CN113309784B - Geometric nonlinear adjustable multi-stable-state device - Google Patents

Abstract

The invention provides a geometric nonlinear adjustable multi-stable device, which solves the shortcomings of the existing multi-stable mechanism, such as complex structure, unadjustable stroke, and difficulty in adjusting the number of stable states. The design of nonlinear multistable systems and their applications are poorly studied problems. The geometrically nonlinear adjustable multistable device provides a basic multistable unit through the configuration of the elastic element, the support and the second mass, and can realize the variation between different multistable mechanisms by using the property of adjustable geometric parameters. , The variant process does not need to add any other devices, effectively avoids the efficiency and cost problems caused by the loading and unloading of different multi-stable mechanisms, and has the characteristics of practicality, low energy consumption, and low cost.

Description

A Geometrically Nonlinear Tunable Multistable Device

technical field

The invention belongs to the technical field of nonlinear dynamics and control, and relates to a geometric nonlinear adjustable multi-stable device.

Background technique

Geometric nonlinear systems have been widely used in aerospace, aviation, navigation, weaponry, medical treatment, machining, energy harvesting and other fields. The simplest form of a geometrically nonlinear system is a single-degree-of-freedom monostable structure, where the system has only one stable equilibrium state and one oscillating mass. In recent years, scholars at home and abroad have proposed a new type of geometric nonlinear quasi-zero stiffness vibration isolator by using the method of connecting a monostable positive stiffness element and a bistable negative stiffness element in parallel. The quasi-zero stiffness vibration isolation system has excellent characteristics such as high static and low dynamic stiffness, which can improve the vibration isolation accuracy and achieve lower frequency vibration isolation, but there are still problems such as ultra-low frequency and resonance. Limited by the research progress of geometric nonlinear dynamics, the design theory, control strategy and application of geometric nonlinear multi-stable systems are still in the exploratory stage, especially the tunable multi-stable mechanisms that satisfy multiple specific functions have become constraints. The key to improving the performance and accuracy of mechanical equipment.

At present, Chinese patents CN100837947A and CN101799086 all propose a multi-stable mechanism using a single flexible bistable mechanism combined with a multi-stage link-slider mechanism; Chinese patent CN102556934A proposes using four guide grooves and a moving slider combined with multiple magnets Designed multistable mechanisms; US patents US2009/0186196A1 and US2007/01200011A1 propose multistable mechanisms that rely on residual stress to produce multi-stage plastic deformation of the structure. However, the above-mentioned existing multi-stable mechanisms have disadvantages such as complex structure, inability to adjust the stroke, and difficulty in adjusting the number of stable states, and little research has been done on the design and application of geometrically nonlinear multi-stable systems with high-order quasi-zero stiffness characteristics. .

Therefore, starting from the development needs of aerospace, equipment, machining, energy harvesting, etc., it is urgent to design a geometrically nonlinear adjustable multi-stable mechanism that meets multiple specific functions to improve the technical level of ultra-low frequency energy harvesting and vibration isolation. and technological maturity to promote quality and quality improvement in aerospace, machining, energy harvesting, etc.

SUMMARY OF THE INVENTION

The purpose of the present invention is to solve the shortcomings of the existing multi-stable mechanism, such as complex structure, inability to adjust the stroke, and difficulty in adjusting the number of stable states. However, it provides a geometrically nonlinear tunable multistable device that satisfies several specific functions.

To achieve the above object, the technical solution provided by the present invention is:

A geometric nonlinear adjustable multi-stable device, which is special in that it includes a rectangular frame, a multi-stable unit, a first connecting rod, a first mass block and a first guide rail;

The rectangular frame is composed of an upper adjusting frame, a lower adjusting frame and fixing frames on both sides;

Both ends of the first guide rail are respectively connected with the upper adjustment frame and the lower adjustment frame, and the first guide rail is arranged in parallel with the fixing frames on both sides, and the upper adjustment frame and the lower adjustment frame can be along the first guide rail. Move up and down to adjust the spacing;

the first mass block is slidably arranged on the first guide rail;

The multi-stable unit is located between the first guide rail and the fixing frame on one side, and includes a support and an elastic element;

The elastic element is an element that is symmetrical up and down, and its two ends are respectively installed on the upper side adjustment frame and the lower side adjustment frame through the support; its center point is connected with the first mass block through the first connecting rod;

Definition: the distance between the upper adjustment frame and the lower adjustment frame and the center point is a, the distance between the support and the first guide rail is b, and the length of the first link is c;

By adjusting a, b, and c, the displacement and the steady state number of the first mass can be adjusted. The size of a is achieved by changing the positions of the upper and lower adjusting frames on the first guide rail, b by changing the position of the support, and c by changing the length of the first link.

