Anti-vibration optical fiber connector assembly based on inertia decoupling and viscoelastic damping

Abstract

The invention discloses an anti-vibration optical fiber connector assembly based on inertia decoupling and viscoelastic damping, and belongs to the technical field of optical fiber sensing. The optical fiber connector assembly comprises: a connector housing assembly; the suspension insertion core module is arranged in the connector shell assembly, and the head of the suspension insertion core module is provided with an optical fiber insertion core; the inertial mass unit is arranged at the tail part of the suspension insertion core module; the viscoelastic damping layer is filled in a gap among the suspension insertion core module, the inertia mass unit and the connector shell assembly, so that the suspension insertion core module is supported in the connector shell assembly in a suspension manner; the viscoelastic damping layer is used for absorbing vibration energy transmitted to the connector shell assembly from the outside and is matched with the inertial mass unit to isolate the influence of vibration on the optical fiber insertion core; on the premise that a standard physical interface is reserved, external high-frequency vibration crosstalk is effectively filtered out through physical isolation, photoelastic effect noise and end face reflection fluctuation are eliminated, and the detection precision and stability of the DAS are remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of fiber optic sensing technology, and in particular to an anti-vibration fiber optic connector assembly based on inertial decoupling and viscoelastic damping. Background Technology

[0002] Distributed acoustic sensing systems (DAS) are widely used in power cable monitoring, pipeline security, border perimeter protection, and marine communication fiber optic cable monitoring because they can achieve continuous real-time monitoring over long distances and with high spatial resolution.

[0003] However, in actual deployment, the performance of DAS is still limited by vibration and noise interference. DAS technology achieves accurate perception of external physical disturbances by analyzing Rayleigh scattering signals propagating back along the sensing fiber. This technology connects the device's fiber optic port to the field sensing fiber optic interface, sending a search light pulse (analog signal). When this pulse propagates along the fiber optic cable, external vibrations modulate its phase, and it is then transmitted back to the device via the backscattered light pulse (analog signal).

[0004] In practical applications, when using a standard digital fiber optic communication interface to connect DAS devices and sensing fibers, non-target vibrations such as the operating vibrations of air conditioner compressors and fans, the working vibrations of surrounding cabinet equipment, and the disturbances caused by maintenance personnel walking around can modulate the fiber at the connection interface in the form of "vibration crosstalk" through physical carriers such as fiber optic distribution frames (ODFs) and fiber optic patch cords. This results in strong background noise, leading to a deterioration in the DAS signal-to-noise ratio, a reduction in detection range, and a decrease in detection accuracy. More importantly, this type of vibration will also directly affect the contact state between the fiber optic patch cord and the DAS terminal interface core layer, including but not limited to abnormalities such as contact gaps, induced core layer misalignment, and end-face contamination, generating strong reflected waves that may prevent the DAS from effectively detecting the target signal.

[0005] Currently, the solution to this problem is to remove the fixed fiber optic interface and directly splice the fiber optic cables to the equipment ports and field sensors. However, in some special locations, such as high-end computer rooms (power systems, banks, military sites, etc.) where fiber optic cables have been laid according to standards, it is strictly forbidden to damage the existing cabling structure or remove the standard interface.

[0006] Therefore, there is an urgent need for a device that can retain the standard interface form while effectively isolating physical vibration crosstalk. Summary of the Invention

[0007] The purpose of this invention is to provide an anti-vibration fiber optic connector assembly based on inertial decoupling and viscoelastic damping, aiming to solve the problems of high background noise and unstable contact caused by environmental vibration transmitted by ODF and patch cords in existing DAS. This assembly can achieve "dynamic and static isolation" at the fiber optic interface without changing the existing data center cabling standards.

[0008] To achieve the above-mentioned objectives, the present invention employs the following technical solution: An anti-vibration fiber optic connector assembly based on inertial decoupling and viscoelastic damping includes: Connector housing assembly; A floating ferrule module is located inside the connector housing assembly, and the head of the floating ferrule module is provided with an optical fiber ferrule. An inertial mass unit is located at the tail of the levitation ferrule module to increase the inertial mass of the levitation ferrule module; A viscoelastic damping layer is filled in the gap between the levitation ferrule module, the inertial mass unit, and the connector housing assembly to levitate and support the levitation ferrule module within the connector housing assembly. The viscoelastic damping layer is used to absorb the vibration energy transmitted from the outside to the connector housing assembly, and works with the inertial mass unit to isolate the effect of vibration on the fiber optic ferrule.

