Optical fiber sensing performance testing device for distributed optical fiber self-monitoring FRP rod

Abstract

The application provides a fiber sensing performance testing device for a distributed optical fiber self-monitoring FRP rod, and belongs to the field of intelligent structure testing. The device solves the problem of quantitative determination of the sensing performance of the existing distributed optical fiber self-monitoring FRP rod on a sudden strain. The device comprises a base, a sliding block and a fiber demodulator. The base is provided with a rod fixing and limiting structure along the axial direction. The end of the base is provided with a sliding block track along the axial direction. The sliding block track is slidably connected with the sliding block. The sliding block is also provided with a rod fixing structure along the axial direction. The displacement quantitative stretching of the optical fiber in the self-monitoring FRP rod after ring cutting is realized by sliding the sliding block. The fiber demodulator is used to realize the fiber strain distribution under the multi-stage stretching displacement. The peak strain-displacement ratio in the strain distribution is used as the quantitative index of the fiber sensing performance, so that the sensing performance testing and quantization are realized, and the accuracy of the sensing performance determination is improved.

Description

Technical Field

[0001] The present invention belongs to the field of intelligent structural materials, and in particular relates to an optical fiber sensing performance testing device for distributed optical fiber self-monitoring FRP rods. Background Art

[0002] A distributed fiber-optic self-monitoring FRP rod is an intelligent component with an outer layer of FRP material and an inner layer of distributed fiber-optic sensors. Deploying distributed fiber-optic self-monitoring FRP rods in civil engineering structures can monitor both structural damage and damage to the FRP itself. The sensing performance of distributed fiber-optic self-monitoring FRP rods is affected by a variety of factors, including the type of optical fiber, the type and thickness of the fiber jacket, the type of pultruded resin, and the thickness of the FRP. Sensing performance determines the effectiveness of the self-monitoring FRP rod in detecting damage. Excellent sensing performance makes the self-monitoring FRP rod more sensitive to sudden strain changes, resulting in sharper sudden strain peaks, which facilitates the quantification and location of damage to the FRP rod itself and the surrounding structure. Therefore, specific test methods and operational procedures are required to quantify the sensing performance of the self-monitoring FRP rod.

[0003] Traditional self-monitoring FRP rod sensing performance methods include average strain calculation and strain gauge comparison. The average strain method quantifies sensing performance by comparing the average strain calculated after stretching a length of the self-monitoring FRP rod with the measured strain and calculating the relative error between the two. The strain gauge comparison method quantifies sensing performance by attaching strain gauges to the rod surface, stretching the rod for a certain distance, and calculating the relative error between the strain measured by the strain gauges and the strain measured by the optical fiber at the same location. However, in both testing methods, the entire stressed section of the rod is stretched, without experiencing a sudden change in strain at a specific location. This completely contradicts the engineering requirement for quantitatively locating damage through sharp strain changes.

[0004] Therefore, there is an urgent need for a quantitative test device to monitor the sensing performance of FRP rods for strain mutations using distributed optical fiber self-monitoring. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to propose a fiber optic sensing performance testing device for distributed fiber optic self-monitoring FRP rods, so as to solve the problem that the existing self-monitoring rod sensing performance testing method cannot quantify the strain mutation recognition ability of distributed self-monitoring FRP rods.

[0006] The technical solution adopted by the present invention is as follows: a fiber optic sensing performance test device for distributed fiber optic self-monitoring FRP rods, comprising a base, a slider and an optical fiber demodulator, wherein the base is provided with a rod fixing and limiting structure along the axial direction, the end of the base is provided with a slider track along the axial direction, the slider track is slidably connected to the slider, and the slider is also provided with a rod fixing structure along the axial direction; two sets of fixing grooves are respectively opened in the upper and lower sections of the self-monitoring FRP rod, so that the diameter of the fixing groove is smaller than the diameter of the self-monitoring FRP rod and larger than the diameter of the optical fiber, and a rod fixing structure is provided in the middle section of the self-monitoring FRP rod. An annular incision is made, so that the FRP layer at the annular incision is completely broken and only the optical fiber is connected; the upper section of the self-monitoring FRP rod is clamped on the fixed structure of the base, the middle section of the self-monitoring FRP rod is placed on the limiting structure of the base, and the lower section of the self-monitoring FRP rod is clamped on the fixed structure on the slider, and the slider is moved to realize the quantitative stretching of the displacement of the self-monitoring FRP rod. The optical fiber demodulator is used to realize the strain distribution monitoring of the self-monitoring FRP rod under different tensile displacements, and finally the peak strain-displacement ratio is used as the quantitative indicator of the sensing performance test of the self-monitoring FRP rod.

