CN105067213A - Large-scale structure vibration characteristic test pulse excitation apparatus and application method thereof - Google Patents

Abstract

The invention belongs to a pulse excitation source excitation device, in particular to a pulse excitation device for a large-scale structure vibration characteristic test and a using method thereof. Technical solution: The device is designed as a suspended pendulum structure, which is convenient for personnel to operate and apply force; a series of matching hammer heads are designed and processed, which can be applied to different structures in multi-frequency band tests; the vibration characteristics of large structures can be changed according to the requirements of the test. The way the device works, pulsed excitation signals are applied from multiple directions. Beneficial effects: the pulse excitation device and its use method designed by the present invention can be quickly and conveniently applied to the vibration characteristic test of large structures under field working conditions, providing transient excitation; and the acceleration amplitude of pulse excitation can be controlled and adjusted value and impact time. The technical problems of insufficient excitation energy, low frequency loading and rough frequency response curve of the existing vibration excitation device on large structures are solved.

Description

A large-scale structural vibration characteristic test pulse excitation device and its application method

technical field

The invention belongs to a pulse excitation source excitation device, in particular to a pulse excitation device for a large-scale structure vibration characteristic test and a using method thereof.

Background technique

Vibration characteristic test, also known as modal test, is to obtain the vibration response and frequency response function curve of the product structure through a specific type of excitation method, and analyze a series of structures including modal frequency, modal shape, modal mass, damping, etc. Inherent characteristic parameters can provide important data basis for structural anti-seismic vibration design, model correction and system control.

Large-scale launch vehicles, aircraft, building bridges and other engineering structures need to consider and solve system dynamics problems during the design process. By conducting modal tests on the project site, the vibration characteristic parameters of the structure under working conditions can be accurately and effectively obtained. When conducting field modal tests on large structures, it is necessary to have an excitation source that can provide low-frequency, large-scale levels. With the traditional vibrator, the excitation force cannot reach an effective magnitude and frequency due to problems such as the travel of the moving coil, the fixing of the base, and the time-consuming installation. However, the emerging time-domain non-excitation mode identification method has defects such as incomplete data acquisition and poor parameter identification accuracy, and the identified data cannot meet the requirements of product structure design. Therefore, there is a need for a fast, simple, effective, low-frequency, and large-scale excitation method that can obtain vibration characteristic parameters that meet large-scale structures at the engineering site.

Contents of the invention

The purpose of the present invention is to provide a large-scale structure vibration characteristic test pulse excitation device and its use method to address the technical problems of insufficient excitation energy, low-frequency load and rough frequency response curve of the existing vibration excitation device on large structures.

The technical scheme that realizes the object of the present invention:

A pulse excitation device for large-scale structural vibration characteristics test, including excitation hammer head, double-headed stud, load cell, sensor protection container, main rod transition adapter, main loading rod, operating handle and suspension clamp; excitation hammer head and The load cell is connected, the load cell is installed in the sensor protection container, and the sensor protection container is connected with the main loading rod through the main rod transition adapter; the suspension clamp is a two-petal structure, connected and fixed on the main loading rod for The entire pulse excitation device is suspended horizontally or vertically; one or more operating handles are fixed on the main loading rod.

Both ends of the main loading rod are equipped with a main rod transition adapter, and the main rod transition adapter at the other end of the main loading rod is connected to the extension push rod through the extension push rod connector.

The excitation hammer head is connected with the load cell through a double-ended stud.

The excitation hammer head includes a force transmission material and a base.

The hanging hoop is connected with the lifting device through lifting lugs.

The force transmission material is high molecular compound, high molecular polymer or metal material. If the structural frequency is within 0 to 100 Hz, the force-transmitting material is selected from polymer compounds; for the structural frequency of 80 to 600 Hz, the described force-transmitting material is selected from high-molecular polymers; Aluminum, nickel or other metallic materials.

