization target.

[0032] Furthermore, after the optimization target is met, a structural density cloud map of the thin-walled cover plate model is obtained, including the following steps:

[0033] Set the cell density threshold for the thin-walled cover model;

[0034] The part of the design area that is larger than the unit density threshold is retained, and the rest is removed to obtain the structural density cloud map of the thin-walled cover model.

[0035] A thin-wall cover design system based on topological simulation, comprising:

[0036] Building units, used to build topological simulation models, including super unit models and thin-walled cover plate models;

[0037] An excitation unit, used to set the excitation source of the super unit model;

[0038] Setting unit, used to set the constraint conditions and optimization objectives of the thin-walled cover model;

[0039] The test unit is used to simulate and solve the thin-walled cover plate model through the excitation source based on the constraint conditions, and determine whether the simulation solution results meet the optimization target. If not, the constraint conditions are adjusted and the simulation solution is performed again until the result meets the optimization target;

[0040] An analysis unit, used to obtain a structural density cloud map of the thin-walled cover plate model after the optimization target is met;

[0041] A data unit is used to reconstruct a thin-walled cover plate model based on a structural density cloud map, perform equivalent radiation power simulation, obtain a simulated equivalent radiation power curve, and obtain an equivalent radiation power curve of an existing empirical design;

[0042] The output unit is used to determine whether the reconstructed thin-walled cover plate model meets the constraints of the last adjustment and whether the value of the equivalent radiation power curve is lower than the value of the equivalent radiation power curve of the existing empirical design. If both are yes, the reconstructed thin-walled cover plate model will be used as the final design model. Otherwise, the constraints will be modified and returned to the test unit.

[0043] Furthermore, the construction unit is used to:

[0044] Construct thin-walled cover plate model;

[0045] Build a motor model;

[0046] Construct a gearbox model that is transmission-connected to the motor model;

[0047] Construct a controller housing model located on the surface of the motor model and connected to the thin-walled cover model;

[0048] The motor model, gearbox model and controller housing model are condensed into a super unit model.

[0049] Furthermore, the excitation unit comprises:

[0050] A coupling module is used to couple central nodes in the stator tooth surface of the motor model and the bearing chamber of the gearbox model, and establish an unconstrained substructure interface degree of freedom set based on the central node;

[0051] A first excitation module is used to determine electromagnetic excitation as a first excitation source, which is applied to an unconstrained substructure interface degree of freedom set corresponding to a stator tooth surface of the motor model;

[0052] The second excitation module is used to determine the gear shaft excitation as the second excitation source, which is applied to the unconstrained substructure interface degree of freedom set corresponding to the bearing chamber of the gearbox model.

[0053] Furthermore, the setting unit is used to:

[0054] Set the optimization target, set the thin-walled cover plate model as the equivalent sound radiation power response output component, and set the equivalent sound radiation power value to the minimum peak value in the full frequency range;

[0055] Set the first constraint condition to set the first-order drum mode frequency of the thin-walled cover model to ≥700Hz;

[0056] The second constraint condition is set to set the volume percentage of the design area of ​​the thin-walled cover plate model to ≤0.35, and the design area is located inside the non-design area, and the non-design area is the area where the thin-walled cover plate model is connected to the controller housing model.

[0057] Furthermore, the testing unit comprises:

[0058] A test module, used for applying gear shaft excitation to the bearing chamber of the gearbox model, and applying electromagnetic excitation to the stator tooth surface of the motor model;

[0059] An acquisition module is used to obtain the equivalent acoustic radiation power of the thin-walled cover plate model under the influence of gear excitation and electromagnetic excitation;

[0060] The judgment module is used to judge whether the equivalent sound radiation power meets the optimization target. If not, the constraint conditions are adjusted and tested again until the equivalent sound radiation power meets the optimization target.

[0061] Furthermore, the analysis unit comprises:

[0062] The setting module is used to set the cell density threshold of the thin-walled cover model;

[0063] The analysis module is used to retain the part of the design area that is larger than the unit density threshold and remove the rest to obtain the structural density cloud map of the thin-walled cover model.

