Device and method for identifying full-field dynamic modal parameters of test piece in high-temperature environment

Abstract

The invention relates to the field of dynamic characteristic measurement, and particularly discloses a full-field dynamic modal parameter identification device and method for a test piece in a high-temperature environment, and the device comprises a clamp, a vibration table, an external bearing frame, a laser Doppler assembly, a quartz heating bin, a quartz lamp tube, a thermocouple and a power controller, the quartz heating bin is placed on the external bearing frame, an opening is formed in the bottom of the quartz heating bin, the clamp enables a tested piece clamped by the clamp to be located in the quartz heating bin through the opening, a thermocouple is arranged on the clamp, and at least two quartz lamp tubes are arranged on the inner side wall of the quartz heating bin. At least two quartz lamp tubes form a quartz lamp tube array which is uniformly distributed up and down, the quartz lamp tubes are electrically connected with the power controller, and the laser Doppler assembly is arranged right in front of the quartz heating bin, so that the problems of low heating rate and non-uniform heating in the traditional heating methods such as electromagnetic heating and resistance wire heating are solved; and the measured data is more reliable.

Description

Technical Field

[0001] The present invention relates to the technical field of dynamic characteristic measurement, and in particular to a device and method for identifying full-field dynamic modal parameters of a specimen in a high-temperature environment. Background Art

[0002] With the continuous development of modern science and technology, various sophisticated and complex mechanical structures have emerged in the field of mechanical research, such as aerospace engine blades, spacecraft shells, and engine crankshafts of high-speed racing cars and military ships in the field of transportation. Based on the research on structural appearance design, people's requirements for the mechanical properties of structures are gradually increasing. Modal research on mechanical structures is an important means of studying their mechanical properties. By obtaining the resonant frequency, modal vibration shape and damping ratio of the corresponding structure, the characteristics of the main modes of each order of the structure within a certain susceptible frequency range can be clarified, and the actual response of the structure under various external or internal vibration sources in this frequency band can be predicted, thereby judging the stability of the mechanical properties of the corresponding mechanical structure.

[0003] In high-temperature modal testing, there is a lack of full-field dynamic test systems that can load external excitations, so the heating equipment is selected to combine a quartz heating chamber and a vibration table. Due to the limitations of the high-temperature environment, the use of contact test methods, such as a single high-temperature accelerometer, cannot obtain the dynamic modal parameters of the specimen, such as the natural frequency and the corresponding vibration mode. If multiple high-temperature accelerometers are used to obtain the natural frequency and the corresponding vibration mode, the weight of the test object will increase and the vibration of the test object will be affected due to the weight of the sensor itself and the existence of supporting cables. The currently commonly used non-contact binocular vision acquisition method based on digital image correlation depends on the speckle production quality of the specimen surface and the surface illumination quality. In the high temperature range of -200℃, the binocular vision system can barely collect data normally and complete the test. However, as the temperature rises, the specimen will undergo oxidation and optical interference effects in the high temperature environment due to the temperature rise, and the color change phenomenon will be presented. The speckle quality will also be reduced due to the color change. At the same time, the external light source will also reduce the light quality on the specimen surface due to the color change. Therefore, the binocular vision test system cannot be tested normally to obtain experimental data in a more stable temperature environment.

[0004] However, in actual working conditions, there are many cases where the temperature is higher than 200°C, such as the temperature in front of the high-pressure turbine guide vanes of aircraft engines, especially turbofan engines, which can reach 1100°C-1900°C, and the temperature at the tail nozzle is generally between 500°C-800°C. In this case, the existing technology cannot obtain accurate full-field dynamic modal parameters. Summary of the invention

[0005] In order to solve the above problems, the present invention provides a device and method for identifying the full-field dynamic modal parameters of a specimen in a high-temperature environment. In a high-temperature test environment heated by a quartz lamp, multiple laser Doppler vibrometers are used to project light beams onto the surface of the test object to form a dot matrix, thereby obtaining vibration data on the surface of the specimen. In the later data processing, the points in the dot matrix and the data collected at each point are fitted to obtain the dynamic modal parameters of the specimen, including the natural frequency and the corresponding vibration mode.

