A monolithic torsional vibration suppression superstructure based on topology optimization

Abstract

The application relates to the technical field of superstructure vibration isolation, in particular to a monolithic torsional vibration suppression superstructure based on topological optimization. The superstructure comprises a ring-shaped plate structure, the center of the ring-shaped plate structure is a rigid shaft connecting area, the edge is a closed external connecting rigid area; the area between the rigid shaft connecting area and the external connecting rigid area is a topological design area; a plurality of hollow gap areas are arranged in the topological design area, and solid material areas connecting the rigid shaft connecting area and the external connecting rigid area are arranged between adjacent gap areas; the gap areas are centrosymmetric about the center point of the ring-shaped plate structure. The application realizes the quasi-zero stiffness characteristic through material topological distribution in the closed ring-shaped design domain, so that the high torque transmission capability is realized, and the low-frequency torsional vibration is effectively isolated and suppressed.

Description

Technical Field

[0001] This application relates to the field of superstructure vibration isolation technology, and in particular to an integral torsional vibration suppression superstructure based on topology optimization. Background Technology

[0002] In aviation and marine applications, the shafting / drivetrain that drives propellers not only needs to continuously transmit stable torque, but is also inevitably affected by low-frequency torsional vibrations caused by the aerodynamic / hydrodynamic excitation of the reducer and propeller. Low-frequency torsional vibrations can lead to shafting fatigue, loosening of connectors, and increased noise radiation, thus affecting the reliability of the propulsion system. Therefore, effectively isolating low-frequency torsional vibrations while ensuring torque transmission capability has always been a crucial engineering requirement in the field of propulsion shaft vibration control.

[0003] Commonly used torsion springs, couplings, or rubber / metal elastic elements in existing engineering typically exhibit approximately linear torsional stiffness characteristics. To improve torque carrying capacity, these structures often require increased static stiffness. However, this increased static stiffness simultaneously raises the system's equivalent dynamic stiffness, making it difficult to lower the vibration isolation initiation frequency and achieve effective isolation in the low-frequency range. In other words, traditional torsional elastic elements, limited by their inherent mechanical properties, cannot simultaneously achieve compatibility between "high static stiffness (high torque transmission requirements)" and "low dynamic stiffness (low-frequency vibration isolation requirements)," creating a natural contradiction in low-frequency torsional vibration isolation under high-load conditions.

[0004] To overcome the aforementioned contradictions, torsional quasi-zero stiffness isolators offer a novel technical approach: by introducing a nonlinear mechanical mechanism, the equivalent stiffness is significantly reduced within the operating range, thereby lowering the isolation initiation frequency while maintaining a certain torque transmission capability, achieving low-frequency vibration isolation. However, existing quasi-zero stiffness torsional isolators mostly employ typical "mechanism-based" configurations such as connecting rod-cam-roller-spring and magnetic mechanisms, which typically suffer from problems such as a large number of parts, long assembly chains, sensitivity to assembly precision and clearances, and limitations in friction, wear, and reliability. For applications with limited space, restricted maintenance conditions, and extremely high reliability requirements, the aforementioned mechanism-based solutions face significant challenges in terms of volume, assembly implementation, long-term stability, and environmental adaptability.

[0005] Therefore, the demand for integral vibration-damping superstructures is gradually becoming more prominent. Summary of the Invention

[0006] The purpose of this application is to provide a topology-optimized integral torsional vibration damping superstructure that simultaneously possesses lightweight, high torque transmission capability, and low-frequency vibration isolation performance.

[0007] The overall torsional vibration damping superstructure based on topology optimization provided in this application includes an annular plate structure, wherein the center of the annular plate structure is a rigid shaft connection area and the edge is a closed external connection rigid area. The area between the rigid shaft connection area and the external connection rigid area is the topology design area; a number of hollowed-out gap areas are set in the topology design area, and solid material areas connecting the rigid shaft connection area and the external connection rigid area are respectively set between adjacent gap areas; The void region is symmetrical about the center point of the annular plate structure; By discretizing the topology design area, generating an initial void region, obtaining the initial torque-rotation angle relationship curve of the integral torsional vibration damping superstructure, and iteratively adjusting the shape and range of the initial void region according to the error between the initial torque-rotation angle relationship curve and the target curve, the final void region is obtained when the error between the torque-rotation angle relationship curve and the target curve reaches a set range.