[0007] Furthermore, the base includes a base body, a base rod lower fixing sleeve and a base rod lower limiting sleeve, the base rod lower fixing sleeve is an upper and lower two-lobed combination structure with through holes at both ends matching the diameter of the fixing groove, the base rod lower limiting sleeve is an upper and lower two-lobed combination structure with through holes at both ends having the same diameter as the self-monitoring FRP rod, the lower lobe of the base rod lower fixing sleeve is axially fixed to the upper section of the base body, and the lower lobe of the base rod lower limiting sleeve is axially fixed to the middle section of the base body, the slider includes a slider body and a slider rod lower fixing sleeve, the slider rod lower fixing sleeve is an upper and lower two-lobed combination structure with through holes at both ends matching the diameter of the fixing groove, and the lower lobe of the slider rod lower fixing sleeve is axially fixed to the slider body On the top, the upper section of the self-monitoring FRP rod is clamped in the lower petal of the fixed sleeve under the base rod, the middle section of the self-monitoring FRP rod is placed in the lower petal of the lower limit sleeve of the base rod, the lower section of the self-monitoring FRP rod is clamped in the lower petal of the fixed sleeve under the slider rod, the upper and lower petal covers of the fixed sleeve under the base rod are merged and fixedly connected by the fixing sleeve and the fastening screws, the upper and lower petal covers of the lower limit sleeve of the base rod are merged and fixedly connected by the limiting sleeve and the fastening screws, the upper and lower petal covers of the fixed sleeve under the slider rod are merged and fixedly connected by the fixing sleeve and the fastening screws; tightening knobs are provided on both sides of the slider body, and the displacement of the slider body on the slider track is constrained by the tightening knobs to achieve different displacement quantitative stretching.

[0008] Furthermore, the upper petal of the lower limit sleeve of the base rod is a two-part structure, and a gap is left between the two sets of upper petals for observing the optical fiber stretching amount in the middle section of the FRP rod.

[0009] Furthermore, the fiber optic interrogator is used to realize full-field strain distribution monitoring of the rod, and adopts a weak grating fiber technology, OFDR technology or BOTDA / R technology interrogator.

[0010] Another object of the present invention is to provide a testing method for optical fiber self-monitoring FRP rods obtained by the testing device as described above, comprising the following steps:

[0011] S1. Rod ring cutting: Two sets of fixing grooves are set at both ends of the self-monitoring FRP rod by grinding, and a rod cut is set in the middle of the self-monitoring FRP rod by ring cutting and bending, so that the FRP layer at the rod cut is completely broken and only the optical fiber is connected;

[0012] S2. Rod body embedding: clamp the upper section of the self-monitoring FRP rod into the lower petal of the fixing sleeve under the base rod, place the middle section of the self-monitoring FRP rod into the lower petal of the lower limit sleeve under the base rod, and clamp the lower section of the self-monitoring FRP rod into the lower petal of the fixing sleeve under the slider rod;

[0013] S3. Rod sleeve limiting: Combine the upper and lower flaps of the fixing sleeve under the base rod and fix them together through the fixing buckle and the fastening screw. Combine the upper and lower flaps of the limiting sleeve under the base rod and fix them together through the limiting buckle and the fastening screw. Combine the upper and lower flaps of the fixing sleeve under the slider rod and fix them together through the fixing buckle and the fastening screw. Tighten with the tightening knob.

[0014] S4. Slider sliding: The displacement of the slider is controlled by tightening and loosening the tightening knob, and the fiber optic demodulator is used to monitor the full-length strain distribution of the self-monitored FRP rod under different displacements. The peak strain-displacement ratio is calculated by extracting the strain peak in the strain distribution using the formula.

[0015]

[0016] Where R is the peak strain-displacement ratio; τ max is the maximum peak value in the strain distribution; d is the tensile displacement.

[0017] Furthermore, the greater the peak strain-displacement ratio is, the more sensitive the optical fiber in the self-monitoring FRP rod is to monitoring sudden strain changes, and the better the sensing performance is.

[0018] Beneficial effects and advantages of the present invention:

[0019] 1. Simulation of sudden strain conditions: By setting a cutout in the middle of the self-monitoring FRP rod and achieving strict axial stretching of the rod through components such as the base, slider, slider track, and limit sleeve, the concentrated sudden strain condition is simulated, which is closer to the real monitoring environment.

