Impact-resistant quasi-distributed temperature strain composite sensor and packaging method

Abstract

The application relates to the technical field of high-temperature sensing, and discloses an anti-impact quasi-distributed temperature and strain composite sensor and a packaging method, which comprise a packaging substrate, a sensing optical fiber and a packaging cover plate; a long slot penetrating to both ends is arranged at the center of the packaging substrate; the packaging substrate is arranged on the packaging cover plate and is used for packaging the long slot; a sensing section of the sensing optical fiber is fixedly arranged in the long slot; a Bragg grating and a hollow optical fiber are separately arranged on the sensing section of the sensing optical fiber; a transition beam is arranged on the packaging substrate at a position corresponding to the Bragg grating; a connecting beam is arranged on the packaging cover plate at a position corresponding to the Bragg grating; and annular structures for shielding the side airflow of the Bragg grating are arranged on both sides of the transition beam. The application can realize the temperature and strain monitoring of the surface of an object in a high-temperature environment, and has the advantages of high anti-impact capacity, small size, high reliability and high measurement precision.

Description

Technical Field

[0001] The present invention belongs to the technical field of high-temperature sensing, and in particular relates to a shock-resistant quasi-distributed temperature-strain composite sensor and a packaging method. Background Art

[0002] With the development of aerospace technology, solid rocket engines have gradually become the dominant force in the aerospace field due to their simple structure, high reliability, and long storage time. During engine operation, the high temperature and high pressure environment inside the combustion chamber causes the engine casing and key components to undergo complex thermal-mechanical coupling effects. These extreme operating conditions place stringent demands on the reliability of the structure. Therefore, strain testing of engine structures in high-temperature environments is crucial, which not only helps to optimize the design and improve safety, but also ensures the stable operation of the engine under extreme conditions. Currently, strain testing usually uses resistance strain gauges for measurement. However, due to limited temperature resistance, poor anti-electromagnetic interference ability, and insufficient long-term stability, the application of resistance strain gauges in high-temperature environments is limited.

[0003] Fiber optic sensors, with their significant advantages such as high-temperature resistance, immunity to electromagnetic interference, and excellent long-term stability, have been widely used for measuring multiple physical quantities in extremely harsh environments. Strain sensors based on fiber Bragg Grating (FBG) and fiber Fabry-Perot (FP) interferometry are the most widely used. However, in practical applications, common packaging methods can cause fiber breakage under high-impact conditions, thus affecting measurement accuracy. Furthermore, when measuring in high-temperature environments, sensors are susceptible to cross-interference between temperature and strain, severely limiting measurement accuracy and applicability.

[0004] Therefore, it is necessary to improve the packaging structure of the optical fiber sensor to achieve accurate measurement in a large impact environment. Summary of the Invention

[0005] In order to overcome the problems of low strain measurement accuracy and poor packaging reliability of optical fiber sensors in high temperature and high shock environments in the existing technology, the present invention proposes a shock-resistant quasi-distributed temperature-strain composite sensor and packaging method to achieve reliable measurement of temperature and strain in harsh environments with high temperature and high shock.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solution: a shock-resistant quasi-distributed temperature-strain composite sensor, comprising a packaging substrate, a sensing optical fiber, and a packaging cover plate; the packaging substrate is provided with a long groove extending through the center to both ends; the packaging cover plate is provided on the packaging substrate for encapsulating the long groove; the sensing segment of the sensing optical fiber is fixedly disposed in the long groove;

[0007] A hollow core optical fiber and a Bragg grating are separately provided on the sensing section of the sensing optical fiber; a transition beam for supporting the Bragg grating is provided on the packaging substrate at a position corresponding to the Bragg grating; and a connecting beam for covering the upper surface of the Bragg grating is provided on the packaging cover at a position corresponding to the Bragg grating;

[0008] The top of the transition beam is flush with the bottom surface of the long groove. An annular structure is provided on both sides of the transition beam. The annular structure is used to block the side airflow of the Bragg grating between the transition beam and the connecting beam.