[0008] In a preferred embodiment, the topology design region is made of TPU material with a Young's modulus of 45MPa~50MPa and a Poisson's ratio of 0.45~0.53.

[0009] In a preferred embodiment, the topology design region is a closed ring with an outer radius greater than or equal to three times its inner radius.

[0010] In a preferred embodiment, the outer radius of the topology design area is 0.06m and the inner radius is 0.02m.

[0011] In a preferred embodiment, it further includes a coupling body and a superstructure connection frame; The integral torsional vibration damping superstructure is stacked and fixedly connected to the superstructure connecting frame, and the coupling body is fixedly connected to the center of the superstructure connecting frame and the integral torsional vibration damping superstructure.

[0012] In a preferred embodiment, the integral torsional vibration damping superstructure is fixedly connected to the edge of the superstructure connecting frame by a number of bolts.

[0013] In a preferred embodiment, the coupling body, the superstructure connection frame, and the bolts are made of aluminum alloy.

[0014] In a preferred embodiment, the design method of the integral torsional vibration damping superstructure includes the following steps: S10. Discretize the topology design area and divide it into several uniformly distributed grid cells. S20. Randomly initialize each of the mesh cells as void cells and solid cells, and the proportion of solid cells is not less than a preset solid volume fraction; S30. Filter and clean the mesh cells so that the gap cells and the solid cells are gathered together to form the gap region and the solid material region, and make the solid material region continuously connect the rigid shaft connection region and the external connection rigid region. S40. The void region and the solid material region are arrayed along the circumferential direction to obtain an integral torsional vibration damping superstructure. S50. Obtain the torque-rotation angle relationship curve of the integral torsional vibration damping superstructure, and calculate the error between the torque-rotation angle relationship curve and the target curve; S60. Repeat steps S20 to S50, iteratively adjusting the shape and range of the gap region. When the error between the torque-angle relationship curve and the target curve reaches a set range, the final gap region is obtained.

[0015] In a preferred embodiment, the following steps are also included: S31. Identify the boundary points between the void region and the solid material region, and smooth the boundary points using spline fitting to form a continuous and smooth geometric boundary.

[0016] In a preferred embodiment, the volume fraction of the solid is not less than 0.5.

[0017] This application has the following beneficial effects: The monolithic superstructure obtained through topology optimization design in this application possesses the fundamental characteristic of near-zero stiffness, achieving a mechanical property match of "high static stiffness and low dynamic stiffness" while meeting the requirements for high torsional load transmission. Specifically, under rated torsional load, the torque-rotation response curve of the superstructure exhibits plateau characteristics within the target operating range, making its equivalent torsional stiffness level close to zero, thereby significantly reducing the system's equivalent dynamic stiffness and shifting the initial vibration isolation frequency forward. Therefore, when low-frequency torsional vibrations are generated by the external environment and transmitted to the shaft system or support structure, this superstructure can effectively isolate the input vibration with a low vibration transmission rate, significantly attenuating the low-frequency vibration energy transmitted to the internal equipment, thereby improving the operational stability and safety of the internal equipment. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 An exploded view of an integral torsional vibration damping superstructure provided in this application embodiment; Figure 2 A top view schematic diagram of an integral torsional vibration damping superstructure coupling provided in an embodiment of this application; Figure 3 A schematic diagram illustrating the design method of an integral torsional vibration damping superstructure; Figure 4 The graph shows the relationship between the reaction torque, equivalent stiffness, and rotation angle of the integral torsional vibration damping superstructure. Figure 5 A schematic diagram showing the relationship between the transmissivity and frequency of an integral torsional vibration damping superstructure. Figure 6 This is a schematic diagram of another type of integral torsional vibration damping superstructure. Figure 7 This is a schematic diagram of another type of integral torsional vibration damping superstructure. Figure 8 This is a schematic diagram of another type of integral torsional vibration damping superstructure. Figure 9 This is a schematic diagram of another type of integral torsional vibration damping superstructure. Numbering on the map: 1-Topology-optimized vibration-damping superstructure; 2-Superstructure connection frame; 3-Coupling body; 4-Bolt; 5-Nut; 6-Topology design area; 7-External connection rigid area; 8-Rigid shaft connection area. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and labeled in the accompanying drawings can generally be arranged and designed in various different configurations.

