Novel multi-degree-of-freedom nonlinear energy trap and application thereof

Abstract

The invention relates to the technical field of structural vibration suppression, and provides a novel multi-degree-of-freedom non-linear energy trap and application thereof, and the multi-degree-of-freedom non-linear energy trap comprises a plurality of single-degree-of-freedom non-linear energy traps with combined damping and combined rigidity and a spacecraft structure capable of applying the multi-degree-of-freedom non-linear energy traps. The invention provides a novel multi-degree-of-freedom nonlinear energy trap with combined damping and combined rigidity. The novel multi-degree-of-freedom nonlinear energy trap is formed by connecting a plurality of single-degree-of-freedom nonlinear energy traps with combined damping and combined rigidity in series, wherein each single-degree-of-freedom nonlinear energy trap is composed of a mass block, a combined damping object and a combined rigidity object. According to the novel multi-degree-of-freedom nonlinear energy trap, the excellent vibration reduction effect can be achieved, then the dynamic characteristic of a spacecraft under the extreme service condition is improved, the good protection effect can be achieved for the spacecraft and some precise structures highly sensitive to vibration, and the service life of equipment is effectively prolonged.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of structural vibration suppression, in particular to a new multi-degree-of-freedom nonlinear energy sink for suppressing vibration of a structure to be damped and a spacecraft structure using the multi-degree-of-freedom nonlinear energy sink. BACKGROUND

[0002] A spacecraft will face a complex and severe dynamic environment during launch, on-orbit operation and re-entry, including dynamic loads generated by spacecraft engine operation, impact loads transmitted to the spacecraft during separation, random loads generated during attitude and orbit control, etc. The complex and severe dynamic environment will cause harmful structural vibrations of the spacecraft, which will cause the precision of the spacecraft structure (such as precision structures and sensitive structures) to decrease or affect the normal operation, and even cause the structure to be damaged. Therefore, in order to ensure the normal operation of the spacecraft in the complex and severe dynamic environment, it is of great significance to effectively suppress the vibration of the spacecraft. The nonlinear energy sink is a passive damping method, which has been widely concerned by scholars due to its low cost, simple structure and easy maintenance.

[0003] The nonlinear energy sink is a light accessory connected to the object to be damped, which can cause the vibration energy to be rapidly and unidirectionally transferred from the object to be damped to the nonlinear energy sink. Compared with the linear damper, the nonlinear energy sink has a wider vibration damping bandwidth.

[0004] After searching, the authorized announcement number CN112182881B is a nonlinear energy sink optimal stiffness solving method based on platform phenomenon, which obtains an optimal stiffness analytical solution that breaks away from the constraints of initial conditions, is applied to the design of a nonlinear damper, has simple actual operation, good optimization effect, great value and development prospect; but the existing nonlinear energy sink is mostly a single-degree-of-freedom type, and the research on multi-degree-of-freedom nonlinear energy sink is less, and the operation effect of the spacecraft in the complex and severe dynamic environment is poor. Therefore, a new type of multi-degree-of-freedom nonlinear energy sink and its application are proposed. SUMMARY

[0005] The present application proposes a new type of multi-degree-of-freedom nonlinear energy sink and its application, which solves the problems mentioned in the background art.

[0006] The technical scheme of the present application is as follows: A new type of multi-degree-of-freedom nonlinear energy sink, comprising a plurality of single-degree-of-freedom nonlinear energy sinks with combined damping and combined stiffness; The new type of multi-degree-of-freedom nonlinear energy sink with combined damping and combined stiffness is composed of a plurality of single-degree-of-freedom nonlinear energy sinks corresponding to the number of degrees of freedom in series; Each single-degree-of-freedom nonlinear energy sink is composed of a mass block, a combined damping object and a combined stiffness object; Each combined damping object is composed of a linear damping object and a cubic damping object in parallel, and each combined stiffness object is composed of a linear stiffness object and a cubic stiffness object in parallel.

[0007] As a further technical solution of the present application, the degree of freedom of the nonlinear energy sink is not less than two degrees of freedom.

[0008] As a further technical solution of the present application, the linear damping object is a damping object providing linear restoring force, such as a linear damper.

[0009] As a further technical solution of the present application, the linear stiffness object is a stiffness object providing linear restoring force, such as a linear spring.

[0010] As a further technical solution of the present application, the cubic damping object is a damping object providing cubic restoring force, such as a high polymer rubber material with cubic restoring force or a parallel electromechanical device.

[0011] As a further technical solution of the present application, the cubic stiffness object is a stiffness object providing cubic restoring force, such as a geometric structure composed of multiple linear stiffness objects.

