Design method of hydraulic rubber composite vibration isolation device

Abstract

The application discloses a design method of a hydraulic rubber composite damping device, belongs to the technical field of vibration isolation installation of aviation equipment, and is used for the design of a hydraulic rubber composite vibration isolation device, can shorten the design time of the vibration isolation device, and improves the safety of research and development tests. The method comprises the following steps: S1, according to the stiffness and damping requirements of an engine at different frequencies, performing parameter matching theoretical calculation, simulation and design to obtain target parameters of the damping device, including static stiffness, dynamic stiffness and damping coefficients at different frequencies; S2, building a lumped parameter simulation model of the damping device, adjusting key parameters of the damping device to meet the target parameters of step S1, the key parameters including an equivalent piston area, bulk stiffness, flow channel damping coefficient and inertia coefficient of the damping device; and S3, designing the static stiffness, equivalent piston area, bulk stiffness and flow channel parameters of the damping device to form a design scheme, and meeting the key parameters of step S2.

Description

Technical Field

[0001] The invention belongs to the technical field of aviation equipment vibration isolation installation, and particularly relates to a design method of a hydraulic rubber composite vibration isolation device. Background Art

[0002] Aircraft engine vibration isolation systems primarily utilize hydraulic rubber composite vibration isolation devices for vibration isolation. Because aircraft engines need to transmit significant thrust and torque to the aircraft, high requirements are placed on the hydraulic rubber composite vibration isolation devices used. If the connection stiffness between the engine and the isolation system is high, the majority of the engine vibration will still be transmitted directly to the aircraft body. This is especially true during landing, where the amplification factor of the engine's impact acceleration during landing must be as small as possible. This requires the hydraulic rubber composite vibration isolation device to have low stiffness and high damping at specific impact frequencies during landing. The dynamic stiffness must increase rapidly after the dynamic stiffness valley frequency and then stabilize after reaching its peak value.

[0003] However, the technical requirements for engine vibration reduction and impact resistance vary among aircraft of different models, and are determined by the aircraft structure and engine model. Therefore, the hydraulic rubber composite vibration isolation devices used in new aircraft need to be redesigned to ensure that their performance parameters meet the requirements of the new aircraft. This not only consumes a lot of time, but also requires a large number of landing tests, and safety during the landing tests cannot be guaranteed.

[0004] Therefore, a design method for a hydraulic rubber composite vibration isolation device is needed, which can quickly carry out targeted design according to the technical requirements of engine vibration reduction and impact resistance of different types of aircraft, shorten the design time of the hydraulic rubber composite vibration isolation device, and improve the safety of R&D tests. Summary of the Invention

[0005] The present invention provides a design of a hydraulic rubber composite vibration isolation device, which is used for designing a hydraulic rubber composite vibration isolation device to ensure that the device can meet the specific impact frequency and vibration isolation requirements during landing of a new model aircraft, shorten the design time of the hydraulic rubber composite vibration isolation device, and improve the safety of aircraft research and development tests.

[0006] To achieve the above objectives, a design method for a hydraulic rubber composite vibration isolation device includes the following steps:

[0007] Step S1, performing parameter matching theoretical calculation, simulation, and design based on the technical requirements of stiffness and damping of the target engine at different frequencies to obtain target parameters of the hydraulic rubber composite vibration damping device, wherein the target parameters include static stiffness, and dynamic stiffness and damping coefficient at different frequencies;

[0008] Step S2: Determine and build a lumped parameter simulation model of the hydraulic rubber composite vibration isolation device based on the basic structure of the hydraulic rubber composite vibration isolation device, and adjust key parameters of the hydraulic rubber composite vibration isolation device to meet the target parameters obtained in step S1. The key parameters include the equivalent piston area, volume stiffness, flow channel damping coefficient, and inertia coefficient of the hydraulic rubber composite vibration isolation device;

[0009] Step S3: Design the static stiffness, equivalent piston area, volume stiffness, and flow channel parameters of the hydraulic rubber composite vibration damping device to form a preliminary design scheme for the hydraulic rubber composite vibration damping device so that it meets the key parameters obtained in step S2.