[0021] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0022] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0023] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention. In addition, the terms "first," "second," "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0024] Furthermore, terms such as "horizontal," "vertical," and "sag" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0025] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0026] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0027] Topology optimization, as an important method in the field of structural design in recent years, provides a new technical approach for the reverse customization of monolithic torsional vibration-damping superstructures. This method, driven by performance indicators, automatically generates the structural configuration by rationally arranging materials in space within a given design domain and constraints. It can be used to synergistically meet multiple objectives such as load-bearing capacity, stiffness curves, and low-frequency vibration isolation within a finite volume.

[0028] like Figure 1 and Figure 2 As shown, the core of the integral torsional vibration damping superstructure provided in this embodiment is the topology-optimized vibration damping superstructure 1, which includes an annular plate structure. The center of the annular plate structure is a rigid shaft connection area 8, and the edge is a closed external connection rigid area 7. The area between the rigid shaft connection area 8 and the external connection rigid area 7 is the topology design area 6; several hollowed-out gap areas are set in the topology design area 6, and solid material areas connecting the rigid shaft connection area 8 and the external connection rigid area 7 are respectively set between adjacent gap areas. The void region is centrally symmetrical about the center point of the annular plate-like structure; The shape of the void region is obtained through topology optimization design, which will be described in detail later.

[0029] The material distribution and configuration are determined in the topology design zone 6 through topology optimization to achieve the target torque-rotation response and torsional vibration damping performance; the external connection rigid zone 7 and the rigid shaft connection zone 8 are the external connection rigid zone and the rigid shaft connection zone, respectively, used to achieve reliable assembly and torque transmission with external components.

[0030] The integral torsional vibration damping superstructure provided in this embodiment may also include a coupling body 3, a superstructure connection frame 2, and a topology-optimized vibration damping superstructure 1. The topology-optimized vibration damping superstructure 1 and the superstructure connecting frame 2 are stacked and fixedly connected at the edges by several bolts 4 and nuts 5. The coupling body 3 is fixedly connected to the center of the superstructure connecting frame 2 and the topology-optimized vibration damping superstructure 1. The combined structure can be used as a coupling.

[0031] The topology-optimized vibration-damping superstructure 1 is made entirely of TPU material, with a Young's modulus of 45 MPa to 50 MPa and a Poisson's ratio of 0.45 to 0.53. In this embodiment, the Young's modulus of the topology-optimized vibration-damping superstructure 1 is 48 MPa and the Poisson's ratio is 0.49.

[0032] The coupling body 3, the superstructure connecting frame 2, the bolts 4, and the nuts 5 are all made of aluminum alloy.

[0033] Specifically, the topology design region 6 is a closed ring with an outer radius greater than or equal to three times its inner radius. In this embodiment, the outer radius of the topology design region 6 is 0.06m and the inner radius is 0.02m.

[0034] like Figures 3-5 As shown, the design method of the integral torsional vibration damping superstructure includes the following steps: S10. Discretize the topology design area and divide it into several uniformly distributed grid cells. S20. Randomly initialize each of the mesh cells as void cells and solid cells, and the proportion of solid cells is not less than a preset solid volume fraction; Specifically, a rectangular design domain of size 40×30 is discretized into 1200 uniformly distributed 1×1 mesh elements. This design uses a binary encoding scheme to define element attributes: where "1" represents a solid element (material present) and "0" represents a void element (material absent). Based on this, the design variables can be expressed in the following form: , in, The design variable matrix consists of 0 and 1 elements of size L×H (40×30). During initialization, the global solid volume fraction within the design domain is first ensured to meet the preset value of 0.58, i.e., the area ratio of solid material is 58%. Under this constraint, except for the pre-specified boundary elements, the remaining internal elements are initialized to 0 or 1 in a random manner.

[0035] To meet the boundary load requirements of the structure under actual working conditions, the top three and bottom three rows of elements in the design domain are pre-defined as solid elements. This setting ensures that the load-bearing boundaries have sufficient material distribution during topology optimization, thereby improving the mechanical performance and computational stability of the structure.

