A detachable and assembled double-material origami multi-stage quasi-zero stiffness vibration isolator

Abstract

This invention discloses a detachable and assembleable dual-material origami multi-stage quasi-zero stiffness vibration isolator, composed of several origami unit cells. Each origami unit cell includes an upper support beam, a lower support beam, and a dual-material folding body connecting the upper and lower support beams. The dual-material folding body includes several rigid plates and several flexible creases. The rigid plates are interconnected through the flexible creases, and are also connected to the upper and lower support beams respectively through the flexible creases. Based on the kinematic principle of rigid origami, this invention utilizes the rigid plates to provide strict geometric constraints, ensuring that the plates do not bend during structural deformation, forcing all deformation energy to concentrate at the flexible creases. The flexible creases act as elastic hinges, providing the system's load-bearing capacity and restoring force through large-angle folding deformation.

Description

Technical Field

[0001] This invention relates to the field of vibration control and engineering structure technology, specifically to a detachable and assembleable dual-material origami multi-stage quasi-zero stiffness vibration isolator. Background Technology

[0002] In fields such as precision instrument transportation, aerospace load protection, and vehicle engineering, vibration isolation systems often require extremely low dynamic stiffness to isolate low-frequency and ultra-low-frequency vibrations. However, traditional linear vibration isolators, in order to lower the natural frequency, inevitably lead to excessive static displacement, resulting in poor system stability and insufficient load-bearing capacity. Quasi-zero stiffness technology, through the parallel connection of negative stiffness mechanisms and positive stiffness elements, achieves the characteristics of "high static stiffness and low dynamic stiffness," effectively solving the aforementioned contradiction.

[0003] Existing quasi-zero stiffness vibration isolators mostly employ combinations of magnetic springs, pre-compressed curved beams, or mechanical linkages, resulting in complex structures, large volumes, and high assembly precision requirements. In recent years, flexible metamaterials based on origami principles have attracted attention due to their lightweight and foldable characteristics. However, existing origami-based vibration isolators are mostly manufactured using a single material. If rigid materials (such as metals or hard plastics) are used, fatigue fractures easily occur at the creases during repeated folding, and large-stroke deformation is difficult to achieve; if soft materials (such as rubber) are used, the overall structural load-bearing capacity is too low to meet the requirements of heavy-duty operating conditions.

[0004] Furthermore, existing origami vibration isolation structures are typically integrally molded, and their stiffness characteristics and load-bearing capacity are fixed once manufactured. Faced with complex and ever-changing engineering environments (such as variations in load mass and excitation frequency), a single, fixed structure is difficult to adapt to, lacking the flexibility for on-site adjustments and the adaptability to multi-stage vibration isolation. Therefore, this invention proposes a detachable and assembleable dual-material origami multi-stage quasi-zero stiffness vibration isolator. Summary of the Invention

[0005] In view of the problems existing in the prior art, the present invention proposes a detachable and assembleable dual-material origami multi-stage quasi-zero stiffness vibration isolator. It adopts a design combining soft and hard materials to solve the contradiction between load-bearing capacity and lifespan, and realizes programmable and multi-stage adjustment of vibration isolation performance through modular disassembly and assembly.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows: A detachable and assembleable dual-material origami multi-stage quasi-zero stiffness vibration isolator comprises several origami unit cells. Each origami unit cell includes an upper support beam, a lower support beam, and a dual-material folding body connecting the upper and lower support beams. The dual-material folding body includes several rigid plates and several flexible creases. The rigid plates are interconnected through the flexible creases and are respectively connected to the upper and lower support beams through the flexible creases. The upper surface of the upper support beam and the lower surface of the lower support beam are provided with male-female mating structures for modular connection. Through the male-female mating structures, multiple origami unit cells can be stacked in series along the direction of force or spliced ​​side by side along the direction perpendicular to the direction of force.

[0007] Furthermore, the rigid plate surface is made of a first material, and the flexible crease is made of a second material, wherein the elastic modulus of the first material is greater than that of the second material.

[0008] Furthermore, the male-female mating structure includes a positioning pin at one end of the upper support beam and a positioning pin hole at the other end, as well as a positioning pin and a positioning pin hole at the corresponding position of the lower support beam; both the positioning pin and the positioning pin hole are perpendicular to the surface of the support beam, and the outer diameter of the positioning pin and the inner diameter of the positioning pin hole adopt an interference fit or a clearance fit, which is used to realize the rapid assembly and disassembly and positioning of adjacent origami unit cells.