[0006] In order to achieve the above object, the present invention provides a device and method for identifying full-field dynamic modal parameters of a specimen under a high temperature environment, and the technical solution adopted is as follows:

[0007] According to a first aspect of the present invention, there is provided a device for identifying full-field dynamic modal parameters of a specimen in a high-temperature environment, comprising a fixture, a vibration table, an external load-bearing frame, a laser Doppler component, a quartz heating chamber, a quartz lamp, a thermocouple and a power controller, wherein the fixture is fixed on the vibration table, the quartz heating chamber is placed on the external load-bearing frame, an opening is arranged at the bottom of the quartz heating chamber, the fixture enables the test piece clamped by the fixture to be located in the quartz heating chamber through the opening, the thermocouple is arranged on the fixture, the temperature measuring end of the thermocouple is in contact with the test piece, at least two quartz lamps are arranged on the inner side wall of the quartz heating chamber, the at least two quartz lamps form a quartz lamp array evenly distributed up and down, the quartz lamp is electrically connected to the power controller, the laser Doppler component is arranged in front of the quartz heating chamber, and the power controller is arranged outside the quartz heating chamber.

[0008] Furthermore, the clamp comprises a clamp base, a clamp column and a clamp frame, the upper end of the clamp base is fixedly connected to the lower end of the clamp column, and the upper end of the clamp column is fixedly connected to the clamp frame.

[0009] Furthermore, the clamp frame includes a base, a first vertical plate and a second vertical plate, the first vertical plate and the second vertical plate are both fixedly connected to the upper end of the base, the lower end of the base is fixedly connected to the upper end of the clamp column, and the first vertical plate and the second vertical plate are both arrayed with threaded holes.

[0010] Furthermore, it also includes a temperature display, which is electrically connected to the thermocouple to display the temperature signal collected by the thermocouple.

[0011] Furthermore, the laser Doppler component is used to emit an indicator red light to the tested object, the dot matrix center point of the indicator red light is located at the center of the region of interest of the tested object, and the non-dot matrix center points of the indicator red light are distributed in an equidistant matrix within the region of interest.

[0012] Furthermore, the laser Doppler assembly includes at least two Doppler vibrometers, and the at least two Doppler vibrometers are arranged in a matrix directly in front of the quartz heating chamber.

[0013] According to a second aspect of the present invention, a method for identifying full-field dynamic modal parameters of a specimen in a high temperature environment is provided. Based on the full-field dynamic modal parameter identification device for a specimen in a high temperature environment as described above, the method comprises:

[0014] Turning on the laser Doppler assembly, and making the center point of the dot matrix of the red light indicator emitted by the laser Doppler assembly located at the center of the region of interest of the tested object, and the non-dot matrix center points of the red light indicator distributed in a matrix with equal spacing within the region of interest;

[0015] Controlling the heating power of the quartz lamp switch by the power controller to control the temperature in the quartz heating chamber;

[0016] Turning on the vibration table to provide external excitation to the tested object;

[0017] Using the laser Doppler component to collect vibration data;

[0018] Based on the vibration data, a Bayesian operating mode calculation is performed to obtain a processed power spectrum density function and extract the natural frequency corresponding to the energy peak;

[0019] According to the positions of the dot matrix points of the red light indicator emitted by the laser Doppler component on the tested object, the vibration mode data corresponding to the extracted natural frequency are arranged in space and surface fitting is performed to obtain the dynamic modal parameters under high temperature environment.

[0020] Further, the laser Doppler component is turned on, and the center point of the dot matrix of the red light indicator emitted by the laser Doppler component is located at the center of the region of interest of the tested object, and the non-dot matrix center points of the red light indicator are distributed in an equidistant matrix in the region of interest, specifically including:

[0021] Turn on the red indicator light of the laser Doppler assembly, and adjust the relative position of the laser Doppler assembly according to the dot matrix of the red indicator light on the tested object until the center point of the dot matrix is ​​located at the center of the region of interest of the tested object, and the remaining points are distributed in an equidistant matrix within the region of interest.

[0022] Furthermore, before turning on the laser Doppler component, the method further includes:

[0023] Assemble a full-field dynamic modal parameter identification device for the test piece in the high temperature environment.