[0036] S30. Filter and clean the mesh cells so that the gap cells and the solid cells are gathered together to form the gap region and the solid material region, and make the solid material region continuously connect the rigid shaft connection region and the external connection rigid region. Specifically, to eliminate small-scale cavities, isolated solid islands, non-physical connections, and checkerboard patterns generated during discretization, a filtering and cleaning process was introduced in the post-processing stage. After filtering, the structural entity exhibits stronger mechanical load-bearing capacity and topological continuity; however, jagged structures still exist at the boundaries, which will cause convergence problems in subsequent finite element analysis. Therefore, a boundary point identification algorithm is used to extract and identify the boundaries between the solid and voids. Subsequently, the identified boundary points are smoothed using spline fitting to form continuous and smooth geometric boundaries. After completing the preprocessing of the rectangular topology, the fitted boundary points are further transformed into a quarter-sector structure through conformal mapping. This conformal mapping process is based on the following formula:

[0037] in,( , The polar coordinates are obtained after conformal mapping. To facilitate subsequent finite element analysis and computer-aided design geometry derivation, they are ultimately converted back to Cartesian coordinates, as follows: .

[0038] S40. The void region and the solid material region are arrayed along the circumferential direction to obtain a topology-optimized vibration-damping superstructure. Specifically, in order to construct a complete topological torsional superstructure, the obtained quarter-sector topological structure is arrayed counterclockwise along the circumference. Through this array operation, the basic structural units are arranged periodically in the circumference, thereby forming a torsional superstructure with complete geometric shape and continuous mechanical properties.

[0039] S50. Obtain the torque-rotation angle relationship curve of the topology-optimized vibration-damping superstructure, and calculate the error between the torque-rotation angle relationship curve and the target curve; Specifically, the commercial finite element software ANSYS_APDL was used to perform steady-state torsional calculations on the topology-optimized integral torsional vibration-damping superstructure described in this embodiment. This yielded the reaction torques of all nodes on the inner radius boundary and the corresponding equivalent stiffness curves as a function of the rotation angle θ, as shown below. Figure 4 As shown in the figure, the torque-rotation response of this superstructure exhibits a clear plateau characteristic in the target operating range, corresponding to a significant decrease in the equivalent stiffness within this range. This demonstrates the basic characteristics of high static stiffness and low dynamic stiffness inherent in quasi-zero stiffness structures, thus providing a mechanical basis for low-frequency torsional vibration isolation.

[0040] By comparing several key points of the torque-angle relationship curve with the target curve, the error of the comparison can be obtained.

[0041] S60. Repeat steps S20 to S50, iteratively adjusting the shape and range of the gap region. When the error between the torque-angle relationship curve and the target curve reaches a set range, the final gap region is obtained.

[0042] To verify the vibration isolation effect of the topology-optimized monolithic torsional vibration suppression superstructure, a fixed constraint was applied to the outer radius of the superstructure, and an equivalent lever arm mass block was connected to the inner radius end. Subsequently, a simple harmonic torque excitation with an amplitude of 0.01 N·m was applied to the mass block, and the output torque response was extracted at the outer radius. According to the definition of vibration transmissibility, T = 20 * log10(A out / A in ), A in A represents the amplitude of the input excitation torque. out The output torque amplitude is extracted at the outer radius. The vibration transmissibility curve of the topology-optimized integral torsional vibration-damping superstructure is shown below. Figure 5 As shown in the figure, the initial vibration isolation frequency of this superstructure can be as low as 4 Hz, and it achieves a wide frequency range vibration isolation effect above 4 Hz, indicating that it has a significant ability to suppress and isolate low-frequency torsional vibration.

[0043] To further achieve customized design of the platform region's torque level, corresponding rotation angle position, and platform region width, four different target torque-rotation angle curves were established based on the reverse design method. Based on these, four topology-optimized integral torsional vibration-damping superstructure configurations were obtained, such as... Figures 6-9 As shown. Among them, Figure 6 The corresponding target torque is 0.8 N·m, the target angle is 0.25 rad, and the platform width is 0.05 rad; Figure 7 The corresponding target torque is 2.0 N·m, the target angle is 0.20 rad, and the platform width is 0.05 rad; Figure 8 The corresponding target torque is 0.8 N·m, the target angle is 0.25 rad, and the platform width is 0.15 rad; Figure 9 The corresponding target torque is 3.0 N·m, the target angle is 0.22 rad, and the platform width is 0.05 rad. As can be seen from the above comparison, the reverse topology optimization framework described in this application can achieve programmable customization of the configuration for different target platform parameters, providing more flexible design space for low-frequency torsional vibration isolation applications under multiple operating conditions.