[0009] A plurality of Bragg gratings with different central wavelengths are separately arranged on the sensing section of the sensing optical fiber; a transition beam for supporting the Bragg grating is provided at a position corresponding to each Bragg grating on the packaging substrate; a connecting beam for covering the upper surface of the Bragg grating is provided at a position corresponding to each Bragg grating on the packaging cover; and an annular structure is provided on both sides of each transition beam.

[0010] On the packaging substrate, a transition piece is provided between each transition beam. The thickness of the transition piece is the same as that of the annular structure. The transition piece is narrow at both ends and wide in the middle to achieve stress transition.

[0011] On the packaging cover plate, connecting pieces are provided between the transition beams, and the shape of the connecting pieces is the same as that of the transition pieces.

[0012] The package cover is fixedly connected to the package substrate by spot welding; a pair of welding spots are respectively provided at both ends of the package cover, and a pair of welding spots are also provided on each connecting piece.

[0013] The thickness of the packaging cover plate is less than 1 / 2 of the thickness of the packaging substrate.

[0014] The width of the transition beam and the connecting beam is equal to the long groove; the top of the annular structure is flush with the surface of the packaging substrate;

[0015] The thickness of the packaging substrate is 0.3 mm to 1.5 mm, and the length of the hollow-core optical fiber is 100 μm to 1000 μm.

[0016] A first fixing plate is provided at both ends of the packaging substrate, and a plurality of first through holes are provided on the first fixing plate. A second fixing plate is correspondingly provided at both ends of the packaging cover plate, and a plurality of second through holes are provided on the second fixing plate. The first through holes and the second through holes are used to cooperate with screws to fix the sensor; a plurality of glue filling holes are provided on the packaging cover plate at positions corresponding to the long grooves, and the glue filling holes are used to fill high-temperature inorganic glue to fix the sensing optical fiber.

[0017] The packaging substrate is provided with a square groove for accommodating a hollow-core optical fiber. The hollow-core optical fiber is in a relaxed state, and the Bragg grating is in a pre-tensioned state.

[0018] In addition, the present invention also provides a packaging method for the shock-resistant quasi-distributed temperature-strain composite sensor, comprising the following steps:

[0019] Step S1: polishing the processed packaging substrate and packaging cover, and using an ultrasonic cleaning machine to remove surface impurities;

[0020] Step S2: placing the sensing segments including the Bragg grating and the hollow core fiber in the sensing optical fiber at corresponding positions in the long groove inside the packaging substrate;

[0021] Step S3: Using a multi-dimensional displacement platform to stretch the sensing fiber, ensuring that the Bragg grating of the sensing fiber is in a pre-tightened state, and using high-temperature inorganic glue to pre-fix the Bragg grating to the packaging substrate, with the glue application position located at both ends of the Bragg grating;

[0022] Step S4: Align the ends of the packaging substrate and the packaging cover plate, use a spot welder to achieve a tight connection between the packaging substrate and the packaging cover plate, and then pour high-temperature inorganic glue into the ends of each Bragg grating inside through each glue injection hole on the packaging cover plate;

[0023] Step S5: using a tube furnace to heat and cure the high-temperature inorganic adhesive to ensure that the sensing optical fiber is tightly fixed in the long groove of the packaging substrate.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. Traditional Bragg grating sensors are susceptible to mechanical damage in large impact environments, affecting measurement accuracy. The present invention fixes the sensing optical fiber at the center of the packaging base, encapsulates the sensing optical fiber through a flat-plate packaging substrate and a packaging cover, and respectively provides a transition beam and a connecting beam on the packaging substrate and the packaging cover to protect but not seal the Bragg grating, thereby avoiding the problem of reduced test sensitivity caused by fully enclosed packaging and expanding the strain measurement range of the sensor; and providing an annular structure on both sides of the transition beam to improve the impact resistance of the sensor and avoid grating damage caused by direct exposure to impact loads; and, utilizing the characteristics that the Bragg grating is sensitive to temperature and strain, while the hollow fiber is only sensitive to temperature, temperature compensation can be used to effectively suppress the cross-interference between temperature and strain, thereby improving strain measurement accuracy and long-term stability; in addition, finite element simulation analysis confirms that the sensor with an annular structure generates greater strain when the same strain is applied, so the present invention can effectively increase the strain test sensitivity of the sensor.

