CN106908096A - Ultralow frequency simple harmonic oscillation displacement and stretch bending composite strain comprehensive test device - Google Patents

Abstract

The invention provides an ultra-low frequency simple harmonic vibration displacement and tensile-bending composite strain comprehensive test device, which is composed of a frame structure and two sets of mechanisms on the frame bottom plate. One set consists of two sets of centering crank slider mechanisms, one adjustable speed motor and a pair of test workpieces vertically suspended on the frame structure through plate beam hooks; the other set consists of simple harmonic vibration mechanism, one adjustable It consists of a high-speed motor and a test workpiece vertically suspended on the frame structure through the plate beam hook. The test workpiece is equipped with a weight set, and the test workpiece can be loaded by putting the weight on the weight tray. The invention not only can generate simple harmonic vibration displacement and tension-bending compound strain signals with controllable frequency and amplitude, but also realizes synchronous comparison between multi-frequency signals and single-frequency signals.

Description

Comprehensive test device for ultra-low frequency simple harmonic vibration displacement and tensile bending composite strain

technical field

The invention relates to an ultra-low frequency dynamic, static, and dynamic test system, in particular to an ultra-low frequency simple harmonic vibration displacement and tensile-bending compound strain comprehensive test device.

Background technique

At present, the frequency of ultra-low frequency displacement vibration and tensile and bending composite strain test devices is not single enough, and the signal collection is relatively monotonous.

Ultra-low frequency displacement vibration and tensile and bending compound strain test device adopts mechanical mechanism to make parts produce reciprocating motion. Since the motion stroke and frequency of the driving mechanism are known, it can provide a vibration signal with known amplitude and frequency, but this device generates a multi-frequency signal, which means that the signal can be divided into different frequency bands in the frequency domain. Each frequency band has its own center frequency. Generally, it is difficult to see it from the time domain, and it can only be analyzed from the frequency domain.

The existing ultra-low frequency displacement vibration and tensile and bending composite strain test device can provide ultra-low frequency vibration displacement and strain physical signals for comprehensive vibration and strain tests, as well as debugging and calibration of test systems or instruments, but the signal collection line is relatively simple. The analysis and comparison of multi-channel signal collection cannot be provided, so the accuracy and stability of the collected signals cannot be determined.

Contents of the invention

The purpose of the present invention is to overcome the defects of the prior knowledge and provide a comprehensive test platform for ultra-low frequency simple harmonic vibration and tensile and bending composite strain. The test device can not only generate simple harmonic vibration single-frequency signals with controllable frequency and amplitude, but also can synchronously compare and analyze multi-frequency signals and single-frequency signals, and can also generate dynamic and static strain stress signals with controllable frequency and strain. And the device can also be used as a calibration platform to provide standard ultra-low frequency simple harmonic vibration and strain physical signals for the debugging and calibration of test systems or instruments. By changing the number and installation position of the acceleration sensors, the device can also realize the synchronous measurement of the two-axis acceleration of the simple harmonic vibration mechanism.

The technical solution adopted in the present invention is: the main body of the test device is a steel frame structure with a certain quality and a stable foundation. A plate girder hook is fixed at one end, and the connecting line of two plate girder hooks at the same end on different upper beams is perpendicular to the upper beam. The steel frame structure is set on the frame bottom plate, and two sets of mechanisms are arranged on the frame bottom plate. One set is composed of two sets of centering crank slider mechanisms and the first adjustable speed motor. The output shaft of the first adjustable speed motor is parallel to the upper beam, and the distance from the two upper beams is equal. In the initial position state, Two sets of centering crank slider mechanisms are symmetrical about the output shaft of the first adjustable speed motor. The other set consists of a simple harmonic vibration mechanism and a second adjustable speed motor with the same parameters. The second adjustable speed motor is arranged opposite to the first adjustable speed motor, and its output shaft is also parallel to the upper beam. The first adjustable speed motor and the second adjustable speed motor are fixed through screw holes on the frame bottom plate. The screw holes on the bottom plate of the frame are evenly distributed at intervals of 20mm×20mm. Motors of different sizes can be fixed on the bottom plate through appropriate screw holes. Therefore, the model of the motor can be selected according to the test needs, so as to meet the requirements of different speed ranges. At the same time, different auxiliary equipment can also be configured to meet different experimental needs.