[0009] Furthermore, the dual-material folded body is formed using a dual-nozzle fused deposition modeling or multi-material injection molding integrated additive manufacturing process.

[0010] Furthermore, the first material is polylactic acid, nylon, or carbon fiber reinforced composite material, and the second material is thermoplastic polyurethane or thermoplastic elastomer.

[0011] Furthermore, the origami unit cell is a variant based on the Kresling origami configuration or the Miura-ori origami configuration.

[0012] Furthermore, the rigid plate includes symmetrically distributed trapezoidal and triangular plates. When the origami unit cell is compressed by axial pressure, the trapezoidal and triangular plates rotate relative to each other around the flexible crease under rigid constraints. When the folding angle of the rigid plate reaches a preset critical geometric range, the spatial geometric configuration of the dual-material folding body enters a mechanical critical state. At this time, the axial bearing capacity of the structure does not change significantly with the increase of axial displacement, directly forming a mechanical response plateau period, thus exhibiting a quasi-zero stiffness characteristic with approximately zero dynamic stiffness.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: 1) This invention is based on the kinematics principle of rigid origami. It utilizes the rigid plate surface to provide strict geometric constraints, ensuring that the plate surface does not bend when the structure deforms, and forcing all deformation energy to concentrate at the flexible crease. The flexible crease acts as an elastic hinge, providing the system's load-bearing capacity and restoring force through large-angle folding deformation. 2) This invention adopts a dual-material integrated design, using a rigid plate surface (PLA) to bear high static loads and a flexible fold (TPU) to bear large deformation folds, effectively solving the contradiction between the easy fatigue fracture of a single rigid material and the low load-bearing capacity of a single soft material, and significantly improving the service life and load-bearing performance of the vibration isolator; 3) This invention achieves rapid assembly and disassembly in a "Lego-like" manner by setting standardized positioning pins and pin holes; users can adjust the configuration of the vibration isolator according to actual working conditions without professional tools, which greatly improves the flexibility of engineering applications; 4) This invention has programmable multi-level quasi-zero stiffness characteristics; through simple series stacking, multiple quasi-zero stiffness intervals can be constructed on the force-displacement curve, so that the same device can adapt to a wide range of varying load masses, solving the problem of narrow working range of traditional QZS vibration isolators. 5) The present invention has a compact structure and achieves quasi-zero stiffness by utilizing the geometric nonlinearity of origami. It does not require additional springs or magnetic components, making it easy to carry out low-cost, mass-produced customized production through 3D printing technology. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the overall structure of a single origami unit cell of the present invention; Figure 2 for Figure 1 Enlarged detail image of point A in the middle; Figure 3 for Figure 1 Enlarged detail image of section B in the middle; Figure 4 for Figure 1 Enlarged detail of section C; Figure 5 for Figure 1 Enlarged detail image of section D in the middle; Figure 6 This is a schematic diagram illustrating the folding and deformation principle of the origami unit cell of the present invention during the compression process; Figure 7 This is a three-dimensional schematic diagram of two origami unit cells assembled longitudinally in series according to the present invention; Figure 8 This is a three-dimensional schematic diagram of two origami unit cells connected in parallel laterally according to the present invention. Figure 9 This is a three-dimensional schematic diagram of the box structure assembled from four origami unit cells of the present invention; Figure 10 The diagram shows the multi-level quasi-zero stiffness force-displacement characteristic curves and corresponding assembly principle diagrams under different assembly configurations of the present invention.

[0015] In the diagram: 1. Upper support beam; 2. Rigid plate surface; 3. Flexible crease; 4. Lower support beam; 5. Positioning pin; 6. Positioning pin hole. Detailed Implementation

[0016] The present invention will be further described below with reference to the accompanying drawings, but the scope of protection of the present invention is not limited to the scope described.