Further, the elastic element is an elastic element of any shape that can generate restoring force; for example, a beam, a plate, a mechanical spring or an electromagnetic spring, and the elastic mechanism constructed therefrom, and the arrangement and number thereof are arbitrary. Correspondingly, depending on the elastic element, the support can be designed to be hinged or fixed with the elastic element.

Further, the elastic element includes a second mass block, a second guide rail and two springs; one end of the second guide rail is installed at the midpoint of the fixing frame, and the second guide rail is perpendicular to the first guide rail; the first guide rail is arranged vertically. The two mass blocks are slidably arranged on the second guide rail, and the opposite sides thereof are respectively connected with the supports arranged on the upper adjustment frame and the lower adjustment frame through a linear spring; or, the elastic element is a buckling beam.

The geometrically nonlinear adjustable multi-stable device utilizes the property of adjustable geometric parameters, and provides a basic multi-stable unit through the configuration of the elastic element, the support and the second mass, so as to realize the second guide rail within the preset displacement range. B steady-state systems, so that the first mass fixed on the first guide rail has at most A=B*2 steady states, and the displacement and the number of steady states of the first mass can be adjusted by adjusting a, b, and c. . The number of stable states of a multi-stable element is arbitrary, including monostable, bistable, multi-stable, and even zero-stiffness mechanisms with infinite stable states.

Further, the connecting rod, the first mass and the second mass are rigid elements of any shape, such as rods, shafts, beams, plates or curved structures.

On the basis of the above-mentioned geometric nonlinear adjustable multi-stable device, the present invention also discloses the following three systems, which are:

1. The multi-stable vibration energy harvesting system based on the above-mentioned geometrically nonlinear adjustable multi-stable device is special in that:

Electromechanical conversion elements are provided on both the first mass and the elastic element.

The specific performance is as follows: install electromechanical conversion elements on both the first mass block and the second mass block; paste the electromechanical conversion elements at the maximum deformation of the spring, and paste the electromechanical conversion elements at the positions close to both ends of the buckling beam.

Further, the electromechanical conversion element adopts an electromagnetic electromechanical conversion element (eg, permanent magnet + conductive coil) or a piezoelectric electromechanical conversion element (eg, piezoelectric ceramic or piezoelectric film). Wherein, the electromechanical conversion elements on each component can be the same or different, so as to form an electromagnetic, piezoelectric or electromagnetic-piezo hybrid vibration energy harvesting system.

Utilize the above-mentioned device, the concrete vibration energy collection method steps are as follows:

1) Adjust the parameters a, b and c so that the multi-stable unit is in a preset multi-stable state, that is, a multi-stable vibration energy harvesting system is obtained.

2) Apply basic excitation in the y direction of the first guide rail, or apply excitation on the first mass block, and the multi-stable vibration energy harvesting system starts to work.

The above-mentioned multi-stable vibration energy harvesting system can be used for multi-direction-multi-level broadband low-frequency-ultra-low frequency, weak excitation intensity and other vibration energy harvesting.

2. The nonlinear vibration isolation system based on the above-mentioned geometrically nonlinear adjustable multi-stable device is special in that:

Both the first mass block and the elastic element are provided with electro-mechanical conversion elements; and a bearing elastic element is added on the first mass block to provide the first mass block with a constant force that is collinear and equal in magnitude to the direction of gravity it is subjected to. .

Utilize the above-mentioned device, the concrete vibration isolation method steps are as follows:

1) Adjust the parameters a, b and c to make the multistable element have different nonlinear stiffness or zero stiffness characteristics, including: quasi-zero stiffness characteristics, high-order quasi-zero stiffness characteristics, softening effect, hardening effect, softening-hardening effect, etc. , so that the load is placed in a certain gravity environment, including but not limited to a zero-microgravity suspension state, that is, a nonlinear vibration isolation system with preset displacement and frequency band is obtained.

2) Apply basic excitation in the y direction of the first guide rail, or apply excitation on the first mass block, and the nonlinear vibration isolation system starts to work.

