A fixed clamping device and a system for extracting a target image using acoustic signals

Abstract

On the one hand, the present disclosure provides a fixed clamping device, which includes a first bracket, a second bracket, and a third bracket; the first bracket, the second bracket, and the third bracket are sequentially fixed on a first slide rail through connecting elements; the first bracket and the third bracket are U-shaped brackets, and there are first push plates on the extending arms at both ends of the U-shaped brackets, and the first push plates are used to clamp the test piece to be tested; the second bracket is used to fixedly install an acoustic emission sensor. The device can facilitate the installation of the acoustic emission sensor and does not affect the shooting field of view of the speckle measurement surface of the test piece, providing conditions for realizing the synchronous monitoring of acoustic waves and images when the test piece to be tested deforms. On the other hand, a system for extracting a target image using an acoustic wave signal by adopting the fixed clamping device of the present disclosure is provided. The system realizes the synchronous monitoring of acoustic wave signals and full-field image information when the test piece to be tested deforms, thereby realizing the accurate extraction of the target image and avoiding analyzing too much data.

Description

Technical Field

[0001] The present disclosure belongs to the field of indoor rock deformation monitoring, and specifically relates to a fixed clamping device and a system for extracting a target image using acoustic wave signals. Background Art

[0002] As an energy output form of detection technologies such as acoustic emission and microseismic, acoustic wave signals provide a basis for predicting and controlling disasters. As a non-destructive testing technology, due to the superiority of its functions, researchers have regarded acoustic emission detection technology as a convenient and efficient indoor rock deformation detection technology. However, due to the particularity of the structure of acoustic emission instrument components, it is impossible to achieve the isolated operation of acoustic emission sensors, and fixation operations must be carried out regardless of the material or part being detected. The current fixation methods of acoustic emission sensors mainly include the following: (1) bonding the acoustic emission sensor to the test specimen with glue; (2) designing a general fixing component to surround and fix one or more acoustic emission sensors on the surface of the test specimen. For the former, when the test specimen deforms and breaks, the acoustic emission sensor may fall off; for the latter, the surrounding fixing component will block the test specimen, affecting the synchronous use of other rock detection technologies.

[0003] According to the research direction, another technology used in deformation monitoring is the digital image correlation method. This technology requires spraying speckles on the reserved test surface of the test specimen, and then performing online and full-field strain measurement by taking pictures. The data result is the image information of the entire loading process of the speckle shooting surface of the test specimen. Therefore, after the deformation detection of the test specimen, a large number of deformation pictures will be obtained. According to the research direction requirements, it is necessary to screen out several digital images before and after certain large deformations of the test specimen from a large number of images for correlation calculation to obtain the target deformation information. Summary of the Invention

[0004] To address some of the above problems, on the one hand, the present disclosure proposes a fixed clamping device. In this technical solution, the device includes a first bracket, a second bracket, and a third bracket; the first bracket, the second bracket, and the third bracket are sequentially fixed on a first slide rail through connecting elements; the first bracket and the third bracket are U-shaped brackets, and there are first push plates on the outstretched arms at both ends of the U-shaped brackets, and the first push plates are used to clamp the test specimen; the second bracket is used to fixedly install an acoustic emission sensor.

[0005] When performing rock deformation detection, compared with the prior art, the device can stably hold the specimen to be tested without blocking the speckle shooting surface required when using the digital image correlation method technology. Secondly, a position for installing an acoustic emission sensor is provided, facilitating the acquisition of sound waves generated when the specimen to be tested deforms. Therefore, the device helps to synchronously collect sound waves and images when the specimen to be tested deforms, without interference from each other; and synchronous monitoring provides a prerequisite for using the sound wave signal to intercept the deformation images within the target time period for accurate analysis of the target data.

[0006] On the other hand, the present disclosure proposes a system for extracting target images using sound wave signals by implementing the fixed clamping device described in the present disclosure. The system includes an acoustic emission detector, a digital image correlation method detector, and a universal testing machine; the acoustic emission detector, the digital image correlation method detector, and the universal testing machine are all connected to a power switch; the system further includes a fixed clamping device, a synchronous trigger module, a receiving module, a noise adjustment module, a threshold setting module, an interval determination module, a recording module, and an intercepting module.