[0010] like Figure 1 As shown, the dynamic stiffness of the hydraulic rubber composite vibration isolation device gradually decreases with the increase of frequency in the low frequency band, and rapidly increases to a peak value after reaching a valley value, and then tends to stabilize with the increase of frequency; the loss factor of the vibration isolation device, that is, the loss angle, gradually increases with the increase of frequency at the beginning, and rapidly decreases after reaching a peak value, and stabilizes at a smaller value. In the stiffness and damping technical requirements for engine installation, it is required that the dynamic stiffness of the hydraulic rubber composite vibration isolation device show a downward trend in a certain small frequency band and be less than the static stiffness, and at the same time have a larger damping coefficient. The traditional design method is carried out through trial production and testing methods. In order to achieve the required vibration isolation performance for the target engine, the hydraulic rubber composite vibration isolation device needs to undergo long-term and extensive adjustment and testing, and needs to go through multiple rounds of structural version optimization, and the design cycle is relatively long. The design method of the present invention constructs a centralized parameter simulation model of a hydraulic-rubber composite vibration isolation device, adjusts key parameters of the hydraulic rubber, such as the equivalent piston area, volumetric stiffness, flow channel diameter, and length, and then performs a structural design of the hydraulic-rubber composite vibration isolation device to achieve the required vibration isolation performance. No actual product trial production is required before the design is finalized. Multiple rounds of virtual model verification and optimization are performed to finalize the final structural design. Because the version cycle of virtual model simulation verification and optimization is much shorter than that of trial production and experimental verification, the design cycle and cost can be significantly shortened.

[0011] Preferably, in step S2, the basic structure of the hydraulic rubber composite vibration isolation device based on which the concentrated parameter simulation model of the hydraulic rubber composite vibration damping device is constructed is as follows: the hydraulic rubber composite vibration isolation device includes an upper body and a lower body, the upper body is connected to the lower body through a flow channel plate, the upper body and the lower body are symmetrically arranged at the upper and lower ends of the flow channel plate, respectively enclosing a first hydraulic chamber and a second hydraulic chamber with the flow channel plate, the first hydraulic chamber is connected to the second hydraulic chamber through a flow channel opened on the flow channel plate, the upper body and the lower body both include a hydraulic chamber sleeve and a rubber spring, the outer end of each rubber spring is embedded with a connecting core shaft that can be connected to the vibration isolation mounting device on the aircraft engine. The use of a standard mechanism model can significantly shorten the design cycle.

[0012] Preferably, in step S2, when adjusting the key parameters of the hydraulic rubber composite damping device, the static stiffness is 1.6-2.4 times of the target parameter obtained in step S1. Designing the hydraulic cavity will reduce the static stiffness of the hydraulic rubber composite damping device, so it is designed to be 1.6-2.4 times of the technical requirement value to ensure that the static stiffness of the damping device after design meets the technical requirements.

[0013] Preferably, in step S2, the key parameters of the hydraulic rubber composite damping device are adjusted according to the following formula, so that the dynamic stiffness of the hydraulic rubber composite damping device about vibration frequency s And the damping coefficient Meet the target parameters obtained in step S1:

[0014]

[0015] Wherein, The combined stiffness of the two rubber springs (2), The damping coefficient, The equivalent piston area of the flow channel plate (5), , And the volume stiffness of the first hydraulic cavity (4) and the second hydraulic cavity (6) are respectively, And The flow channel damping coefficient and the inertia coefficient are respectively, The average pressure at static balance, The initial displacement, Can be obtained by simulation calculation, , , , , , , And The values of and can be directly set.

[0016] Preferably, in step S3, the static stiffness is adjusted by adjusting the material of the rubber spring, increasing or decreasing the thickness of the rubber layer, and changing the structure of the partition plate.

[0017] Preferably, in step S3, the equivalent piston area is adjusted by increasing the volume of the hydraulic cavity.

[0018] Preferably, in step S3, the volume stiffness is adjusted by adjusting the shape and structure of the hydraulic cavity.

