Ammonia hydrogen energy structure material constant strain rate and constant load stress corrosion synchronous monitoring platform based on acoustic emission and implementation method thereof

Abstract

The invention provides an ammonia hydrogen energy structure material constant strain rate and constant load stress corrosion synchronous monitoring platform based on acoustic emission and an implementation method thereof. Comprising a gas supply and pressurization system, a constant strain rate and constant load stress corrosion synchronous test system, a gas leakage safety control system, an acoustic emission and digital image correlation (DIC) technology online monitoring analysis system, a temperature control system and a computer integrated analysis system. In-situ dynamic analysis of stress corrosion crack propagation is realized in combination with a DIC technology; the temperature control system realizes accurate temperature control on the corrosion test reaction kettle through an independent temperature control module; the computer integrated analysis system processes multi-source data, and establishes dynamic mapping between acoustic emission characteristic parameters and corrosion crack growth rate. The platform solves the problems of off-line monitoring, single loading mode and the like of a traditional corrosion test, captures a corrosion-induced crack propagation process in real time, improves test efficiency and analysis comprehensiveness, and provides powerful support for research on corrosion behaviors of ammonia hydrogen energy structural materials.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of acoustic emission detection, and in particular to an ammonia-hydrogen energy structural material constant strain rate and constant load stress corrosion synchronous monitoring platform based on acoustic emission and an implementation method thereof. BACKGROUND

[0002] Hydrogen energy, as the cleanest energy with the highest energy density, has become a key carrier for building a new energy system. However, hydrogen atoms can easily penetrate into the metal lattice to cause hydrogen embrittlement, resulting in a sharp drop in material strength and deterioration of toughness, which seriously threatens the safe operation of hydrogen storage equipment and transportation pipelines. In particular, under high-pressure hydrogen conditions, the synergistic effect of hydrogen embrittlement and stress corrosion can accelerate material failure, which has become a technical bottleneck restricting the large-scale application of hydrogen energy.

[0003] Ammonia is considered the most promising hydrogen energy transport medium due to its high hydrogen storage density (17-18 wt.%) and ambient pressure liquefaction characteristics. Through the "ammonia-hydrogen" conversion technology, cross-regional efficient allocation of hydrogen energy can be achieved, but this process involves harsh conditions such as liquid ammonia storage and transportation, high-temperature cracking. Studies have shown that not only does liquid ammonia cause stress corrosion cracking of metal materials, but the hydrogen atoms in its decomposition products also penetrate into the material to cause hydrogen embrittlement damage. This coupling effect of corrosion-hydrogen embrittlement significantly exacerbates material performance degradation. Therefore, stress corrosion testing of ammonia-hydrogen energy structural materials is crucial to ensure the safe and stable operation of ammonia-hydrogen energy systems.

[0004] Currently, conventional corrosion performance testing systems rely on offline monitoring methods, which cannot capture the stress corrosion crack initiation and dynamic expansion process in real time. In addition, existing corrosion performance testing systems can usually only achieve a single loading mode. SUMMARY

[0006] Therefore, the present application aims to provide an ammonia-hydrogen energy structural material constant strain rate and constant load stress corrosion synchronous monitoring platform based on acoustic emission and an implementation method thereof, which solves the problems of offline detection lag and single loading mode limitation in traditional testing methods, and realizes multi-mode loading, real-time tracking of corrosion crack expansion, and multi-parameter collaborative analysis of material stress corrosion behavior under high-pressure ammonia-hydrogen environment, simulating the dynamic response of materials to strain rate, load, temperature, and other factors under ammonia-hydrogen stress corrosion conditions.