[0026] 2. The sensor structure of the present invention is easy to expand and can be expanded into multiple Bragg gratings and ring structures with different central wavelengths arranged in series, thereby realizing the multi-point strain testing requirements under large impact environments; in addition, the flat-plate setting of the packaging substrate and the packaging cover allows the sensor to be rigidly connected and fixed on the object to be measured, which can effectively reduce the damage to the optical fiber interface under large impact environments and improve the measurement stability. At the same time, it also makes the sensor detachable and reusable, thereby increasing the flexibility of application.

[0027] 3. In this invention, the sensor is packaged using a method of spot welding followed by glue potting. First, the optical fiber and the packaging structure are pre-fixed using high-temperature inorganic glue. The packaging substrate and packaging cover are then connected by spot welding, and finally, the glue potting is performed. Spot welding provides a high-strength mechanical connection, improving impact resistance, while glue potting further enhances the protection of the optical fiber on top of spot welding, preventing fatigue damage to the optical fiber caused by minor vibrations under impact, significantly improving the reliability and long-term stability of the sensor in high-impact environments.

[0028] In summary, the shock-resistant quasi-distributed temperature-strain composite sensor and packaging method provided by the present invention have the advantages of strong shock resistance, high sensitivity, strong scalability and high stability, and can meet the application requirements of extreme working conditions such as aerospace. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A schematic diagram of the three-dimensional structure of a shock-resistant quasi-distributed temperature-strain composite sensor provided by an embodiment of the present invention;

[0030] Figure 2 Schematic diagram of the three-dimensional structure of the packaging substrate in an embodiment of the present invention;

[0031] Figure 3 Schematic diagram of the three-dimensional assembly of the packaging substrate and optical fiber in an embodiment of the present invention;

[0032] Figure 4 Schematic diagram of the three-dimensional structure of the packaging cover plate in an embodiment of the present invention;

[0033] Figure 5 Schematic diagram of the reflection spectrum of the sensing optical fiber in an embodiment of the present invention;

[0034] Figure 6 is a schematic diagram of a finite element simulation in an embodiment of the present invention;

[0035] In the figure: 1- packaging substrate, 2- sensing optical fiber, 3- packaging cover, 11- ring structure, 12- transition beam, 13- transition plate, 14- square groove, 15- long groove, 16- first through hole, 17- first fixing plate, 21- Bragg grating, 22- hollow core optical fiber, 31- connecting beam, 32- connecting plate, 33- welding point, 34- second through hole, 35- glue filling hole, 36- second fixing plate. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present invention, not all the embodiments; based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0037] like Figures 1-4 As shown, an embodiment of the present invention provides a shock-resistant, quasi-distributed temperature-strain composite sensor, comprising a packaging substrate 1, a sensing optical fiber 2, and a packaging cover plate 3. Both the packaging substrate 1 and the packaging cover plate 3 are flat-plate structures. The packaging substrate 1 is provided with a long groove 15 extending from the center to both ends. The packaging cover plate 3 is mounted on the packaging substrate 1 to encapsulate the long groove 15. The sensing segment of the sensing optical fiber 2 is fixedly mounted in the long groove 15.

[0038] A hollow-core optical fiber 22 and a Bragg grating 21 are separately arranged on the sensing section of the sensing optical fiber 2, a transition beam 12 for supporting the Bragg grating 21 is arranged on the packaging substrate 1 at a position corresponding to the Bragg grating 21, and a connecting beam 31 for covering the upper surface of the Bragg grating 21 is arranged on the packaging cover plate 3 at a position corresponding to the Bragg grating 21.

[0039] The top of the transition beam 12 is flush with the bottom of the long slot 15 . An annular structure 11 is provided on both sides of the transition beam 12 . The annular structure 11 is used to block the side airflow of the Bragg grating 21 between the transition beam 12 and the connecting beam 31 .