[0020] 2. Eliminates the influence of circumferential pressure: By setting fixed grooves at both ends of the self-monitoring FRP rod, ensuring that the diameter of the fixed groove is larger than the outer diameter of the optical fiber but smaller than the diameter of the through-hole of the fixing sleeve, and at the same time, the diameter of the through-hole is smaller than the diameter of the rod, the rod body can be stretched toward both ends under the traction of the slider, but is not affected by the circumferential extrusion of the fixing sleeve under the rod, which affects the tensile strain distribution. This is something that traditional chuck-type stretching devices do not have, thereby improving the accuracy of sensing performance measurement.

[0021] 3. Quantified axial tensile displacement: By tightening and loosening the tightening knob and controlling the position of the slider, the tensile displacement can be easily and quickly controlled quantitatively.

[0022] 4. Provides quantitative indicators of sensing performance: The peak strain-displacement ratio is given as a quantitative indicator for sensing performance testing. The larger the peak strain-displacement ratio, the more sensitive the optical fiber in the self-monitoring FRP rod is to strain mutation monitoring and the better the sensing performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Schematic diagram of an optical fiber sensing performance testing device for distributed optical fiber self-monitoring FRP rods of the present invention;

[0024] Figure 2 This is a schematic diagram of a base and a slider fixing an FRP rod of an optical fiber sensing performance testing device for distributed optical fiber self-monitoring FRP rods of the present invention;

[0025] Figure 3 A schematic diagram of the base of a fiber optic sensing performance testing device for distributed fiber optic self-monitoring FRP rods according to the present invention;

[0026] Figure 4 A schematic diagram of a slider of a fiber optic sensing performance testing device for distributed fiber optic self-monitoring FRP rods according to the present invention;

[0027] Figure 5 A schematic diagram of a self-monitoring FRP rod of an optical fiber sensing performance testing device for distributed optical fiber self-monitoring FRP rods according to the present invention;

[0028] Figure 6 A schematic diagram of a self-monitoring FRP rod embedding of an optical fiber sensing performance testing device for distributed optical fiber self-monitoring FRP rods according to the present invention;

[0029] Figure 7A flow chart of a method for testing the optical fiber sensing performance of a distributed optical fiber self-monitoring FRP rod according to the present invention;

[0030] Figure 8 Schematic diagram of sudden strain distribution and peak strain-displacement ratio calculation for a method for testing optical fiber sensing performance of a distributed optical fiber self-monitoring FRP rod according to the present invention; DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and specific practical cases. The implementation cases herein are used to explain the present invention but do not limit the present invention.