[0064] Beneficial effects of the present invention:

[0065] 1. The method of the present invention constructs a topological simulation model, then sets an excitation source of the topological simulation model, and sets constraints. Then, the thin-walled cover plate model is tested according to the excitation source and the constraints until a thin-walled cover plate model that meets the requirements is obtained. Finally, a density cloud map of the thin-walled cover plate model is obtained, stiffeners are set, and test analysis is performed. This process changes the traditional empirical design method, and uses simulation design to perform topological optimization of vibration and noise reduction on thin-walled parts such as cover plates, obtains the optimal position of the stiffeners on the surface of the thin-walled plate, and the height and width distribution of the stiffeners. Structural design is performed according to the topological optimization results, shortening the design cycle of thin-walled plates, achieving lightweight design while reducing structural vibration response and noise radiation characteristics.

[0066] 2. The present invention controls the weight of the optimal cover solution of this scheme by directly constraining the first-order drum modal frequency of the thin-walled cover plate model and indirectly constraining and optimizing the volume percentage of the thin-walled cover plate model, minimizing the vibration response of the cover plate in the entire frequency band, reducing the radiation noise ability of the cover plate under the action of electromagnetic excitation force and gear shaft excitation force, and weakening the external radiation noise of the cover plate, thereby optimizing the noise, vibration and acoustic roughness performance of the electric drive system.

[0067] Other features and advantages of the present invention will be described in the following description, and partly become obvious from the description, or be understood by implementing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures pointed out in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0069] Figure 1 A flow chart of a thin-walled cover plate design method based on topological simulation of the present invention is shown;

[0070] Figure 2 A super unit simulation model diagram of the present invention is shown;

[0071] Figure 3 The schematic diagram of the structure of the thin-walled cover plate model is shown;

[0072] Figure 4 The structural density cloud diagram of the thin-walled cover plate model is shown;

[0073] Figure 5 A schematic diagram of the rib distribution of the thin-walled cover plate model is shown;

[0074] Figure 6 A comparison diagram of the equivalent radiated power vibration response between the topological design structure and the empirical design structure is shown;

[0075] Figure 7 A structural diagram of a thin-walled cover plate design system based on topological simulation of the present invention is shown.

[0076] In the attached figure:

[0077] 1. The first reinforcing rib; 2. The second reinforcing rib; 3. The third reinforcing rib; 4. The fourth reinforcing rib; 5. The fifth reinforcing rib; 6. The sixth reinforcing rib; 7. The seventh reinforcing rib; 8. The eighth reinforcing rib; 9. The ninth reinforcing rib. DETAILED DESCRIPTION

[0078] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are 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 creative work are within the scope of protection of the present invention.

[0079] A thin-wall cover design method based on topological simulation, such as Figure 1 As shown, the following steps are included:

[0080] S1: Construct a topological simulation model, including a super-element model and a thin-walled cover plate model.

[0081] S2: Set the excitation source of the super unit model.

[0082] S3: Set the constraints and optimization objectives of the thin-walled cover model.

[0083] S4: Based on the constraint conditions, the thin-walled cover plate model is simulated and solved through the excitation source to determine whether the simulation solution results meet the optimization objectives. If not, the constraint conditions are adjusted and the simulation solution is performed again until the results meet the optimization objectives.

[0084] S5: After the optimization target is met, the structural density cloud map of the thin-walled cover plate model is obtained.

[0085] S6: Based on the structural density cloud map, the thin-walled cover plate model is reconstructed, and the equivalent radiation power simulation is performed to obtain the simulated equivalent radiation power curve diagram, and at the same time, the equivalent radiation power curve diagram of the existing empirical design is obtained.

[0086] S7: Determine whether the reconstructed thin-walled cover plate model meets the constraints of the last adjustment and whether the value of the equivalent radiation power curve is lower than the value of the equivalent radiation power curve of the existing empirical design. If both are yes, the reconstructed thin-walled cover plate model is used as the final design model. Otherwise, modify the constraints and return to S4.

[0087] The following is a detailed description of S1-S6 with reference to the accompanying drawings:

[0088] like Figure 2 As shown in the figure, it distinguishes between the super unit model and the thin-walled cover plate model, where the super unit is mainly composed of a motor a, a gear box b, and a controller housing c, where the gear box b is connected to the motor a in a transmission manner, and the controller housing c is installed on the surface of the motor a, so each module of the super unit can construct a model separately. Figure 3As shown, it is a thin-walled cover model, which is modeled based on the controller cover, and the controller cover is matched with the controller housing c through screws.