[0040] In this embodiment, the strip-shaped structure of the connecting beam 31 and the transition beam 12 effectively improves the sensitivity of the sensor, enabling it to accurately measure strain changes from subtle to drastic, thereby enhancing the accuracy of strain testing. The width of the connecting beam 31 and the transition beam 12 is equal to the width of the long slot 15.

[0041] In this embodiment, the top of the annular structure 11 is flush with the surface of the packaging substrate 1, that is, the thickness of the annular structure 11 is the same as that of the packaging substrate 1. When airflow blows toward the Bragg grating 21 from the side, the annular structure 11 can effectively shield and protect the Bragg grating 21, preventing most of the airflow from directly impacting the side surface of the Bragg grating 21. At the same time, because the Bragg grating 21 is firmly pressed against the packaging substrate 1 and the packaging cover 3, and the depth of the long groove 15 is substantially consistent with the diameter of the sensing fiber 2, even if a small amount of airflow enters the side, it will not significantly interfere with the strain measurement. In addition, the structure of the transition beam 12 and the connecting beam 31 only forms an encapsulation for the upper and lower surfaces of the Bragg grating 21, avoiding the problem of reduced test sensitivity caused by fully enclosed packaging, expanding the strain measurement range of the sensor, reducing the complexity of the packaging processing, and improving the sensor's yield rate.

[0042] Specifically, in this embodiment, three Bragg gratings 21 with different central wavelengths are separately arranged on the sensing segment of the sensing optical fiber 2, transition beams 12 for supporting the Bragg gratings 21 are provided at positions corresponding to each Bragg grating 21 on the packaging substrate 1, and connecting beams 31 for covering the upper surface of the Bragg grating 21 are provided at positions corresponding to each Bragg grating 21 on the packaging cover plate 3; and an annular structure 11 is provided on both sides of each transition beam 12.

[0043] In addition, in this embodiment, the number of Bragg gratings 21 separately provided on the sensing segment of the sensing optical fiber 2 can also be set to 1-2 or 4-6 as needed. In this case, the number of transition beams 12 on the packaging substrate 1 and the number of connecting beams 31 on the packaging cover 3 are matched according to the number of Bragg gratings 21.

[0044] Specifically, in this embodiment, Figure 2 As shown, on the packaging substrate 1, a transition piece 13 is provided between each transition beam 12. The thickness of the transition piece 13 is the same as that of the annular structure 11, and its width is narrow at both ends and wide in the middle, so as to achieve stress transition and avoid deformation caused by excessive stress concentration, which may cause deformation of the packaging substrate 1 or even the Bragg grating 21 to break due to stress concentration at the bonding point.

[0045] like Figure 3 As shown, on the package cover plate 3, connecting pieces 32 are provided between each connecting beam 31, and the shape of the connecting piece 32 is the same as that of the transition piece 13. The connecting piece 32 can effectively buffer the impact of the upper airflow on the sensor surface.

[0046] Specifically, in this embodiment, the thickness of the packaging substrate 1 is 0.3mm~1.5mm. When the material thickness is less than 0.3mm, it is difficult to process and it is difficult to withstand a large impact exceeding Mach 3. When the thickness is higher than 1.5mm, it will affect the deformation of the test position itself, resulting in increased measurement errors.

[0047] In this embodiment, the hollow-core optical fiber 22 forms an FP cavity in the sensing optical fiber 2. The hollow-core optical fiber 22 is in a relaxed state and is only affected by temperature. The temperature is measured by monitoring the change in the free spectrum range.

[0048] In this embodiment, the Bragg grating 21 is in a pre-tensioned state and is subjected to the simultaneous effects of temperature and strain, and the strain and temperature are measured by monitoring the drift of the central wavelength of the Bragg grating.

[0049] In this embodiment, the amplified spontaneous emission light source enters the sensing fiber 2 through a circulator, and the reflected light generated by the three groups of Bragg gratings and hollow core fiber 22 inside the sensing fiber enters the spectrometer through the circulator for spectral analysis, thereby achieving strain and temperature measurement. Figure 5 As shown, it is a schematic diagram of the reflection spectrum in the sensing optical fiber 2; since three Bragg gratings with different wavelengths are set on the sensing optical fiber, its reflection spectrum has three reflection peaks. In addition, the FP cavity formed by the hollow-core optical fiber 22 makes the reflection spectrum have periodic reflection peaks.

