Shock absorber based on elastic beam boundary loading nonlinear inertia elimination and isolation inerter structure

Abstract

The invention belongs to the technical field of shock absorbers, and particularly relates to a shock absorber based on an elastic beam boundary loading nonlinear inertia elimination and isolation inerter structure, which comprises an elastic beam, a shock absorption inerter structure, a vibration isolation inerter structure, a bottom plate and a support column, the lower surfaces of the two ends of the elastic beam are fixedly connected with the upper ends of the vibration isolation inerter structures correspondingly, the lower ends of the vibration isolation inerter structures are fixedly connected with the bottom plate, the side faces of the two ends of the elastic beam are rotationally connected with one ends of the vibration elimination inerter structures correspondingly, and the other ends of the vibration elimination inerter structures are rotationally connected with the supporting columns correspondingly. On one hand, negative stiffness is provided for the boundary of the elastic beam structure, the inherent frequency of the elastic beam structure is reduced, and therefore the vibration isolation effect is achieved; on one hand, vibration suppression is conducted on the elastic beam, the amplitude during resonance is effectively reduced, and therefore the vibration reduction effect is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of vibration dampers, and in particular relates to a vibration damper based on an elastic beam boundary loading nonlinear inertia elimination inertia capacity structure. Background Art

[0002] As a basic structural unit, elastic beams are widely used and are indispensable in engineering fields such as construction, aviation, aerospace, and shipbuilding. These structures are always affected by various external excitations and produce complex vibrations. If they are not effectively controlled, the structural stability and working accuracy of the system may be greatly affected by vibration, resulting in damage to the mechanical precision structure, reduced accuracy, index drift, and other problems. Therefore, in order to avoid these problems, we must effectively suppress the vibration of the machine. Existing shock absorbers have the following problems:

[0003] 1) Complex structure: The structure of the hydraulic shock absorber is relatively complex, the maintenance cost is high, and it is prone to failure;

[0004] 2) High technical requirements: Electromagnetic shock absorbers use electromagnetic force to adjust the vibration reduction effect, which is extremely costly and the technology is relatively complex;

[0005] 3) Aging problem: Plastic spring shock absorbers are prone to aging and have a short service life;

[0006] 4) The two pre-compressed transverse springs in the quasi-zero stiffness spring produce negative stiffness in the vertical direction and nonlinear stiffness. The derived negative stiffness and nonlinear stiffness expressions are obtained through Taylor expansion. The expanded formulas have countless orders, which introduces complex nonlinear dynamic behaviors and may even have chaotic responses. In most cases in engineering, nonlinearity is not desired, which greatly reduces the stability of the beam.

[0007] 5) The negative stiffness generated by the quasi-zero stiffness spring is basically determined when the structure is installed. If you need to change the negative stiffness value, you can only change the value by replacing the spring or changing the body structure to adjust the spring compression. The stiffness value of the spring itself is affected by its own properties. The accurate stiffness value of the spring needs to be measured before use, and it will be difficult to find a spring with ideal stiffness. Summary of the invention

[0008] In order to solve the above technical problems, the present invention provides a vibration damper based on an elastic beam boundary loading nonlinear inertia elimination inertia capacity structure.

[0009] The present invention is implemented in this way. It provides a vibration absorber based on an elastic beam boundary loaded nonlinear inertia isolation and inertia capacity structure, including an elastic beam, a vibration isolation and inertia capacity structure, a vibration isolation and inertia capacity structure, a base plate and a support column. The elastic beam is arranged in parallel with the base plate. The lower surfaces of both ends of the elastic beam are respectively fixedly connected to the upper end of a vibration isolation and inertia capacity structure, the lower end of the vibration isolation and inertia capacity structure is fixedly connected to the base plate, the side surfaces at both ends of the elastic beam are respectively rotatably connected to one end of a vibration isolation and inertia capacity structure, the other end of the vibration isolation and inertia capacity structure is respectively rotatably connected to a support column, and the lower end of the support column is fixedly connected to the base plate.

[0010] Preferably, the vibration isolation inertia structure comprises a spring chamber, a vibration isolation screw, a first vibration isolation shell, a second vibration isolation shell and a vibration isolation flywheel, a spring is arranged in the spring chamber, a through hole is arranged at the position where the spring chamber and the first vibration isolation shell are connected, the other end of the first vibration isolation shell is connected to the vibration isolation screw nut, an end of the second vibration isolation shell close to the first vibration isolation shell is provided with a vibration isolation screw bearing, one end of the spring is fixedly connected to an end of the spring chamber inner wall away from the first vibration isolation shell, and the other end is rotatably connected to the vibration isolation screw, the vibration isolation screw passes through the through hole between the spring chamber and the first vibration isolation shell, is threadedly connected in the vibration isolation screw nut, and is rotatably connected to the vibration isolation screw bearing, and one end of the vibration isolation screw located in the second vibration isolation shell is fixedly connected to the vibration isolation flywheel;

[0011] The outer wall of the spring chamber away from the first vibration isolation shell and the outer wall of the second vibration isolation shell away from the first vibration isolation shell are both provided with first connecting ends, and the vibration isolation inertia structure is fixedly connected to the lower surface of the elastic beam and the bottom plate through two first connecting joints.