The present invention also provides a test system of the above-mentioned large-scale structural vibration characteristic test pulse excitation device, including the structure to be tested, the device suspension system, the pulse excitation device, the test site fixed bracket, the data acquisition analyzer, and the signal transmission cable And the vibration sensor; the pulse excitation device is suspended on the fixed support of the test site through the device suspension system, and the vibration sensor is installed on the structure to be tested. The vibration sensor introduces the vibration signal into the data acquisition analyzer at the station through the signal transmission cable, and the pulse excitation The load cell of the device is connected with the data acquisition analyzer through the signal transmission cable.

The present invention also includes a method for using the above-mentioned large-scale structural vibration characteristic test pulse excitation device, which is characterized in that it includes the following steps in sequence:

Step 1. Preparations

Step 1.1. According to the test object, select the load cell with the correct range and frequency response bandwidth, and perform calibration and verification on it;

Step 1.2, the assembly of the pulse excitation device, connect the excitation hammer head, load cell, main rod transition adapter and main loading rod in sequence, and install the auxiliary parts such as the operating handle and the extension push rod;

Step 1.3, determine the test station, assemble the data acquisition analyzer at the station according to the requirements;

Step 2. On-site installation work

Step 2.1, build a solid test site fixing bracket at the test site to hang the pulse excitation device;

Step 2.2. Install suspension clamps and lifting lugs at the center of gravity of the main loading rod of the pulse excitation device. The lifting lugs are connected to the suspension system of the device and suspended at the fixed bracket at the test site;

Step 2.3, according to the structural characteristics of the structure to be tested, install a vibration sensor at the position to be measured, and connect the signal transmission cable, and introduce the vibration signal into the data acquisition analyzer at the station;

Step 2.4, connect the force sensor to the signal transmission cable, and the signal transmission cable is introduced into the data acquisition analyzer at the test station to obtain the force signal;

Step 3. Stimulus and Response Channel Debug Work

Step 3.1. After the installation of the pulse excitation device is completed, carry out force channel debugging; observe whether the time-frequency curve of the force channel response obtained by the data acquisition analyzer meets the structural test requirements by impacting the structure to be tested, otherwise replace the corresponding excitation hammer head;

Step 3.2. Under the pulse excitation, the time-frequency curve of the structural vibration response can be obtained at the same time, and the data signals of each response channel are checked in turn whether they are normal, otherwise, the troubleshooting of the connection of each link is carried out;

Step 4. Test performed

Step 4.1. 2 to 4 operators hold the operating handle and use the pulse excitation device to hit the structure under test to obtain the pulse signal; this process should be repeated many times, and the normal data is selected for average processing to obtain a high-quality frequency response function ;

Step 4.2, replace different excitation positions and excitation directions, and obtain frequency domain data with a complete structure. At this time, it is necessary to repeat the work of step 4.1 until the data is obtained completely;

Step 5. End of test

Analyze the vibration characteristic parameters of the structure through the data obtained from the test in step 4.

The beneficial effects of the present invention are:

The invention solves the problems of insufficient excitation energy, inability to load at low frequencies, rough frequency response curves and the like on large-scale structures in the traditional vibration exciter excitation mode. The device is designed as a suspended pendulum structure, which is convenient for personnel to operate and apply force; a series of supporting hammer heads are designed and processed, which can be applied to different structures in multi-frequency band tests; the work of the device can be changed according to the needs of large-scale structure vibration characteristics tests In this way, pulse excitation signals are applied from various directions. The pulse excitation device and its use method designed by the present invention can be quickly and conveniently applied to the vibration characteristic test of large structures under field working conditions, providing transient excitation; and can control and adjust the acceleration amplitude and impact of pulse excitation time.