[0032] Example 1

[0033] like Figure 1-6As shown, this embodiment provides a fiber optic sensing performance test device for distributed fiber self-monitoring FRP rods, including a base 1, a slider 2 and an optical fiber demodulator 4. The base 1 is provided with a rod fixing and limiting structure along the axial direction, and the end of the base 1 is provided with a slider track 103 along the axial direction. The slider track 103 is slidably connected to the slider 2, and the lower end of the slider 2 is provided with a wedge-shaped protrusion, which can slide on the wedge-shaped slider groove 201 of the slider track 103. The slider 2 is also provided with a rod fixing structure along the axial direction; two groups of fixing grooves 302 are respectively opened on the upper and lower sections of the self-monitoring FRP rod 3, so that the diameter of the fixing groove 302 is smaller than the diameter of the self-monitoring FRP rod 3 and larger than the diameter of the optical fiber 301. The middle section of the self-monitoring FRP rod 3 is provided with an annular incision 303, so that the FRP layer at the annular incision 303 is completely broken and only the optical fiber 301 is connected; the upper section of the self-monitoring FRP rod 3 is clamped on the fixed structure of the base 1, the middle section of the self-monitoring FRP rod 3 is placed on the limiting structure of the base 1, and the lower section of the self-monitoring FRP rod 3 is clamped on the fixed structure on the slider 2, and the slider 2 is moved to realize the quantitative stretching of the displacement of the self-monitoring FRP rod 3. The optical fiber demodulator 4 is used to realize the strain distribution monitoring of the self-monitoring FRP rod 3 under different tensile displacements, and finally the peak strain-displacement ratio is used as the quantitative index of the sensing performance test of the self-monitoring FRP rod 3; the base 1 includes a bottom The seat body, the base rod lower fixing sleeve 101 and the base rod lower limiting sleeve 102, the base rod lower fixing sleeve 101 is an upper and lower two-lobed combination structure with through holes at both ends matching the diameter of the fixing groove 302, the base rod lower limiting sleeve 102 is an upper and lower two-lobed combination structure with through holes at both ends having the same diameter as the self-monitoring FRP rod 3, the lower lobe of the base rod lower fixing sleeve 101 is axially fixed to the upper section of the base body, the lower lobe of the base rod lower limiting sleeve 102 is axially fixed to the middle section of the base body, the slider 2 includes a slider body and a slider rod lower fixing sleeve 202, the slider rod lower fixing sleeve 202 is an upper and lower two-lobed combination structure with through holes at both ends matching the diameter of the fixing groove 302, the The lower petal of the slider rod lower fixing sleeve 202 is axially fixed to the slider body, the upper section of the self-monitoring FRP rod 3 is clamped in the lower petal of the base rod lower fixing sleeve 101, the middle section of the self-monitoring FRP rod 3 is placed in the lower petal of the base rod lower limiting sleeve 102, the lower section of the self-monitoring FRP rod 3 is clamped in the lower petal of the slider rod lower fixing sleeve 202, the upper and lower petal covers of the base rod lower fixing sleeve 101 are merged and fixedly connected with the fastening screws through the fixing buckle 104, the upper and lower petal covers of the base rod lower limiting sleeve 102 are merged and fixedly connected with the fastening screws through the limiting buckle 105, the upper and lower petal covers of the slider rod lower fixing sleeve 202 are merged and fixedly connected with the fastening screws through the fixing buckle 104;Tightening knobs 108 are provided on both sides of the slider body, which constrain the slider body's displacement on the slider track 103, achieving varying quantitative stretching. The upper lobe of the base rod lower limit sleeve 102 is a two-part structure, with a gap between the two sets of lobe for observing the stretching of the optical fiber 301 in the middle section of the FRP rod 3. The fiber optic interrogator 4 is used to monitor the full-field strain distribution of the rod, employing weak grating fiber technology, OFDR technology, or BOTDA / R technology.

[0034] Example 2

[0035] like Figure 7 As shown, this embodiment provides a testing method for optical fiber self-monitoring FRP rods, using the equipment shown in Example 1, including the following steps:

[0036] S1. Rod ring cutting: Two sets of fixing grooves 302 are set at both ends of the self-monitoring FRP rod 3 by grinding, and a rod cut 303 is set in the middle of the self-monitoring FRP rod 3 by ring cutting and bending, so that the FRP layer at the rod cut 303 is completely broken and only the optical fiber 301 is connected;

[0037] S2. Rod body embedding: clamp the upper section of the self-monitoring FRP rod 3 into the lower petal of the base rod lower fixing sleeve 101, place the middle section of the self-monitoring FRP rod 3 into the lower petal of the base rod lower limiting sleeve 102, and clamp the lower section of the self-monitoring FRP rod 3 into the lower petal of the slider rod lower fixing sleeve 202;

[0038] S3. Rod sleeve limiting: Combine the upper and lower flaps of the fixing sleeve 101 under the base rod and fix them together through the fixing buckle 104 and the fastening screws. Combine the upper and lower flaps of the limiting sleeve 102 under the base rod and fix them together through the limiting buckle 105 and the fastening screws. Combine the upper and lower flaps of the fixing sleeve 202 under the slider rod and fix them together through the fixing buckle 104 and the fastening screws. Tighten with the tightening knob 108.

[0039] S4, slider sliding: The displacement of the slider 2 is controlled by tightening and loosening the tightening knob 108, and the optical fiber demodulator 4 is used to monitor the full-length strain distribution of the self-monitoring FRP rod 3 under different displacements, such as Figure 8 As shown, the peak strain-displacement ratio is calculated by extracting the strain peak in the strain distribution using Formula 1. The larger the peak strain-displacement ratio is, the more sensitive the optical fiber 301 in the self-monitoring FRP rod 3 is to the strain mutation monitoring, and the better the sensing performance is.

[0040]

[0041] Where R is the peak strain-displacement ratio; τ maxis the maximum peak value in the strain distribution; d is the tensile displacement.