[0007] The fixed clamping device is used to hold the specimen to be tested; the synchronous trigger module controls the acoustic emission detector, the digital image correlation method detector, and the universal testing machine to work simultaneously; the receiving module is used to receive sound wave information and the collected images; the noise adjustment module is used to remove the noise caused by internal or external reasons in the experiment from the sound wave information; the threshold setting module is used to set the sound wave threshold; the interval determination module is used to determine the time interval t for sound wave acquisition; the recording module records the moment when the peak value of the denoised sound wave reaches the set sound wave threshold and records it as T i (i = 1, 2, 3...); the intercepting module intercepts the target images of each time period [T i -t, T i +t](i = 1, 2, 3...) from the collected full-field deformation images in combination with the moment recorded by the recording module.

[0008] Compared with the prior art, by using the fixed clamping device, the system enables the simultaneous use of two deformation monitoring technologies, and the sound wave signal and the full-field image information can be synchronously monitored without interference from each other; and synchronous monitoring provides a prerequisite for using the sound wave signal to intercept the deformation images within the target time period for accurate analysis of the target data, avoiding the analysis of excessive data due to research requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 is a schematic structural diagram of the fixed clamping device of the present disclosure;

[0010] Figure 2 is a schematic structural diagram of the rocker arm of the acoustic emission sensor sleeve of the fixed clamping device of the present disclosure;

[0011] Figure 3-1 It is a front view schematic diagram of the fixed clamping device of the present disclosure during single-sided shooting operation;

[0012] Figure 3-2 It is a top view schematic diagram of the fixed clamping device of the present disclosure during single-sided shooting operation;

[0013] Figure 4 It is another structural schematic diagram of the fixed clamping device of the present disclosure;

[0014] Figure 5 It is a partial schematic diagram of the adjustable V-shaped frame of the fixed clamping device of the present disclosure;

[0015] Figure 6-1 It is a front view schematic diagram of the fixed clamping device of the present disclosure during double-sided shooting operation;

[0016] Figure 6-2 It is a top view schematic diagram of the fixed clamping device of the present disclosure during double-sided shooting operation;

[0017] Figure 7 It is a structural schematic diagram of a system for extracting a target image using acoustic wave signals according to the present disclosure;

[0018] Figure 8 It is a schematic diagram of the acoustic wave recorded by the recording module when reaching the set threshold;

[0019] Description of the markings in the figure:

[0020] 1-1, the first bracket; 1-2, the second bracket; 1-3, the third bracket; 2-1, the first slide rail; 2-2, the second slide rail; 2-3 the third slide rail; 3-1, the first push plate support foot; 3-2, the fixed support foot of the second slide rail; 4, the double-branch push plate; 5, the rocker arm; 6, the sliding and fixing bolt; 7, the adjustable V-shaped bracket; 8, the single-branch V-shaped push plate; 9, the specimen to be tested; 10, the spring; 11, the local shooting device of digital image correlation method; 12, the acoustic emission sensor; 13, the acoustic wave threshold line; 14, the peak of the acoustic wave; 101, the U-shaped bracket extension arm; 102, the first hole; 103, the second hole; 501, the acoustic emission sensor sleeve; 502, the rocker arm bolt; 701, the adjustable V-shaped bracket extension arm; 702, the rotating bearing; 703, the bearing connecting plate; 1101, the camera; 1102, the shooting field of view; Ⅰ, the fixed clamping device; Ⅱ, the acoustic emission detector; Ⅲ, the digital image correlation method detector; Ⅳ, the universal testing machine; A, the noise adjustment module; B, the threshold setting module; C, the interval determination module; D, the receiving module; E, the recording module; F, the intercepting module; G, the same triggering module, T 1 , T 2 , T 3 , T 4 , T 5 It is a schematic indication mark for the moment of reaching the acoustic wave threshold. Detailed implementation manners

[0021] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

[0022] In the description of the present application, it should be understood that the orientation or positional relationships indicated by the terms "upper", "lower", "middle", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present application.

[0023] In the description of the present application, it should be noted that, unless otherwise clearly defined and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection or an integral connection. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific situations.

[0024] The terms "first", "second" and "third" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined with "first", "second" and "third" may explicitly or implicitly include one or more of such features.