[0089] To build Figure 2 and Figure 3 In the simulation model, S1 specifically includes the following steps:

[0090] S101: Construct a thin-walled cover plate model.

[0091] S102: Construct a motor model.

[0092] S103: Construct a gearbox model that is transmission-connected to the motor model.

[0093] S104: Construct a controller housing model located on the surface of the motor model and connected to the thin-walled cover model.

[0094] S105: The motor model, the gearbox model and the controller housing model are condensed into a super unit model.

[0095] It should be noted that in order to perform calculations quickly, the simulation model in S1 is divided into two parts. One part is used as the basic model, including the shell and stator grid model of the electric drive assembly except the controller cover, and related settings are performed to form a super unit model that can be used for fast calculations. The other part is the design model used for optimizing the concept of the controller cover, that is, the thin-walled cover model in S101.

[0096] It should be further explained that when building the super-unit model, the electric drive assembly housing model is first divided into finite element meshes in professional finite element software, and the obtained mesh model is rigidly connected according to the actual bolt connection relationship. The bolt holes on the controller housing connected to the cover plate are coupled with RBE2 (rigid bar element2, rigid bar element) to obtain the central node, and then the central nodes coupled out of the cover plate are used to establish a constrained substructure interface degree of freedom set (BSET). This point set is the position of the bolt fit, which is used for subsequent connection with the controller cover plate (i.e., the thin-walled cover plate model). In addition, RBE2 is used to couple the central nodes in the reducer bearing chamber.

[0097] S2 includes the following steps:

[0098] S201: Coupling out central nodes in the stator tooth surface of the motor model and the bearing chamber of the gearbox model, respectively, and establishing an unconstrained substructure interface degree of freedom set based on the central nodes. S202: Determine electromagnetic excitation as the first excitation source, and apply it to the unconstrained substructure interface degree of freedom set corresponding to the stator tooth surface of the motor model. S203: Determine gear shaft excitation as the second excitation source, and apply it to the unconstrained substructure interface degree of freedom set corresponding to the bearing chamber of the gearbox model.

[0099] It should be noted that in S201-S203, the nodes (6) coupled from the stator tooth surface and the bearing chamber are established as an unconstrained substructure interface degree of freedom set (CEST), which can be used to subsequently load electromagnetic force on the stator tooth surface and load gear shaft excitation force on the bearing chamber. The above model is calculated by super element generation using the model contraction method to obtain a super element model, hereinafter referred to as SE (Super Element) model.

[0100] It should be further explained that the electromagnetic excitation calculation and loading need to be based on the 2D stator-rotor structure scheme and electromagnetic parameters such as torque, current, and current angle, and the three-dimensional electromagnetic force of the electric drive under full throttle acceleration (WOT) or throttle opening less than 100% (POT) conditions is calculated, and the calculated electromagnetic excitation is loaded on the stator tooth surface node set CSET. The calculation and loading of the gear shaft excitation needs to be based on the test results of the electric drive semi-anechoic chamber, and the torque and speed segments with poor noise performance are selected to calculate the excitation force of the gear shaft system meshing process, decouple the forces in the three directions of XYZ of each bearing seat of the shaft system, and apply them to the bearing room coupling node set CSET established in S2.

[0101] S3 includes the following steps:

[0102] S301: Setting an optimization target, setting the thin-walled cover plate model as an equivalent sound radiation power response output component, and setting the value of the equivalent sound radiation power to the minimum peak value in the full frequency range.

[0103] S302: Set the first constraint condition to set the first-order drum-shaped modal frequency of the thin-walled cover model to ≥700 Hz.

[0104] S303: Set the second constraint condition to set the volume percentage of the design area of ​​the thin-walled cover model to ≤0.35.

[0105] It should be noted that if Figure 3 As shown in the figure, it is a thin-walled cover model, in which the design area is located inside the non-design area, marked as A, and the non-design area is the area where the thin-walled cover model is connected to the controller housing model, marked as B. In addition, for constraints and optimization targets, any one of the first-order drum modal frequency, volume percentage, and equivalent sound radiation power can be the optimization target, but the other two will be used as constraints.