[0042] Example 3

[0043] It is now necessary to quantify the sensing performance of a 5mm diameter OFDR distributed fiber self-monitoring CFRP rod. The internal fiber diameter is 1mm. The operation steps are as follows:

[0044] S1. Circumferential cutting of the rod body: Fixing grooves are set at both ends of a 1000mm long CFRP rod body by grinding, so that the diameter of the fixing grooves is 3mm, and the diameter of the through hole of the fixing sleeve under the rod is 4mm. The rod notch is set by circular cutting and bending the CFRP rod body, so that the FRP layer at the rod notch is completely broken and only the optical fiber is connected;

[0045] S2. Rod embedding: embed the rod fixing grooves at both ends of the CFRP rod into the solid sleeve under the rod, and embed the middle part of the rod into the limit sleeve under the rod;

[0046] S3, rod sleeve limit, close the rod fixing sleeves at both ends and the rod limit sleeve in the middle, and fix them with the fixing sleeve buckle and the limit sleeve buckle respectively, and tighten them with the tightening knob;

[0047] S4. The slider slides, and the displacement of the slider is controlled by tightening and loosening the tightening knob on the slider to 0 mm, 1 mm, and 2 mm respectively. The OFDR technology fiber optic demodulator is used to monitor the full-length strain distribution of the rod under different displacements, and the strain peak in the strain distribution is extracted to calculate the peak strain-displacement ratio.

[0048] Example 4

[0049] It is now necessary to quantitatively measure the sensing performance of a 10 mm diameter BOTDA / R distributed optical fiber self-monitoring GFRP rebar. The internal optical fiber diameter is 2 mm. The operation steps are as follows:

[0050] S1. Circular cutting of the reinforcement body: Fiber fixing grooves are set at both ends of a 2000mm long GFRP reinforcement body by grinding, so that the diameter of the fixing groove is 6mm and the diameter of the through hole of the reinforcement fixing sleeve is 8mm. The reinforcement body is circularly cut and bent to form reinforcement cuts, so that the FRP layer at the reinforcement cut is completely broken and only the optical fiber is connected.

[0051] S2, embedding the reinforcement body: embed the reinforcement fixing grooves at both ends of the GFRP reinforcement body into the solid sleeve under the reinforcement body, and embed the middle part of the reinforcement body into the reinforcement limit sleeve under the reinforcement body;

[0052] S3, rib sleeve limit, close the rib fixing sleeves at both ends and the rib limit sleeve in the middle, and fix them with the fixing sleeve buckle and the limit sleeve buckle respectively, and tighten them with the tightening knob;

[0053] S4. The slider slides. By tightening and loosening the tightening knob on the slider, the slider displacement is controlled to 0 mm, 3 mm, 6 mm, and 9 mm, respectively. The BOTDA / R technology fiber optic demodulator is used to monitor the full-length strain distribution of the tendon under different displacements. The strain peak in the strain distribution is extracted and the peak strain-displacement ratio is calculated.

Claims

1. A fiber optic sensing performance testing device for distributed fiber optic self-monitoring FRP rods, comprising a base (1), a slider (2) and a fiber optic demodulator (4), characterized in that: The base (1) is provided with a rod fixing and limiting structure along the axial direction, the end of the base (1) is provided with a slider track (103) along the axial direction, the slider track (103) is slidably connected to the slider (2), and the slider (2) is also provided with a rod fixing structure along the axial direction; two groups of fixing grooves (302) are respectively provided on the upper and lower sections of the self-monitoring FRP rod (3), so that the diameter of the fixing groove (302) is smaller than the diameter of the self-monitoring FRP rod (3) and larger than the diameter of the optical fiber (301); an annular incision (303) is provided in the middle section of the self-monitoring FRP rod (3), so that the FRP layer at the annular incision (303) is completely broken and only the optical fiber (301) is connected; the self-monitoring FRP rod (3) is connected to the self-monitoring FRP rod (3) The upper section of the self-monitoring FRP rod (3) is clamped on the fixed structure of the base (1), the middle section of the self-monitoring FRP rod (3) is placed on the limiting structure of the base (1), the lower section of the self-monitoring FRP rod (3) is clamped on the fixed structure on the slider (2), and the slider (2) is moved to achieve quantitative stretching of the displacement of the self-monitoring FRP rod (3). The optical fiber demodulator (4) is used to monitor the strain distribution of the self-monitoring FRP rod (3) under different tensile displacements, and finally the peak strain-displacement ratio is used as a quantitative indicator for the sensing performance test of the self-monitoring FRP rod (3); the base (1) includes a base body, a base rod lower fixing sleeve (101) and a base rod lower limiting sleeve (102), and the base rod lower fixing sleeve (101) is used to monitor the strain distribution of the self-monitoring FRP rod (3) under different tensile displacements. ) is a combined structure of upper and lower lobes with through holes at both ends having a diameter matching that of the fixing groove (302), the lower limit sleeve (102) of the base rod is a combined structure of upper and lower lobes with through holes at both ends having a diameter the same as that of the self-monitoring FRP rod (3), the lower lobe of the lower fixing sleeve (101) of the base rod is axially fixed to the upper section of the base body, the lower lobe of the lower limiting sleeve (102) of the base rod is axially fixed to the middle section of the base body, the slider (2) comprises a slider body and a slider rod lower fixing sleeve (202), the slider rod lower fixing sleeve (202) is a combined structure of upper and lower lobes with through holes at both ends having a diameter matching that of the fixing groove (302), the lower lobe of the lower fixing sleeve (202) of the slider rod is axially fixed to the middle section of the slider body, On the block body, the upper section of the self-monitoring FRP rod (3) is clamped in the lower flap of the base rod lower fixing sleeve (101), the middle section of the self-monitoring FRP rod (3) is placed in the lower flap of the base rod lower limiting sleeve (102), the lower section of the self-monitoring FRP rod (3) is clamped in the lower flap of the slider rod lower fixing sleeve (202), the upper and lower flap covers of the base rod lower fixing sleeve (101) are combined and fixedly connected through the fixing sleeve buckle (104) and the fastening screw, the upper and lower flap covers of the base rod lower limiting sleeve (102) are combined and fixedly connected through the limiting sleeve buckle (105) and the fastening screw, and the upper and lower flap covers of the slider rod lower fixing sleeve (202) are combined and fixedly connected through the fixing sleeve buckle (104) and the fastening screw;Tightening knobs (108) are provided on both sides of the slider body, and the displacement of the slider body on the slider track (103) is constrained by the tightening knobs (108), thereby achieving different displacement quantitative stretching.