[0025] In one embodiment, according to the requirements of digital image monitoring technology, after spraying speckles on the monitoring surface of the test piece to be tested, a universal testing machine is used to apply a deformation force to the test piece to be tested, an acoustic emission detector is used to monitor the sound waves during the deformation of the test piece to be tested, and a digital image correlation method detector is used to take images of the monitoring surface at the same time. A fixed clamping device is used in this embodiment, and the device includes three parts: upper, middle and lower, which are the first bracket, the second bracket and the third bracket respectively. Among them, the first bracket, the second bracket and the third bracket are sequentially fixed on the first slide rail through connecting elements. The first bracket and the third bracket are U-shaped brackets, and there are first push plates on the two outstretched arms of the U-shaped bracket, and the first push plates are used to clamp the test piece to be tested; the second bracket is used to fixedly install an acoustic emission sensor.

[0026] In this embodiment, the fixed clamping device includes upper, middle, and lower parts. These three parts are fixed on the same slide rail by connecting elements and can slide freely on the rail to change their positions, facilitating the installation of test specimens at different heights. The upper and lower parts are a U-shaped bracket. For convenient use, some holes are provided on the U-shaped bracket, and these holes are used to install different accessories. For example, a first push plate is installed on the extending arms at both ends of the U-shaped bracket, and the first push plate is used to clamp the test specimen. In this structure, the test specimen can be stably clamped, and it is also convenient to apply deformation pressure to the test specimen from the up and down directions. At the same time, the U-shaped opening does not affect the shooting of the monitoring surface by the digital image correlation method detector. The second bracket in the middle part is used to install and fix the acoustic emission sensor. During use, the acoustic emission sensor is closely attached to the test specimen to monitor the sound waves when the test specimen deforms. Therefore, the device makes it possible to use two monitoring technologies simultaneously and synchronously collect acoustic wave information and image information.

[0027] Specifically, in order to facilitate the clamping of different test specimens, the shape and structure of the first push plate are designed. According to different shapes, the first push plate can be further divided into a single-branch V-shaped push plate and a double-branch push plate. Structurally, the first push plate includes a support surface, support feet, nuts, and springs; the support surface is connected to the support feet; after the support feet are sleeved with springs, the first push plate is fixed on the extending arms of the first bracket and the third bracket through nuts. The shape of the first push plate can be selected according to the number of monitoring surfaces or the shape of the test specimen. The number of the first push plates can also be determined according to the need to stabilize the test specimen. When installing the test specimen, the spring in the first push plate is in a compressed state. When the test specimen expands and deforms, the clamping force of the first push plate is adjusted through the dynamic compression of the spring, so as not to affect the deformation of the test specimen.

[0028] In order not to block the speckle monitoring surface of the test specimen and be applicable to test specimens of different shapes, the second bracket is preferably a U-shaped bracket or an adjustable V-shaped bracket in structure. Both of these brackets are of an open type. Acoustic emission sensors can be installed on the extending arms at both ends. In this design, the test specimen is firmly fixed in the center of the entire device by the first bracket and the third bracket. After the acoustic emission sensors are installed, the sound waves generated when the test specimen deforms can be monitored, and the open brackets do not block the monitoring surface of the test specimen, reserving a shooting area for the acquisition of digital images.

[0029] In order to facilitate the installation and disassembly of the acoustic emission sensors on the second bracket, the acoustic emission sensors can be installed on the acoustic emission sensor sleeves. The acoustic emission sensor sleeves are located on the rocker arms; thus, the acoustic emission sensors are installed on the extending arms of the second bracket through the rocker arms. By adjusting the tightness of the connecting parts, the position of the rocker arm in the vertical direction of the test specimen can be adjusted to place the acoustic emission sensors at the selected acoustic wave monitoring positions.

[0030] Further, a second slide rail is added and the rocker arm is mounted on the second slide rail, so that the position of the acoustic emission sensor can be adjusted in the left - right horizontal position. During installation, the second slide rail is fixedly mounted on the extension arm of the second bracket through two feet. If springs are added to the feet for fixing the second slide rail, when the test piece to be tested expands and deforms, through the compression of the springs, the acoustic emission sensor can be closely attached to the test piece without affecting the deformation of the test piece. If springs are installed, when installing the second slide rail, the two feet can be respectively sleeved with springs and then fixed on the extension arm of the second bracket, so that the acoustic emission sensor is closely attached to the test piece and the springs are in a compressed state.