[0024] Furthermore, the steps of assembling the full-field dynamic modal parameter identification device of the specimen in the high temperature environment include:

[0025] Fix the fixture base to the vibration table surface;

[0026] Place the quartz heating chamber on an external load-bearing frame. The quartz heating chamber has an opening at the bottom. Align the center of the opening with the center of the fixture base. Pass the fixture column through the bottom opening of the quartz heating chamber and install and fix it on the fixture base. Install the fixture frame on the upper end of the fixture column.

[0027] Fix the test piece on the constructed fixture;

[0028] Installing a thermocouple on a fixture, with the temperature measuring end of the thermocouple placed on the observation surface of the test piece and in contact with the test piece;

[0029] Connect the thermocouple to the temperature display outside the quartz heating chamber;

[0030] The laser Doppler assembly is placed right in front of the quartz heating chamber, and a plurality of Doppler vibrometers included in the laser Doppler assembly are arranged in a matrix.

[0031] The present invention has at least the following beneficial effects:

[0032] 1) The present invention can reliably identify high-temperature dynamic modal parameters and overcome the problems of low heating rate and uneven heating faced by traditional heating methods such as electromagnetic heating and resistance wire heating, making the measured data more reliable.

[0033] 2) External excitation using a vibration table can provide excitation with precise parameters, thereby improving the excitation effect and enhancing the test quality.

[0034] 3) The test equipment is a laser Doppler vibrometer, which can make the measurement frequency range larger (the upper limit of the equipment test range is 40M), so it can provide reliable data for subsequent research on high-order frequency bands.

[0035] 4) Since the Doppler vibrometer test is less affected by high temperature than the binocular vision system, the dynamic modal parameters under higher temperature environment can be obtained and the integrity of the test data can be guaranteed. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for the specific embodiments or the description of the prior art. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn according to the actual scale.

[0037] Figure 1 A principle structure diagram of a device for identifying full-field dynamic modal parameters of a specimen in a high-temperature environment according to an embodiment of the present invention is shown.

[0038] Figure 2 The actual structure diagram of a device for identifying full-field dynamic modal parameters of a specimen in a high-temperature environment according to an embodiment of the present invention is shown.

[0039] Figure 3 A schematic diagram of a device for identifying full-field dynamic modal parameters of a specimen in a high-temperature environment according to an embodiment of the present invention is shown in a state where a quartz heating chamber is opened.

[0040] Figure 4 A schematic diagram of temperature display of a device for identifying full-field dynamic modal parameters of a specimen in a high-temperature environment according to an embodiment of the present invention is shown.

[0041] Figure 5 The figure shows a projection diagram of a red indicator light of a Doppler vibrometer on a measured object according to an embodiment of the present invention.

[0042] Figure 6 A fixture structure diagram of a device for identifying full-field dynamic modal parameters of a specimen in a high-temperature environment according to an embodiment of the present invention is shown.

[0043] Figure 7 FIG. 4 shows a power spectrum density function diagram of GH3030 at 300° C. according to an embodiment of the present invention.

[0044] Figure 8 The vibration mode diagrams of the object under test corresponding to the first two energy peaks of the power spectrum of GH3030 at 300°C according to an embodiment of the present invention are shown, wherein (a) represents the first-order vibration mode of the test piece at high temperature, and (b) represents the second-order vibration mode of the test piece at high temperature.

[0045] In the figure, 100 is a fixture, 101 is a fixture base, 102 is a fixture column, 103 is a fixture frame, 1031 is a base, 1032 is a first vertical plate, 1033 is a second vertical plate, 1034 is a threaded hole, 200 is a vibration table, 300 is an external load-bearing frame, 400 is a laser Doppler component, 500 is a quartz heating chamber, 600 is a quartz lamp, 700 is a thermocouple, 800 is a power controller, 900 is a test piece, and 1000 is a temperature display. DETAILED DESCRIPTION

[0046] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0047] In the description of the present invention, unless otherwise specified, "plurality" means two or more than two; the orientations or positional relationships indicated by the terms "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0048] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0049] The specific implementation of the present invention is further described in detail below in conjunction with the drawings and examples.

