Active and passive composite vibration reduction connecting pipe

Abstract

An active and passive composite vibration reduction connecting pipe is characterized by comprising an installation connector structure (1), rubber bodies (2), a fastener (3), a piezoelectric actuator (4), a piezoelectric actuator installation fastener (5) and a cylindrical coasting body (6), the installation connector structure (1) is connected with the rubber bodies (2) in a vulcanization mode, the two rubber bodies (2) are connected with the cylindrical coasting body (6) through the installation connector structure (1), and the connection mode is that the fastener (3) is installed. The four piezoelectric actuators (4) are installed on the cylindrical inertia body (6) through the fasteners (5), the cylindrical inertia body (6) is a steel structural member, and the cylindrical inertia body (6) and the two flexible colloids (2) form a sandwich structure to achieve vibration decoupling.

Description

Technical Field

[0001] The present invention relates to marine vibration damping components, and in particular to a main - passive composite vibration damping pipe joint applied to the vibration reduction and noise reduction project of marine equipment. Background Art

[0002] Pipeline vibration is the main transmission channel of ship vibration and noise. Although the existing vibration damping pipe joints can achieve a certain vibration damping effect, there are the following technical defects:

[0003] 1. The passive vibration damping structure has a poor control effect on low - frequency line spectra (<200 Hz)

[0004] 2. Single - passive control is difficult to balance the suppression of broadband vibration

[0005] 3. The traditional structure has vibration coupling problems, resulting in a complex energy transfer path. Therefore, in order to continuously improve the vibration reduction and noise reduction performance of ships, the optimized design of vibration damping pipe joints is necessary. Summary of the Invention

[0006] According to the above - mentioned technical background, the present invention aims to provide a main - passive composite vibration damping pipe joint, which takes into account low - frequency line spectra and broadband vibration control, and provides diverse choices for the selection of vibration damping components of marine equipment.

[0007] A main - passive composite vibration damping pipe joint includes a mounting joint structure, a colloid, fasteners, a piezoelectric actuator, piezoelectric actuator mounting fasteners, and a cylindrical inertial body. The colloid is flexible, and the mounting joint structure is vulcanized and connected to the colloid; two colloids are connected to the cylindrical inertial body through the mounting joint structure, and the connection method is the installation of fasteners; four piezoelectric actuators are installed on the cylindrical inertial body through fasteners; the cylindrical inertial body is a steel structural member, and other materials can be selected for the cylindrical inertial body according to the application scenario. Together with two flexible colloids, it forms a "sandwich" structure to achieve vibration decoupling.

[0008] The main advantages of a main - passive composite vibration damping pipe joint:

[0009] 1. The main - passive composite vibration damping pipe joint provided by the present invention takes into account low - frequency line spectra and broadband vibration control.

[0010] 2. The structure of the present invention is compact, easy to install and disassemble, improving the convenience of construction and maintenance for workers. Description of the Drawings

[0011] Appendix Figure 1 Assembly drawing of a main - passive composite vibration damping pipe joint

[0012] Appendix Figure 2 View A of a main - passive composite vibration damping pipe joint

[0013] Appendix Figure 3A-A Cross-sectional View of a Hybrid Active and Passive Vibration Isolation Pipe Joint

[0014] Appendix Figure 4 B-B Cross-sectional View of a Hybrid Active and Passive Vibration Isolation Pipe Joint Detailed Implementation Manner

[0015] A hybrid active and passive vibration isolation pipe joint, which comprises a mounting joint structure (1), a colloid (2), a fastener (3), a piezoelectric actuator (4), a piezoelectric actuator mounting fastener (5), and a cylindrical inertial body (6). The mounting joint structure (1) is vulcanized and connected to the colloid (2); two colloids (2) are connected to the cylindrical inertial body (6) through the mounting joint structure (1), and the connection method is the installation of the fastener (3); four piezoelectric actuators (4) are installed on the cylindrical inertial body (6) through the fastener (5); the cylindrical inertial body (6) is a steel structure part (other materials can be selected according to the application scenario), and together with two flexible colloids (2), it forms a "sandwich" structure to achieve vibration decoupling.

[0016] A method for using a hybrid active and passive vibration isolation pipe joint:

[0017] 1. System integration and installation of the hybrid active and passive vibration isolation pipe joint

[0018] Pipe connection: The flange surfaces of the mounting joint structures (1) at both ends of the hybrid active and passive vibration isolation pipe joint are connected to the ship pipeline system. ASME B16.5 standard flanges are used for connection, and M20 bolts are used for fastening.

[0019] Control system wiring: The cables of the piezoelectric actuators (4) are connected to a multi-channel adaptive controller, and the input end of the controller is connected to ICP type acceleration sensors (sensitivity 100mV / g, frequency response range 5 - 5000Hz) arranged at both ends of the ship pipeline.

[0020] Sealing treatment: Apply EPDM rubber sealant to the flange surfaces of the mounting joint structure (1), and externally wrap 3 layers of anti-corrosion heat shrinkable sleeves (temperature resistance -40°C to 120°C), which are suitable for the humid salt spray environment of ships.