Description of drawings

Fig. 1 is the structural composition schematic diagram of the present invention;

Fig. 2 is the schematic diagram of horizontal excitation working state of the present invention;

Fig. 3 is a schematic diagram of the longitudinal excitation working state of the present invention;

Fig. 4 is the composition diagram of the test system of the pulse excitation device of the large-scale structural vibration characteristic test;

The power spectral density energy curve excited by the pulse excitation device during the test in Fig. 5;

Fig. 6 Time-domain amplitude diagram of the excitation force of the pulse excitation device during the test.

In the figure, 1-excitation hammer head, 2-stud stud, 3-load sensor, 4-sensor protection container, 5-main rod transition adapter, 6-main loading rod, 7-extended push rod connector, 8-extension push rod, 9-operating handle, 10-suspension clamp, 11-hanging lug, 201-tested structure, 202-device suspension system, 203-pulse excitation device, 204-test site fixing bracket, 205-data Acquisition analyzer, 206-signal transmission cable, 207-vibration sensor.

Detailed ways

The present invention will be described in further detail below in conjunction with the accompanying drawings and embodiments.

This embodiment provides a large-scale structural vibration characteristic test pulse excitation device, which belongs to the vibration excitation subsystem in the vibration characteristic test system. Its structural composition is shown in Figure 1, including excitation hammer head 1, double-headed stud 2, load cell 3, sensor protection container 4, main rod transition adapter 5, main loading rod 6, extension push rod connector 7, Extend the push rod 8, the operating handle 9, the suspension clamp 10 and the lifting lug 11. The working mode of the device includes horizontal and vertical excitation. Figure 2 and Figure 3 show the two working modes of the device. By changing the suspension position, the test structure can be excited in multiple directions.

The excitation hammer 1 is connected to the load cell 3 through the double-headed stud 2. The excitation hammer 1 is a replaceable section. The design of the excitation hammer 1 consists of a complete series, which is suitable for the dynamic characteristic test of different structures in multiple frequency bands. The excitation hammer 1 includes a force-transmitting material and a base that are fixedly connected; the force-transmitting material is in the shape of a ball head, and the force-transmitting material directly collides with the structure to be tested, and its mechanical properties play a decisive role in the quality of the test curve; usually, When the structural frequency is within 0 to 100Hz, the force transmission material is made of high-elastic polymer compound; for the structural frequency of 80 to 600Hz, the force transmission material is made of slightly harder polymer; for the structural frequency of 500 to 2000Hz, the force transmission material is copper Metal materials such as aluminum or nickel are used as hammer heads;

The base of the excitation hammer head 1 is cylindrical, which can be matched with the hammer head. It is fixedly connected with the force sensor 3 through the stud 2. When the excitation hammer head 1 needs to be replaced, it is only necessary to disconnect the stud 2 and The connection of the base can be disassembled, and the operation is convenient and quick.

The load cell 3 is installed in the sensor protection container 4 to prevent the test force signal from being disturbed by the outside; the size, type, range and frequency response range of the load cell 3 are designed and selected according to the characteristics of the structure to be tested.

The upper part of the sensor protection container 4 is a cylindrical structure, the side wall of the cylinder has a gap, and the lower part has a cylindrical structure with external threads. lead out.

The main loading rod 6 is the main body of the pulse excitation device. The main loading rod 6 is a solid cylinder, and the two bottom surfaces respectively have metric coarse thread internal thread holes for connecting the main rod transition adapter 5 .

The main rod transition adapter 5 is a two-stage stepped coaxial cylinder, and one end of the protrusion is fixedly connected with the main loading rod 6 through a metric coarse thread; the bottom surface of the other end of the main rod transition adapter 5 is processed with an internal thread hole. It is used to connect with the rest of the device; one main rod transition adapter 5 is connected with the sensor protection container 4, and the other is connected with the extension push rod connector 7.