[0017] like Figure 1 As shown, this invention discloses a detachable and assembleable dual-material origami multi-stage quasi-zero stiffness vibration isolator, whose basic constituent unit is an origami unit cell. This origami unit cell includes a parallel upper support beam 1 and a lower support beam 4, and a dual-material folding body located between them. The dual-material folding body includes several rigid plates 2 and several flexible creases 3. The rigid plates 2 are interconnected through the flexible creases 3, and the rigid plates 2 are respectively connected to the upper support beam 1 and the lower support beam 4 through the flexible creases 3.

[0018] This embodiment is manufactured using multi-material 3D printing technology. The large-area board surface is a rigid board surface 2, printed using high-modulus PLA (polylactic acid) material; the joints between the rigid board surface 2 and the joint between the rigid board surface 2 and the crossbeam are flexible creases 3, printed using high-elasticity TPU (thermoplastic polyurethane) material.

[0019] The core design concept of this invention lies in achieving ideal rigid origami kinematics using dual materials. In traditional single-material origami, the rigid plate 2 often bends along with the creases, leading to unpredictable mechanical properties and insufficient load-bearing capacity. In this invention, the rigid plate 2 is a PLA rigid plate, which acts as a kinematic constraint element, and its stiffness is much greater than that of the flexible crease 3, which is a TPU flexible crease. Therefore, during structural compression, the PLA plate remains flat, approximating a rigid body, forcing all geometric deformation to concentrate on the TPU flexible crease. At this time, the TPU crease acts as a distributed elastic hinge, and the elastic internal force (including bending and tensile strain energy) generated during folding constitutes the macroscopic load-bearing capacity and restoring force of the vibration isolator.

[0020] Furthermore, such as Figure 2-5 As shown, locating pin holes 6 and locating pin posts 5 are integrated at both ends of the upper support beam 1 and the lower support beam 4, respectively. The locating pin post 5 is a cylindrical protrusion, and the locating pin hole 6 is a corresponding round hole. Both are designed with a slight interference fit, which ensures the tightness of the connection during assembly, prevents loosening during vibration, and allows users to disassemble and reassemble it by hand.

[0021] Figure 6 The motion mechanism and coordinate definition of the structure are illustrated. The left side represents the initial state, and the right side represents the compressed state. A local coordinate system is established, and the folding angle is defined as... When vertical pressure is applied, the structural height decreases. Due to the geometric constraints of rigid plate 2, relative rotation occurs between the plates, causing a change in the dihedral angle.

[0022] To verify and design the quasi-zero stiffness characteristics of this structure, this embodiment establishes an energy method theoretical model based on the kinematics of rigid origami. The total potential energy of the system mainly consists of the elastic deformation energy at the flexible folds. Based on the rigid origami assumption, the rigid plate 2 is considered as a rigid body without energy storage, and the total potential energy can be expressed as the superposition of bending potential energy and tensile potential energy at all flexible folds. According to the kinematic closed-loop equation of rigid origami, the nonlinear geometric relationship between the structural height and the folding angle is derived. Then, by differentiating the total potential energy with respect to displacement, the theoretical relationship between load force and displacement is obtained: .

[0023] Due to the inherent strong geometric nonlinearity of origami configurations such as Kresling or Miura-ori, the kinematic properties of the structure enter a mechanically critical range within a specific compression stroke. Within this range, the mechanical response dominated by the evolution of the origami geometry couples with the hyperelastic behavior of the TPU material, causing the rate of change of the structure's axial load with respect to displacement, i.e., its dynamic stiffness, to naturally approach zero. Figure 8 As shown in the theoretical prediction curve, by optimizing the design of the plate geometry parameters, including the sector angle and the initial folding angle, the position of this critical interval can be precisely controlled, thereby constructing a quasi-zero stiffness platform with an approximate slope of zero on the force-displacement curve. Within this platform interval, the structure undergoes sufficient large-angle folding deformation, maintaining the high static load-bearing capacity derived from the large deformation stress of the TPU material while exhibiting extremely low dynamic stiffness, thus achieving excellent low-frequency vibration isolation.

[0024] Furthermore, such as Figure 7 and Figure 8 As shown, this invention supports multiple assembly modes. Figure 5 The vertically connected mode is shown, in which the lower support beam 4 of the previous origami unit cell and the upper support beam 1 of the next origami unit cell are locked together by a pin hole. Figure 8 It demonstrates a box structure formed by horizontal parallel connections, where four unit cells enclose a closed space, greatly enhancing lateral stability.