[0031] According to the needs of the observation surface of the test piece to be tested, the second bracket is selected as a U - shaped bracket or an adjustable V - shaped bracket. For example, a U - shaped bracket is usually used to monitor the deformation occurring on one surface. When it is necessary to monitor the deformation occurring on two surfaces, an adjustable V - shaped bracket can be selected. When the second bracket is an adjustable V - shaped bracket, it can be used in cooperation with a third slide rail; the third slide rail is fixedly mounted on the first slide rail through a connecting element; the two extension arms of the adjustable V - shaped bracket are connected to a connecting plate through rotating bearings; the connecting plate is fixedly mounted on the third slide rail through a connecting element.

[0032] When the horizontal projection of the test piece to be tested is square, the third slide rail can be not used, and the adjustable V - shaped bracket is directly fixedly mounted on the first slide rail through a connecting element. In this case, when installing the second bracket, the two extension arms of the adjustable V - shaped bracket are connected to a bearing connecting plate through rotating bearings, and then the connecting plate is directly fixedly mounted on the first slide rail through a connecting element.

[0033] For the convenience of installation, the first holes and second holes are provided on the first bracket, the second bracket and the third bracket. The second holes are used for installing accessories, such as the first push plate, the second slide rail, etc. The first holes of the first bracket and the third bracket are used for mounting them on the first slide rail through connecting elements. For the first holes of the second bracket, when the second bracket is an adjustable V - shaped bracket used alone, the first holes are used for mounting it on the first slide rail through connecting elements; when the second bracket is used in cooperation with the third slide rail as an adjustable V - shaped bracket, the first holes are used for mounting the adjustable V - shaped bracket on the third slide rail through connecting elements.

[0034] To facilitate the understanding of the technical solution of the present disclosure, the following is combined with the attached Figure 1-7 for a detailed description.

[0035] In one embodiment, the use is as Figure 1The fixed clamping device shown. In this fixed clamping device, it includes a first bracket (1-1), a second bracket (1-2), and a third bracket (1-3). The first bracket (1-1), the second bracket (1-2), and the third bracket (1-3) are U-shaped brackets. There are first holes (102) on the first bracket (1-1), the second bracket (1-2), and the third bracket (1-3). A sliding fixing bolt (6) passes through the first holes (102) to sequentially fix the first bracket (1-1), the second bracket (1-2), and the third bracket (1-3) on the first slide rail (2-1). The first slide rail (2-1) enables the first bracket (1-1), the second bracket (1-2), and the third bracket (1-3) to slide freely, so as to install test specimens of different heights. To facilitate the installation of different accessories, there are second holes (103) on each U-shaped bracket extension arm (101). For example, to facilitate clamping the test specimen, first push plates are installed on the extension arms (101) of the two U-shaped brackets of the first bracket (1-1) and the third bracket (1-3). Figure 1 The first push plate in it is a double-branch push plate (4). There are two first push plate feet (3-1), which jointly support a support surface. During installation, pass the feet through the spring, insert them into the second hole (103), and then fix them with nuts. To not affect the deformation of the test specimen, the spring needs to be in a compressed state during installation.

[0036] Figure 1 The second bracket (1-2) is also a U-shaped bracket. A second slide rail (2-2) is installed on the U-shaped bracket extension arm. During installation, pass the fixed feet (3-2) of the second slide rail through the holes at both ends of the second slide rail (2-2), then through the spring, insert them into the second hole of the second bracket, and fix them with nuts.

[0037] A rocker arm (5) of an acoustic emission sensor sleeve is installed on the second slide rail (2-2). The schematic diagram of the rocker arm (5) is as shown in Figure 2 shown. At one end of the rocker arm (5), there is an acoustic emission sensor sleeve (501) for placing the acoustic emission sensor. Through the cooperation of the second slide rail (2-2) and the rocker arm bolt (502), the rocker arm (5) can slide left and right, and at the same time, it can also rotate 360° freely in the vertical direction of the test specimen through the rocker arm bolt, so as to realize the all-round monitoring of the acoustic emission test surface of the test specimen.