[0012] Further preferably, the spring is rotatably connected to the vibration isolation screw via a connecting bearing.

[0013] Further preferably, shaft supports are provided on the lower surface of the elastic beam and the bottom plate, and the vibration isolation and inertia capacity structure is fixedly connected to the lower surface of the elastic beam and the shaft supports on the bottom plate through the two first connecting joints.

[0014] Further preferably, the vibration-absorbing inertia structure comprises a first vibration-absorbing housing, a second vibration-absorbing housing and a vibration-absorbing lead screw, a vibration-absorbing lead screw nut is connected to one end of the first vibration-absorbing housing close to the second vibration-absorbing housing, a vibration-absorbing lead screw bearing is connected to one end of the second vibration-absorbing housing close to the first vibration-absorbing housing, the vibration-absorbing lead screw is threadedly connected in the vibration-absorbing lead screw nut and rotatably connected in the vibration-absorbing lead screw bearing, and one end of the vibration-absorbing lead screw passing through the vibration-absorbing lead screw bearing is fixedly connected to the vibration-absorbing flywheel;

[0015] One end of the first vibration-absorbing shell away from the second vibration-absorbing shell and one end of the second vibration-absorbing shell away from the first vibration-absorbing shell are both provided with second connecting ends, and the vibration-absorbing inertia structure is rotatably connected to both ends of the elastic beam and the corresponding support column through the two second connecting ends.

[0016] Further preferably, connecting structures are provided on both sides of both ends of the elastic beam and on the support column, and the connecting structure includes a connecting bearing seat, a connecting rod and a connecting bearing. The connecting bearing seat is fixed on both sides of both ends of the elastic beam and on the support column, and two parallel connecting arms are provided on the connecting bearing seat. The two ends of the connecting rod are fixedly connected to the two connecting arms, and the connecting bearing is rotatably connected to the connecting rod. Connecting holes are provided on the two second connecting ends of the vibration-absorbing inertia structure, and the second connecting ends are fixedly connected to the connecting bearings of the connecting structure at corresponding positions through the connecting holes.

[0017] Further preferably, a vibration isolation limit ring is fixedly connected to one side of the vibration isolation screw bearing located in the second vibration isolation housing, and the vibration isolation limit ring is rotationally and limitably connected to the vibration isolation screw;

[0018] A vibration-absorbing limit ring is fixedly connected to one side of the vibration-absorbing screw bearing located in the second vibration-absorbing housing, and the vibration-absorbing limit ring is rotationally and limitably connected to the vibration-absorbing screw.

[0019] Further preferably, a vibration isolation fixing ring is provided on the vibration isolation screw at a side of the vibration isolation flywheel away from the vibration isolation screw bearing, and the vibration isolation fixing ring fixes the vibration isolation flywheel on the vibration isolation screw;

[0020] A vibration-absorbing fixing ring is provided on the vibration-absorbing screw at the side of the vibration-absorbing flywheel away from the vibration-absorbing screw bearing, and the vibration-absorbing fixing ring fixes the vibration-absorbing flywheel on the vibration-absorbing screw.

[0021] Further preferably, the vibration-absorbing inertia capacity structure is rotatably connected to the top end of the support column.

[0022] Compared with the prior art, the advantages of the present invention are:

[0023] A vibration damper based on an elastic beam boundary loading nonlinear inertia isolation and inertia capacity structure is provided. The isolation and inertia capacity structure is loaded on the boundary of the elastic beam. On the one hand, negative stiffness is provided for the boundary of the elastic beam structure, thereby reducing the natural frequency of the elastic beam structure, thereby achieving a vibration isolation effect; on the other hand, vibration of the elastic beam is suppressed, so that the amplitude at resonance is effectively reduced, thereby achieving a vibration reduction effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The overall structure diagram of the shock absorber based on the elastic beam boundary loading nonlinear inertia elimination inertia capacity structure provided by the present invention;

[0025] Figure 2 It is the structural diagram of the vibration isolation inertia capacity structure;

[0026] Figure 3 This is the structural diagram of the vibration-absorbing inertia capacity structure;