[0009] According to the vibration-resistant fiber optic connector assembly based on inertial decoupling and viscoelastic damping, the front end of the connector housing assembly is provided with a spiral opening for rigid locking with an external fiber optic patch panel or equipment port.

[0010] According to the vibration-resistant fiber optic connector assembly based on inertial decoupling and viscoelastic damping, the connector housing assembly has a cylindrical cavity inside, and the inner wall of the cavity is provided with rough texture or retaining groove to enhance the bonding force with the viscoelastic damping layer.

[0011] According to the vibration-resistant fiber optic connector assembly based on inertial decoupling and viscoelastic damping, the inner wall of the connector housing assembly is also provided with a limiting keyway, and the front end of the floating ferrule module is provided with a positioning key. The positioning key is located in the limiting keyway, forming a limiting stop mechanism.

[0012] According to the vibration-resistant fiber optic connector assembly based on inertial decoupling and viscoelastic damping, the gap between the positioning key and the limiting keyway is in the micrometer range.

[0013] According to the vibration-resistant fiber optic connector assembly based on inertial decoupling and viscoelastic damping, the gap between the limiting keyway and the positioning key is also filled with the material of the viscoelastic damping layer.

[0014] According to the vibration-resistant fiber optic connector assembly based on inertial decoupling and viscoelastic damping, the inertial mass unit is a ring structure, which is sleeved and fixed to the tail of the suspended ferrule module.

[0015] According to the vibration-resistant fiber optic connector assembly based on inertial decoupling and viscoelastic damping, the fiber optic connector assembly further includes: a fiber stress relief cavity; The fiber stress relief cavity is located at the tail of the connector housing assembly to isolate the axial tension and radial jitter transmitted by the external optical cable sheath.

[0016] According to the vibration-resistant fiber optic connector assembly based on inertial decoupling and viscoelastic damping, the fiber optic cable extending from the tail of the fiber optic ferrule is in a bent state and suspended within the fiber stress relief cavity.

[0017] According to the described anti-vibration fiber optic connector assembly based on inertial decoupling and viscoelastic damping, the fiber stress relief cavity is filled with a gel medium.

[0018] Compared with the prior art, the beneficial effects of the present invention include at least the following: 1. This invention designs a connector housing assembly and a suspended ferrule module, sets an inertial mass unit at the tail of the suspended ferrule module, and fills a viscoelastic damping layer between the connector housing assembly and the suspended ferrule module. While retaining the standard physical interface, it can effectively physically isolate high-frequency crosstalk from mechanical vibrations such as fans and air conditioners in the computer room environment, eliminate photoelastic phase noise and end-face reflection fluctuations at the interface, improve the DAS signal-to-noise ratio, achieve significant noise reduction, and significantly improve the detection accuracy and stability of DAS.

[0019] 2. By suspending the ferrule module within the connector housing assembly and designing the fiber stress relief cavity, this invention ensures that even if the external patch cord is disturbed, the ferrule end face maintains stable physical contact, eliminating reflected wave fluctuations and guaranteeing stable contact. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this disclosure or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the overall structure of the vibration-resistant fiber optic connector assembly based on inertial decoupling and viscoelastic damping of the present invention. Figure 2 This is a schematic diagram of the overall structure of the anti-vibration fiber optic connector assembly based on inertial decoupling and viscoelastic damping, taking the FC / APC interface as an example. Figure 3 The following are comparative experimental data graphs of a preferred embodiment of the present invention; wherein, (a) is the detection signal result using a common FC / APC interface fiber optic patch cord; and (b) is the detection signal result using an FC / APC interface fiber optic patch cord with the connector assembly provided in Embodiment 2 of the present invention. In the figure: 1. Connector housing assembly; 11. Limiting keyway; 2. Floating ferrule module; 21. Fiber optic ferrule; 22. Positioning key; 3. Inertial mass unit; 4. Viscoelastic damping layer; 5. Fiber optic stress relief cavity. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of this invention. The embodiments described in this application are merely some embodiments of this invention, and not all embodiments. Based on the spirit of this invention, any other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this invention.

[0023] In the description of this invention, it should be noted that the terms "front," "rear," "inner," "outer," "right," "left," "both ends," "one end," and "the other end," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0024] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0025] like Figure 1 As shown, Embodiment 1 of the present invention provides a highly stable anti-vibration fiber optic connector assembly based on inertial decoupling and viscoelastic damping specifically for distributed acoustic sensing systems, capable of physically isolating environmental vibration noise, including: Connector housing assembly 1.