[0050] Specifically, in this embodiment, the length of the hollow-core optical fiber 22 is 100 microns to 1000 microns. This length range ensures that the Fabry-Perot cavity can operate stably within its normal demodulation range.

[0051] Specifically, in this embodiment, the package cover plate 3 is fixedly connected to the package substrate 1 by spot welding. The thickness of the package cover plate 3 is less than 1 / 2 of the thickness of the package substrate 1. If the material is too thick, it will be difficult to achieve spot welding connection between the package cover plate 3 and the package substrate 1.

[0052] Specifically, if Figure 3 As shown, in this embodiment, the package cover plate 3 is provided with multiple pairs of welding points 33. Specifically, a pair of welding points 33 is provided at each end of the package cover plate 3, and each connecting piece 32 is also provided with a pair of welding points 33. In this embodiment, the large surface structure of the connecting piece 32 can increase the number of welding points to achieve an effective connection between the package cover plate 3 and the package substrate 1. In addition, the connecting piece 32 can also be provided with a glue injection hole 35 to achieve pre-tightening and fixation of the sensing optical fiber 2.

[0053] Further, if Figure 2 As shown, in this embodiment, both ends of the package substrate 1 are provided with a first fixing plate 17, and the first fixing plate 17 is provided with a plurality of first through holes 16;Figure 3 As shown, second fixing plates 36 are provided at each end of the package cover plate 3. These second fixing plates 36 are provided with multiple second through-holes 34 corresponding to the positions of the first through-holes 16. These first through-holes 16 and second through-holes 34 are used to secure the sensor to the surface to be tested for temperature and strain testing. In this embodiment, the first fixing plates 17 increase the sensor's force-bearing area, effectively reducing resistance in high-impact flow environments, preventing the formation of vortices, and preventing stress concentration on the sensor's sides.

[0054] Further, if Figure 3 As shown, in this embodiment, the packaging cover plate 3 is provided with a plurality of glue holes 35 at positions corresponding to the long grooves 15 , and the glue holes 35 are used to inject high-temperature inorganic glue to fix the sensing optical fiber 2 . The glue holes 35 are provided at both ends of the Bragg grating 21 .

[0055] Further, if Figure 4 As shown, in this embodiment, a square groove 14 is provided on the packaging substrate 1 at a position corresponding to the hollow core optical fiber 22. The square groove 14 is used to accommodate the hollow core optical fiber 22 to ensure that the hollow core optical fiber 22 is not affected by strain and is only affected by temperature.

[0056] In this embodiment, by providing the annular structures 11 on both sides of the Bragg grating 21 on the packaging substrate 1, the strain generated in the Bragg grating 21 can be increased, thereby improving the test sensitivity of the entire sensor. Figure 6 The figure below is a schematic diagram of the results of the finite element simulation analysis. By applying a fixed load to the two first through holes 16 and the two second through holes 34 on the right side, and applying a 10N vertical pressure to the two first through holes 16 and the two second through holes 34 on the left side, it is found that the strain is maximum at each transition beam 12 and the connecting beam 31, while the strain is essentially non-existent at each transition piece 13 and the connecting piece 32.

[0057] Specifically, an embodiment of the present invention further provides a packaging method for a shock-resistant quasi-distributed temperature-strain composite sensor, comprising the following steps:

[0058] Step S1: polishing the processed packaging substrate 1 and packaging cover 3, and using an ultrasonic cleaning machine to remove surface impurities.

[0059] Step S2 : placing the sensing segment including the Bragg grating 21 and the hollow core fiber 22 in the sensing optical fiber 2 at a corresponding position in the long groove 15 inside the packaging substrate 1 .