[0106] In S4, the thin-walled cover plate model is simulated and solved by the excitation source to determine whether the simulation solution results meet the optimization target. If not, the constraint conditions are adjusted and the simulation solution is performed again until the result meets the optimization target, including the following steps:

[0107] S401: Apply gear shaft excitation to the bearing chamber of the gearbox model, and apply electromagnetic excitation to the stator tooth surface of the motor model. S402: Obtain the equivalent acoustic radiation power of the thin-walled cover plate model under the influence of gear excitation and electromagnetic excitation. S403: Determine whether the equivalent acoustic radiation power meets the optimization target. If not, adjust the constraint conditions and test again until the equivalent acoustic radiation power meets the optimization target.

[0108] It should be noted that in S401, the gear shaft excitation and electromagnetic excitation are respectively input into the two CEST point sets to simulate the forces of the motor model and the gearbox model, because when the motor is working, a radial component force will be generated in the output shaft, which can cause vibration and noise of the motor, and the electromagnetic excitation can simulate the component force, and then simulate the vibration and noise of the motor model. Similarly, when the gearbox is working, noise will be generated at the meshing point, and the gear shaft excitation can simulate the force there, thereby generating noise. The thin-walled cover plate model will generate corresponding signals by receiving these vibrations and noises, and a thin-walled cover plate model that meets the requirements can be obtained by constraining, analyzing and adjusting the generated signals.

[0109] In S5, after the optimization target is met, a structural density cloud map of the thin-walled cover plate model is obtained, including the following steps:

[0110] S501: Setting a cell density threshold of a thin-walled cover plate model. S502: Retaining a portion of the design region that is greater than the cell density threshold and removing the rest to obtain a structural density cloud map of the thin-walled cover plate model.

[0111] It should be noted that if Figure 4 As shown in the figure, the optimization results that meet the design parameters are selected for post-processing analysis to obtain the optimized structural density cloud map. The unit density threshold is set to 0.55, and the structures with design areas larger than the threshold are retained, and the rest are removed. Finally, Figure 4 The black areas in the figure are areas where the cell density is greater than the threshold.

[0112] S7 includes the following steps:

[0113] S701: Construct a thin-walled cover plate model with reinforcement ribs based on the structural density cloud map;

[0114] S702: Determine whether the thin-walled cover plate model with reinforcing ribs meets the constraints of the last adjustment, and at the same time determine whether the value of the equivalent radiation power curve is lower than the value of the equivalent radiation power curve of the existing empirical design; if both are yes, the reconstructed thin-walled cover plate model is used as the final design model, otherwise modify the constraints and re-execute S4-S8.

[0115] It should be noted that when designing a thin-walled cover plate model with reinforcing ribs, Figure 4The structural density cloud map is used to identify the stress concentration areas in the structure. Figure 5 Arrange the starting points of the reinforcement ribs as shown, and ensure that they are located close to the edge bolt holes. This can significantly improve the overall strength of the structure. Finally, multiple reinforcement ribs are formed inside the controller cover, staggered to connect the key bolt points, and improve the overall structural rigidity of the cover. Specifically, Figure 5 Nine reinforcing ribs are arranged on the model of the medium-thin-wall cover plate, and several screw holes are opened on the upper, lower, left and right edges of the model (non-designed areas), wherein the first reinforcing rib 1 and the second reinforcing rib 2 are located in the upper left corner, one end of the first reinforcing rib 1 is connected to the second screw hole position on the left edge, and the other end is connected to the first screw hole position on the upper side (from left to right), one end of the second reinforcing rib 2 is close to the first reinforcing rib 1, and the other end is connected to the second screw hole position on the upper side. The third reinforcing rib 3 and the fourth reinforcing rib 4 are located in the upper right corner, wherein one end of the third reinforcing rib 3 is connected to the third screw hole position on the upper side, and the other end is connected to the second screw hole position on the right edge (from top to bottom); one end of the fourth reinforcing rib 4 is connected to the fourth screw hole position on the upper side, and the other end is connected to the first screw hole position on the right edge. Moreover, based on the inherent bending mode vibration type of the cover plate, cross-interconnected reinforcing ribs are formed at the bending vibration type portion of the cover plate to help reduce the vibration response and noise radiation capacity of the structure. Specifically, among the interconnected reinforcing ribs, the fifth reinforcing rib 5 starts from the third screw hole on the right side, and the other end extends to the middle position of the design area; the sixth reinforcing rib 6 starts from the fourth screw hole on the lower side (from left to right) and extends to the middle of the design area; the seventh reinforcing rib 7 starts from the second screw hole on the lower side and extends to the middle of the design area, and crosses with the sixth reinforcing rib 6 until it contacts the fifth reinforcing rib 5; the eighth reinforcing rib 8 extends from the fourth screw hole position on the left side to the middle until it contacts the sixth reinforcing rib 6; one end of the ninth reinforcing rib 9 is connected to the third screw hole position on the left side, and the other end is connected to the third screw hole position on the upper side, with an arc section in the middle, which contacts the fifth reinforcing rib 5 and the sixth reinforcing rib 6 respectively, forming a "mouth"-shaped rib structure. By reference Figure 4 and Figure 5 , the correspondence between the layout of the stiffeners and the structural density cloud map can be clearly seen, thus ensuring that the arrangement of the stiffeners can effectively support and strengthen the weak parts of the structure.