[0050] Embodiment 1:

[0051] The embodiment of the present invention provides a device for identifying full-field dynamic modal parameters of a specimen under a high temperature environment, such as Figures 1 to 3As shown, the full-field dynamic modal parameter identification device of the specimen under high temperature environment includes a fixture 100, a vibration table 200, an external load-bearing frame 300, a laser Doppler component 400, a quartz heating chamber 500, a quartz lamp 600, a thermocouple 700 and a power controller 800. The fixture 100 is fixed on the vibration table 200, the quartz heating chamber 500 is placed on the external load-bearing frame 300, and an opening is set at the bottom of the quartz heating chamber 500. The fixture 100 allows the test piece 900 clamped by the fixture 100 to be located at the opening. Inside the quartz heating chamber 500, the thermocouple 700 is arranged on the fixture 100, and the temperature measuring end of the thermocouple 700 is in contact with the test piece 900. At least two quartz lamp tubes 600 are arranged on the inner wall of the quartz heating chamber 500. At least two quartz lamp tubes 600 form a quartz lamp tube array evenly distributed up and down. The quartz lamp tubes 600 are electrically connected to the power controller 800. The laser Doppler component 400 is arranged directly in front of the quartz heating chamber 500, and the power controller 800 is arranged outside the quartz heating chamber 500.

[0052] In the device, the fixture 100 is used to clamp and fix the object to be tested, that is, the test piece 900. The fixture 100 is fixed on the vibration table 200. The vibration table 200 is used to give external excitation to the object to be tested. The test piece 900 clamped by the fixture 100 is located in the quartz heating chamber 500. The thermocouple 700 arranged on the fixture 100 is used to collect the temperature signal of the test piece 900. According to the collected temperature signal, the power of the quartz lamp 600 is controlled by the power controller 800 so that the temperature of the test piece 900 is raised to the set test temperature. The laser Doppler component 400 is used to collect vibration data of the test piece 900 under the set test temperature environment and when the vibration table 200 gives external excitation, and Bayesian operational modal calculation is performed based on the vibration data to obtain the processed power spectral density function, extract the natural frequency corresponding to the energy peak, and according to the point position of the laser Doppler component 400 on the test object, the vibration mode data corresponding to the extracted natural frequency are arranged in space and surface fitting is performed to obtain complete dynamic modal parameters under high temperature environment.

[0053] In an exemplary embodiment, Figure 6 As shown, the clamp 100 includes a clamp base 101 , a clamp column 102 and a clamp frame 103 . The upper end of the clamp base 101 is fixedly connected to the lower end of the clamp column 102 , and the upper end of the clamp column 102 is fixedly connected to the clamp frame 103 .

[0054] Specifically, the clamp frame 103 includes a base 1031, a first vertical plate 1032 and a second vertical plate 1033. The first vertical plate 1032 and the second vertical plate 1033 are fixedly connected to the upper end of the base 1031, and the lower end of the base 1031 is fixedly connected to the upper end of the clamp column 102. The first vertical plate 1032 and the second vertical plate 1033 are arrayed with threaded holes 1034.

[0055] The fixture base 101 is installed on the vibration table 200, and the fixture column 102 connected to the fixture base 101 is to facilitate the installation of the fixture frame 103. The base 1031 included in the fixture frame 103 is convenient for assembling the fixture frame 103 on the fixture column 102. The assembly method of the fixture base 101 and the vibration table 200, and the fixture column 102 and the base 1031 can all be a threaded assembly method. The fixture frame 103 is used to clamp the test piece 900, and it mainly fixes the two ends of the test piece 900 through the threaded holes 1034 set on the first vertical plate 1032 and the second vertical plate 1033, so that the test piece 900 is clamped and fixed.

[0056] In an exemplary embodiment, Figure 4 As shown, the device further includes a temperature display 1000, and the temperature display 1000 is electrically connected to the thermocouple 700 to display the temperature signal collected by the thermocouple.

[0057] In an exemplary embodiment, the laser Doppler assembly 400 is used to emit an indicator red light to the tested object, the dot matrix center point of the indicator red light is located at the center of the region of interest of the tested object, and the non-dot matrix center points of the indicator red light are distributed in an equidistant matrix within the region of interest. Figure 2 As shown, the laser Doppler assembly 400 includes at least two Doppler vibrometers 401 , and the at least two Doppler vibrometers 401 are arranged in a matrix in front of the quartz heating chamber 500 . Figure 5 The projection of the red indicator light of the Doppler vibrometer on the object being measured is shown.