[0060] In this embodiment, a femtosecond laser is used to inscribe multiple Bragg gratings 21 with different central wavelengths on the surface of the sensing fiber 2. The inscription positions correspond to the positions of the transition beams 12 on the packaging substrate 1. A hollow-core fiber 22 is fused to the tail end of the sensing fiber 2 using a fiber fusion splicer. A short section of fiber is then fused to the end of the hollow-core fiber 22. The fusion position of the hollow-core fiber 22 corresponds to the position of the square groove 14 inside the packaging substrate 1. After the processing of the sensing fiber 2 is completed, the Bragg gratings 21 and the hollow-core fiber 22 are placed in the correct positions.

[0061] Step S3: Use a multi-dimensional displacement platform to stretch the sensing optical fiber 2 to ensure that the Bragg grating 21 of the sensing optical fiber 2 is in a pre-tightened state, and use high-temperature inorganic glue to pre-fix the Bragg grating 21 and the packaging substrate 1, with the glue coating position located at both ends of the Bragg grating 21.

[0062] Step S4: Align the two ends of the packaging substrate 1 and the packaging cover plate 3, use a spot welding machine to achieve a tight connection between the packaging substrate 1 and the packaging cover plate 3, and then inject high-temperature inorganic glue into the two ends of each internal Bragg grating 21 through each glue injection hole 35 on the packaging cover plate 3.

[0063] Step S5: Use a tube furnace to heat and cure the high-temperature inorganic adhesive to ensure that the sensing optical fiber 2 is tightly fixed in the long groove 15 of the packaging substrate 1. After curing is complete, the multi-dimensional displacement platform is removed. Since the outer side of the hollow-core optical fiber 22 is not fixed, the hollow-core optical fiber 22 is in a relaxed state. The two sides of each Bragg grating 21 are fixed by the high-temperature inorganic adhesive, and therefore, they are in a pre-tensioned state.

[0064] In summary, the application provides an anti-impact quasi-distributed temperature and strain composite sensor, which utilizes the shift of the center wavelength of the Bragg grating 21 and the change of the free spectral range of the Fabry-Perot resonant cavity in the hollow optical fiber 22 to realize the synchronous measurement of temperature and strain, and can effectively reduce the cross interference between temperature and strain. Moreover, in the application, the ring structure 11 is arranged on the packaging substrate 1, which not only significantly improves the sensitivity of strain testing, but also enhances the stability of the optical fiber sensor in the impact environment through the packaging of the packaging substrate 1 and the packaging cover plate 3 on the sensing optical fiber 2, avoids the problem that the optical fiber is easily peeled off or broken in a large impact environment, and affects the measurement reliability, and at the same time, makes the sensor detachable and reusable, and improves the flexibility of application. At the same time, the structure is convenient for expansion, and through the arrangement of a plurality of Bragg gratings 21 with different center wavelengths and ring structures 11, multi-point measurement of strain can be realized, and through the through holes passing through the two ends of the sensor, the sensor is rigidly connected with the measured object through the screws, and the test accuracy of the sensor is improved. In addition, the sensor in the application is packaged by the method of spot welding first and then pouring glue, and the sensing optical fiber is protected as a whole in the packaging, which further improves the reliability of the sensor, and makes it have practical application value in high temperature and high pressure harsh environments such as aerospace, boiler combustion and weapon equipment.

[0065] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the application, and not to limit them; although the application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the application.

Claims

1. A shock-resistant quasi-distributed temperature-strain composite sensor, characterized in that: The invention comprises a packaging substrate (1), a sensing optical fiber (2) and a packaging cover plate (3); a long groove (15) extending from the center of the packaging substrate (1) to both ends is provided, and the packaging cover plate (3) is provided on the packaging substrate (1) for packaging the long groove (15); the sensing section of the sensing optical fiber (2) is fixedly provided in the long groove (15); A hollow-core optical fiber (22) and a plurality of Bragg gratings (21) with different central wavelengths are separately provided on the sensing section of the sensing optical fiber (2); transition beams (12) for supporting the Bragg gratings (21) are provided on the packaging substrate (1) at positions corresponding to the respective Bragg gratings (21); transition plates (13) are provided between the respective transition beams (12); the transition plates (13) are narrow at both ends and wide in the middle to achieve stress transition; and connection beams (31) for covering the upper surface of the Bragg gratings (21) are provided on the packaging cover plate (3) at positions corresponding to the respective Bragg gratings (21); The top of the transition beam (12) is flush with the bottom surface of the long slot (15), and an annular structure (11) is provided on both sides of each transition beam (12). The annular structure (11) is used to block the side airflow of the Bragg grating (21) between the transition beam (12) and the connecting beam (31).