[0116] It should be further explained that, based on the above conceptual structure, CAD digital model reconstruction was performed. Compared with the original structural scheme, the controller cover was reduced by 4.9% in weight. The model obtained by topology optimization was brought into the assembly for modal frequency simulation and equivalent sound radiation power (ERP) response simulation. The simulation results are shown in the figure. Figure 6 Shown is the comparison between simulation design and empirical design: Figure 6The vertical axis is the first-order drum-shaped modal frequency and normal vibration response (equivalent radiated power) of the thin-walled cover plate, and the horizontal axis is the frequency. The vibration response of the thin-walled cover plate obtained by topological design under electromagnetic excitation and gear shaft excitation is lower than that of the empirical design. In addition, at the first drum-shaped modal frequency of the controller, the equivalent sound radiation efficiency of the topological optimization scheme is reduced by about 2dB, which effectively reduces the noise radiation capacity of the controller-type thin-walled cover plate, verifying the effectiveness of the topological optimization design of vibration and noise reduction of thin-walled panels.

[0117] like Figure 7 As shown, a thin-walled cover design system based on topological simulation includes:

[0118] Building units, used to build topological simulation models, including super unit models and thin-walled cover plate models;

[0119] An excitation unit, used to set the excitation source of the super unit model;

[0120] Setting unit, used to set the constraint conditions and optimization objectives of the thin-walled cover model;

[0121] The test unit is used to simulate and solve the thin-walled cover plate model through the excitation source based on the constraint conditions, and determine whether the simulation solution results meet the optimization target. If not, the constraint conditions are adjusted and the simulation solution is performed again until the result meets the optimization target;

[0122] An analysis unit, used to obtain a structural density cloud map of the thin-walled cover plate model after the optimization target is met;

[0123] A data unit is used to reconstruct a thin-walled cover plate model based on a structural density cloud map, perform equivalent radiation power simulation, obtain a simulated equivalent radiation power curve, and obtain an equivalent radiation power curve of an existing empirical design;

[0124] The output unit is used to determine whether the reconstructed thin-walled cover plate model meets the constraints of the last adjustment and whether the value of the equivalent radiation power curve is lower than the value of the equivalent radiation power curve of the existing empirical design. If both are yes, the reconstructed thin-walled cover plate model will be used as the final design model. Otherwise, the constraints will be modified and returned to the test unit.

[0125] The construction unit is used to construct a thin-walled cover plate model; construct a motor model; construct a gearbox model that is transmission-connected to the motor model; construct a controller housing model that is located on the surface of the motor model and connected to the thin-walled cover plate model; and condense the motor model, the gearbox model, and the controller housing model into a super-unit model.

[0126] The excitation unit comprises:

[0127] A coupling module is used to couple central nodes in the stator tooth surface of the motor model and the bearing chamber of the gearbox model respectively, and establish an unconstrained substructure interface degree of freedom set based on the central node; a first excitation module is used to determine electromagnetic excitation as the first excitation source, which is applied to the unconstrained substructure interface degree of freedom set corresponding to the stator tooth surface of the motor model; and a second excitation module is used to determine gear shaft excitation as the second excitation source, which is applied to the unconstrained substructure interface degree of freedom set corresponding to the bearing chamber of the gearbox model.

[0128] The setting unit is used to: set the optimization target, set the thin-walled cover plate model as the equivalent sound radiation power response output component, and set the value of the equivalent sound radiation power to the minimum peak value in the entire frequency range; set the first constraint condition, set the first-order drum modal frequency of the thin-walled cover plate model to ≥700Hz; set the second constraint condition, set the volume percentage of the design area of ​​the thin-walled cover plate model to ≤0.35, and the design area is located on the inner side of the non-design area, and the non-design area is the area where the thin-walled cover plate model is connected to the controller housing model.