[0012] As a further technical solution of the present application, the total mass of the multi-degree-of-freedom nonlinear energy sink is much smaller than the mass of the structure to be damped.

[0013] The present application also includes an application of a new multi-degree-of-freedom nonlinear energy sink, which is used to connect any structure to be damped of the new multi-degree-of-freedom nonlinear energy sink, and the structure to be damped is a spacecraft and its internal structure.

[0014] The working principle and beneficial effects of the present application are as follows: 1. The present application is a new type of nonlinear energy sink structure, which provides a guiding idea for the research and development of nonlinear energy sinks. The proposed new multi-degree-of-freedom nonlinear energy sink belongs to passive damping technology, has the advantages of simple structure, low cost and easy maintenance, and can effectively suppress the vibration of spacecraft and its internal structure to ensure the normal operation of spacecraft in extreme service environments. BRIEF DESCRIPTION OF DRAWINGS

[0015] The present application will be further described in detail below in combination with the drawings and specific embodiments.

[0016] Figure 1 The figure is a multi-degree-of-freedom nonlinear energy sink with combined damping and combined stiffness according to an embodiment of the present application. Figure 2 The figure is a system with a multi-degree-of-freedom nonlinear energy sink according to an embodiment of the present application. Figure 3 Schematic diagram of a two-degree-of-freedom nonlinear energy well with combined damping and combined stiffness according to an embodiment of the present invention; Figure 4 Schematic diagram of a three-degree-of-freedom nonlinear energy well with combined damping and combined stiffness according to an embodiment of the present invention; Figure 5 Schematic diagram of a five-degree-of-freedom nonlinear energy well with combined damping and combined stiffness according to an embodiment of the present invention; Figure 6 Schematic diagram of each single-degree-of-freedom nonlinear energy well with combined damping and combined stiffness according to an embodiment of the present invention; Figure 7 Schematic diagram of the composition of combined damping in each single-degree-of-freedom nonlinear energy well according to an embodiment of the present invention; Figure 8 Schematic diagram of the composition of the combined stiffness in each single-degree-of-freedom nonlinear energy well according to an embodiment of the present invention. DETAILED DESCRIPTION

[0017] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0018] Reference Figure 1 , schematically illustrating a novel multi-degree-of-freedom nonlinear energy well with combined damping and combined stiffness according to an embodiment of the present invention. This energy well is used to suppress vibrations in a structure to be damped. In this embodiment of the present invention, it is particularly used to damp vibrations in spacecraft structures.

[0019] The spacecraft's structures can include, for example, precision structures and sensitive structures. Precision structures and sensitive structures refer to structures that require high precision and are susceptible to vibration, respectively. For example, precision structures can include structures such as space telescopes and Earth-staring cameras that require high directional accuracy and stability. Sensitive structures can include structures such as large folding solar panels on a spacecraft. These large and flexible structures are susceptible to vibrations caused by external disturbances, which can affect their normal operation.

[0020] It is understandable that the structure of the spacecraft may also be other structures that can generate vibrations during launch, on-orbit operation and re-entry. Figure 2, schematically shows a novel multi-degree-of-freedom nonlinear energy well connected to a structure to be damped according to an embodiment of the present invention, in which 1 is a multi-degree-of-freedom nonlinear energy well and 2 is a structure to be damped. Here, the structure to be damped is simplified to a linear structure, which consists of a mass block. v 1. Linear stiffness objects v 2 and linear damping objects v 3 composition.

[0021] The novel multi-degree-of-freedom nonlinear energy well of the present invention, where multi-degree-of-freedom refers to no less than two degrees of freedom, is assumed to have the following number of degrees of freedom: n ,Right now n ≥ 2. Example 1

[0022] when n = 2, the multi-degree-of-freedom nonlinear energy well with combined damping and combined stiffness refers specifically to a two-degree-of-freedom nonlinear energy well with combined damping and combined stiffness, as shown in the schematic diagram. Figure 3 shown. Example 2

[0023] when n = 3, the multi-degree-of-freedom nonlinear energy well with combined damping and combined stiffness refers specifically to a three-degree-of-freedom nonlinear energy well with combined damping and combined stiffness, as shown in the schematic diagram. Figure 4 shown. Example 3

[0024] when n = 5, the multi-degree-of-freedom nonlinear energy well with combined damping and combined stiffness refers specifically to a five-degree-of-freedom nonlinear energy well with combined damping and combined stiffness, as shown in the schematic diagram. Figure 5 shown.

[0025] It should be noted that the value of n is mainly determined by factors such as the size of the equipment, the degree of precision, the working environment, and the requirements for vibration reduction, and is set and adjusted according to user needs.