[0044] In summary, this application introduces topology optimization technology and combines it with the quasi-zero stiffness mechanism to achieve low dynamic stiffness and low-frequency vibration isolation while ensuring high torque transmission capability, thereby effectively alleviating the contradiction of "high load-bearing capacity and low-frequency vibration isolation" in traditional torsional vibration isolators; and it can be reverse-customized according to the target torque-rotation angle curve to adapt to different load levels and working torsional angle ranges. This application employs a closed-loop iterative approach combining genetic algorithms and commercial finite element analysis, using curve error as the evaluation metric for global search and updates. This approach enables the rapid acquisition of topology-optimized, integral torsional vibration-damping superstructure configurations that satisfy different target curves, thereby improving design efficiency and shortening the development cycle.

[0045] The superstructure obtained in this application is an integral, integrated configuration with a simple structure, fewer parts, and no assembly required. This reduces assembly errors and maintenance costs, while also offering advantages in terms of lightweight, integration, and miniaturization, making it suitable for space-constrained engineering scenarios.

[0046] This application has good engineering feasibility and can be integrated into a single piece using traditional machining or additive manufacturing. This facilitates the manufacture of complex topological configurations and ensures consistency, thereby enhancing its engineering application and promotion value.

[0047] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A monolithic torsional vibration damping superstructure based on topology optimization, characterized in that, It includes an annular plate-like structure, wherein the center of the annular plate-like structure is a rigid shaft connection area, and the edges are closed external connection rigid areas; The area between the rigid shaft connection area and the external connection rigid area is the topology design area; a number of hollowed-out gap areas are set in the topology design area, and solid material areas connecting the rigid shaft connection area and the external connection rigid area are respectively set between adjacent gap areas; The void region is symmetrical about the center point of the annular plate structure; By discretizing the topology design area, generating an initial void region, obtaining the initial torque-rotation angle relationship curve of the integral torsional vibration damping superstructure, and iteratively adjusting the shape and range of the initial void region according to the error between the initial torque-rotation angle relationship curve and the target curve, the final void region is obtained when the error between the torque-rotation angle relationship curve and the target curve reaches a set range.

2. The integral torsional vibration damping superstructure according to claim 1, characterized in that, The topology design area is made of TPU material with a Young's modulus of 45MPa~50MPa and a Poisson's ratio of 0.45~0.

53.

3. The integral torsional vibration damping superstructure according to claim 1, characterized in that, The topology design region is a closed ring with an outer radius greater than or equal to three times its inner radius.

4. The integral torsional vibration damping superstructure according to claim 3, characterized in that, The outer radius of the topology design area is 0.06m, and the inner radius is 0.02m.

5. The integral torsional vibration damping superstructure according to any one of claims 1 to 4, characterized in that, It also includes the coupling body and the superstructure connection frame; The integral torsional vibration damping superstructure is stacked and fixedly connected to the superstructure connecting frame, and the coupling body is fixedly connected to the center of the superstructure connecting frame and the integral torsional vibration damping superstructure.

6. The integral torsional vibration damping superstructure according to claim 5, characterized in that, The integral torsional vibration damping superstructure is fixedly connected to the edge of the superstructure connecting frame by a number of bolts.

7. The integral torsional vibration damping superstructure according to claim 6, characterized in that, The coupling body, the superstructure connection frame, and the bolts are made of aluminum alloy.

8. The integral torsional vibration damping superstructure according to claim 1, characterized in that, Its design method includes the following steps: S10. Discretize the topology design area and divide it into several uniformly distributed grid cells. S20. Randomly initialize each of the mesh cells as void cells and solid cells, and the proportion of solid cells is not less than a preset solid volume fraction; S30. Filter and clean the mesh cells so that the gap cells and the solid cells are gathered together to form the gap region and the solid material region, and make the solid material region continuously connect the rigid shaft connection region and the external connection rigid region. S40. The void region and the solid material region are arrayed along the circumferential direction to obtain an integral torsional vibration damping superstructure. S50. Obtain the torque-rotation angle relationship curve of the integral torsional vibration damping superstructure, and calculate the error between the torque-rotation angle relationship curve and the target curve; S60. Repeat steps S20 to S50, iteratively adjusting the shape and range of the gap region. When the error between the torque-angle relationship curve and the target curve reaches a set range, the final gap region is obtained.

9. The integral torsional vibration damping superstructure according to claim 8, characterized in that, It also includes the following steps: S31. Identify the boundary points between the void region and the solid material region, and smooth the boundary points using spline fitting to form a continuous and smooth geometric boundary.

10. The integral torsional vibration damping superstructure according to claim 8, characterized in that, The volume fraction of the entity is not less than 0.5.

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