[0129] The test unit includes:

[0130] The test module is used to apply gear shaft excitation to the bearing chamber of the gearbox model, and to apply electromagnetic excitation to the stator tooth surface of the motor model; the acquisition module is used to obtain the equivalent acoustic radiation power of the thin-walled cover plate model under the influence of gear excitation and electromagnetic excitation; the judgment module is used to judge whether the equivalent acoustic radiation power meets the optimization target. If not, the constraint conditions are adjusted and tested again until the equivalent acoustic radiation power meets the optimization target.

[0131] The analysis units include:

[0132] The setting module is used to set the unit density threshold of the thin-walled cover model; the analysis module is used to retain the part of the design area that is larger than the unit density threshold and remove the rest to obtain the structural density cloud map of the thin-walled cover model.

[0133] Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent substitutions for some of the technical features therein; and these modifications or substitutions do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A thin-walled cover plate design method based on topological simulation, characterized in that: The following steps are involved: Construct topological simulation models, including super-element models and thin-walled cover plate models; Set the excitation source of the super unit model; Set constraints and optimization objectives for the thin-walled cover model; Cycle steps: Based on the constraints, the thin-walled cover plate model is simulated and solved through the excitation source to determine whether the simulation solution meets the optimization goal. If not, the constraints are adjusted and the simulation solution is performed again until the result meets the optimization goal; After the optimization target is met, the structural density cloud map of the thin-walled cover plate model is obtained; Reconstruct the thin-wall cover plate model based on the structural density cloud map, perform equivalent radiation power simulation, obtain the simulated equivalent radiation power curve, and obtain the equivalent radiation power curve of the existing empirical design; Determine whether the reconstructed thin-walled cover plate model meets the constraints of the last adjustment and whether the value of the equivalent radiation power curve is lower than the value of the equivalent radiation power curve of the existing empirical design. If both are yes, the reconstructed thin-walled cover plate model will be used as the final design model. Otherwise, modify the constraints and return to the loop step.

2. A thin-walled cover plate design method based on topological simulation according to claim 1, characterized in that: Building a topology simulation model includes the following steps: Construct thin-walled cover plate model; Build a motor model; Construct a gearbox model that is transmission-connected to the motor model; Construct a controller housing model located on the surface of the motor model and connected to the thin-walled cover model; The motor model, gearbox model and controller housing model are condensed into a super unit model.

3. The thin-walled cover plate design method based on topological simulation according to claim 2 is characterized in that: Setting the excitation source of the superelement model includes the following steps: The central nodes are coupled out in the stator tooth surface of the motor model and the bearing chamber of the gearbox model respectively, and the unconstrained substructure interface degree of freedom set is established based on the central nodes; Electromagnetic excitation is set as the first excitation source and applied to the unconstrained substructure interface degree of freedom set corresponding to the stator tooth surface of the motor model; The gear shaft excitation is set as the second excitation source and applied to the unconstrained substructure interface degree of freedom set corresponding to the bearing chamber of the gearbox model.

4. The thin-walled cover plate design method based on topological simulation according to claim 3 is characterized in that: Setting the constraints for the thin-walled cover model includes the following steps: Set the optimization target, set the thin-walled cover plate model as the equivalent sound radiation power response output component, and set the equivalent sound radiation power value to the minimum peak value in the full frequency range; Set the first constraint condition to set the first-order drum mode frequency of the thin-walled cover model to ≥700Hz; The second constraint condition is set to set the volume percentage of the design area of ​​the thin-walled cover plate model to ≤0.35, and the design area is located inside the non-design area, and the non-design area is the area where the thin-walled cover plate model is connected to the controller housing model.

5. The thin-walled cover plate design method based on topological simulation according to claim 4, characterized in that: The thin-walled cover plate model is simulated and solved by the excitation source to determine whether the simulation solution meets the optimization goal. If not, the constraint conditions are adjusted and tested again until the result meets the optimization goal, including the following steps: Applying gear shaft excitation to the bearing chamber of the gearbox model, and applying electromagnetic excitation to the stator tooth surface of the motor model; Obtain the equivalent acoustic radiation power of the thin-walled cover model under the influence of gear excitation and electromagnetic excitation; Determine whether the equivalent sound radiation power meets the optimization target. If not, adjust the constraint conditions and test again until the equivalent sound radiation power meets the optimization target.