[0038] Figure 3-1 and Figure 3-2They are respectively the front view schematic diagram and the top view schematic diagram of a fixed clamping device during single-sided shooting operation. Among them, the specimen to be tested (9) is firmly fixed in the middle of the device. Springs (10) are provided between the double push plate (4) and the U-shaped bracket, and between the second slide rail and the U-shaped bracket. Through the spring (10), the fixed clamping device does not affect the compression and expansion of the specimen to be tested, and makes the acoustic emission sensor (12) closely adhere to the specimen to be tested, so as to monitor the sound waves generated when the specimen to be tested deforms. In Figure 3-2 In the schematic diagram, the digital image correlation method local shooting device (11) is placed directly in front of the U-shaped opening of the specimen to be tested, and the speckle measurement surface of the specimen to be tested is completely and clearly located in the shooting field of view (1102) of the camera (1101).

[0039] Adopt Figure 1 the fixed clamping device in, which is usually convenient for single-sided digital image correlation method shooting of the specimen to be tested. When in use, it can be installed according to the following steps:

[0040] S100. Select the first push plate as the double push plate, install springs on the feet of the double push plate, and then fix them on the arms of the first bracket and the third bracket;

[0041] S200. Select the second bracket as the U-shaped bracket, put springs on the feet of the second slide rail, and fix them on the arm of the second bracket;

[0042] S300. Install the emission sensor sleeve rocker arm on the second slide rail;

[0043] S400. Place the specimen to be tested in the center of the device, adjust the positions of the first bracket and the third bracket; adjust the nuts of the double push plate to clamp the specimen to be tested and make the spring in a compressed state;

[0044] S500. Place the sprayed measurement surface of the specimen to be tested facing outward, insert the acoustic emission sensor into the sleeve of the rocker arm, adjust the position and angle of the rocker arm, and adjust the nuts on the feet to make the spring in a compressed state and make the acoustic emission sensor closely adhere to the specimen to be tested.

[0045] After installation, the position and angle of the rocker arm can be further adjusted according to the acoustic emission monitoring position.

[0046] In another embodiment, when using the device of the present disclosure to perform double-sided deformation monitoring on the specimen to be tested, it can be understood in combination with Figure 4 -6. In this embodiment, the second bracket is an adjustable V-shaped bracket.

[0047] Figure 4 is a schematic diagram of the combined use of the adjustable V-shaped bracket (7) and the third slide rail (2-3). In Figure 4Among them, the first bracket and the third bracket remain unchanged and are still U-shaped brackets. In order to display the two monitoring surfaces of the test piece to be tested, the first push plate adopts a single-branch V-shaped push plate (8), and the first push plate support leg (3-1) is one, supporting a V-shaped support surface. The single-branch V-shaped push plate uses the V-shaped support surface to clamp the edge or corner of the test piece to be tested, and stable clamping of the test piece to be tested can be achieved through the cooperation of multiple single-branch V-shaped push plates. The third slide rail (2-3) of the second bracket is fixed on the first slide rail through a sliding bolt. As shown in the figure, the first slide rail and the third slide rail are perpendicular to each other. The adjustable V-shaped bracket of the second bracket is fixed on the third slide rail (2-3) through a sliding and fixing bolt. On the adjustable V-shaped bracket, a second slide rail (2-2) is installed, and both ends of it are installed and fixed on the extension arm of the adjustable V-shaped bracket through the fixed support legs (3-2) of the second slide rail. A spring is installed on the support leg between the second slide rail and the extension arm. A rocker arm (5) is installed on the second slide rail (2-2), and at one end of the rocker arm (5) there is an acoustic emission sensor sleeve (501) for placing an acoustic emission sensor. Through the cooperation of the second slide rail (2-2) and the rocker arm bolt (502), the rocker arm (5) can slide left and right, and 360° free rotation can be achieved by adjusting the rocker arm bolt, so as to realize the all-round monitoring of the acoustic emission surface to be tested of the test piece.

[0048] For the schematic diagram of the adjustable V-shaped bracket (7) as Figure 5 shown. The adjustable V-shaped bracket (7) includes an adjustable V-shaped bracket extension arm (701), a rotating bearing (702) and a bearing connecting plate (703). The two adjustable V-shaped bracket extension arms are connected to the bearing connecting plate (703) through the rotating bearing (702). There is a first hole (102) on the bearing connecting plate (703), and there is a second hole (103) on the adjustable V-shaped bracket extension arm (701).