[0027] Figure 4 is a structural diagram of the connection structure;

[0028] Figure 5 The transient response time history under initial displacement excitation: (a) left end point of the beam; (b) midpoint of the beam;

[0029] Figure 6 The wavelet transform time-frequency diagram of transient response under initial displacement excitation: (a) left end point of the uncontrolled system beam; (b) midpoint of the uncontrolled system beam; (c) left end point of the beam of the present invention; (d) midpoint of the beam of the present invention;

[0030] Figure 7 The vibration reduction effect of the present invention is U=0.001m: (a) the first-order resonance peak at the left endpoint; (b) the third-order resonance peak at the left endpoint; (c) the first-order resonance peak at the midpoint; (d) the third-order resonance peak at the midpoint;

[0031] Figure 8 The vibration reduction effect of the present invention is U=0.002m: (a) the first-order resonance peak at the left endpoint; (b) the third-order resonance peak at the left endpoint; (c) the first-order resonance peak at the midpoint; (d) the third-order resonance peak at the midpoint;

[0032] Fig. 9 The vibration reduction effect of the present invention is U=0.003m: (a) the first-order resonance peak at the left endpoint; (b) the third-order resonance peak at the left endpoint; (c) the first-order resonance peak at the midpoint; (d) the third-order resonance peak at the midpoint. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0034] refer to Figure 1 , Figure 2 , Figure 3 and Figure 4 The present invention provides a vibration damper based on an elastic beam boundary loading nonlinear inertia isolation and inertia capacity structure, comprising an elastic beam 1, a vibration isolation and inertia capacity structure 4, a vibration isolation and inertia capacity structure 22, a base plate 10 and a support column 2. The elastic beam 1 is arranged parallel to the base plate 10, and the lower surfaces of both ends of the elastic beam 1 are respectively fixedly connected to the upper end of a vibration isolation and inertia capacity structure 22, and the lower end of the vibration isolation and inertia capacity structure 22 is fixedly connected to the base plate 10. The side surfaces at both ends of the elastic beam 1 are respectively rotatably connected to one end of a vibration isolation and inertia capacity structure 4, and the other end of the vibration isolation and inertia capacity structure 4 is respectively rotatably connected to a support column 2, and the lower end of the support column 2 is fixedly connected to the base plate 10.

[0035] When the shock absorber provided by the present invention is used, the base plate 10 is fixed to a vibrating device by bolt connection. When vibration occurs, the elastic beam 1 performs axial movement up and down, driving the vibration isolation inertia structure 22 to perform telescopic movement up and down, and the vibration absorption inertia structure 4 performs telescopic movement in an oblique direction. On the one hand, negative stiffness is provided for the boundary of the elastic beam 1, thereby reducing the natural frequency of the elastic beam 1, thereby achieving a vibration isolation effect; on the other hand, the vibration of the elastic beam 1 is suppressed, so that the amplitude during resonance is effectively reduced, thereby achieving a vibration reduction effect.

[0036] As a specific implementation method of the vibration isolation inertia capacity structure 22, the vibration isolation inertia capacity structure 22 includes a spring chamber 25, a vibration isolation screw 15, a first vibration isolation shell 23, a second vibration isolation shell 24 and a vibration isolation flywheel 19, a spring 7 is arranged in the spring chamber 25, a through hole is arranged at the position where the spring chamber 25 and the first vibration isolation shell 23 are connected, the other end of the first vibration isolation shell 23 is connected to the vibration isolation screw nut 16, and the end of the second vibration isolation shell 24 close to the first vibration isolation shell 23 is provided with a vibration isolation screw bearing 17, one end of the spring 7 is fixedly connected to the end of the inner wall of the spring chamber 25 away from the first vibration isolation shell 23, and the other end is rotatably connected to the vibration isolation screw 15, the vibration isolation screw 15 passes through the through hole between the spring chamber 25 and the first vibration isolation shell 23, is threadedly connected in the vibration isolation screw nut 16, and is rotatably connected to the vibration isolation screw bearing 17, and the end of the vibration isolation screw 15 located in the second vibration isolation shell 24 is fixedly connected to the vibration isolation flywheel 19;

[0037] The upward and downward telescopic movement of the vibration isolation inertia structure 22 is converted into the telescopic movement of the spring 7 on the one hand, and into the rotation of the vibration isolation screw 15 on the other hand. The rotation of the vibration isolation screw 15 drives the vibration isolation flywheel 19 to rotate. The natural frequency of the controlled system is reduced by increasing the parametric mass through the vibration isolation inertia structure 22, thereby achieving the vibration isolation effect.