2. The optical fiber sensing performance testing device for distributed optical fiber self-monitoring FRP rod according to claim 1, characterized in that: The upper lobes of the base rod lower limit sleeve (102) are of a two-part structure, with a gap left between the two sets of upper lobes for observing the stretching amount of the optical fiber (301) in the middle section of the FRP rod (3).

3. The optical fiber sensing performance testing device for distributed optical fiber self-monitoring FRP rod according to claim 2, characterized in that: The optical fiber demodulator (4) is used to realize full-field strain distribution monitoring of the rod, and adopts a demodulator using weak grating optical fiber technology, OFDR technology or BOTDA / R technology.

4. A testing method for optical fiber self-monitoring FRP rod obtained by using the testing device according to any one of claims 1 to 3, characterized in that: The following steps are involved: S1, rod body ring cutting: two sets of fixing grooves (302) are set at both ends of the self-monitoring FRP rod (3) by grinding, and a rod cut (303) is set in the middle of the self-monitoring FRP rod (3) by ring cutting and bending, so that the FRP layer at the rod cut (303) is completely broken and only the optical fiber (301) is connected; S2, rod body embedding: clamping the upper section of the self-monitoring FRP rod (3) into the lower petal of the base rod lower fixing sleeve (101), placing the middle section of the self-monitoring FRP rod (3) into the lower petal of the base rod lower limiting sleeve (102), and clamping the lower section of the self-monitoring FRP rod (3) into the lower petal of the slider rod lower fixing sleeve (202); S3, rod sleeve limiting: the upper and lower flaps of the fixing sleeve (101) under the base rod are combined and fixedly connected by the fixing sleeve buckle (104) and the fastening screw, the upper and lower flaps of the limiting sleeve (102) under the base rod are combined and fixedly connected by the limiting sleeve buckle (105) and the fastening screw, the upper and lower flaps of the fixing sleeve (202) under the slider rod are combined and fixedly connected by the fixing sleeve buckle (104) and the fastening screw; and tightened with the tightening knob (108); S4. Slider sliding: The displacement of the slider (2) is controlled by tightening and loosening the tightening knob (108), and the full-length strain distribution of the self-monitoring FRP rod (3) under different displacements is monitored by the optical fiber demodulator (4). The peak strain-displacement ratio is calculated by extracting the strain peak value in the strain distribution using formula (1). （1） Where, is the peak strain-displacement ratio; is the maximum peak value in the strain distribution; is the tensile displacement.

5. A testing method for optical fiber self-monitoring FRP rod according to claim 4, characterized in that: The greater the peak strain-displacement ratio, the more sensitive the optical fiber (301) in the self-monitoring FRP rod (3) is to monitoring sudden strain changes, and the better the sensing performance.

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