[0026] The connector housing assembly 1 has a standard spiral opening at its front end for rigidly locking with an external fiber optic distribution frame (ODF) or device port.

[0027] The connector housing assembly 1 has a cylindrical cavity inside, and the inner wall of the cavity is provided with rough texture or retaining groove to enhance the bonding force with the viscoelastic damping layer 4.

[0028] The spiral joint is an M8 spiral joint.

[0029] Preferably, but not limitingly, the connector housing assembly 1, as a receiver of external mechanical vibration, is a rigid structure and may be made of nickel-plated brass.

[0030] The floating ferrule module 2 is located inside the connector housing assembly 1.

[0031] The head of the suspended ferrule module 2 is provided with an optical fiber ferrule 21 for optical signal coupling.

[0032] The suspended ferrule module 2 is used to carry and protect the optical fiber ferrule.

[0033] Preferably, but not limitingly, the fiber optic ferrule 21 may be a standard ceramic ferrule.

[0034] The interface type of the fiber optic ferrule 21 can be selected from standard interfaces such as LC, SC, FC / APC or ST, and the overall dimensions of the fiber optic connector assembly conform to the corresponding International Electrotechnical Commission (IEC) fiber optic connector interface standard.

[0035] An inertial mass unit 3 is located at the tail of the levitation ferrule module 2 to increase the inertial mass m of the levitation ferrule module 2.

[0036] The inertial mass unit 3 is made of a high-density material, such as tungsten alloy, copper alloy or stainless steel.

[0037] Preferably, but not limitingly, the inertial mass unit 3 is a ring structure, which is sleeved and fixed to the tail of the levitation ferrule module 2 without affecting the optical path.

[0038] A viscoelastic damping layer 4 is filled in the gap between the suspended ferrule module 2, the inertial mass unit 3 and the connector housing assembly 1 to construct a "mass-damping" low-pass filter system, so that the suspended ferrule module 2 is suspended and supported in the connector housing assembly 1, so that there is no rigid mechanical contact between the two, thereby reducing the connection stiffness k and increasing the damping coefficient c.

[0039] Preferably, but not limitingly, the viscoelastic damping layer 4 may be made of non-Newtonian fluid gel, high-damping silicone rubber, high-damping thixotropic silicone gel or damping grease, which has a high loss factor for dissipating shear vibration energy.

[0040] The viscoelastic damping layer 4 is used to absorb the vibration energy transmitted from the outside to the connector housing assembly 1, and works with the inertial mass unit 3 to form a mechanical low-pass filter to isolate the influence of vibration on the fiber optic ferrule 21. The vibration is a vibration with a frequency greater than 50Hz.

[0041] The fiber optic connector assembly further includes: a fiber stress relief cavity 5, to achieve mechanical decoupling of the fiber optic cable tension; The fiber stress relief cavity 5 is located at the tail of the connector housing assembly 1 to isolate the axial tension and radial jitter transmitted by the external optical cable sheath. The optical fiber extending from the tail of the optical fiber ferrule 21 is in a bent state and suspended within the optical fiber stress relief cavity 5. The bent state is a non-linear shape with redundant length, serving as a stress relief section.

[0042] The stress relief section is suspended in the fiber stress relief cavity 5 in a spiral, S-shaped bend, or wave shape.

[0043] The fiber stress relief cavity 5 is filled with a gel medium.

[0044] The gel medium is a low-modulus gel medium.

[0045] The inner wall of the connector housing assembly 1 is also provided with a limiting keyway 11, and the front end of the floating ferrule module 2 is provided with a positioning key 22; The positioning key 22 is disposed in the limiting keyway 11 to form a limiting stop mechanism.

[0046] The gap between the positioning key 22 and the limiting keyway 11 is within the micrometer range, which can ensure that the floating ferrule module 2 floats relative to the connector housing assembly 1 within the micrometer range, and also ensure that its maximum displacement is limited during macroscopic insertion and removal operations to ensure the effectiveness of insertion and removal.

[0047] The gap between the limiting keyway 11 and the positioning key 22 is also filled with the material of the viscoelastic damping layer 4.

[0048] The gap between the positioning key 22 and the limiting keyway 11 also contains a viscoelastic damping layer 4.

[0049] Implementation principle: This invention is based on the theory of mechanical vibration isolation and the principle of acoustic impedance mismatch: Inertial decoupling and mechanical low-pass filtering: For a mass-spring-damped system, its natural frequency By increasing the inertial mass m of the suspended part and reducing the connection stiffness k, the natural frequency of the system can be designed to be extremely low, for example, below 10 Hz.