[0025] Figure 7The diagram illustrates a longitudinal cascade assembly mode, where the lower support beam 4 of the upper origami unit cell and the upper support beam 1 of the lower origami unit cell are closely fitted together, achieving male-female mating and axial locking through pre-set positioning pins 5 and positioning pin holes 6. This cascade mode allows the deformation stroke of the origami structure to be linearly superimposed longitudinally, thereby significantly expanding the effective working displacement range of the vibration isolator.

[0026] Figure 8 It demonstrates a lateral side-by-side splicing mode, in which two or more unit cells are assembled side by side through a lateral connection structure. This mode can multiply the load-bearing stiffness of the system.

[0027] Figure 9 The design showcases a box-like assembly pattern, where four origami unit cells are connected end-to-end via corner pin holes to form a closed rectangular space. This structure leverages the advantages of closed-loop topology, significantly enhancing the system's lateral stiffness and overturning stability while retaining low vertical stiffness, effectively preventing structural instability when the height-to-diameter ratio is too large.

[0028] Furthermore, the core advantage of this invention lies in its ability to achieve "programmable" mechanical properties through different assembly methods. For example... Figure 10 As shown in the figure, the experimental measurement data (Exp.) and theoretical predictions under two typical assembly strategies are compared.

[0029] See Figure 10 The diagram on the right illustrates how changing the connection topology of the unit cells can significantly alter the overall stiffness characteristics of the system. The curve at the bottom of the diagram represents the response of a hierarchical stacked structure (i.e., the pyramidal stacked configuration shown in the lower right corner of the diagram). In this configuration, due to the different numbers of side-by-side connected unit cells in each level (e.g., 1 in the top layer, 2 in the middle layer, and 3 in the bottom layer), or due to pre-set parameter differences, the unit cells in the stacked levels do not buckle simultaneously, but rather exhibit a "multi-level buckling" pattern.

[0030] Specifically, when compressive displacement is applied, the system initially exhibits a linearly increasing mechanical response. When the load reaches the first critical value (approximately...),... When the first layer of unit cells, which has lower stiffness or is under concentrated stress, enters the quasi-zero stiffness state first, forming the first quasi-zero stiffness plateau on the force-displacement curve. The corresponding effective vibration isolation stroke is... Within this region, although the compressive displacement increases, the reaction force remains essentially constant, achieving excellent vibration isolation for this level of light load.

[0031] As compressive displacement continues to increase, the first layer of unit cells is compacted or enters the hardening stage, and the force continues to rise. Subsequently, the second layer, or unit cells with higher stiffness, are activated and buckle, forming a second quasi-zero stiffness plateau on the force-displacement curve, corresponding to a load increase to approximately [value missing]. At this point, the system is able to isolate vibrations from medium-weight loads.

[0032] Similarly, if the number of side-by-side connected units is increased or the number of series layers is adjusted, the overall load-bearing capacity of the system will be further improved. The red curve at the top of the figure shows the response under the high load-bearing configuration (i.e., the 2×2 rectangular array structure shown in the upper right corner of the figure), and the load corresponding to the quasi-zero stiffness platform formed by it reaches... arrive level.

[0033] This stepped force-displacement curve characteristic confirms the invention's strong adaptability to various operating conditions. Users do not need to replace the main vibration isolator; they only need to adjust the series-parallel combination of the standard unit cells (i.e., as shown in the image). Figure 10 (As shown on the right, a block-style stacking method) can achieve adaptation. The near-zero stiffness vibration isolation operating point for equipment of different weights truly realizes the on-site reconfigurability and customization of vibration isolation performance.

[0034] The multi-level quasi-zero stiffness characteristic is achieved through the following assembly methods: multiple origami unit cells with the same or different mechanical properties are connected in series, side by side, or mixed and assembled; when origami unit cells with different stiffness characteristics are connected in series, as the compressive displacement increases, each unit cell undergoes buckling deformation in sequence due to the difference in the buckling critical load, thereby forming multiple stepped quasi-zero stiffness plateau regions on the force-displacement curve of the overall structure; when multiple origami unit cells are connected side by side to form a box structure or array structure, the load-bearing capacity of the vibration isolator increases exponentially while maintaining the quasi-zero stiffness characteristic unchanged.