[0007] To achieve the above-mentioned purpose, the present application adopts the following technical solution: an ammonia-hydrogen energy structural material constant strain rate and constant load stress corrosion synchronous monitoring platform based on acoustic emission, comprising a gas supply and pressurization system, a constant strain rate and constant load stress corrosion synchronous testing system, a gas leakage safety control system, an acoustic emission and digital image correlation DIC online monitoring and analysis system, and a computer integrated analysis system (8). The gas supply and pressurization system comprises a plurality of gas cylinders (1), a gas pressurization system (2), an air compressor (20), a stop valve (19), and a flow meter (18), the gas cylinders (1) are connected to the gas pressurization system (2) through independent pressure-resistant pipelines, and the gas is input into the constant-strain-rate and constant-load-stress corrosion synchronous testing system through the stop valve (19) and the flow meter (18); The constant-strain-rate and constant-load-stress corrosion synchronous testing system comprises a constant-strain-rate stress corrosion testing device (10) and a constant-load-stress corrosion testing device (17) arranged in parallel, and a temperature control device (9), the constant-strain-rate stress corrosion testing device (10) and the constant-load-stress corrosion testing device (17) are connected to the temperature control device (9) respectively, the constant-strain-rate stress corrosion testing device (10) is provided with a constant-strain-rate stress corrosion testing device high-pressure reaction kettle (13), and the constant-load-stress corrosion testing device (17) is provided with a constant-load-stress corrosion testing device high-pressure reaction kettle (16). The gas leakage safety control system comprises an anti-explosion variable-frequency exhaust machine (3), an audible-light alarm (4), a gas control host (5), and an ammonia and hydrogen gas concentration detector (6), the anti-explosion variable-frequency exhaust machine (3), the audible-light alarm (4), and the ammonia and hydrogen gas concentration detector (6) are connected to the gas control host (5), and the gas control host (5) is connected to a computer integrated analysis system (8). The acoustic emission and DIC online monitoring and analysis system comprises an acoustic emission acquisition system (7), a wireless acoustic emission sensor, and a camera (14). The computer integrated analysis system (8) is used for integrated processing of real-time data output by the constant-strain-rate stress corrosion testing device (10), the constant-load-stress corrosion testing device (17), the acoustic emission acquisition system (7), the camera (14), and the temperature control device (9), so as to realize multi-parameter collaborative monitoring and analysis.

[0008] In a preferred embodiment, the air compressor (20) is connected to the gas pressurization system (2), the gas pressurization system (2) is provided with two gas outlets, and is connected to the constant-strain-rate stress corrosion testing device high-pressure reaction kettle (13) and the constant-load-stress corrosion testing device high-pressure reaction kettle (16) through independent pipelines respectively.

[0009] In a preferred embodiment, the side walls of the constant-strain-rate stress corrosion testing device high-pressure reaction kettle (13) and the constant-load-stress corrosion testing device high-pressure reaction kettle (16) are provided with a heat preservation cavity layer, and the heat preservation cavity layer is provided with a temperature control medium inlet (21) and a temperature control medium outlet (23), and the temperature control medium inlet (21) and the temperature control medium outlet (23) are connected to the temperature control device (9).

[0010] In a preferred embodiment: the high-pressure reactor (13) of the constant-strain-rate stress corrosion testing device is provided with a cover (32), the upper pull rod (29) enters the high-pressure reactor (13) through the cover (32); the outer wall of the upper pull rod (29) and the cover (32) are sealed by an O-shaped sealing ring (27); further comprising a pressure gauge (26), the probe of the pressure gauge (26) enters the high-pressure reactor (13) through the cover (32); further comprising a temperature sensor (30), the probe of the temperature sensor (30) enters the high-pressure reactor (13) through the cover (32); the high-pressure reactor (13) of the constant-strain-rate stress corrosion testing device is further provided with an upper clamp (34) and a lower clamp (37); the constant-strain-rate test sample (12) is clamped between the upper clamp (34) and the lower clamp (37), the two ends of the constant-strain-rate test sample (12) are specifically the acoustic emission sensor arrangement position (35) of the constant-strain-rate test sample, used for placing the first wireless acoustic emission sensor (111); the middle gauge section of the constant-strain-rate test sample (12) is the DIC identification sub-area (36) of the constant-strain-rate test sample.

[0011] In a preferred embodiment: the high-pressure reactor (16) of the constant-load stress corrosion testing device is provided with a left clamp (44) and a right clamp (47), and is provided with an adjusting clamp (43) outside the high-pressure reactor (16), the constant-load test sample (15) is clamped between the left clamp (44) and the right clamp (47); the two ends of the adjusting clamp (43) are connected with the left clamp (44) and a lever (42), the other end of the lever (42) is connected with a weight (41) arranged outside the high-pressure reactor (16) of the constant-load stress corrosion testing device; the constant-load stress corrosion testing device (17) is provided with a shock-absorbing washer (40), which is located below the weight (41); the two ends of the constant-load test sample (15) are provided as the acoustic emission sensor arrangement position (45) of the constant-load test sample, which is used for placing the second wireless acoustic emission sensor (112), and the middle gauge section of the constant-load test sample (15) is the DIC identification sub-area (46) of the constant-load test sample.