[0038] In order to facilitate the connection between the vibration isolation inertia capacity structure 22 and the elastic beam 1 and the base plate 10, as an improvement of the technical solution, the outer wall of the spring chamber 25 at one end away from the first vibration isolation shell 23 and the outer wall of the second vibration isolation shell 24 at one end away from the first vibration isolation shell 23 are both provided with a first connecting end, and the vibration isolation inertia capacity structure 22 is fixedly connected to the lower surface of the elastic beam 1 and the base plate 10 through two first connecting joints.

[0039] In order to facilitate the rotational connection between the spring 7 and the vibration isolation screw 15, as an improvement of the technical solution, the spring 7 is rotationally connected to the vibration isolation screw 15 via a connecting bearing.

[0040] In order to facilitate the connection between the first connecting joint and the elastic beam 1 and the base plate 10, as an improvement of the technical solution, an axial support 9 is provided on the lower surface of the elastic beam 1 and the base plate 10, and the vibration isolation inertia structure 22 is fixedly connected to the lower surface of the elastic beam 1 and the axial support 9 on the base plate 10 through the two first connecting joints.

[0041] As a specific implementation of the vibration-absorbing inertia-capacity structure 4, the vibration-absorbing inertia-capacity structure 4 includes a first vibration-absorbing housing 26, a second vibration-absorbing housing 27 and a vibration-absorbing lead screw 6. A vibration-absorbing lead screw nut 28 is connected to one end of the first vibration-absorbing housing 26 close to the second vibration-absorbing housing 27, and a vibration-absorbing lead screw bearing 3 is connected to one end of the second vibration-absorbing housing 27 close to the first vibration-absorbing housing 26. The vibration-absorbing lead screw 6 is threadedly connected in the vibration-absorbing lead screw nut 28 and rotatably connected in the vibration-absorbing lead screw bearing 3. One end of the vibration-absorbing lead screw 6 passing through the vibration-absorbing lead screw bearing 3 is fixedly connected to the vibration-absorbing flywheel 8.

[0042] The telescopic movement of the vibration-damping inertia structure 4 is converted into the rotational movement of the vibration-damping screw 6. The vibration-damping screw 6 rotates itself, and then drives the vibration-damping flywheel 8 fixedly connected to it to rotate. It obtains a large inertia with a very small mass, affects the vibration in the form of a parasitic mass, and thus achieves a vibration reduction effect.

[0043] In order to facilitate the connection between the vibration-absorbing inertia structure 4 and the elastic beam 1 and the support column 2, as an improvement of the technical solution, a second connecting end is provided at one end of the first vibration-absorbing shell 26 away from the second vibration-absorbing shell 27 and at one end of the second vibration-absorbing shell 27 away from the first vibration-absorbing shell 26. The vibration-absorbing inertia structure 4 is rotatably connected to both ends of the elastic beam 1 and the corresponding support column 2 through the two second connecting ends.

[0044] Specifically, connecting structures 5 are provided on both sides of both ends of the elastic beam 1 and on the support column 2, and the connecting structure 5 includes a connecting bearing seat 13, a connecting rod 12 and a connecting bearing 11. The connecting bearing seat 13 is fixed on both sides of both ends of the elastic beam 1 and on the support column 2. Two parallel connecting arms are provided on the connecting bearing seat 13. Both ends of the connecting rod 12 are fixedly connected to the two connecting arms. The connecting bearing 11 is rotatably connected to the connecting rod 12. The two second connecting ends of the vibration-absorbing inertia structure 4 are provided with connecting holes, and the second connecting ends are fixedly connected to the connecting bearings 11 of the connecting structure 5 at corresponding positions through the connecting holes.

[0045] In order to further limit the position of the vibration isolation screw bearing 17 on the vibration isolation screw 15 and the position of the vibration isolation screw bearing 3 on the vibration isolation screw 6, as an improvement of the technical solution, a vibration isolation limit ring 18 is fixedly connected to one side of the vibration isolation screw bearing 17 located in the second vibration isolation housing 24, and the vibration isolation limit ring 18 is rotatably and limitably connected to the vibration isolation screw 15;

[0046] A vibration-absorbing limit ring 14 is fixedly connected to one side of the vibration-absorbing screw bearing 3 located in the second vibration-absorbing housing 27 , and the vibration-absorbing limit ring 14 is rotationally and limitably connected to the vibration-absorbing screw 6 .

[0047] The so-called limiting connection, for example, can be provided with an annular groove on the lead screw and an annular protrusion on the limiting ring, and the annular groove matches the annular protrusion.