[0021] 2. Operation control process

[0022] Passive mode initialization:

[0023] After the system is powered on, the controller automatically detects the basic vibration spectrum of the ship pipeline (sampling rate 10kHz), identifies the energy distribution in the frequency band of 50 - 2000Hz through FFT analysis, and establishes an initial vibration baseline database.

[0024] Active control activation:

[0025] When it is detected that the amplitude of the characteristic frequency (such as the 150Hz line spectrum excited by the main engine) exceeds the threshold (set to 0.5mm / s2 ) When starting, active control is initiated.

[0026] The controller generates an anti-phase control signal according to the LMS algorithm, driving the piezoelectric actuator (4) in the corresponding quadrant to generate a dynamic voltage of ±800V, with a maximum actuation force output of 120N (corresponding to a displacement of 20μm).

[0027] The phase difference of the piezoelectric actuator is adjusted in real time using the gradient descent method (adjustment accuracy ±5°) to ensure that the vibration cancellation effect is stable within the range of ±3dB.

[0028] Intelligent mode switching:

[0029] A dual-threshold control strategy is set: when the energy ratio of high-frequency vibration (>500Hz) exceeds 70%, the active control is automatically turned off to reduce power consumption; when the sudden increase amplitude of the low-frequency line spectrum (<200Hz) reaches 6dB, full-power active suppression is immediately initiated.

[0030] 3. Deepening of the mechanism of action

[0031] (1) Hierarchical passive vibration damping

[0032] High-frequency energy dissipation (200 - 2000Hz): The butyl rubber colloid (2) converts mechanical vibration energy into heat through the viscoelastic hysteresis effect of molecular chains. The measured loss factor at 300Hz reaches 0.35, and the vibration transmission loss T L = 20log 10 (1 + E r ·tanδ / 2) ≈ 18dB (E r is the rubber / steel elastic modulus ratio = 0.0003).

[0033] Medium-frequency tuning (50 - 200Hz): The mass-spring effect of the steel inertial body (6) forms a dynamic anti-resonance point, and its natural frequency f n By adjusting the wall thickness of the inertial body (12mm in this embodiment), f n = 90Hz, resulting in a natural attenuation of 8 - 10dB within a bandwidth of ±15Hz.

[0034] (2) Precise active control intervention

[0035] Line spectrum cancellation: Four groups of piezoelectric actuators (4) form a MIMO control system. When a 150Hz line spectrum is detected: The piezoelectric actuator (4) generates a reverse inertial force F = ma = 4 × 0.5kg × 9.8m / s 2 = 19.6N (the effective mass of a single group of piezoelectric actuators is 0.5kg).

[0036] Through phase optimization, the vibration velocity amplitude is reduced from 1.2mm / s to 0.15mm / s, corresponding to a 23dB reduction in the acceleration level.

[0037] Modal decoupling: Four groups of piezoelectric actuators (4) apply asymmetric excitation forces to break the structural symmetric modes (such as breathing mode, bending mode), and the measured modal density in the frequency band of 200 - 400 Hz is reduced by 40%.

[0038] (3) Composite synergistic effect

[0039] Frequency band connection optimization: At the 200 Hz crossover frequency point, the active control gain automatically decreases by 6 dB / oct to avoid positive feedback with the passive attenuation region.

[0040] Energy path management: The "sandwich" structure forces the vibration wave to cross different impedance interfaces three times (steel → rubber → steel), and combined with the wave interference effect of the piezoelectric actuator (4), the equivalent impedance of the vibration transmission path is increased to 0.5×10 6 N·s / m 3 (The traditional structure is only 2.1×10 6 ).

[0041] Measured performance data

[0042] A comparative test was carried out on the auxiliary machine pipeline system of XX type frigate (excitation force 20N RMS):

[0043] Frequency range Traditional rubber joint Passive mode of the present invention Active mode of the present invention Compound mode 50 - 100Hz -3dB -5dB -18dB -20dB 100 - 200Hz -6dB -8dB -22dB -23dB 200 - 500Hz -12dB -15dB -18dB 500 - 2000Hz -18dB -21dB -24dB

[0044] The data shows that the composite mode achieves 23 dB attenuation in the key line spectrum region (100 - 200 Hz), which is 15 dB higher than that of the single passive mode; the overall insertion loss in the broadband reaches more than 18 dB, meeting the A-level standard of GJB 4058 - 2000 ship pipeline vibration isolator.

[0045] Application under special working conditions

[0046] 1. Protection against large impact loads: When the main - passive composite vibration - damping joint system withstands an explosion shock (pulse width 5 ms, peak value 500 m / s 2 ):

[0047] The rubber layer absorbs transient energy through large deformation (allowing a shear strain of 35%); the piezoelectric actuator (4) switches to the displacement sensor mode and real - time feeds back the structural deformation to the safety system.