[0012] In a preferred embodiment: the ammonia hydrogen gas concentration detector (6) is arranged above the corrosion testing platform, monitors the ammonia hydrogen gas concentration in real time and transmits it to the gas control host (5); when the gas concentration reaches the set threshold value, the gas control host (5) triggers the audible and light alarm of the sound-light alarm (4) and increases the exhaust volume of the explosion-proof variable frequency exhaust fan (3).

[0013] In a preferred embodiment: the first wireless acoustic emission sensor (111) and the second wireless acoustic emission sensor (112) capture the elastic wave signals generated by the sample during the experiment, and transmit the signals to the computer integrated analysis system (8) through the acoustic emission collection system (7).

[0014] In a preferred embodiment: the sidewall of the high-pressure reaction kettle (13) of the constant-strain-rate stress corrosion testing device and the high-pressure reaction kettle (16) of the constant-load stress corrosion testing device is provided with a visual window (22), and the camera (14) collects images of the DIC identification sub-area (36) of the constant-strain-rate testing sample and the DIC identification sub-area (46) of the constant-load testing sample in real time through the visual window (22) and transmits the images to the computer integrated analysis system (8).

[0015] In a preferred embodiment, the DIC technology is combined to analyze the random white background black point coating on the surface of the DIC identification sub-area of the testing sample before the experiment starts, and the initial image of the DIC identification sub-area is recorded by the camera (14) before the test. During the test, the positions of the black points will move due to stress. The position distribution of each black point is captured in real time by the camera (14) and compared with the initial image to obtain the position change of the black points. The corresponding stress is calculated by the computer analysis integrated system (8), so as to obtain the real-time dynamic stress field distribution information of the gauge section of the testing sample, and realize in-situ dynamic tracking of crack propagation.

[0016] The application also provides an implementation method of an acoustic emission-based ammonia-hydrogen energy structural material constant-strain-rate and constant-load stress corrosion synchronous monitoring platform, based on the acoustic emission-based ammonia-hydrogen energy structural material constant-strain-rate and constant-load stress corrosion synchronous monitoring platform, comprising the following steps: Step (1): a first wireless acoustic emission sensor (111) and a camera are arranged at both ends of the constant-strain-rate testing sample (12), and a second wireless acoustic emission sensor (112) and a camera are arranged at both ends of the constant-load testing sample (15), and the cameras are all aimed at the DIC identification sub-area, and the focal length and the field of view are calibrated; Step (2): the sensitivity of the acoustic emission sensor is calibrated through the lead breaking test, the signal filtering threshold is set to reduce noise, the computer DIC system is started, the camera lens distortion is calibrated, and the loading rate is adjusted to match the collection frequency, and the time synchronization calibration of the acoustic emission and the DIC equipment is completed; Step (3): during loading, the acoustic emission collection system collects the elastic wave signals generated in the deformation process of the sample in real time, the DIC technology synchronously captures the dynamic data of displacement and strain in the deformation process of the sample, and the deformation dynamics of the strain concentration area in the gauge section are tracked, and the two types of data are accurately associated through a unified time stamp. Step (4): Based on the crack initiation and propagation node positioning of acoustic emission amplitude jump and counting rate peak, the high strain region of crack tip is identified in combination with the strain gradient field measured by DIC technology; based on the information entropy theory, the acoustic emission signal energy distribution is quantified, and the mapping relationship between the crack propagation rate and stress intensity factor is established; Step (5): The acoustic emission characteristic parameters, strain field distribution and crack morphology data are integrated to construct a multi-dimensional correlation model of "signal characteristics-strain evolution-crack propagation".