[0049] When using Figure 4 the device in

[0050] S101. Select the first push plate as a single-branch V-shaped push plate, install a spring on its support leg and then fix it;

[0051] S201. Select the second bracket as an adjustable V-shaped bracket and a third slide rail; install the third slide rail on the first slide rail to make the two perpendicular; then install the adjustable V-shaped bracket on the third slide rail;

[0052] S301. Install a spring on the support leg for fixing the second slide rail and then fix it on the adjustable V-shaped bracket.

[0053] S401. Install the rocker arm on the second slide rail;

[0054] S501: Place the specimen to be tested with the sprayed surfaces to be measured facing outwards correctly, with the inner surfaces facing inwards, in the center of the entire device. Adjust the positions of the first bracket and the third bracket, and adjust the single V-shaped pusher plate so that it clamps the specimen to be tested and the spring is in a compressed state.

[0055] S601: Insert the acoustic emission sensor into the sleeve of the rocker arm. Adjust the position and angle of the rocker arm, and adjust the nuts on the support feet so that the spring is in a compressed state and the acoustic emission sensor can closely adhere to the specimen to be tested.

[0056] After installation, the position and angle of the rocker arm of the acoustic emission sensor sleeve can continue to be adjusted according to the acoustic emission monitoring position.

[0057] Figure 6-1 and Figure 6-2 are respectively the front view schematic diagram and the top view schematic diagram of the fixed clamping device during the double-sided shooting operation.

[0058] In the above two methods, the first pusher plate is selected according to the shape of the specimen to be tested or the shooting requirements. It can be either a double-branch pusher plate or a single V-shaped pusher plate, or a combination of both. To better clamp the specimen to be tested, the supporting surface of the pusher plate can be deformed according to the outer shape of the specimen to be tested, and all these should be understood to be within the scope of protection of the present disclosure. The supporting surface and the support feet can be integrated or assembled.

[0059] In the above method, the third slide rail is not necessarily used. When the third slide rail is not used, the adjustable V-shaped bracket can be directly placed on the first slide rail, for example, when the horizontal projection of the specimen to be tested is square.

[0060] In still another embodiment, using the fixed clamping device of the present disclosure, in cooperation with the use of an acoustic emission detector, an acoustic emission sensor, a digital image correlation method detector, a universal testing machine, and a power switch, a system for extracting a target image using acoustic wave signals is formed. Through the system, it is possible to synchronously collect the acoustic waves and deformation images generated when the specimen to be tested deforms, enabling the system to accurately extract the target image, thereby effectively reducing the workload of the image data used to calculate the deformation information during the selected target time period.

[0061] Figure 7 is a schematic structural diagram of a system for extracting a target image using acoustic wave signals. In Figure 7 the system includes an acoustic emission detector (Ⅱ), a digital image correlation method detector (Ⅲ), and a universal testing machine (Ⅳ). The acoustic emission detector (Ⅱ), the digital image correlation method detector (Ⅲ), and the universal testing machine (Ⅳ) are all connected to the power switch, and the power switch is not shown in Figure 7It is schematically shown in the figure. The system further includes a fixed clamping device (Ⅰ), a synchronization trigger module (G), a receiving module (D), a noise adjustment module (A), a threshold setting module (B), an interval determination module (C), a recording module (E), and a truncation module (F); the fixed clamping device is used to clamp the specimen to be tested; the synchronization trigger module controls the simultaneous operation of the acoustic emission detector, the digital image correlation method detector, and the universal testing machine. Among them, the universal testing machine applies pressure to the specimen to be tested from two directions, causing the specimen to be tested to deform; the receiving module is used to receive acoustic wave information and full-field image information; the noise adjustment module is used to remove the noise caused by internal or external reasons in the experiment from the acoustic wave information; the threshold setting module is used to set the acoustic wave threshold; the interval determination module is used to determine the time interval t for acoustic wave acquisition; the recording module is used to record the moment when the acoustic wave peak reaches the set acoustic wave threshold and record it as T i (i = 1, 2, 3...), as Figure 8 shown, when the acoustic wave peak (14) reaches the set acoustic wave threshold line (13), its corresponding moment will be recorded, as shown by T in the figure 1 , T 2 , T 3 , T 4 , T 5 shown; the "reach" means that the peak value of the acoustic wave peak is greater than or equal to the set acoustic wave threshold; the truncation module truncates the deformation images of each time period [T i - t, T i + t](i = 1, 2, 3...) from the collected deformation images.