The suspension clamp 10 is used to suspend the entire pulse excitation device horizontally or vertically to change the working mode of the pulse excitation device; the suspension clamp 10 is two semi-circular ring structures, which are fixed on the main loading rod 6 through screw connection; The ear 11 is connected to the lifting device, and the pulse excitation device of this embodiment can be used in different directions by changing the installation method of the lifting ear 11. As shown in Figure 2 and Figure 3, when the lifting ear 11 is installed vertically with the main loading rod 6 , for horizontal lifting, when the lifting lug 11 is installed in parallel with the main loading bar 6, it is vertical lifting.

The extension push rod 8 is a cylindrical structure, which is connected with the main rod transition adapter 5 at one end of the main loading rod 6 through the extension push rod connector 7 in the horizontal excitation mode, so as to ensure the control of the position of the loading point when the pulse excitation load is applied. , keep the balance of the device and improve the working range of the pulse excitation device; the extension push rod 8 is not installed in the vertical excitation mode.

The operating handle 9 is a cylindrical structure, fixedly installed on the main loading rod 6, and can be loaded by 2 to 4 people at the same time.

The pulse excitation device of this embodiment has been successfully applied to a new type of launch vehicle shooting range erected state modal test. Figure 4 is a composition diagram of the field test system of the pulse excitation device. In the figure, 201 is the launch vehicle rocket body/large structure, 202 203 is the large-scale structural vibration characteristic test pulse excitation device of the present invention, 204 is the test site fixed bracket, 205 is the data acquisition analyzer, 206 is the signal transmission cable, and 207 is the vibration sensor. The pulse excitation device is suspended on the fixed support of the test site through the device suspension system. A vibration sensor is installed on the structure to be tested. The vibration sensor introduces the vibration signal into the data acquisition analyzer at the station through the signal transmission cable. The sensor is connected with the data acquisition analyzer through the signal transmission cable. Figure 5 is the power spectrum energy curve obtained by the pulse excitation device multiple times, and the low frequency band of the energy can cover the lowest 0.05Hz; Figure 6 is the time domain amplitude curve of a certain excitation, and the pulse excitation force reaches 1.4E4N. The test data shows that the device of the present invention solves the problem of low-frequency and large-scale excitation force demand, and realizes the rapid installation and debugging of the excitation equipment. At the same time, the device fully complies with the launch safety operation guidelines of the launch vehicle shooting range, and fully meets the safety requirements of operators and rocket body equipment. .

The test operation steps of applying the pulse excitation device of the structural vibration characteristic test of this embodiment are: 1. Inspection and calibration of the test equipment; 2. Installation and wiring of the test sensor on the structure; 3. Installation of the on-site pulse excitation device; 4. Select the excitation hammer head, and debug the test channel; 5. The test is carried out, and the data is collected and obtained; 6. The dynamic characteristic parameters are analyzed; 7. After the test, the measurement excitation system is disconnected. The specific usage method is as follows:

Step 1. Preparations

a. According to the test object, select the load cell 3 with the correct range and frequency response bandwidth, and carry out calibration and verification on it.

b. Assembling the pulse excitation device, connect the excitation hammer head 1, the force sensor 3, the main rod transition adapter 5, and the main loading rod 6 in sequence, and install the auxiliary parts such as the operating handle 9 and the extension push rod 8.

c. Determination of the test station, assemble the data acquisition analyzer and other equipment at the station according to the requirements.

Step 2. On-site installation work

a. Build a stable support 204 at the test site to suspend the pulse excitation device; the distance between the support 204 and the tested structure 201 should be moderate to facilitate the normal operation of the pulse excitation device, and the specific form can be determined according to the site environment.

b. Install the suspension clamp 10 and the lifting lug 11 at the center of gravity of the main loading rod 6 of the pulse excitation device. The lifting lug 11 is connected with the device suspension system 202 and suspended at the fixed bracket 204 built on site.

c. According to the structural characteristics of the test object, correctly install the vibration sensor 207 at the key position, and connect the signal transmission cable 206, and introduce the vibration signal into the data acquisition analyzer 205 at the station.

d. Connect the load cell 3 inside the pulse excitation device to the signal transmission cable 206, and the signal transmission cable 206 is introduced into the data acquisition analyzer 205 at the test station to obtain force signals.