[0017] Compared with the prior art, the present application has the following beneficial effects: the present application is independently operated by the constant strain rate and constant load testing device, solves the limitation of single loading mode of traditional equipment, realizes synchronous testing of dynamic and static load working conditions, realizes real-time tracking of the whole process of material from micro-crack initiation to macroscopic fracture by means of acoustic emission and DIC technology, breaks through the lagging nature of offline detection, provides real-time data for corrosion mechanism research, adopts precise control of gas pressure, temperature, strain rate and load, constructs a high-precision ammonia hydrogen stress corrosion testing environment, matches the gas leakage sound-light alarm-emergency exhaust interlocking system and computer integrated analysis system for synchronous analysis of multi-source data, provides safety guarantee and comprehensive basis for material performance evaluation. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is the overall structure schematic diagram of the preferred embodiment of the present application; Figure 2 It is the high-pressure reaction kettle structure schematic diagram of the constant strain rate stress corrosion testing device of the preferred embodiment of the present application; Figure 3 It is the high-pressure reaction kettle structure schematic diagram of the constant load stress corrosion testing device of the preferred embodiment of the present application; Figure 4 It is the implementation process schematic diagram of the acoustic emission and DIC online monitoring and analysis system of the preferred embodiment of the present application; The label description is as follows: 1-gas cylinder; 2-gas booster system; 3-explosion-proof variable frequency exhaust machine; 4-acoustic light alarm; 5-gas control host; 6-ammonia hydrogen gas concentration detector; 7-acoustic emission collection system; 8-integrated analysis system computer; 9-temperature control device; 10-constant strain rate stress corrosion testing device; 111-first wireless acoustic emission sensor, 112-second wireless acoustic emission sensor; 12-constant strain rate test sample; 13-constant strain rate stress corrosion testing device high pressure reaction kettle; 14-camera; 15-constant load test sample; 16-constant load stress corrosion testing device high pressure reaction kettle; 17-constant load stress corrosion testing device; 18-flow meter; 19-stop valve; 20-air compressor; 21-temperature control medium inlet; 22-visual window; 23-temperature control medium outlet; 24-nut; 25-gas inlet; 26-pressure gauge; 27-O-shaped sealing ring; 28-upper bolt; 29-upper pull rod; 30-temperature sensor; 31-exhaust port; 32-kettle cover; 33-kettle body; 34-upper clamp; 35-constant strain rate test sample acoustic emission sensor arrangement position; 36-constant strain rate test sample DIC identification sub-area; 37-lower clamp; 38-lower bolt; 39-lower pull rod; 40-damping washer; 41-weight; 42-lever; 43-adjusting clamp; 44-left clamp; 45-constant load test sample acoustic emission sensor arrangement position; 46-constant load test sample DIC identification sub-area; 47-right clamp. DETAILED DESCRIPTION

[0019] The application will be further described below in conjunction with the drawings and examples.

[0020] It should be noted that the following detailed description is illustrative only and is intended to provide further description of the present application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0021] It should be noted that the terms used herein are only intended to describe specific embodiments and are not intended to limit the exemplary embodiments according to the present application; as used herein, the singular form is intended to include the plural form unless the context clearly indicates otherwise, and furthermore, it should be understood that when the terms "comprise" and / or "include" are used in the specification, there is a presence of the features, steps, operations, devices, components and / or combinations thereof.

[0022] Reference Figures 1-4 An ammonia hydrogen energy structure material constant strain rate and constant load stress corrosion synchronous monitoring platform based on acoustic emission includes a gas supply and booster system, a constant strain rate and constant load stress corrosion synchronous testing system, a gas leakage safety control system, an acoustic emission and DIC online monitoring and analysis system, and a computer integrated analysis system 8. The gas supply and pressurization system comprises a plurality of gas cylinders 1, a gas pressurization system 2, an air compressor 20, a stop valve 19, and a flow meter 18, the gas cylinders 1 are connected to the gas pressurization system 2 through independent pressure-resistant pipelines, the gas is input to the constant strain rate and constant load stress corrosion synchronous testing system through the stop valve 19 and the flow meter 18; the gas cylinders 1 are provided with three, respectively for storing ammonia, hydrogen and nitrogen, and the gas cylinders 1 enter the gas pressurization device 2 through independent pipelines.

[0023] The constant strain rate and constant load stress corrosion synchronous testing system comprises a constant strain rate stress corrosion testing device 10 and a constant load stress corrosion testing device 17 which are arranged in parallel, and a temperature control device 9, the constant strain rate stress corrosion testing device 10 and the constant load stress corrosion testing device 17 are connected to the temperature control device 9 respectively; the constant strain rate stress corrosion testing device 10 is provided with a constant strain rate stress corrosion testing device high-pressure reaction kettle 13, and the constant load stress corrosion testing device 17 is provided with a constant load stress corrosion testing device high-pressure reaction kettle 16. The gas leakage safety control system comprises an explosion-proof variable frequency exhaust machine 3, an audible and visual alarm 4, a gas control host 5, and an ammonia hydrogen gas concentration detector 6, the explosion-proof variable frequency exhaust machine 3, the audible and visual alarm 4, and the ammonia hydrogen gas concentration detector 6 are connected to the gas control host 5, and the gas control host 5 is connected to a computer integrated analysis system 8. The acoustic emission and DIC online monitoring and analysis system comprises an acoustic emission acquisition system 7, a wireless acoustic emission sensor, and a camera 14; the camera 14 is provided with two, respectively for acquiring information in the constant strain rate stress corrosion testing device high-pressure reaction kettle 13 and the constant load stress corrosion testing device high-pressure reaction kettle 16, and the camera 14 is arranged on a multi-dimensional adjusting support which is similar to a camera support available on the market, and details are not described herein.