The above nonlinear vibration isolation system can be used for multi-body-multi-stage low-frequency-ultra-low frequency vibration isolation, ground simulation of gravity environment, modal testing, etc.

3. The multi-level tunable multi-stable system based on the above-mentioned geometrically nonlinear tunable multi-stable device is characterized in that:

Electromechanical conversion elements are arranged on both the first mass block and the elastic element;

The connecting rod guide rail device includes a third guide rail and a third mass;

the third guide rail is perpendicular to the first guide rail;

The third mass block is slidably arranged on the third guide rail, and is connected with the first mass block through the second connecting rod.

Further, in order to ensure the symmetry of the system, the geometric nonlinear adjustable multi-stable device is symmetrically arranged on the other side of the connecting rod guide rail device, and the first guide rail in the device is perpendicular to the third guide rail, The first mass is connected with the third mass through the third connecting rod.

Further, according to the needs, a plurality of link guide rail devices and geometrically nonlinear adjustable multi-stable devices can be sequentially added in the above-mentioned manner to form a multi-level adjustable multi-stable system; m=n*2 ^s-1 , where n is the number of stable states of the multistable unit.

Utilize the above-mentioned device, the specific multi-level arrangement method steps are as follows:

1) The multi-stage adjustable multi-stable system is obtained through the sliding of each stage mass block on the connecting rod guide rail and the steady-state change of the initial steady-state unit.

2) Adjust the parameters a, b and c so that the multistable unit satisfies the geometrically nonlinear adjustable multistable mechanism with multiple specific functions; the number of stable states of the s-th multistable system is m=n*2 ^{s- 1} , n is the steady state number of the multi-stable unit; the steady state number of each stage can be adjusted by the geometric parameters a, b, c and the length of the guide rail.

3) Apply basic excitation in the guiding direction of the guide rail of the s-th stage, or apply excitation on the mass block, and the multi-stage adjustable multi-stable device starts to work.

The above-mentioned multi-stage adjustable multi-stable system can be used for multi-body-multi-stage gravity environment ground simulation, multi-body-multi-stage low-frequency-ultra-low frequency vibration isolation, multi-body-multi-stage modal testing, multi-directional-multi-stage vibration energy harvesting Wait.

The advantages of the present invention are:

1. The present invention has the advantages of simple structure, good adjustability, adjustable steady state number and steady state position, and high repeatability. Especially through the adjustment of geometric nonlinear parameters, the variation between different multi-stable mechanisms can be realized, and the modification process does not need to add any other devices, effectively avoiding the system efficiency and cost caused by loading and unloading different multi-stable mechanisms. It has the characteristics of practicality, low energy consumption and low cost. Therefore, the mechanism of the present invention can be used as a key element to realize the multi-level, multi-body and multi-stable state of the system, and has broad application prospects in the fields of aerospace, aviation, navigation, weapon equipment, medical treatment, machining, energy collection and the like.

2. The present invention is suitable for energy collection, vibration isolation and space gravity environment ground simulation in low frequency and ultra-low frequency vibration environments, including but not limited to aerospace, aviation, navigation, weapon equipment, medical treatment, electromechanical systems, machining, intelligent machinery Design and other fields to install such geometrically nonlinear tunable multistable devices.

Description of drawings

Fig. 1 is the structural principle schematic diagram of the geometric nonlinear adjustable multi-stable system according to the present invention;

2 is a schematic diagram of the structural principle of the geometrically nonlinear tunable multi-stable system described in Embodiment 1 of the present invention;

FIG. 3 is a schematic diagram of the structural principle of the geometrically nonlinear tunable multi-stable system described in the second embodiment of the present invention.

The reference numbers are as follows:

1-upper side adjustment frame, 2-left side fixing frame, 3-multi-stable unit, 31-support, 32-spring, 33-second mass, 34-second guide rail, 4-first link, 5- First mass, 6- First guide rail, 7- Electromechanical conversion element, 71- Permanent magnet, 72- Conductive coil, 73- Piezoelectric ceramic or piezoelectric film, 8- Bearing elastic element, 9- Link guide rail Components, 91-third mass, 92-second link, 93-third rail.

Detailed ways

The content of the present invention is described in further detail below in conjunction with the accompanying drawings and specific embodiments:

The basic device is:

A geometrically nonlinear adjustable multistable device includes a rectangular frame, a multistable unit, a first connecting rod, a first mass and a first guide rail.