Step 3. Stimulus and Response Channel Debug Work

a. After the installation of the pulse excitation device is completed, debug the force channel; observe whether the time-frequency curve of the force channel response meets the structural test requirements by impacting the structure to be tested, otherwise replace the corresponding hammer head.

b. Under the pulse excitation, the time-frequency curve of the structural vibration response can be obtained at the same time, and the data signals of each response channel can be checked in turn whether it is normal, otherwise, the troubleshooting of the connection of each link can be carried out.

Step 4. Test performed

a. 2 to 4 operators hold the operating handle and use the pulse excitation device to hit the structure under test to obtain pulse signals; the impact should avoid continuous strikes, hysteresis and other conditions; this process should be repeated many times, and normal data should be selected for averaging processing to obtain high-quality frequency response functions.

b. Change different excitation positions and excitation directions to obtain frequency domain data with a complete structure. At this time, it is necessary to repeat the steps until the data is obtained completely.

Step 5. End of test

a. Analyze the vibration characteristic parameters of the structure through the data obtained through the test.

b. After confirming that the data is correct, withdraw the pulse excitation device at the test site; disconnect and recover all channel cables.

The advantages of the large-scale structural vibration characteristic test pulse excitation device of this embodiment are:

Using specially made excitation hammer head force transmission material, the magnitude of pulse excitation force can reach 10E4N.

According to the stiffness characteristics of the structure to be tested, by changing different excitation hammer heads 1, the effective range of pulse excitation energy in the frequency domain can reach 0.1-1000 Hz.

The device of the invention has two working modes, which can meet the requirements of different excitation positions of large-scale structures in the field, so as to obtain frequency response functions of vibration characteristics with complete structures.

Compared with the traditional vibration exciter excitation method, it is more convenient and faster to use the pulse excitation device for the vibration characteristic test on the engineering site of a large structure, which reduces the installation and debugging time of the test excitation equipment.

The present invention omits the power amplification link, and the excitation device does not need to be driven by strong alternating current, adopts a direct current power supply mode, and has high reliability and safety.

Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. If these modifications and variations fall within the scope of the claims of the present invention and their equivalent technologies, the present invention also intends to include these modifications and variations.

Claims (9)