[0024] The computer integrated analysis system 8 is used for integrated processing of real-time data output by the constant strain rate stress corrosion testing device 10, the constant load stress corrosion testing device 17, the acoustic emission acquisition system 7, the camera 14, and the temperature control device 9, and realizes multi-parameter collaborative monitoring and analysis; the computer integrated analysis system 8 synchronously collects multi-source data such as acoustic emission parameters, temperature, load, and strain rate, establishes dynamic mapping of acoustic emission characteristic parameters and stress corrosion crack propagation rate through built-in algorithms, and supports real-time display, storage, and remote monitoring.

[0025] The air compressor 20 is connected to the gas pressurization system 2, the gas pressurization system 2 is provided with two gas outlets which are respectively connected to the constant strain rate stress corrosion testing device high-pressure reaction kettle 13 and the constant load stress corrosion testing device high-pressure reaction kettle 16 through independent pipelines.

[0026] The side wall of the high-pressure reaction kettle 13 of the constant strain rate stress corrosion testing device and the high-pressure reaction kettle 16 of the constant load stress corrosion testing device is provided with a heat preservation cavity layer, and the heat preservation cavity layer is provided with a temperature control medium inlet 21 and a temperature control medium outlet 23; the temperature control medium inlet 21 and the temperature control medium outlet 23 are connected with a temperature control device 9, a temperature sensor 30 feeds back the temperature in real time, the heating / cooling power is adjusted through a proportional, integral and differential (PID) control algorithm, and precise temperature control is realized.

[0027] The high-pressure reaction kettle 13 of the constant strain rate stress corrosion testing device is provided with a kettle cover 32, the upper pull rod 29 enters the high-pressure reaction kettle 13 of the constant strain rate stress corrosion testing device through the kettle cover 32; the outer side wall of the upper pull rod 29 and the kettle cover 32 are sealed through an O-shaped sealing ring 27; further comprising a pressure gauge 26, the probe of the pressure gauge 26 enters the high-pressure reaction kettle 13 of the constant strain rate stress corrosion testing device through the kettle cover 32; further comprising a temperature sensor 30, the probe of the temperature sensor 30 enters the high-pressure reaction kettle 13 of the constant strain rate stress corrosion testing device through the kettle cover 32; the high-pressure reaction kettle 13 of the constant strain rate stress corrosion testing device is further provided with an upper clamp 34 and a lower clamp 37; the upper clamp 34 and the lower clamp 37 clamp a constant strain rate testing sample 12 therebetween, axial stretching is realized through high-precision servo motor driving, both ends of the constant strain rate testing sample 12 are specifically acoustic emission sensor arrangement positions 35 of the constant strain rate testing sample, for placing a first wireless acoustic emission sensor 111; the middle gauge section of the constant strain rate testing sample 12 is a DIC identification sub-area 36 of the constant strain rate testing sample. The O-shaped sealing ring 27 guarantees the sealing property between the pull rod and the kettle body, the pressure gauge 26 displays the internal pressure, and temperature uniformity is realized through temperature control medium circulation.

[0028] The left clamp 44 and the right clamp 47 are arranged in the high-pressure reaction kettle 16 of the constant load stress corrosion testing device, and the adjusting clamp 43 is arranged outside the high-pressure reaction kettle 16 of the constant load stress corrosion testing device, and the constant load testing sample 15 is clamped between the left clamp 44 and the right clamp 47; the left clamp 44 and the lever 42 are connected at two ends of the adjusting clamp 43, and the weight 41 arranged outside the high-pressure reaction kettle 16 of the constant load stress corrosion testing device is connected at the other end of the lever 42; the stable load is applied through the lever amplification multiple of the weight gravity, and the adjusting clamp 43 calibrates the lever balance; the constant load stress corrosion testing device 17 is provided with the shock pad 40, and the shock pad 40 is located below the weight 41; the two ends of the constant load testing sample 15 are provided with the acoustic emission sensor arrangement position 45 of the constant load testing sample, the acoustic emission sensor arrangement position 45 of the constant load testing sample is used for placing the second wireless acoustic emission sensor 112, and the middle calibration section of the constant load testing sample 15 is the DIC identification sub-area 46 of the constant load testing sample; the lever 42 takes the low-friction bearing as a fulcrum, one end applies gravity through the weight 41, and the other end is rigidly connected with the left clamp 45 through the adjusting clamp 43, and the stable load is applied to the sample through the lever system of the weight gravity by using the lever principle, and the bending experiment is realized. Before the experiment, the lever is calibrated horizontally through the adjusting clamp 43, the weight 41 and the base shock pad 40 are kept at a certain distance, and it is ensured that the static load is stably transmitted to the sample, and the corrosion environment under the static stress is effectively simulated.