[0019] The rubber body structure is "dug" to design the hydraulic chamber. The orthographic projection area of ​​the hydraulic chamber is slightly larger than the equivalent piston area to ensure that the preliminary design value is close to the target value. Finite element simulation is then performed on the preliminary structure to calculate its static stiffness, equivalent piston area, and volumetric stiffness. Static stiffness can be adjusted by increasing or decreasing the thickness of the rubber layer, adjusting the partition and other structures, and increasing or decreasing the projected area by increasing or decreasing the volume of the hydraulic chamber, thereby adjusting the equivalent piston area. Volumetric stiffness can be adjusted by adjusting the shape and structure of the hydraulic chamber. Since these three parameters have the characteristic of affecting each other, multiple rounds of adjustment, verification, and optimization are required during the adjustment process to ultimately achieve a precise design.

[0020] Preferably, in step S3, the channel is designed with a flow channel tube or flow channel groove or other structures in the flow channel plate, and is precisely designed according to matching diameter and length to achieve adjustment of the flow channel damping coefficient and inertia coefficient.

[0021] Preferably, the design method further includes step S4, performing precise simulation of the fluid-solid coupling dynamic performance of the preliminary design scheme obtained in step S3, calculating the variation pattern of the dynamic stiffness and damping value of the structural scheme at different frequencies and amplitudes, and performing local structural adjustment and optimization based on the simulation results to meet the technical requirements of the target engine, thereby obtaining the final design scheme of the hydraulic rubber composite vibration damping device.

[0022] Preferably, the design method further includes step S5, wherein the final design scheme formed in step S4 is subjected to sample trial production and static and dynamic stiffness test verification to verify the dynamic and static performance of the sample, and then the hydraulic rubber vibration damping device is installed into the vibration damping system for vibration isolation and drop test verification.

[0023] The present invention is described in detail below with reference to the embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0025] Figure 1 The graph of the dynamic stiffness and loss angle of the hydraulic rubber composite vibration isolation device changing with frequency;

[0026] Figure 2 Schematic diagram of the flow of a design method for a hydraulic rubber composite vibration isolation device according to an embodiment of the present invention;

[0027] Figure 3 This is a schematic diagram of the appearance of a hydraulic rubber composite vibration isolation device according to an embodiment of the present invention;

[0028] Figure 4 This is a schematic diagram of the tilted appearance of a hydraulic rubber composite vibration isolation device according to an embodiment of the present invention;

[0029] Figure 5 This is a three-dimensional cross-sectional view of a hydraulic rubber composite vibration isolation device according to an embodiment of the present invention;

[0030] Figure 6 This is a vertically symmetrical cross-sectional view of the hydraulic rubber composite vibration isolation device according to an embodiment of the present invention.

[0031] The above drawings include the following reference numerals:

[0032] 1. Hydraulic chamber sleeve; 2. Rubber spring; 3. Connecting core shaft; 4. First hydraulic chamber; 5. Flow channel plate; 51. Flow channel; 6. Second hydraulic chamber. DETAILED DESCRIPTION

[0033] The embodiments of the present invention are described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered by the claims.

[0034] See also Figure 2 In a preferred embodiment of the present invention, a design method is provided, comprising the following steps:

[0035] Step S1: performing parameter matching theoretical calculation, simulation, and design based on the technical requirements of stiffness and damping of the target engine at different frequencies to obtain target parameters of the hydraulic rubber composite vibration damping device, wherein the target parameters include static stiffness, and dynamic stiffness and damping coefficient at different frequencies;

[0036] Step S2, see Figure 3-6 , comprising an upper body and a lower body, the upper body being connected to the lower body via a flow channel plate (5), the upper body and the lower body being symmetrically arranged at the upper end and the lower end of the flow channel plate (5), respectively enclosing a first hydraulic chamber (4) and a second hydraulic chamber (6) with the flow channel plate (5), the first hydraulic chamber (4) being communicated with the second hydraulic chamber (6) via a flow channel (51) provided on the flow channel plate (5), the upper body and the lower body both comprising a hydraulic chamber sleeve (1) and a rubber spring (2), the outer end of each of the rubber springs (2) being embedded with a connecting core shaft (3) which can be connected to a vibration isolation mounting device on an aircraft engine;