1. A large-scale structural vibration characteristic test pulse excitation device is characterized in that: it includes an excitation hammer (1), a stud (2), a load cell (3), a sensor protection container (4), and a main rod transition Adapter (5), main loading rod (6), operating handle (9) and suspension clamp (10); The excitation hammer head (1) is connected with the load cell (3), the load cell (3) is installed in the sensor protection container (4), and the sensor protection container (4) is connected to the main loading rod through the main rod transition adapter (5). (6) connection; the suspension clamp (10) is a two-lobe structure, which is connected and fixed on the main loading rod (6), and is used to suspend the whole pulse excitation device horizontally or vertically; the main loading rod (6) is fixed with One or more operating handles (9). 2. A kind of large-scale structural vibration characteristic test pulse excitation device as claimed in claim 1, is characterized in that: the two ends of described main loading rod (6) are all equipped with main rod transition adapter (5), and main loading rod (6) The main rod transition adapter (5) at the other end is connected with the extension push rod (8) through the extension push rod connector (7). 3. A large-scale structural vibration characteristic test pulse excitation device according to claim 1 or 2, characterized in that: the excitation hammer head (1) is connected to the load cell (3) through a stud (2) . 4. A large-scale structural vibration characteristic test pulse excitation device according to claim 1 or 2, characterized in that: the excitation hammer head (1) includes a force-transmitting material and a base. 5. A large-scale structural vibration characteristic test pulse excitation device according to claim 1 or 2, characterized in that: the suspension clamp (10) is connected to the lifting device through a lifting lug (11). 6. A pulse excitation device for large-scale structure vibration characteristic test according to claim 4, characterized in that: said force transmission material is high molecular compound, high molecular polymer or metal material. 7. The pulse excitation device for a large-scale structural vibration characteristic test as claimed in claim 6, characterized in that: the structural frequency is within 0 to 100 Hz, and the force transmission material is selected from polymer compounds; the structural frequency is 80 to 600 Hz, so The force transmission material is selected from high molecular polymer; the structural frequency is 500 to 2000 Hz, and the force transmission material is selected from copper, aluminum, nickel or other metal materials. 8. A test system of a large-scale structural vibration characteristic test pulse excitation device as claimed in claim 1, characterized in that: comprise a structure to be tested (201), a device suspension system (202), a pulse excitation device (203), a test On-site fixed bracket (204), data acquisition analyzer (205), signal transmission cable (206) and vibration sensor (207); the pulse excitation device (203) is suspended on the test site fixed bracket (204) through the device suspension system (202) ), a vibration sensor (207) is installed on the tested structure (201), and the vibration sensor (207) introduces the vibration signal into the data acquisition analyzer (205) at the station through the signal transmission cable (206), and the pulse excitation device The load cell (3) of (203) is connected with the data acquisition analyzer (205) through the signal transmission cable (206). 9. A method for using the large-scale structural vibration characteristic test pulse excitation device as claimed in claim 1, characterized in that it comprises the following steps in sequence: Step 1. Preparations Step 1.1, according to the test object, select the load cell (3) with the correct range and frequency response bandwidth, and perform calibration and verification on it; Step 1.2, the assembly of the pulse excitation device, connect the excitation hammer head (1), load cell (3), main rod transition adapter (5) and main loading rod (6) in sequence, and install the operating handle (9) and Extend the push rod (8) to these accessories; Step 1.3, determine the test station, assemble the data acquisition analyzer (205) at the station as required; Step 2. On-site installation work Step 2.1, build a solid test site fixing bracket (204) at the test site to suspend the pulse excitation device (203); Step 2.2. Install the suspension clamp (10) and lifting lug (11) at the center of gravity of the main loading rod (6) of the pulse excitation device. The lifting lug (11) is connected to the suspension system (202) of the device and suspended on the test site to fix the bracket ( 204); Step 2.3, according to the structural characteristics of the tested structure (201), install the vibration sensor (207) at the position to be measured, and connect the signal transmission cable (206), and introduce the vibration signal into the data acquisition analyzer (205) at the station )Inside; Step 2.4, connect the force sensor (3) to the signal transmission cable (206), and the signal transmission cable (206) is introduced into the data acquisition analyzer (205) at the test station to obtain the force signal; Step 3. Stimulus and Response Channel Debug Work Step 3.1, after the installation of the pulse excitation device (203) is completed, the force channel debugging is carried out; by impacting the tested structure (201), observe whether the time-frequency curve of the force channel response obtained by the data acquisition analyzer (205) meets the structural test requirements , otherwise replace the corresponding excitation hammer head (1); Step 3.2. Under the pulse excitation, the time-frequency curve of the structural vibration response can be obtained at the same time, and the data signals of each response channel are checked in turn whether they are normal, otherwise, the troubleshooting of the connection of each link is carried out; Step 4. Test performed Step 4.1, 2 to 4 operators hold the operating handle (9), use the pulse excitation device (203) to hit the structure under test (201), and obtain the pulse signal; this process should be repeated many times, and the normal data is selected for averaging processing to obtain high-quality frequency response functions; Step 4.2, replace different excitation positions and excitation directions, and obtain frequency domain data with a complete structure. At this time, it is necessary to repeat the work of step 4.1 until the data is obtained completely; Step 5. End of test Analyze the vibration characteristic parameters of the structure through the data obtained from the test in step 4.