[0029] The ammonia hydrogen gas concentration detector 6 is arranged above the corrosion testing platform, and the ammonia hydrogen gas concentration is monitored in real time and transmitted to the gas control host computer 5; when the gas concentration reaches the set threshold value, the gas control host computer 5 triggers the audible and visual alarm of the sound-light alarm 4, and increases the exhaust capacity of the explosion-proof frequency conversion exhaust machine 3, to form a “monitoring-alarm-exhaust” safety interlocking.

[0030] The first wireless acoustic emission sensor 111 and the second wireless acoustic emission sensor 112 capture the elastic wave signals generated by the sample in the experiment process, and transmit the signals to the computer integrated analysis system 8 through the acoustic emission collection system 7.

[0031] The side wall of the high-pressure reaction kettle 13 of the constant-strain-rate stress corrosion testing device and the high-pressure reaction kettle 16 of the constant-load stress corrosion testing device is provided with a visual window 22, the camera 14 collects images of the DIC identification sub-area 36 of the constant-strain-rate testing sample and the DIC identification sub-area 46 of the constant-load testing sample through the visual window 22 in real time and transmits the images to the computer integrated analysis system 8, and the DIC technology is combined, that is, random white bottom black point coating is performed on the surface of the DIC identification sub-area of the testing sample before the experiment starts, and the initial image of the DIC identification sub-area is recorded by the camera (14) before the test. During the test, the positions of the black points will move due to stress, the position distribution of each black point is captured in real time by the camera (14) and compared with the position change of the black points in the initial image, the corresponding stress is calculated through the computer analysis integrated system (8), so that the real-time dynamic stress field distribution information of the gauge length section of the testing sample is obtained, and in-situ dynamic tracking of crack propagation is realized.

[0032] An implementation method of an acoustic emission-based ammonia-hydrogen energy structural material constant-strain-rate and constant-load stress corrosion synchronous monitoring platform, based on the acoustic emission-based ammonia-hydrogen energy structural material constant-strain-rate and constant-load stress corrosion synchronous monitoring platform, comprising the following steps: Step 1: A first wireless acoustic emission sensor 111 and a camera are arranged at both ends of the constant-strain-rate testing sample 12, and a second wireless acoustic emission sensor 112 and a camera are arranged at both ends of the constant-load testing sample 15, and the cameras are all aimed at the DIC identification sub-area, and the focal length and the field of view are calibrated; Step 2: The sensitivity of the acoustic emission sensor is calibrated through a lead breaking test, the signal filtering threshold is set for noise reduction, the computer DIC system is started, the camera lens distortion is calibrated and the loading rate is adjusted to match the collection frequency, and the time synchronization calibration of the acoustic emission and the DIC equipment is completed; Step 3: During loading, the acoustic emission collection system collects elastic wave signals generated in the deformation process of the sample in real time, the DIC technology synchronously captures dynamic data of displacement and strain in the deformation process of the sample, and the deformation dynamics of the strain concentration area in the gauge length section are tracked, and the two types of data are accurately associated through a unified time stamp; Step 4: The crack initiation and expansion nodes are located based on the amplitude sudden increase of the acoustic emission and the peak value of the counting rate, and the high-strain area at the crack tip is identified based on the strain gradient field measured by the DIC technology; the energy distribution of the acoustic emission signal is quantified based on the information entropy theory, and the mapping relationship between the energy distribution and the crack propagation rate and the stress intensity factor is established; Step 5: The acoustic emission characteristic parameters, the strain field distribution and the crack morphology data are integrated to construct a multi-dimensional correlation model of “signal characteristics-strain evolution-crack propagation”.