[0058] Embodiment 2:

[0059] The embodiment of the present invention provides a method for identifying full-field dynamic modal parameters of a specimen in a high temperature environment. Based on the full-field dynamic modal parameter identification device for a specimen in a high temperature environment described in Example 1, the method comprises the following steps:

[0060] Step 1: Fix the fixture base to the tabletop of the vibration table.

[0061] Step 2: Place the quartz heating chamber on an external load-bearing frame. The quartz heating chamber has an opening at the bottom. Align the center of the opening with the center of the base. Pass the fixture column through the bottom opening of the quartz heating chamber and install it on the fixture base. Then install the upper part of the fixture.

[0062] Step 3: Fix the object to be tested to the constructed fixture.

[0063] In this embodiment, the target material is GH3030 (GH3030 nickel-based alloy).

[0064] Step 4, installing a thermocouple for measuring temperature on a fixture, and placing the temperature measuring end of the thermocouple on and in contact with the observation surface of the object to be measured.

[0065] Step 5: The thermocouple is connected to the temperature display outside the heating chamber to monitor the temperature of the object under test in real time.

[0066] Step 6: Place the Doppler vibrometers in front of the quartz heating chamber in a matrix arrangement.

[0067] Step 7, turn on the red indicator light of the Doppler vibrometer, and adjust the relative position of the Doppler vibrometer according to the dot matrix of the red indicator light on the object to be measured, until the center point of the dot matrix is ​​located at the center of the region of interest of the object to be measured, and the remaining points are distributed in an evenly spaced matrix within the region of interest.

[0068] Step 8, open the control cabinet of the quartz heating chamber, and control the heating power of the quartz lamp and the temperature inside the quartz heating chamber by adjusting the power of the quartz heating chamber.

[0069] In this embodiment, the temperature in the quartz heating chamber is controlled at 300°C.

[0070] Step 9, open the vibration table connected to the fixture to apply external excitation to the object under test.

[0071] Step 10: The Doppler vibrometers arranged in a matrix start synchronously collecting data for 30 seconds.

[0072] Step 11, the collected data is subjected to Bayesian operational mode calculation to obtain a processed power spectrum density function and extract the natural frequency corresponding to the energy peak.

[0073] like Figure 7 As shown, it is the power spectrum density function diagram of GH3030 at 300℃.

[0074] Step 12: Arrange the vibration mode data corresponding to the extracted natural frequency in space and perform surface fitting according to the position of the Doppler vibrometer on the measured object to obtain complete dynamic modal parameters in a high temperature environment.

[0075] like Figure 8As shown, the vibration modes of the measured object corresponding to the first two energy peaks of the power spectrum of GH3030 at 300°C.

[0076] The above implementation modes are only used to illustrate the present invention, but not to limit the present invention. Ordinary technicians in the relevant technical field can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, all equivalent technical solutions also belong to the scope of the present invention. The patent protection scope of the present invention should be defined by the claims.

Claims

1. A full-field dynamic modal parameter identification device for a specimen in a high temperature environment, characterized in that: The invention comprises a fixture, a vibration table, an external load-bearing frame, a laser Doppler component, a quartz heating chamber, a quartz lamp, a thermocouple and a power controller, wherein the fixture is fixed on the vibration table, the quartz heating chamber is placed on the external load-bearing frame, an opening is arranged at the bottom of the quartz heating chamber, the fixture enables the test piece clamped by the fixture to be located in the quartz heating chamber through the opening, the thermocouple is arranged on the fixture, the temperature measuring end of the thermocouple is in contact with the test piece, at least two quartz lamps are arranged on the inner side wall of the quartz heating chamber, at least two quartz lamps form a quartz lamp array evenly distributed up and down, the quartz lamp is electrically connected to the power controller, the laser Doppler component is arranged in front of the quartz heating chamber, and the power controller is arranged outside the quartz heating chamber.

2. The full-field dynamic modal parameter identification device for a specimen in a high temperature environment according to claim 1, characterized in that: The clamp comprises a clamp base, a clamp column and a clamp frame, the upper end of the clamp base is fixedly connected to the lower end of the clamp column, and the upper end of the clamp column is fixedly connected to the clamp frame.