[0035] This invention also proposes a method for using a detachable and assembleable dual-material origami multi-stage quasi-zero stiffness vibration isolator, comprising the following steps: 1) Select an appropriate number of origami unit cells based on the weight and size of the equipment to be isolated and the available installation space on site; 2) Determine the assembly configuration: If increased load-bearing capacity is required, connect multiple unit cells laterally side-by-side (e.g., Figure 8 ) or enclosed box structure (such as Figure 9 If increased vibration isolation stroke is required, multiple unit cells can be connected in series longitudinally (e.g., Figure 7 If it is necessary to adapt to varying loads or multi-level vibration isolation, different numbers of unit cells can be hierarchically connected (e.g., Figure 10 (The pyramid configuration in the middle) 3) Using the positioning pins 5 and positioning pin holes 6 on the supporting beam, manually press and splice the unit cells to complete the assembly; 4) Place the assembled vibration isolator between the vibration source and the precision equipment, and adjust the preload to make it work in the quasi-zero stiffness platform region of the force-displacement curve, so as to achieve efficient low-frequency vibration isolation.

Claims

1. A detachable and assembleable dual-material origami multi-stage quasi-zero stiffness vibration isolator, characterized in that... It comprises several origami unit cells, each of which includes an upper support beam (1), a lower support beam (4), and a dual-material folding body connected between the upper support beam (1) and the lower support beam (4). The dual-material folding body includes several rigid plates (2) and several flexible creases (3). The rigid plates (2) are interconnected through the flexible creases (3), and the rigid plates (2) are connected to the upper support beam (1) and the lower support beam (4) respectively through the flexible creases (3). The upper surface of the upper support beam and the lower surface of the lower support beam are provided with a male-female mating structure for modular connection. Through the male-female mating structure, multiple origami unit cells can be stacked in series along the direction of force or spliced ​​side by side along the direction perpendicular to the direction of force.

2. The detachable and assembleable dual-material origami multi-stage quasi-zero stiffness vibration isolator according to claim 1, characterized in that... The rigid plate (2) is made of a first material, and the flexible crease (3) is made of a second material, wherein the elastic modulus of the first material is greater than that of the second material.

3. The detachable and assembleable dual-material origami multi-stage quasi-zero stiffness vibration isolator according to claim 1, characterized in that... The male-female mating structure includes a positioning pin (5) at one end of the upper support beam (1) and a positioning pin hole (6) at the other end, as well as a positioning pin (5) and a positioning pin hole (6) at the corresponding position of the lower support beam (4); the positioning pin (5) and the positioning pin hole (6) are both perpendicular to the surface of the support beam, and the outer diameter of the positioning pin (5) and the inner diameter of the positioning pin hole (6) adopt an interference fit or a clearance fit, which is used to realize the rapid assembly and disassembly and positioning of adjacent origami unit cells.

4. The detachable and assembleable dual-material origami multi-stage quasi-zero stiffness vibration isolator according to claim 1, characterized in that... The dual-material folded body is formed using a dual-nozzle fused deposition modeling or multi-material injection molding integrated additive manufacturing process.

5. A detachable and assembleable dual-material origami multi-stage quasi-zero stiffness vibration isolator according to claim 2, characterized in that... The first material is polylactic acid, nylon, or carbon fiber reinforced composite material, and the second material is thermoplastic polyurethane or thermoplastic elastomer.

6. The detachable and assembleable dual-material origami multi-stage quasi-zero stiffness vibration isolator according to claim 1, characterized in that... The origami unit cell is a variant based on the Kresling origami configuration or the Miura-ori origami configuration.

7. A detachable and assembleable dual-material origami multi-stage quasi-zero stiffness vibration isolator according to claim 6, characterized in that... The rigid plate (2) includes trapezoidal plates and triangular plates that are symmetrically distributed. When the origami unit cell is compressed by axial pressure, the trapezoidal plate and the triangular plate rotate relative to each other around the flexible crease (3) under rigid constraints. When the folding angle of the rigid plate (2) reaches the preset critical geometric range, the spatial geometric configuration of the dual-material folding body enters the mechanical critical state. At this time, the axial bearing capacity of the structure does not change significantly with the increase of axial displacement, directly forming a mechanical response plateau period, thus exhibiting a quasi-zero stiffness characteristic with approximately zero dynamic stiffness.

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