Claims

1. A synchronous monitoring platform for constant strain rate and constant load stress corrosion of ammonia-hydrogen energy structural materials based on acoustic emission, characterized in that: It includes a gas supply and pressurization system, a constant strain rate and constant load stress corrosion synchronous testing system, a gas leakage safety control system, an acoustic emission and digital image correlation DIC online monitoring and analysis system, and a computer integrated analysis system (8). The gas supply and pressurization system includes multiple gas cylinders (1), a gas pressurization system (2), an air compressor (20), a shut-off valve (19), and a flow meter (18). The gas cylinders (1) are connected to the gas pressurization system (2) through independent pressure-resistant pipelines. The gas is input to the constant strain rate and constant load stress corrosion synchronous test system through the shut-off valve (19) and the flow meter (18). The constant strain rate and constant load stress corrosion synchronous testing system includes a constant strain rate stress corrosion testing device (10) and a constant load stress corrosion testing device (17) connected in parallel, and a temperature control device (9). The constant strain rate stress corrosion testing device (10) and the constant load stress corrosion testing device (17) are respectively connected to the temperature control device (9). The constant strain rate stress corrosion testing device (10) is equipped with a constant strain rate stress corrosion testing device high pressure reactor (13), and the constant load stress corrosion testing device (17) is equipped with a constant load stress corrosion testing device high pressure reactor (16). The gas leak safety control system includes an explosion-proof variable frequency exhaust fan (3), an audible and visual alarm (4), a gas control host (5), and an ammonia-hydrogen gas concentration detector (6). The explosion-proof variable frequency exhaust fan (3), the audible and visual alarm (4), and the ammonia-hydrogen gas concentration detector (6) are all connected to the gas control host (5). The gas control host (5) is connected to a computer integrated analysis system (8). The acoustic emission and DIC online monitoring and analysis system includes an acoustic emission acquisition system (7), a wireless acoustic emission sensor and a camera (14). The computer integrated analysis system (8) is used to integrate and process the real-time data output by the constant strain rate stress corrosion test device (10), the constant load stress corrosion test device (17), the acoustic emission acquisition system (7), the camera (14), and the temperature control device (9) to realize multi-parameter collaborative monitoring and analysis.

2. The synchronous monitoring platform for constant strain rate and constant load stress corrosion of ammonia-hydrogen energy structural materials based on acoustic emission according to claim 1, characterized in that: The air compressor (20) is connected to the gas pressurization system (2). The gas pressurization system (2) is provided with two air outlets, which are respectively connected to the high-pressure reactor (13) of the constant strain rate stress corrosion test device and the high-pressure reactor (16) of the constant load stress corrosion test device through independent pipelines.

3. The synchronous monitoring platform for constant strain rate and constant load stress corrosion of ammonia-hydrogen energy structural materials based on acoustic emission according to claim 1, characterized in that: The high-pressure reactor (13) of the constant strain rate stress corrosion test device and the high-pressure reactor (16) of the constant load stress corrosion test device are provided with a heat insulation cavity layer on their side walls, and the heat insulation cavity layer has a temperature control medium inlet (21) and a temperature control medium outlet (23); the temperature control medium inlet (21) and the temperature control medium outlet (23) are connected to a temperature control device (9).

4. The synchronous monitoring platform for constant strain rate and constant load stress corrosion of ammonia-hydrogen energy structural materials based on acoustic emission according to claim 1, characterized in that: The high-pressure reactor (13) of the constant strain rate stress corrosion testing device is equipped with a lid (32). The upper pull rod (29) enters the high-pressure reactor (13) through the lid (32). The outer wall of the upper pull rod (29) is sealed to the lid (32) by an O-ring (27). A pressure gauge (26) is also included, with its probe entering the high-pressure reactor (13) through the lid (32). A temperature sensor (30) is also included, with its probe entering the high-pressure reactor (13) through the lid (32). The constant strain rate stress corrosion testing device is housed in a high-pressure reactor (13). An upper clamp (34) and a lower clamp (37) are also provided within the high-pressure reactor (13). A constant strain rate test specimen (12) is held between the upper clamp (34) and the lower clamp (37). The two ends of the constant strain rate test specimen (12) are specifically designated as acoustic emission sensor placement positions (35) for placing the first wireless acoustic emission sensor (111). The middle gauge length of the constant strain rate test specimen (12) is the DIC identification sub-region (36) of the constant strain rate test specimen.

5. The synchronous monitoring platform for constant strain rate and constant load stress corrosion of ammonia-hydrogen energy structural materials based on acoustic emission according to claim 1, characterized in that: The high-pressure reactor (16) of the constant load stress corrosion testing device is equipped with a left clamp (44) and a right clamp (47). An adjusting clamp (43) is provided outside the high-pressure reactor (16). The constant load test sample (15) is clamped between the left clamp (44) and the right clamp (47). The two ends of the adjusting clamp (43) are connected to the left clamp (44) and the lever (42). The other end of the lever (42) is connected to the outside of the high-pressure reactor (16) of the constant load stress corrosion testing device. The constant load stress corrosion testing device (17) is equipped with a shock-absorbing washer (40), which is located below the weight (41); the two ends of the constant load test specimen (15) are set as acoustic emission sensor arrangement positions (45) of the constant load test specimen, the acoustic emission sensor arrangement positions (45) of the constant load test specimen are used to place the second wireless acoustic emission sensor (112), and the middle gauge length section of the constant load test specimen (15) is the DIC identification sub-region (46) of the constant load test specimen.