[0062] In the system, the structure of the fixed clamping device is not limited to the structure schematically shown in Figure 7 . It can be any structure of the fixed clamping device in the above embodiments selected according to the shape of the object to be tested, the number of image monitoring surfaces, etc., such as Figure 4 the structure schematically shown.

[0063] In this system, it is judged whether the specimen to be tested has some large deformations through acoustic waves. When the acoustic wave reaches or exceeds the set acoustic wave threshold for large deformations, the moment is recorded. By determining the time interval, one or some time ranges are obtained, and then the synchronized trigger deformation images for calculation are limited within this time range. Compared with simply using deformation images to calculate and analyze deformation information, the screening amount of deformation images can be greatly reduced.

[0064] Through the description of the above embodiments, those skilled in the art can clearly understand that the functional modules in the present disclosure system can be implemented by means of software plus necessary general hardware. Of course, they can also be implemented by dedicated hardware including application-specific integrated circuits, dedicated CPUs, dedicated memories, dedicated components, etc. Generally, functions completed by computer programs can be easily implemented by corresponding hardware, and the specific hardware structures for implementing the same function can also be various, such as analog circuits, digital circuits or dedicated circuits, etc. However, in more cases for the present disclosure, software program implementation is a better embodiment.

[0065] In one embodiment, the present disclosure system is used for synchronously collecting sound waves and images, and the usage method of the system is as follows:

[0066] S102. Select the first push plate as a double-branch push plate, install springs on the feet of the double-branch push plate, and then fix it on the arms of the first bracket and the third bracket;

[0067] S202. Select the second bracket as a U-shaped bracket, put springs on the feet of the second slide rail, and fix it on the arm of the second bracket;

[0068] S302. Install a transmitting sensor sleeve rocker arm on the second slide rail;

[0069] S402. Place the specimen to be tested in the center of the device, adjust the positions of the first bracket and the third bracket, and adjust the nuts of the double-branch push plate so that the double-branch push plate holds the specimen to be tested and the springs are in a compressed state;

[0070] S502. Place the sprayed surface to be tested of the specimen to be tested facing outward, insert the acoustic emission sensor into the sleeve of the rocker arm, adjust the position and angle of the rocker arm, and adjust the nuts on the feet so that the springs are in a compressed state and the acoustic emission sensor can closely adhere to the specimen to be tested;

[0071] S602. Adjust the position and angle of the acoustic emission sensor sleeve rocker arm according to the acoustic emission monitoring position;

[0072] S702. Adjust the digital image technology shooting device, reasonably allocate the camera spacing, and adjust the shooting field of view;

[0073] S802. Set the time interval in the confirmation interval module and set the acoustic wave threshold in the determination threshold module;

[0074] S902. Through the same trigger module, synchronously start the acoustic emission detector, digital image correlation method detector, and universal testing machine to enter the working state. The working state is that the universal testing machine applies deformation pressure to the specimen to be tested, the acoustic emission detector monitors the deformation acoustic waves, and the digital correlation method detector monitors the deformation images;

[0075] S1002. Obtain the target deformed image to be analyzed from the interception module.

[0076] Although the embodiments of the present disclosure have been described above in conjunction with the accompanying drawings, the present disclosure is not limited to the above specific embodiments and application fields. The above specific embodiments are merely illustrative and guiding, rather than restrictive. Those of ordinary skill in the art can also make many forms under the inspiration of this specification and without departing from the scope protected by the claims of the present disclosure, and all of these fall within the scope of protection of the present disclosure.