[0037] Based on the basic structure of the hydraulic rubber composite vibration isolation device, a lumped parameter simulation model of the hydraulic rubber composite vibration isolation device is constructed, and key parameters of the hydraulic rubber composite vibration isolation device are adjusted to meet the target parameters obtained in step S1. The key parameters include the equivalent piston area, volume stiffness, flow channel damping coefficient, and inertia coefficient of the hydraulic rubber composite vibration isolation device;

[0038] Among them, when adjusting the key parameters of the hydraulic rubber composite vibration damping device, the adaptation is performed according to twice the static stiffness of the target parameter obtained in step S1; and the key parameters of the hydraulic rubber composite vibration isolation device are adjusted according to the following formula so that the dynamic stiffness of the hydraulic rubber composite vibration isolation device about the vibration frequency s is and damping coefficient Satisfy the target parameters obtained in step S1:

[0039]

[0040] in, is the combined stiffness of the two rubber springs (2), is the damping coefficient, is the equivalent piston area of ​​the flow channel plate (5), 、 and are the volume stiffness of the first hydraulic chamber (4) and the second hydraulic chamber (6), respectively. and are the flow channel damping coefficient and inertia coefficient, is the average pressure in static equilibrium, is the initial displacement, It can be obtained through simulation calculation, 、 、 、 、 、 、 and The value of can be set directly.

[0041] Step S3, designing the static stiffness, equivalent piston area, volume stiffness, and flow channel parameters of the hydraulic rubber composite vibration damping device to form a preliminary design scheme for the hydraulic rubber composite vibration damping device so that it meets the key parameters obtained in step S2;

[0042] The static stiffness of the hydraulic rubber composite vibration damping device is adjusted by adjusting the material of the rubber spring (2), increasing or decreasing the thickness of the rubber layer, and changing the partition structure; the equivalent piston area is adjusted by increasing the volume of the hydraulic cavity; the volume stiffness is adjusted by adjusting the shape and structure of the hydraulic cavity; and the damping coefficient and inertia coefficient of the flow channel are adjusted by designing a flow channel tube or flow channel groove in the flow channel plate and accurately designing them according to matching diameters and lengths. When adjusting these three parameters, the static stiffness is adjusted first, then the equivalent piston area is adjusted, and finally the volume stiffness is adjusted.

[0043] Step S4: Perform precise fluid-structure coupling dynamic performance simulation on the preliminary design scheme obtained in step S3, calculate the variation pattern of dynamic stiffness and damping value of the structural scheme at different frequencies and amplitudes, and perform local structural adjustment and optimization based on the simulation results to meet the technical requirements of the target engine, thereby obtaining the final design scheme of the hydraulic rubber composite vibration damping device.

[0044] Step S5: Produce prototypes and conduct static and dynamic stiffness tests on the final structural solution formed in step S4 to verify the dynamic and static performance of the prototypes. Then, install the hydraulic rubber vibration damping device into the vibration damping system to conduct vibration isolation and drop test verification.

[0045] At this point, the design of the hydraulic rubber composite vibration damping device is completed.

[0046] The above describes in detail the preferred embodiments of the present invention. It should be understood that those skilled in the art can make numerous modifications and variations based on the concepts of the present invention without inventive effort. Therefore, any technical solutions that can be derived by those skilled in the art through logical analysis, reasoning, or limited experimentation based on the concepts of the present invention and the prior art should be within the scope of protection defined by the claims.