[0050] For high-frequency environmental vibrations from the ODF, typically greater than 50Hz, the inertial mass unit 3 remains stationary due to its enormous inertia and does not vibrate with the connector housing assembly 1, thus achieving "controlling stillness with movement".

[0051] Viscoelastic energy dissipation: When subjected to shear force, the viscoelastic damping layer utilizes the internal friction of the polymer material to convert mechanical vibration energy into heat energy for dissipation, thus preventing resonance amplification.

[0052] Cable decoupling: The stress-relieving section in the bent state acts as an extremely soft spring. When the external optical cable is pulled or shaken, the stress-relieving section in the S-bend state undergoes elastic deformation, unloading the force and ensuring that the contact pressure of the front end ferrule is constant, thus eliminating reflection noise.

[0053] like Figure 2 As shown, Embodiment 2 of the present invention provides a preferred embodiment of an anti-vibration fiber optic connector assembly based on inertial decoupling and viscoelastic damping, wherein the interface of the fiber optic ferrule 21 is an FC / APC interface.

[0054] The fiber optic ferrule 21 is made of high-precision zirconia ceramic and the end face is ground to an 8-degree bevel (APC) to ensure that the return loss is greater than 60dB.

[0055] A tungsten alloy inertial mass unit is press-fitted onto the outer rear end of the levitation ferrule module 2 using an interference fit. The tungsten alloy has a high density of 19.3 g / cm³, significantly increasing the inertial mass of the internal levitation portion. The tungsten alloy inertial mass unit has a ring-shaped structure, enclosing the rear end of the levitation ferrule module 2 without affecting the optical path. The levitation ferrule module 2 is inserted into the limiting keyway 11 of the connector housing assembly 1 via a positioning key 22, without directly contacting the wall of the limiting keyway 1.

[0056] All gaps between the connector housing assembly 1 and the suspended ferrule module 2 are filled with high-damping thixotropic silicone gel, specifically high-damping thixotropic silicone gel for radial gaps, axial step gaps, and keyway gaps. After curing, the silicone gel has a jelly-like morphology, suspending and supporting the internal module at its center within the connector housing assembly 1.

[0057] At the keyway, silicone gel fills the space between the positioning key 22 and the limiting keyway 11, forming a flexible connection structure. This prevents macroscopic rotation of the APC end face, maintaining an 8-degree angle alignment, and absorbs micron-level circumferential vibrations. When the external ODF transmits vibrations to the connector housing assembly 1 through the threads, the vibration energy is absorbed by the shear deformation of the silicone gel. Simultaneously, because the suspended ferrule module 2 has a large inertia due to the addition of a tungsten alloy inertial mass unit, it cannot follow the vibrations of the housing and thus remains absolutely still.

[0058] An elongated fiber stress relief cavity is provided at the connector tail. The bare optical fiber, led from the ceramic ferrule tail, is coiled into an S-shape within this cavity after passing through the suspended ferrule module 2. The fiber stress relief cavity is filled with a low-modulus gel medium. When the external optical cable sheath is pulled by maintenance personnel or disturbed by the airflow of the cabinet fan, the tension is completely absorbed by the elastic deformation of the spiral ring, and the end face of the fiber ferrule will not produce any axial displacement, thereby completely eliminating Fresnel reflection noise caused by changes in contact pressure.

[0059] like Figure 3 As shown, Embodiment 3 of the present invention provides comparative experimental data on the detection signals of fiber optic patch cords using ordinary FC / APC interfaces and those using FC / APC interface fiber optic patch cords with connector assemblies provided by the present invention.

[0060] The DAS terminal and ODF were connected using both a standard FC / APC interface fiber optic patch cord and an FC / APC interface fiber optic patch cord with the connector assembly provided by this invention, and a target disturbance was applied at 1000m and the test was carried out.

[0061] Figure 3 (a) shows the detection signal results when using a standard fiber optic patch cord connection. It is evident that due to environmental vibration and noise interference, the system cannot effectively identify the target vibration signal at 1000m. In contrast, Figure 3 (b) shows the detection results after connecting with an optical fiber patch cord using the connector assembly provided by this invention. The DAS can accurately capture the target vibration characteristics. Experimental data shows that, while maintaining the same signal processing algorithm, the connection assembly provided by this invention can significantly improve the target vibration identification accuracy and greatly optimize the system signal-to-noise ratio.