[0026] It should be noted that the novel multi-degree-of-freedom nonlinear energy well with combined damping and combined stiffness provided by the present invention can be regarded as a series connection of multiple single-degree-of-freedom nonlinear energy wells with combined damping and combined stiffness, wherein the schematic diagram of each single-degree-of-freedom nonlinear energy well with combined damping and combined stiffness is as shown in FIG. Figure 6 shown. Figure 6 The single-degree-of-freedom nonlinear energy sink shown is composed of a combined damping 31 and a combined stiffness 21 connected in parallel to a mass block 11 .

[0027] The combined damping 31 in each single-degree-of-freedom nonlinear energy sink can be composed of linear damping 331 and cubic damping 333 in parallel, as shown in the schematic diagram of Figure 7 It can be understood that the object for providing linear damping is a damping object providing linear restoring force, such as linear damping and the like; and the object for providing cubic damping is a damping object providing cubic restoring force, such as high polymer rubber material under certain conditions, parallel electromechanical device and the like.

[0028] It can be conceived that the combined stiffness 21 in each single-degree-of-freedom nonlinear energy sink can be composed of linear stiffness 221 and cubic damping 223 in parallel, as shown in the schematic diagram of Figure 8 It can be conceived that the object for providing linear stiffness is a stiffness object providing linear restoring force, such as linear spring and the like; and the object for cubic stiffness is a stiffness object providing cubic restoring force, such as geometrically composed of multiple linear stiffness objects and the like.

[0029] In the existing research on nonlinear energy sink, it is disclosed that the nonlinear energy sink has excellent vibration suppression performance, and the new type of multi-degree-of-freedom nonlinear energy sink is one of the types, and the existing research shows that the two-degree-of-freedom nonlinear energy sink has better vibration reduction effect than the single-degree-of-freedom nonlinear energy sink, so it can be concluded that the new type of multi-degree-of-freedom nonlinear energy sink has excellent vibration reduction effect, and further improves the dynamics of the spacecraft under extreme service conditions. The new type of multi-degree-of-freedom nonlinear energy sink is a new type of nonlinear energy sink structure, which provides a guiding idea for the research and development of nonlinear energy sink.

[0030] The new type of multi-degree-of-freedom nonlinear energy sink provided in the application belongs to passive vibration reduction technology, has the advantages of simple structure, low cost and easy maintenance, and can be used for effective vibration suppression of the spacecraft structure generating vibration, so as to ensure the normal operation of the spacecraft under extreme service environment, has excellent vibration reduction performance, and can make the spacecraft and precise structure or high-precision sensitive structure still maintain its original working performance under severe working environment.

[0031] The above is only a preferred embodiment of the application, and is not used to limit the application, and any modification, equivalent replacement, improvement and the like made within the spirit and principle of the application shall be included in the protection scope of the application.

Claims

1. A novel multi-degree-of-freedom nonlinear energy sink, characterized by, A number of single-degree-of-freedom nonlinear energy sinks with combined damping and combined stiffness; A novel multi-degree-of-freedom nonlinear energy sink with combined damping and combined stiffness is formed by connecting a number of single-degree-of-freedom nonlinear energy sinks in series; Each single-degree-of-freedom nonlinear energy sink is formed by a mass, a combined damping object and a combined stiffness object; Each combined damping object is formed by connecting a linear damping object and a cubic damping object in parallel, and each combined stiffness object is formed by connecting a linear stiffness object and a cubic stiffness object in parallel.

2. The novel multi-degree of freedom non-linear energy sink according to claim 1, characterized in that, The nonlinear energy sink has no less than two degrees of freedom.

3. The novel multi-degree of freedom non-linear energy sink according to claim 1, wherein, The linear damping object is a damping object providing linear restoring force.

4. The novel multi-degree of freedom non-linear energy sink of claim 1, wherein, The linear stiffness object is a stiffness object providing linear restoring force.

5. The novel multi-degree of freedom non-linear energy sink according to claim 1, wherein, The cubic damping object is a damping object providing cubic restoring force.

6. The novel multi-degree of freedom non-linear energy sink of claim 1, wherein, The cubic stiffness object is a stiffness object providing cubic restoring force.

7. The novel multi-degree of freedom non-linear energy sink according to claim 1, wherein, The total mass of the multi-degree-of-freedom nonlinear energy sink is less than the mass of the structure to be damped.

8. Use of a new multi-degree-of-freedom nonlinear energy sink, using the new multi-degree-of-freedom nonlinear energy sink of claim 1, characterized in that, The novel multi-degree-of-freedom nonlinear energy sink is used to connect any structure to be damped, such as a spacecraft and its internal structure.

Images