The rectangular frame is composed of an upper adjusting frame, a lower adjusting frame, a left fixing frame and a right fixing frame. The two ends of the first guide rail are respectively connected with the upper side adjusting frame and the lower side adjusting frame, and the first guide rail is arranged in parallel with the fixing frames on both sides, so that both the upper side adjusting frame and the lower side adjusting frame can move up and down along the first guide rail. , adjust the spacing; the first mass block is slidably arranged on the first guide rail.

There are two multi-stable units, which are respectively symmetrically arranged between the first guide rail and the left and right fixed frames. Each multi-stable unit includes a support, an elastic piece, a second mass block and a second guide rail; one end of the second guide rail is installed at the midpoint of the fixed frame, and the second guide rail is perpendicular to the first guide rail; the second mass The block is slidably arranged on the second guide rail; there are two supports, which are respectively fixed on the upper adjustment frame and the lower adjustment frame, and are respectively connected with the second mass block through elastic parts; the first mass block and the second mass The blocks are connected by a first link (both are hinged to the first link).

Definition: the distance between the upper adjustment frame and the lower adjustment frame and the second guide rail is a, the distance between the support and the first guide rail is b, and the length of the first link is c; a, b, and c are all Adjustable, the displacement and steady state number of the first mass can be adjusted by adjusting a, b, and c.

Embodiment 1: Geometrically nonlinear tunable multistable system based on spring-mass system

Referring to Fig. 1, the realization approach of the multistable unit 3 of this scheme is shown in Fig. 2. The support 31 in the multi-stable unit 3 is hinged; the elastic element is a linear spring 32 , which is symmetrically distributed on both sides of the second mass 33 .

The multi-stable vibration energy harvesting system of the geometrically nonlinear adjustable multi-stable device based on the spring-mass system, the electro-mechanical conversion element is arranged on both the first mass block and the elastic element of the basic device.

The multistable vibration energy harvesting method of a geometrically nonlinear tunable multistable device based on a spring-mass system includes the following steps:

The first step is to install the electromechanical conversion element 7. The electromechanical conversion element 7 is composed of a permanent magnet 71 and a conductive coil 72. The permanent magnet 71 is installed on the first mass 5 and the second mass 33, and the conductive coil 72 is arranged on the permanent magnet 71. The direction of movement constitutes an electromagnetic energy harvesting electromechanical system.

In the second step, the parameters a, b and c are adjusted so that the multi-stable unit 3 is in a preset monostable or bistable state, that is, a y-direction bistable or four-stable vibration energy harvesting system is obtained.

In the third step, basic excitation is applied in the guiding direction y direction of the first guide rail 6, or excitation is applied to the first mass 5, and the multi-stable vibration energy harvesting system starts to work.

A vibration isolation system of a geometrically nonlinear adjustable multistable device based on a spring-mass system, an electro-mechanical conversion element is arranged on both the first mass block and the elastic element of the basic device; and a bearing elastic element is added on the first mass block , which provides the first mass with a constant force that is collinear and equal in magnitude to its gravitational direction.

The vibration isolation method of a geometrically nonlinear tunable multistable device based on a spring-mass system includes the following steps:

In the first step, on the basis of the existing electromechanical conversion components, the load-bearing elastic element 8 is continued to be added. The load-bearing elastic element 8 is a spring, which provides the load with a constant force that is collinear and equal in magnitude to the direction of gravity it is subjected to.

In the second step, the parameters a, b and c are adjusted so that the multistable element 3 has different nonlinear stiffnesses, including: quasi-zero stiffness characteristics, hardening effects, etc., that is, a nonlinear vibration isolation system with preset displacement and frequency band is obtained.

In the third step, basic excitation is applied in the guiding direction y direction of the first guide rail 6, or excitation is applied to the first mass 5, and the nonlinear vibration isolation system starts to work.

A multi-level adjustable multi-stable system based on a geometrically nonlinear adjustable multi-stable device of spring-mass system, a connecting rod guide rail device is added to the basic device, and electro-mechanical conversion is set on both the first mass block and the elastic element The connecting rod guide rail device includes a third guide rail and a third mass; the third guide rail is perpendicular to the first guide rail; the third mass block is slidably arranged on the third guide rail, and is connected with the first mass block through the second link connect.