[0048] In order to facilitate the replacement of the flywheel, as an improvement of the technical solution, a vibration isolation fixing ring 20 is provided on the vibration isolation screw 15 on the side of the vibration isolation flywheel 19 away from the vibration isolation screw bearing 17, and the vibration isolation fixing ring 20 fixes the vibration isolation flywheel 19 on the vibration isolation screw 15;

[0049] A vibration-absorbing fixing ring 21 is provided on the vibration-absorbing screw 6 at the side of the vibration-absorbing flywheel 8 away from the vibration-absorbing screw bearing 3 , and the vibration-absorbing fixing ring 21 fixes the vibration-absorbing flywheel 8 on the vibration-absorbing screw 6 .

[0050] According to the needs of different systems, the flywheel can be replaced in time to achieve better vibration isolation effect.

[0051] Preferably, the vibration-absorbing inertia capacity structure 4 is rotatably connected to the top end of the support column 2 .

[0052] The following is a comparative analysis of the vibration reduction effect:

[0053] The expression of the inertia coefficient b of the inertia structure is:

[0054] b=2m(πr / P) 2

[0055] Among them, p is the lead of the screw, m is the mass of the flywheel, and r is the radius of the flywheel.

[0056] Therefore, the inertia parameters of the ideal ball screw inertia structure are completely dependent on the lead of the ball screw and the mass and radius of the flywheel. By substituting actual parameters, the inertia structure can provide the controlled system with an inertia that is many times its own mass, and the inertia parameters can be regulated by adjusting the lead of the ball screw and the mass and radius of the flywheel.

[0057] Applying the generalized Hamiltonian principle, the dynamic equation of the elastic beam is derived through variational and distribution integrals:

[0058]

[0059] The boundary conditions of the elastic beam are

[0060]

[0061] Where: E, L, ρ, Λ, A, l and I are Young's modulus, length, density, viscous damping coefficient, cross-sectional area and moment of inertia of the elastic beam structure respectively; K L With K R are the stiffness coefficients of the vertical constraint springs at both ends of the elastic beam structure; B L With B R are the inertia coefficients of the inertia containers at both ends of the elastic beam structure; C L With C R are the damping coefficients of the two ends of the elastic beam structure; W L With W R are the lateral vibration displacements at both ends of the elastic beam structure; C HL With C HR are the damping coefficients of the oblique damping at both ends of the elastic beam structure; W(X, T) is the lateral vibration displacement of the beam structure; δ represents the Dirac function; U L =U R =U(X, T) is the basic excitation acting on the beam structure, T is the time coordinate, and X is the axial coordinate of the elastic beam.

[0062] Ignoring the damping and nonlinear terms in the equation, the linear derived system dynamics equation and its boundary conditions are as follows:

[0063]

[0064] Assume the solution is:

[0065] W(X,T)=Ψ(X)Q(T)

[0066] Where ψ(X) is the modal function of the elastic beam and Q(T) is the corresponding generalized coordinate;

[0067] Substituting the assumed solution into the linear derived system dynamics equation and its boundary conditions, we get:

[0068]

[0069] Ψ′(0)=0, Ψ′(L)=0,

[0070] EIΨ″′(0)Q(T)+K L Ψ(0)Q(T)+B L Ψ(0)Q″(T)=0,

[0071] EIΨ″′(L)Q(T)-K R Ψ(L)Q(T)-B R Ψ(L)Q″(T)=0

[0072] The system dynamics equation is further sorted out:

[0073]

[0074] Because both sides of the equation are functions of different independent variables, the equation can only be equal to a constant, denoted as -Ω2, deriving equation 1 and equation 2:

[0075] Equation 1: Q″(T)+Ω 2 Q(T)=0

[0076] Equation 2: EIΨ (4) (X)-Ω 2 ρAΨ(X)=0

[0077] The derived equation 1 is a single degree of freedom linear vibration equation, and its general solution is:

[0078] Q(T)=αsin(ΩT+θ)

[0079] Among them, α is the amplitude of vibration, θ is the initial phase angle of vibration, which is determined by the initial conditions;

[0080] Simplify Equation 2 to a differential equation with constant coefficients:

[0081] Ψ (4) (X)-β 4 Ψ(X)=0

[0082] Among them, the relationship between the eigenvalue β and the natural frequency Ω is as follows:

[0083]

[0084] The solution of equation 2 determines the mode function of the bending vibration of the elastic beam. Taking chβX, shβX, cosβX, sinβX as the basic solution system, the general solution of equation 2 is written as:

[0085] Ψ(X)=C1cosβX+C2sinβX+C3chβX+C4shβX

[0086] The frequency equation that the integral constant Cj (j = 1, 2, 3, 4) and the parameter Ω should satisfy is determined by the boundary conditions of the beam, and an infinite number of natural frequencies Ω can be solved. i (i=1,2,…) and the corresponding vibration mode function Ψ i (X)(i=1,2,…), constitutes the i-th main vibration of the system:

[0087] W (i) (X,T)=α i Ψ i (X)Q(T)sin(Ω i T+θ i )

[0088] Among them, the integration constant α i and θi (i=1, 2, ...) is determined by the initial conditions of the system;

[0089] From equation 1, we can get:

[0090] Q″(T)=-Ω 2 Q(T)

[0091] Substituting the above equation into the boundary conditions, the boundary conditions are arranged as follows:

[0092] Ψ′(0)=0, Ψ′(L)=0,

[0093] EIΨ″′(0)+(K L -B L Ω 2 )Ψ(0)=0,

[0094] EIΨ″′(L)-(K R -B R Ω 2 )Ψ(L)=0

[0095] From the boundary condition K-BΩ 2 It can be seen that the positive stiffness provided by the spring and the negative stiffness provided by the inertia container constitute the total stiffness of the whole. By changing the inertia coefficient, the negative stiffness of the inertia container can be changed, thereby changing the total stiffness of the whole, and then changing the natural frequency of the elastic beam.

[0096] Using the above mechanism, the transient response time history of the elastic beam structure supported only by springs (uncontrolled system) and the shock absorber coupled inerter system based on the elastic beam boundary loading nonlinear inertial isolation inerter structure provided by the present invention (shock absorber system in the figure, with inerter) is compared in software. Figure 5 (a)(b). It can be found that the transient response of the present invention has a faster decay speed. The time-frequency diagram shown in 6(a)(b)(c)(d) is obtained by wavelet transform analysis of the transient response time history. As shown in the figure, both the uncontrolled system and the present invention contain only one main frequency component. In other words, under this parameter condition, the natural frequency of the free decay vibration of the present invention is not affected. It can be seen that the present invention has an effective vibration reduction effect on the transient response of the lateral vibration of the elastic beam.

[0097] Steady-state response:

[0098] The vibration reduction performance of the present invention for steady-state response is evaluated by the vibration reduction percentage R A The maximum amplitude of the main resonance of the elastic beam of the uncontrolled system is denoted by A u The maximum amplitude of the main resonance of the elastic beam of the present invention is recorded as A i , then the vibration reduction percentage of the coupled inertia system is

[0099]

[0100] The vibration isolation performance of the present invention is evaluated by the percentage of frequency reduction at the maximum, which is recorded as R Ω The frequency value corresponding to the maximum value of the main resonance frequency response curve of the elastic beam of the uncontrolled system is recorded as Ω u The frequency value corresponding to the maximum value of the main resonance frequency response curve of the elastic beam of the present invention is recorded as Ω i , then the vibration isolation effect percentage of the present invention is

[0101]

[0102] Given a basic excitation amplitude of U = 0.001 m, the steady-state amplitude-frequency response curves of the uncontrolled system and the present invention are as follows: Figure 7 (a)(b)(c)(d). Obviously, the present invention has significant vibration reduction and vibration isolation effects on the main resonance response of the elastic beam. The vibration reduction percentage of the first-order main resonance at the left end point of the beam is 38.9%, and the vibration reduction percentage of the third-order main resonance is 67.3%. The vibration reduction percentage of the first-order main resonance at the midpoint of the beam is 47.8%, but a negative effect is produced at the third-order main resonance. The first-order main resonance frequency at the left end point of the beam is reduced by 45.6%, and the third-order main resonance frequency is reduced by 38.1%. The first-order main resonance frequency at the midpoint of the beam is reduced by 46.1%, and the third-order main resonance is reduced by 38.1%.

[0103] The influence of the basic excitation amplitude on the vibration reduction and isolation effect of the present invention is discussed below. When the basic excitation amplitude is U = 0.002m and U = 0.003m, the vibration reduction effect of the present invention is as follows: Figure 8 (a)(b)(c)(d) and Fig. 9(a)(b)(c)(d) are shown. By comparing the vibration reduction effects of the present invention under three basic excitation amplitudes, it is found that for the first-order main resonance, the change of the excitation amplitude has a significant effect on the vibration reduction effect. For example, the vibration reduction percentage of the present invention is 38.9% when the small excitation amplitude U=0.001m is the first-order main resonance at the left endpoint, and the vibration reduction percentages are 54.1% and 59.5% when the medium excitation amplitude U=0.002m and the large excitation amplitude U=0.003m, respectively. Compared with the small excitation amplitude, the vibration reduction percentages increase by 15.2% and 20.6%, respectively. Obviously, the larger the basic excitation amplitude, the better the vibration reduction effect of the present invention. For the third-order main resonance at the left endpoint, the change of the excitation amplitude has little effect on the vibration reduction effect. For example, the vibration reduction percentage of the third-order main resonance at the left endpoint is 67.3% when the small excitation amplitude U=0.001m, and the vibration reduction percentages are 68.6% and 68.4% respectively when the medium excitation amplitude U=0.002m and the large excitation amplitude U=0.003m. Compared with the small excitation amplitude, the vibration reduction percentages are increased by 1.3% and 1.1% respectively. Obviously, the change of the basic excitation amplitude has little effect on the third-order main resonance. In addition, the analysis of the amplitude-frequency response curve of the present invention shows that the larger the basic excitation amplitude, the stronger the effect of the nonlinear hardening phenomenon of the first-order main resonance response is weakened. The change of the basic excitation amplitude has a relatively small effect on the vibration reduction effect of the inclined inertia at the third-order main resonance.