Claims

1. A design method for a hydraulic rubber composite vibration isolation device, characterized in that: The following steps are involved: Step S1: performing parameter matching theoretical calculation, simulation, and design based on the technical requirements of stiffness and damping of the target engine at different frequencies to obtain target parameters of the hydraulic rubber composite vibration damping device, wherein the target parameters include static stiffness, and dynamic stiffness and damping coefficient at different frequencies; Step S2: Based on the basic structure of the hydraulic rubber composite vibration isolation device, a lumped parameter simulation model of the hydraulic rubber composite vibration damping device is constructed, and key parameters of the hydraulic rubber composite vibration damping device are adjusted to meet the target parameters obtained in step S1. The key parameters include the equivalent piston area, volume stiffness, flow channel damping coefficient, and inertia coefficient of the hydraulic rubber composite vibration damping device. Step S3, designing the static stiffness, equivalent piston area, volume stiffness, and flow channel parameters of the hydraulic rubber composite vibration damping device to form a design scheme for the hydraulic rubber composite vibration damping device so that it meets the key parameters obtained in step S2; In step S2, the key parameters of the hydraulic rubber composite vibration isolation device are adjusted according to the following formula so that the dynamic stiffness of the hydraulic rubber composite vibration isolation device with respect to the vibration frequency s is and damping coefficient Satisfy the target parameters obtained in step S1: in, is the combined stiffness of the two rubber springs (2), is the damping coefficient, is the equivalent piston area of ​​the flow channel plate (5), 、 and are the volume stiffness of the first hydraulic chamber (4) and the second hydraulic chamber (6), respectively. and are the flow channel damping coefficient and inertia coefficient, is the average pressure in static equilibrium, is the initial displacement, It can be obtained through simulation calculation, 、 、 、 、 、 、 and The value of can be set directly; The method further includes: step S4, performing precise simulation of the fluid-structure coupling dynamic performance of the preliminary design scheme obtained in step S3, calculating the variation pattern of the dynamic stiffness and damping value of the structural scheme at different frequencies and amplitudes, and adjusting and optimizing the local structure according to the simulation results to meet the technical requirements of the target engine, thereby obtaining the final design scheme of the hydraulic rubber composite vibration damping device.

2. The design method of the hydraulic rubber composite vibration isolation device according to claim 1 is characterized in that: In step S2, the basic structure of the hydraulic rubber composite vibration isolation device is as follows: the hydraulic rubber composite vibration isolation device includes an upper body and a lower body, the upper body is connected to the lower body through a flow channel plate (5), the upper body and the lower body are symmetrically arranged at the upper end and the lower end of the flow channel plate (5), and respectively enclose a first hydraulic chamber (4) and a second hydraulic chamber (6) with the flow channel plate (5), the first hydraulic chamber (4) is connected to the second hydraulic chamber (6) through a flow channel (51) opened on the flow channel plate (5), and the upper body and the lower body are both provided with a rubber spring (2).

3. The design method of the hydraulic rubber composite vibration isolation device according to claim 2 is characterized in that: In step S2, when adjusting the key parameters of the hydraulic rubber composite vibration damping device, adaptation is performed according to 1.6 to 2.4 times the static stiffness of the target parameter obtained in step S1.

4. The design method of the hydraulic rubber composite vibration isolation device according to claim 3 is characterized in that: In step S3, the combined stiffness is adjusted by adjusting the material of the rubber spring (2), increasing or decreasing the thickness of the rubber layer, and changing the structure of the diaphragm, thereby adjusting the static stiffness of the hydraulic rubber composite vibration isolation device.

5. The design method of the hydraulic rubber composite vibration isolation device according to claim 3 is characterized in that: In step S3 , the equivalent piston area is adjusted by increasing the volume of the hydraulic chamber.

6. The design method of the hydraulic rubber composite vibration isolation device according to claim 3 is characterized in that: In step S3 , the volume stiffness is adjusted by adjusting the shape and structure of the hydraulic chamber.

7. The design method of the hydraulic rubber composite vibration isolation device according to claim 3 is characterized in that: In step S3 , the flow channel damping coefficient and inertia coefficient are adjusted by designing a flow channel tube or flow channel groove structure in the flow channel plate and accurately designing it according to matching diameter and length.

8. The design method of the hydraulic rubber composite vibration isolation device according to claim 1 is characterized in that: The method further includes: step S5, conducting prototype trial production and static and dynamic stiffness test verification on the final design scheme formed in step S4 to verify the dynamic and static performance of the prototype, and then installing the hydraulic rubber vibration damping device into the vibration damping system to conduct vibration isolation and drop test verification.

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