3. The full-field dynamic modal parameter identification device for a specimen in a high temperature environment as claimed in claim 2, characterized in that: The clamp frame includes a base, a first vertical plate and a second vertical plate. The first vertical plate and the second vertical plate are both fixedly connected to the upper end of the base. The lower end of the base is fixedly connected to the upper end of the clamp column. The first vertical plate and the second vertical plate are both arrayed with threaded holes.

4. The full-field dynamic modal parameter identification device for a specimen in a high temperature environment according to claim 1, characterized in that: It also includes a temperature display, which is electrically connected to the thermocouple to display the temperature signal collected by the thermocouple.

5. The full-field dynamic modal parameter identification device for a specimen in a high temperature environment according to claim 1, characterized in that: The laser Doppler assembly is used to emit an indicator red light to the tested object. The dot matrix center point of the indicator red light is located at the center of the region of interest of the tested object, and the non-dot matrix center points of the indicator red light are distributed in an equidistant matrix within the region of interest.

6. The full-field dynamic modal parameter identification device for a specimen in a high temperature environment as claimed in claim 5, characterized in that: The laser Doppler assembly includes at least two Doppler vibrometers, and the at least two Doppler vibrometers are arranged in a matrix in front of the quartz heating chamber.

7. A method for identifying full-field dynamic modal parameters of a specimen in a high temperature environment, characterized in that: Based on the full-field dynamic modal parameter identification device of a specimen in a high temperature environment according to any one of claims 1 to 6, the method comprises: Turning on the laser Doppler assembly, and making the center point of the dot matrix of the red light indicator emitted by the laser Doppler assembly located at the center of the region of interest of the tested object, and the non-dot matrix center points of the red light indicator distributed in a matrix with equal spacing within the region of interest; Controlling the heating power of the quartz lamp switch by the power controller to control the temperature in the quartz heating chamber; Turning on the vibration table to provide external excitation to the tested object; Using the laser Doppler component to collect vibration data; Based on the vibration data, a Bayesian operating mode calculation is performed to obtain a processed power spectrum density function and extract the natural frequency corresponding to the energy peak; According to the positions of the dot matrix points of the red light indicator emitted by the laser Doppler component on the tested object, the vibration mode data corresponding to the extracted natural frequency are arranged in space and surface fitting is performed to obtain the dynamic modal parameters under high temperature environment.

8. The method for identifying full-field dynamic modal parameters of a specimen in a high temperature environment as claimed in claim 7, characterized in that: Turning on the laser Doppler assembly, and making the center point of the dot matrix of the red light indicator emitted by the laser Doppler assembly located at the center of the region of interest of the tested object, and the non-dot matrix center points of the red light indicator are distributed in a matrix with equal spacing within the region of interest, specifically including: Turn on the red indicator light of the laser Doppler assembly, and adjust the relative position of the laser Doppler assembly according to the dot matrix of the red indicator light on the tested object until the center point of the dot matrix is ​​located at the center of the region of interest of the tested object, and the remaining points are distributed in an equidistant matrix within the region of interest.

9. The method for identifying full-field dynamic modal parameters of a specimen in a high temperature environment according to claim 7, characterized in that: Before turning on the laser Doppler assembly, the method further includes: Assemble a full-field dynamic modal parameter identification device for the test piece in the high temperature environment.

10. The method for identifying full-field dynamic modal parameters of a specimen in a high temperature environment according to claim 9, characterized in that: The steps of assembling the full-field dynamic modal parameter identification device of the test piece in the high temperature environment include: Fix the fixture base to the vibration table surface; Place the quartz heating chamber on an external load-bearing frame. The quartz heating chamber has an opening at the bottom. Align the center of the opening with the center of the fixture base. Pass the fixture column through the bottom opening of the quartz heating chamber and install and fix it on the fixture base. Install the fixture frame on the upper end of the fixture column. Fix the test piece on the constructed fixture; Installing a thermocouple on a fixture, with the temperature measuring end of the thermocouple placed on the observation surface of the test piece and in contact with the test piece; Connect the thermocouple to the temperature display outside the quartz heating chamber; The laser Doppler assembly is placed right in front of the quartz heating chamber, and a plurality of Doppler vibrometers included in the laser Doppler assembly are arranged in a matrix.

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