[0104] By comparing the vibration isolation effects of the present invention under three basic excitation amplitudes, it is found that for the first-order main resonance, the change of the excitation amplitude has a significant effect on the vibration reduction effect. For example, the frequency of the first-order main resonance of the left endpoint is reduced by 45.6% when the small excitation amplitude U=0.001m, and the frequency is reduced by 54.6% and 61.0% respectively when the medium excitation U=0.002m and the large excitation amplitude U=0.003m. Compared with the small excitation amplitude, the percentage of frequency reduction increases by 9.0% and 15.4% respectively. Obviously, the larger the basic excitation amplitude, the better the vibration isolation effect of the present invention. For the third-order main resonance of the left endpoint, the change of the excitation amplitude has little effect on the vibration reduction effect. For example, the frequency of the third-order main resonance at the left endpoint is reduced by 38.1% when the small excitation amplitude U=0.001m, and the vibration reduction percentages are 37.1% and 36.5% when the medium excitation amplitude U=0.002m and the large excitation amplitude U=0.003m, respectively. Compared with the small excitation amplitude, the percentage of frequency reduction is reduced by 1.0% and 1.6%, respectively. Obviously, the change of the basic excitation amplitude has little effect on the third-order main resonance at the left endpoint.

[0105] In addition, the analysis of the amplitude-frequency response curve of the present invention shows that the larger the basic excitation amplitude, the stronger the effect of weakening the nonlinear hardening phenomenon of the first-order main resonance response. The change of the basic excitation amplitude has a relatively small effect on the vibration reduction effect of the inclined inertia capacitor at the third-order main resonance.

Claims

1. A vibration absorber based on elastic beam boundary loading nonlinear inertia elimination inertia capacity structure, characterized in that: The invention comprises an elastic beam (1), a vibration-absorbing inertia container structure (4), a vibration-isolating inertia container structure (22), a base plate (10) and a support column (2); the elastic beam (1) and the base plate (10) are arranged in parallel; the lower surfaces at both ends of the elastic beam (1) are respectively fixedly connected to the upper end of a vibration-isolating inertia container structure (22); the lower end of the vibration-isolating inertia container structure (22) is fixedly connected to the base plate (10); the side surfaces at both ends of the elastic beam (1) are respectively rotatably connected to one end of a vibration-absorbing inertia container structure (4); the other end of the vibration-absorbing inertia container structure (4) is respectively rotatably connected to a support column (2); and the lower end of the support column (2) is fixedly connected to the base plate (10).

2. The vibration absorber based on elastic beam boundary loading nonlinear inertia elimination inertia capacity structure according to claim 1 is characterized in that: The vibration isolation inertia structure (22) comprises a spring chamber (25), a vibration isolation screw (15), a first vibration isolation shell (23), a second vibration isolation shell (24) and a vibration isolation flywheel (19); a spring (7) is arranged in the spring chamber (25); a through hole is arranged at a position where the spring chamber (25) and the first vibration isolation shell (23) are connected; the other end of the first vibration isolation shell (23) is connected to a vibration isolation screw nut (16); and the end of the second vibration isolation shell (24) close to the first vibration isolation shell (23) is provided with a vibration isolation screw shaft. A bearing (17), one end of the spring (7) is fixedly connected to an end of the inner wall of the spring chamber (25) away from the first vibration isolation shell (23), and the other end is rotatably connected to the vibration isolation screw (15), the vibration isolation screw (15) passes through the through hole between the spring chamber (25) and the first vibration isolation shell (23), is threadedly connected in the vibration isolation screw nut (16), and is rotatably connected to the vibration isolation screw bearing (17), and one end of the vibration isolation screw (15) located in the second vibration isolation shell (24) is fixedly connected to the vibration isolation flywheel (19); The outer wall of one end of the spring chamber (25) away from the first vibration isolation shell (23) and the outer wall of one end of the second vibration isolation shell (24) away from the first vibration isolation shell (23) are both provided with a first connection end, and the vibration isolation inertia capacity structure (22) is fixedly connected to the lower surface of the elastic beam (1) and the bottom plate (10) through two first connection joints.