Claims

1. A fixed clamping device, characterized in that: the device is used for simultaneously performing acoustic wave detection and speckle detection on a test piece to be tested, and includes a first bracket, a second bracket and a third bracket. The first bracket, the second bracket and the third bracket are sequentially fixed on a first slide rail through connecting elements, and the first bracket, the second bracket and the third bracket can slide on the first slide rail to change positions so as to install test pieces to be tested with different heights; the first bracket and the third bracket are U-shaped brackets, and there are first push plates on the two outstretched arms of the U-shaped brackets. The first push plate includes a supporting surface, supporting feet, nuts and springs. The supporting surface is connected to the supporting feet. After the supporting feet are sleeved with springs, the first push plate is fixed on the outstretched arms of the first bracket and the third bracket through nuts. The first push plate is used for clamping the test piece to be tested. When installing the test piece to be tested, the spring in the first push plate is in a compressed state. When the test piece to be tested undergoes expansion deformation, the dynamic compression of the spring is used to adjust the clamping force of the first push plate; the second bracket is an open U-shaped bracket or an open adjustable V-shaped bracket. A second slide rail is fixedly installed on the outstretched arm of the second bracket through two supporting feet. Springs are sleeved on the supporting feet. A rocker arm is installed on the second slide rail through a connecting member. An acoustic emitter sensor sleeve is installed on the rocker arm. The acoustic emitter sensor sleeve is used for fixedly installing an acoustic emission sensor. By adjusting the vertical position of the rocker arm by using the connecting member, the position of the acoustic emission sensor in the vertical direction of the test piece to be tested can be adjusted. By adjusting the horizontal position of the rocker arm by using the second slide rail, the position of the acoustic emission sensor in the horizontal direction of the test piece to be tested can be changed. And by using the spring in a compressed state, the acoustic emission sensor can be made to closely adhere to the test piece to be tested without affecting the deformation of the test piece to be tested; when the second bracket is an adjustable V-shaped bracket, the device includes a third slide rail. The third slide rail is fixed on the first slide rail through a connecting element. The two outstretched arms of the adjustable V-shaped bracket are connected to a bearing connecting plate through rotating bearings. The bearing connecting plate is fixed on the third slide rail through a connecting element.

2. The fixed clamping device according to claim 1, characterized in that: when the horizontal projection of the test piece to be tested is square, the two outstretched arms of the adjustable V-shaped bracket are connected to a bearing connecting plate through rotating bearings. The bearing connecting plate is fixed on the first slide rail through a connecting element.

3. The fixed clamping device according to claim 1, characterized in that: the first bracket, the second bracket and the third bracket are all provided with first holes and second holes.

4. A system for extracting a target image by using an acoustic wave signal by using the fixed clamping device according to any one of claims 1-3. The system includes an acoustic emission detector, a digital image correlation method detector and a universal testing machine. The acoustic emission detector, the digital image correlation method detector and the universal testing machine are all connected to a power switch, characterized in that: the system further includes a fixed clamping device, a synchronous triggering module, a receiving module, a noise adjustment module, a threshold setting module, an interval determination module, a recording module and a capturing module; The fixed clamping device is used to clamp the specimen to be tested. The steps include: selecting the first push plate as a double-branch push plate, installing springs on the feet of the first push plate and then fixing them on the extending arms of the first bracket and the third bracket, sleeving springs on the feet of the second slide rail and fixing them on the extending arm of the second bracket, installing an acoustic emission sensor sleeve rocker on the second slide rail, placing the specimen to be tested in the center of the device, and adjusting the positions of the first bracket and the third bracket; adjusting the nuts of the double-branch push plate to clamp the specimen to be tested and make the springs in a compressed state; placing the sprayed surface to be tested of the specimen facing outward, inserting the acoustic emission sensor into the sleeve of the rocker, adjusting the position and angle of the rocker, and adjusting the nuts on the feet to make the springs in a compressed state and enable the acoustic emission sensor to closely adhere to the specimen to be tested; The same trigger module controls the simultaneous operation of the acoustic emission detector, the digital image correlation method detector, and the universal testing machine; The receiving module is used to receive acoustic wave information and full-field image information; The noise adjustment module is used to remove the noise caused by internal or external reasons in the experiment from the acoustic wave information; The threshold setting module is used to set the acoustic wave threshold; The interval determination module is used to determine the time interval t for acoustic wave acquisition; The recording module records the moment when the peak value of the denoised acoustic wave reaches the set acoustic wave threshold, and records it as Ti, where i = 1, 2, 3...; The intercepting module intercepts the target images of each time period [Ti - t, Ti + t] from the collected full-field image information in combination with the moments recorded by the recording module, where i = 1, 2, 3...

Images