[0048] 2. Adaptation to low - temperature environment: During the test on the Arctic route at - 30°C:

[0049] Change to silicone rubber colloid (2) (brittleness temperature - 80°C), and the driving voltage of the piezoelectric actuator (4) is increased to 1000 V to compensate for the low - temperature attenuation of the piezoelectric constant d33 (from 650×10 -12 m / V to 520×10 -12 m / V).

[0050] Through the combination of refined structural design and intelligent control strategies, this embodiment solves the technical dilemmas of low-frequency failure and high-frequency limitation of traditional vibration damping joints, providing an innovative solution for ship vibration and noise control.

Claims

1. A main and passive composite vibration damping pipe joint, characterized in that It consists of an installation joint structure (1), a colloid (2), a fastener (3), a piezoelectric actuator (4), a piezoelectric actuator installation fastener (5), and a cylindrical inertial body (6). The installation joint structure (1) is vulcanized and connected to the colloid (2). Two colloids (2) are connected to the cylindrical inertial body (6) through the installation joint structure (1), and the connection method is the installation of the fastener (3). Four piezoelectric actuators (4) are installed on the cylindrical inertial body (6) through the fastener (5). The cylindrical inertial body (6) is a steel structural part, which together with two flexible colloids (2) forms a "sandwich" structure to achieve vibration decoupling.

2. The usage method of a main - passive composite vibration - damping pipe joint according to claim 1, characterized in that: (1). Integrated installation of the main - passive composite vibration - damping pipe joint system Pipeline docking: The flange surfaces of the installation joint structures (1) at both ends of the main - passive composite vibration - damping pipe joint are docked with the ship pipeline system, connected by ASME B16.5 standard flanges, and fastened with M20 bolts; Control system wiring: The cables of the piezoelectric actuators (4) are connected to a multi - channel adaptive controller, and the input end of the controller is connected to ICP - type acceleration sensors (sensitivity 100mV / g, frequency response range 5 - 5000Hz) arranged at both ends of the ship pipeline; Sealing treatment: Apply EPDM rubber sealant to the flange surfaces of the installation joint structures (1), and externally wrap 3 layers of anti - corrosion heat - shrinkable sleeves (temperature resistance - 40°C to 120°C), suitable for the humid salt - fog environment of ships; (2). Operation control process Initialization of passive mode: After the system is powered on, the controller automatically detects the basic vibration spectrum of the ship pipeline (sampling rate 10kHz), identifies the energy distribution in the frequency band of 50 - 2000Hz through FFT analysis, and establishes an initial vibration baseline database; Activation of active control: When the amplitude of the detected characteristic frequency (such as the 150 Hz line spectrum excited by the host) exceeds the threshold value (set to 0.5 mm / s 2 ), active control is initiated; The controller generates an anti - phase control signal according to the LMS algorithm, drives the piezoelectric actuators (4) in the corresponding quadrants to generate a dynamic voltage of ±800V, and outputs the maximum driving force; The phase difference of the piezoelectric actuators is adjusted in real - time by the gradient descent method (adjustment accuracy ±5°) to ensure that the vibration cancellation effect is stable within the range of ±3dB; Intelligent mode switching: Set a double - threshold control strategy: When the energy ratio of high - frequency vibration (>500Hz) exceeds 70%, the active control is automatically turned off to reduce power consumption; when the sudden increase amplitude of the low - frequency line spectrum (<200Hz) reaches 6dB, full - power active suppression is immediately started.

3. The method for using the active and passive composite vibration reduction pipe according to claim 1 is characterized by: Deepening of the action mechanism: (1) Hierarchical action of passive vibration damping High - frequency energy consumption (200 - 2000Hz): The butyl rubber colloid (2) converts mechanical vibration energy into heat energy through the viscoelastic hysteresis effect of molecular chains; Medium - frequency tuning (50 - 200Hz): The mass - spring effect of the steel inertial body (6) forms a dynamic anti - resonance point, and its natural frequency fn is adjusted by adjusting the wall thickness of the inertial body so that fn = 90Hz, and natural attenuation occurs within a bandwidth of ±15Hz; (2) Precise intervention of active control Line spectrum cancellation: Four groups of piezoelectric actuators (4) form a MIMO control system. When a 150Hz line spectrum is detected: the piezoelectric actuators (4) generate a reverse inertial force; The vibration velocity amplitude is reduced through phase optimization, corresponding to the reduction of the acceleration level; Modal decoupling: Four groups of piezoelectric actuators (4) apply asymmetric excitation forces to break the symmetric modes of the structure (such as breathing mode, bending mode); (3) Composite synergistic effect Optimization of frequency band connection: At the 200 Hz crossover frequency point, the active control gain is automatically reduced to avoid positive feedback with the passive attenuation region; Energy path management: The "sandwich" structure forces the vibration wave to cross different impedance interfaces three times (steel → rubber → steel). Combining with the wave interference effect of the piezoelectric actuator (4), the equivalent impedance of the vibration transmission path is increased.

Images