3. The vibration absorber based on elastic beam boundary loading nonlinear inertia elimination inertia capacity structure according to claim 2 is characterized in that: The spring (7) is rotationally connected to the vibration isolation screw (15) via a connecting bearing.

4. The vibration absorber based on elastic beam boundary loading nonlinear inertia elimination inertia capacity structure according to claim 2 is characterized in that: Axle supports (9) are provided on the lower surface of the elastic beam (1) and the bottom plate (10), and the vibration isolation inertia capacity structure (22) is fixedly connected to the lower surface of the elastic beam (1) and the shaft supports (9) on the bottom plate (10) via the two first connection joints.

5. The vibration absorber based on elastic beam boundary loading nonlinear inertia elimination inertia capacity structure according to claim 1 is characterized in that: The vibration-absorbing inertia structure (4) comprises a first vibration-absorbing housing (26), a second vibration-absorbing housing (27) and a vibration-absorbing screw (6); a vibration-absorbing screw nut (28) is connected to one end of the first vibration-absorbing housing (26) close to the second vibration-absorbing housing (27); a vibration-absorbing screw bearing (3) is connected to one end of the second vibration-absorbing housing (27) close to the first vibration-absorbing housing (26); the vibration-absorbing screw (6) is threadedly connected in the vibration-absorbing screw nut (28) and rotatably connected in the vibration-absorbing screw bearing (3); and one end of the vibration-absorbing screw (6) passing through the vibration-absorbing screw bearing (3) is fixedly connected to the vibration-absorbing flywheel (8); One end of the first vibration-absorbing shell (26) away from the second vibration-absorbing shell (27) and one end of the second vibration-absorbing shell (27) away from the first vibration-absorbing shell (26) are both provided with second connecting ends, and the vibration-absorbing inertia structure (4) is rotatably connected to both ends of the elastic beam (1) and the corresponding support column (2) through the two second connecting ends.

6. The vibration absorber based on elastic beam boundary loading nonlinear inertia elimination inertia capacity structure according to claim 5 is characterized in that: A connecting structure (5) is provided on both sides of both ends of the elastic beam (1) and on the support column (2). The connecting structure (5) includes a connecting bearing seat (13), a connecting rod (12) and a connecting bearing (11). The connecting bearing seat (13) is fixed on both sides of both ends of the elastic beam (1) and on the support column (2). Two parallel connecting arms are provided on the connecting bearing seat (13). Both ends of the connecting rod (12) are fixedly connected to the two connecting arms. The connecting bearing (11) is rotatably connected to the connecting rod (12). The two second connecting ends of the vibration-absorbing inertia structure (4) are provided with connecting holes. The second connecting ends are fixedly connected to the connecting bearings (11) of the connecting structure (5) at corresponding positions through the connecting holes.

7. The vibration absorber based on elastic beam boundary loading nonlinear inertia elimination inertia capacity structure according to claim 2 or 5, characterized in that: A vibration isolation limit ring (18) is fixedly connected to one side of the vibration isolation screw bearing (17) located in the second vibration isolation housing (24), and the vibration isolation limit ring (18) is rotationally and limitably connected to the vibration isolation screw (15); A vibration-absorbing limit ring (14) is fixedly connected to one side of the vibration-absorbing screw bearing (3) located in the second vibration-absorbing housing (27), and the vibration-absorbing limit ring (14) is rotationally and limitably connected to the vibration-absorbing screw (6).

8. The vibration absorber based on elastic beam boundary loading nonlinear inertia elimination inertia capacity structure according to claim 2 or 5, characterized in that: A vibration isolation fixing ring (20) is provided on the vibration isolation screw (15) at the side of the vibration isolation flywheel (19) away from the vibration isolation screw bearing (17), and the vibration isolation fixing ring (20) fixes the vibration isolation flywheel (19) on the vibration isolation screw (15); A vibration-absorbing fixing ring (21) is provided on the vibration-absorbing screw (6) at the side of the vibration-absorbing flywheel (8) away from the vibration-absorbing screw bearing (3), and the vibration-absorbing fixing ring (21) fixes the vibration-absorbing flywheel (8) on the vibration-absorbing screw (6).

9. The vibration absorber based on elastic beam boundary loading nonlinear inertia elimination inertia capacity structure according to claim 1 is characterized in that: The vibration-absorbing inertia capacity structure (4) is rotatably connected to the top end of the support column (2).

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