A multi-level arrangement method for a geometrically nonlinear tunable multistable system based on a spring-mass system, including the following steps:

The first step is to add a new link guide rail assembly 9 in a direction perpendicular to the first guide rail 6 . The third mass 91 is slidably arranged on the third guide rail 93 ; the two ends of the second connecting rod 92 are hinged with the third mass 91 and the first mass 5 respectively.

In the second step, in order to ensure the symmetry of the system, an upper-level multi-stable system can be added to the other side of the link guide rail assembly 9 .

In the third step, a multi-stage adjustable multi-stable system is obtained through the sliding of each stage mass block on the link guide rail and the steady-state change of the initial steady-state unit.

In the fourth step, the parameters a, b and c are adjusted so that the multistable unit 3 satisfies the geometrically nonlinear adjustable multistable mechanism with multiple specific functions. The steady state number m=n*2 ^s-1 of the s-th multistable system, where n is the steady state number of the multistable unit 3 . The steady-state number of each stage can be adjusted by geometric parameters a, b, c and rail length.

In the fifth step, the basic excitation is applied to the guiding direction of the guide rail of the s-th stage, or the excitation is applied to the mass block, and the multi-stage adjustable multi-stable device starts to work.

Embodiment 2: Beam-Based Geometrically Nonlinear Tunable Multistable System

Referring to Fig. 1, the realization approach of the multistable unit 3 of this scheme is shown in Fig. 3. The support 31 in the multistable unit 3 is fixed; the elastic element, the second mass and the second guide rail are all replaced by beam buckling.

The vibration energy harvesting method of the beam-based geometrically nonlinear tunable multi-stable system includes the following steps:

The first step is to install the electromechanical conversion element 7. The electromechanical conversion element 7 is composed of a permanent magnet 71, a conductive coil 72 and a piezoelectric ceramic or piezoelectric film 73; the permanent magnet 71 is installed on the first mass block 5, and the conductive coil 72 is arranged on the In the moving direction of the permanent magnet 71, the piezoelectric ceramic or piezoelectric film 73 is pasted on the root of the elastic element 32 to form an electromagnetic-piezoelectric hybrid energy harvesting electromechanical system.

In the second step, the parameters a, b and c are adjusted so that the multi-stable unit 3 is in a preset monostable or bistable state, that is, a y-direction bistable or four-stable vibration energy harvesting system is obtained.

In the third step, basic excitation is applied in the guiding direction y direction of the first guide rail 6, or excitation is applied to the first mass 5, and the multi-stable vibration energy harvesting system starts to work.

The vibration isolation method for the beam-based geometrically nonlinear adjustable multi-stable system includes the following steps:

The first step is to add a load-bearing elastic element 8 on the basis of the existing electromechanical conversion component. The load-bearing elastic element 8 is a spring, which provides the load with a constant force that is collinear and equal in magnitude to the direction of its gravity.

In the second step, the parameters a, b and c are adjusted so that the multistable element 3 has different nonlinear stiffnesses, including: quasi-zero stiffness characteristics, hardening effects, etc., that is, a nonlinear vibration isolation system with preset displacement and frequency band is obtained.

In the third step, basic excitation is applied in the guiding direction y direction of the first guide rail 6, or excitation is applied to the first mass 5, and the nonlinear vibration isolation system starts to work.

The multi-level arrangement method of the beam-based geometrically nonlinear tunable multi-stable system includes the following steps:

The first step is to add a new link guide rail assembly 9 in a direction perpendicular to the last stage of the first guide rail 6 . The third mass 91 is located on the third guide rail 93 ; both ends of the second link 92 are hinged with the third mass 91 and the first mass 5 respectively.

In the second step, in order to ensure the symmetry of the system, an upper-level multi-stable system can be added to the other side of the link guide rail assembly 9 .

In the third step, a multi-stage adjustable multi-stable system is obtained through the sliding of each stage mass block on the link guide rail and the steady-state change of the initial steady-state unit.

In the fourth step, the parameters a, b and c are adjusted so that the multistable unit 3 satisfies the geometrically nonlinear adjustable multistable mechanism with multiple specific functions. The steady state number m=n*2s-1 of the s-th multistable system, where n is the steady state number of the multistable unit 3 . The steady-state number of each stage can be adjusted by geometric parameters a, b, link length c and guide rail length.