6. A thin-walled cover plate design method based on topological simulation according to claim 4 or 5, characterized in that: After the optimization target is met, the structural density cloud map of the thin-walled cover plate model is obtained, including the following steps: Set the cell density threshold for the thin-walled cover model; The part of the design area that is larger than the unit density threshold is retained, and the rest is removed to obtain the structural density cloud map of the thin-walled cover model.

7. A thin-walled cover design system based on topological simulation, characterized in that: include: Building units, used to build topological simulation models, including super unit models and thin-walled cover plate models; An excitation unit, used to set the excitation source of the super unit model; Setting unit, used to set the constraint conditions and optimization objectives of the thin-walled cover model; The test unit is used to simulate and solve the thin-walled cover plate model through the excitation source based on the constraint conditions, and determine whether the simulation solution results meet the optimization target. If not, the constraint conditions are adjusted and the simulation solution is performed again until the result meets the optimization target; An analysis unit, used to obtain a structural density cloud map of the thin-walled cover plate model after the optimization target is met; A data unit is used to reconstruct a thin-walled cover plate model based on a structural density cloud map, perform equivalent radiation power simulation, obtain a simulated equivalent radiation power curve, and obtain an equivalent radiation power curve of an existing empirical design; The output unit is used to determine whether the reconstructed thin-walled cover plate model meets the constraints of the last adjustment and whether the value of the equivalent radiation power curve is lower than the value of the equivalent radiation power curve of the existing empirical design. If both are yes, the reconstructed thin-walled cover plate model will be used as the final design model. Otherwise, the constraints will be modified and returned to the test unit.

8. A thin-walled cover plate design system based on topological simulation according to claim 7, characterized in that: The building blocks are used to: Construct thin-walled cover plate model; Build a motor model; Construct a gearbox model that is transmission-connected to the motor model; Construct a controller housing model located on the surface of the motor model and connected to the thin-walled cover model; The motor model, gearbox model and controller housing model are condensed into a super unit model.

9. The thin-walled cover plate design system based on topological simulation according to claim 7, characterized in that: The excitation unit comprises: A coupling module is used to couple central nodes in the stator tooth surface of the motor model and the bearing chamber of the gearbox model, and establish an unconstrained substructure interface degree of freedom set based on the central node; A first excitation module is used to determine electromagnetic excitation as a first excitation source, which is applied to an unconstrained substructure interface degree of freedom set corresponding to a stator tooth surface of the motor model; The second excitation module is used to determine the gear shaft excitation as the second excitation source, which is applied to the unconstrained substructure interface degree of freedom set corresponding to the bearing chamber of the gearbox model.

10. A thin-walled cover plate design system based on topological simulation according to claim 9, characterized in that: The setting unit is used for: Set the optimization target, set the thin-walled cover plate model as the equivalent sound radiation power response output component, and set the equivalent sound radiation power value to the minimum peak value in the full frequency range; Set the first constraint condition to set the first-order drum mode frequency of the thin-walled cover model to ≥700Hz; The second constraint condition is set to set the volume percentage of the design area of ​​the thin-walled cover plate model to ≤0.35, and the design area is located inside the non-design area, and the non-design area is the area where the thin-walled cover plate model is connected to the controller housing model.

11. A thin-walled cover plate design system based on topological simulation according to claim 10, characterized in that: The test unit comprises: A test module, used for applying gear shaft excitation to the bearing chamber of the gearbox model, and applying electromagnetic excitation to the stator tooth surface of the motor model; An acquisition module is used to obtain the equivalent acoustic radiation power of the thin-walled cover plate model under the influence of gear excitation and electromagnetic excitation; The judgment module is used to judge whether the equivalent sound radiation power meets the optimization target. If not, the constraint conditions are adjusted and tested again until the equivalent sound radiation power meets the optimization target.

12. A thin-walled cover plate design system based on topological simulation according to claim 10 or 11, characterized in that: The analysis unit comprises: The setting module is used to set the cell density threshold of the thin-walled cover model; The analysis module is used to retain the part of the design area that is larger than the unit density threshold and remove the rest to obtain the structural density cloud map of the thin-walled cover model.

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