[0062] Compared with the prior art, the beneficial effects of the present invention include at least the following: 1. This invention designs a connector housing assembly and a suspended ferrule module, sets an inertial mass unit at the tail of the suspended ferrule module, and fills a viscoelastic damping layer between the connector housing assembly and the suspended ferrule module. While retaining the standard physical interface, it can effectively physically isolate high-frequency crosstalk from mechanical vibrations such as fans and air conditioners in the computer room environment, eliminate photoelastic phase noise and end-face reflection fluctuations at the interface, improve the DAS signal-to-noise ratio, achieve significant noise reduction, and significantly improve the detection accuracy and stability of DAS.

[0063] 2. By suspending the ferrule module within the connector housing assembly and designing the fiber stress relief cavity, this invention ensures that even if the external patch cord is disturbed, the ferrule end face maintains stable physical contact, eliminating reflected wave fluctuations and guaranteeing stable contact.

[0064] 3. Strong compatibility: It maintains standard interface forms such as LC, SC, FC / APC or ST, requires no fusion splicing, is plug and play, and meets the cabling specifications and operation and maintenance requirements of high-end data centers.

[0065] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the protection scope of the claims of the present invention.

Claims

1. A vibration-isolating fiber optic connector assembly based on inertial decoupling and viscoelastic damping, characterized in that, Comprising: a connector housing assembly (1); a suspended ferrule module (2) arranged inside the connector housing assembly (1), the suspended ferrule module (2) being provided with a fiber ferrule (21) at the head thereof; an inertial mass unit (3) arranged at the tail of the suspended ferrule module (2) to increase the inertial mass of the suspended ferrule module (2); a viscoelastic damping layer (4) filled in the gap between the suspended ferrule module (2), the inertial mass unit (3) and the connector housing assembly (1) to suspend the suspended ferrule module (2) in the connector housing assembly (1); the viscoelastic damping layer (4) is used to absorb the vibration energy transmitted to the connector housing assembly (1) from the outside, and cooperates with the inertial mass unit (3) to isolate the influence of vibration on the fiber ferrule (21).

2. The vibration-resistant fiber connector assembly based on inertial decoupling and viscoelastic damping according to claim 1, characterized in that: the connector housing assembly (1) is provided with a screw port at the front end thereof for rigid locking with an external fiber distribution frame or device port.

3. The vibration-resistant fiber connector assembly based on inertial decoupling and viscoelastic damping according to claim 1, characterized in that: the inside of the connector housing assembly (1) is a cylindrical cavity, and the inner wall of the cavity is provided with rough texture or retaining groove to enhance the bonding force with the viscoelastic damping layer (4).

4. The vibration-resistant fiber connector assembly based on inertial decoupling and viscoelastic damping according to claim 1, characterized in that: the inner side wall of the connector housing assembly (1) is further provided with a limiting key groove (11), and the suspended ferrule module (2) is provided with a positioning key (22) at the front end thereof; the positioning key (22) is arranged in the limiting key groove (11) to form a limiting stop mechanism.

5. The vibration-resistant fiber connector assembly based on inertial decoupling and viscoelastic damping according to claim 4, characterized in that: the gap between the positioning key (22) and the limiting key groove (11) is in the micron level.

6. The vibration-resistant fiber connector assembly based on inertial decoupling and viscoelastic damping according to claim 5, characterized in that: the gap between the limiting key groove (11) and the positioning key (22) is also filled with the material of the viscoelastic damping layer (4).

7. The vibration-resistant fiber connector assembly based on inertial decoupling and viscoelastic damping according to claim 1, characterized in that: the inertial mass unit (3) is in a ring structure, which is sleeved and fixed to the tail of the suspended ferrule module (2).

8. The vibration-resistant fiber connector assembly based on inertial decoupling and viscoelastic damping according to claim 1, characterized in that: the fiber connector assembly further comprises a fiber stress relief cavity (5); the fiber stress relief cavity (5) is arranged at the tail of the connector housing assembly (1) to isolate the axial tension and radial shaking transmitted by the outer cable sheath.

9. The vibration-resistant fiber connector assembly based on inertial decoupling and viscoelastic damping according to claim 8, characterized in that: the fiber led out of the tail of the fiber ferrule (21) is in a curved state and suspended in the fiber stress relief cavity (5).

10. The vibration-isolating fiber optic connector assembly based on inertial decoupling and viscoelastic damping according to claim 8, characterized in that: The fiber optic stress-relief cavity (5) is filled with a gel medium.

Images