In the fifth step, the basic excitation is applied to the guiding direction of the guide rail of the s-th stage, or the excitation is applied to the mass block, and the multi-stage adjustable multi-stable device starts to work.

The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited to this. Any person skilled in the art can easily think of various equivalents within the technical scope disclosed by the present invention. Modifications or substitutions should be included within the protection scope of the present invention.

Claims (10)

1. A geometrically nonlinear adjustable multistable device, characterized in that: the device comprises a rectangular frame, a multistable unit, a first connecting rod, a first mass block and a first guide rail;

the rectangular frame consists of an upper side adjusting frame, a lower side adjusting frame and fixing frames on two sides;

the two ends of the first guide rail are respectively connected with the upper side adjusting frame and the lower side adjusting frame, the first guide rail is arranged in parallel with the fixing frames on the two sides, and the upper side adjusting frame and the lower side adjusting frame can move up and down along the first guide rail to adjust the distance;

the first mass block is arranged on the first guide rail in a sliding manner;

the multistable unit is positioned between the first guide rail and the fixed frame on one side of the first guide rail and comprises a support and an elastic element;

the elastic element is an element which is symmetrical up and down, and two ends of the elastic element are respectively arranged on the upper side adjusting frame and the lower side adjusting frame through the support; the center point of the first mass block is connected with the center point of the second mass block through a second connecting rod;

defining: the distance between the upper adjusting frame and the central point, the distance between the support and the first guide rail and the distance between the lower adjusting frame and the central point are a, the distance between the support and the first guide rail is b, and the length of the first connecting rod is c;

the displacement and the number of stable states of the first mass block can be adjusted by adjusting a, b and c.

2. The geometrically nonlinear tunable multistable device according to claim 1, characterized in that:

the elastic element is an element which can generate restoring force and has any shape.

3. The geometrically nonlinear tunable multistable device according to claim 2, characterized in that:

the elastic element comprises a second mass block, a second guide rail and two springs;

one end of the second guide rail is arranged at the midpoint of the fixing frame, and the second guide rail is perpendicular to the first guide rail;

the second mass block is arranged on the second guide rail in a sliding manner, and two opposite sides of the second mass block are respectively connected with the supports arranged on the upper adjusting frame and the lower adjusting frame through a linear spring;

alternatively, the resilient element is a buckling beam.

4. The geometrically nonlinear tunable multistable device according to claim 3, characterized in that: the connecting rod, the first mass block and the second mass block are rigid elements in any shapes.

5. A multistable vibration energy harvesting system based on a geometrically nonlinear adjustable multistable device according to any of claims 1-4 wherein:

and the first mass block and the elastic element are both provided with electromechanical conversion elements.

6. A multistable nonlinear vibration isolation system based on the geometrically nonlinear adjustable multistable device of any one of claims 1-4, characterized in that:

the first mass block and the elastic element are both provided with electromechanical conversion elements; and a bearing elastic element is added on the first mass block to provide a constant force which is collinear with the direction of the gravity borne by the first mass block and has the same magnitude with the direction of the gravity borne by the first mass block.

7. A multistage adjustable multistable system based on the geometric nonlinear adjustable multistable device of any one of claims 1-4, characterized in that: also comprises a connecting rod guide rail device which is provided with a connecting rod,

the first mass block and the elastic element are both provided with electromechanical conversion elements;

the connecting rod guide rail device comprises a third guide rail and a third mass block;

the third guide rail is perpendicular to the first guide rail;

the third mass block is arranged on the third guide rail in a sliding mode and is connected with the first mass block through a second connecting rod.

8. The multi-stage tunable multistable system according to claim 7 wherein:

the other side of the connecting rod guide rail device is symmetrically provided with the geometric nonlinear adjustable multi-stable-state device, a first guide rail in the device is vertical to a third guide rail, and a first mass block is connected with a third mass block through a third connecting rod.

9. The multi-stage tunable multistable system according to claim 8 wherein:

according to the requirement, a plurality of connecting rod guide rail devices and geometric nonlinear adjustable multistable devices are sequentially added;

wherein, the steady state number m-n of the s-th stage multi-steady state system is 2^s-1And n is the steady state number of the multi-steady state unit.

10. The multi-stage tunable multistable system according to claim 9 wherein:

the electromechanical conversion element is an electromagnetic electromechanical conversion element or a piezoelectric electromechanical conversion element.

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