6. The synchronous monitoring platform for constant strain rate and constant load stress corrosion of ammonia-hydrogen energy structural materials based on acoustic emission according to claim 1, characterized in that: The ammonia-hydrogen gas concentration detector (6) is deployed above the corrosion test platform to monitor the ammonia-hydrogen gas concentration in real time and transmit it to the gas control host (5). When the gas concentration reaches the set threshold, the gas control host (5) triggers the audible and visual alarm (4) to sound and light alarm, and at the same time increases the exhaust volume of the explosion-proof variable frequency exhaust fan (3).

7. The synchronous monitoring platform for constant strain rate and constant load stress corrosion of ammonia-hydrogen energy structural materials based on acoustic emission according to claim 1, characterized in that: The first wireless acoustic emission sensor (111) and the second wireless acoustic emission sensor (112) capture the elastic wave signal generated by the sample during the experiment, and transmit it to the computer integrated analysis system (8) through the acoustic emission acquisition system (7).

8. The synchronous monitoring platform for constant strain rate and constant load stress corrosion of ammonia-hydrogen energy structural materials based on acoustic emission according to claim 1, characterized in that: The high-pressure reactor (13) of the constant strain rate stress corrosion test device and the high-pressure reactor (16) of the constant load stress corrosion test device are provided with viewing windows (22). The camera (14) acquires images of the DIC identification sub-area (36) of the constant strain rate test sample and the DIC identification sub-area (46) of the constant load test sample in real time through the viewing window (22) and transmits them to the computer integrated analysis system (8).

9. The synchronous monitoring platform for constant strain rate and constant load stress corrosion of ammonia-hydrogen energy structural materials based on acoustic emission according to claim 8, characterized in that: Combining DIC technology analysis, before the experiment begins, random white-background black dots are applied to the surface of the DIC identification sub-region of the test specimen. Before the test, the initial image of the DIC identification sub-region is recorded by camera (14). During the test, these black dots will move due to stress. The position distribution of each black dot is captured in real time by camera (14) and compared with the initial image. The position change of the black dots is calculated by computer analysis integration system (8), thereby obtaining the real-time dynamic stress field distribution information of the gauge length of the test specimen, and realizing in-situ dynamic tracking of crack propagation.

10. A method for implementing a synchronous monitoring platform for constant strain rate and constant load stress corrosion of ammonia-hydrogen energy structural materials based on acoustic emission, characterized in that, A synchronous monitoring platform for constant strain rate and constant load stress corrosion of ammonia-hydrogen energy structural materials based on acoustic emission, as described in any one of claims 1-9, includes the following steps: Step (1): Set a first wireless acoustic emission sensor (111) and a camera at both ends of the constant strain rate test specimen (12), and set a second wireless acoustic emission sensor (112) and a camera at both ends of the constant load test specimen (15). The cameras are all aimed at the DIC recognition sub-region, and the focal length and field of view are calibrated. Step (2): Calibrate the sensitivity of the acoustic emission sensor through the lead breakage test, set the signal filtering threshold for noise reduction; start the computer DIC system, calibrate the camera lens distortion and match the loading rate to adjust the acquisition frequency, and complete the time synchronization calibration of the acoustic emission and DIC equipment. Step (3): During loading, the acoustic emission collection system collects the elastic wave signal generated during the deformation process of the sample in real time, and the DIC technology simultaneously captures the dynamic data of displacement and strain during the deformation process of the sample, focusing on tracking the deformation dynamics of the strain concentration area within the gauge length. The two types of data are accurately correlated through a unified timestamp. Step (4): Based on the sudden increase in acoustic emission amplitude and the peak count rate, locate the crack initiation and propagation nodes, and identify the high strain region at the crack tip by combining the strain gradient field measured by DIC technology; quantify the energy distribution of acoustic emission signal based on the information entropy theory, and establish its mapping relationship with crack propagation rate and stress intensity factor. Step (5): Integrate acoustic emission characteristic parameters, strain field distribution and crack morphology data to construct a multi-dimensional correlation model of "signal characteristics-strain evolution-crack propagation".

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