2. The shock-resistant quasi-distributed temperature-strain composite sensor according to claim 1, characterized in that: The thickness of the transition piece (13) is the same as that of the annular structure (11); On the packaging cover plate (3), connecting pieces (32) are provided between the transition beams (12), and the shape of the connecting pieces (32) is the same as that of the transition pieces (13).

3. The shock-resistant quasi-distributed temperature-strain composite sensor according to claim 2, characterized in that: The packaging cover plate (3) is fixedly connected to the packaging substrate (1) by spot welding; a pair of welding points (33) are respectively provided at both ends of the packaging cover plate (3), and a pair of welding points (33) are also provided on each connecting piece (32).

4. The shock-resistant quasi-distributed temperature-strain composite sensor according to claim 1, characterized in that: The thickness of the packaging cover plate (3) is less than 1 / 2 of the thickness of the packaging substrate (1).

5. The shock-resistant quasi-distributed temperature-strain composite sensor according to claim 1, characterized in that: The width of the transition beam (12) and the connecting beam (31) is equal to the width of the long groove (15); the top of the annular structure (11) is flush with the surface of the packaging substrate (1); The thickness of the packaging substrate (1) is 0.3 mm to 1.5 mm, and the length of the hollow-core optical fiber (22) is 100 μm to 1000 μm.

6. The shock-resistant quasi-distributed temperature-strain composite sensor according to claim 1, characterized in that: Both ends of the packaging substrate (1) are provided with a first fixing plate (17), and the first fixing plate (17) is provided with a plurality of first through holes (16); the two ends of the packaging cover plate (3) are correspondingly provided with a second fixing plate (36), and the second fixing plate (36) is provided with a plurality of second through holes (34); the first through holes (16) and the second through holes (34) are used to cooperate with screws to fix the sensor; the packaging cover plate (3) is provided with a plurality of glue holes (35) at positions corresponding to the long groove (15), and the glue holes (35) are used to fill high-temperature inorganic glue to fix the sensing optical fiber (2).

7. The shock-resistant quasi-distributed temperature-strain composite sensor according to claim 6, characterized in that: The packaging substrate (1) is provided with a square groove (14) for accommodating a hollow-core optical fiber (22); the hollow-core optical fiber (22) is in a relaxed state, and the Bragg grating (21) is in a pre-tensioned state.

8. The packaging method of a shock-resistant quasi-distributed temperature-strain composite sensor according to any one of claims 1 to 7, characterized in that: The following steps are involved: Step S1: polishing the processed packaging substrate (1) and packaging cover (3), and using an ultrasonic cleaning machine to remove surface impurities; Step S2: placing the sensing section of the sensing optical fiber (2) including the Bragg grating (21) and the hollow core optical fiber (22) at a corresponding position in the long groove (15) inside the packaging substrate (1); Step S3: Using a multi-dimensional displacement platform to stretch the sensing optical fiber (2), ensuring that the Bragg grating (21) of the sensing optical fiber (2) is in a pre-tightened state, and using high-temperature inorganic glue to achieve pre-fixation between the Bragg grating (21) and the packaging substrate (1), with the glue application position being located at both ends of the Bragg grating (21); Step S4: aligning the two ends of the packaging substrate (1) and the packaging cover (3), using a spot welding machine to achieve a tight connection between the packaging substrate (1) and the packaging cover (3), and then pouring high-temperature inorganic glue into the two ends of each Bragg grating (21) inside through each glue injection hole (35) on the packaging cover (3); Step S5: using a tube furnace to heat and cure the high-temperature inorganic glue to ensure that the sensing optical fiber (2) is tightly fixed in the long groove (15) of the packaging substrate (1).

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