The simple harmonic vibration mechanism is composed of the second adjustable speed motor, crank, linear bearing, short optical axis frame and long optical axis, slider and track, sensor mounting frame and several brackets, and its structure is composed of: the second adjustable speed The output shaft of the motor is parallel to the upper beam, and the distance between the two upper beams is equal, the output shaft is connected to the crank, the crank is connected to the short optical axis frame through the bearing, the short optical axis frame is fixedly connected to the long optical axis, and the short optical axis frame is composed of The slider on the track is supported, the long optical axis is supported by a bracket and linear bearings, and the long optical axis can be connected with the test workpiece.

The test workpiece is hung vertically on the steel frame structure in the form of free suspension or bolt fastening through plate beam hooks. The basic shape of the test workpiece is fixed, and the size and material are variable. The test workpiece is equipped with a weight kit, put the weight on the weight tray to load the test workpiece, the load is every 500N, and the range is from 0-3000N. Fix the test workpiece on the frame structure, and at the same time connect the test workpiece and the long optical axis at the front end of the simple harmonic vibration mechanism through the connecting rod, so that the test workpiece is just perpendicular to the ground, turn on the speed regulating motor to drive the crank to rotate, and the crank is driven by the linear bearing The short optical axis frame slides on the track with the slider, the long optical axis connected to the short optical axis frame is supported by a linear bearing and reciprocates with the short optical axis frame, and the test workpiece is forced to vibrate under the push of the connecting rod , resulting in simple harmonic vibration in the axial direction of the long optical axis and composite tensile-bending strain of the test workpiece.

In the test, the motor can be adjusted from the static state (0Hz) to the rated speed of the motor. The speed of the motor determines the size of the vibration frequency. By configuring the laser sensor, the rotation cycle of the motor can be accurately measured, so as to obtain the vibration frequency and realize the known generation frequency. The purpose of ultra-low frequency simple harmonic vibration and tension-bend composite strain. If acceleration sensors are respectively arranged in the axial and radial directions of the long optical axis, synchronous measurement of two-axis acceleration signals can be realized. In addition, the vibration of the simple harmonic vibration mechanism and the center crank slider mechanism can be compared, and the connection and difference between the multi-frequency signal and the single-frequency signal can be analyzed simultaneously.

Beneficial effect

The invention has the beneficial effects of combining the functions of the simple harmonic vibration signal generator and the tension-bend compound strain signal generator, in addition to the conventional static strain test, the generation of ultra-low frequency physical signals can be realized by adjusting the motor speed, which is The ultra-low frequency structural vibration and strain test system provides a platform for debugging and calibration. In addition, it can also perform synchronous measurement of two-axis acceleration, and synchronous comparison and analysis of multi-frequency signals and single-frequency signals. It has great potential in the fields of vibration teaching tests and large-scale structural engineering tests. High applicability.

Description of drawings

Fig. 1 is the general structure diagram of the test device of the present invention, and the I region represents the slider crank mechanism, and the II region represents the simple harmonic vibration mechanism;

Fig. 2 is the front view of test device of the present invention;

Fig. 3 is the left view of test device of the present invention;

Fig. 4 is the A-A direction view of Fig. 2 test device of the present invention, shows slider crank mechanism, and A-A is Fig. 2 at the center line to the left section line;

Fig. 5 is the B-B direction view of Fig. 1 test device of the present invention, represents the simple harmonic vibration mechanism, and B-B is Fig. 1's section line to the right at the midline;

In the figure, I crank slider mechanism, II simple harmonic vibration mechanism, 1 upper beam, 2 upper reinforced beam, 3 upper bracket, 4 legs, 5 lower beam, 6 bottom plate, 7 test workpiece, 8 plate hook, 9 weight Code hook, 10 laser sensor, 11 weight rod, 12 weight tray, 13 first motor spindle, 14 motor bracket, 15 guide rail bracket, 16 guide rail, 17 second adjustable motor, 18 crank, 19 long optical axis straight line Bearing, 20 long optical axis, 21 guide rail slider, 22 sensor mounting bracket, 23 low frequency acceleration sensor, 24 displacement sensor magnetic axis, 25 magnetostrictive displacement sensor, 26 linear bearing, 27 short optical axis, 28 short optical axis frame, 29 guide rail seat (including guide rail), 30 fastening device, 31 ejector rod, 32 slider, 33 connecting rod, 34 disc (crank), 35 first adjustable motor, 36 capacitive acceleration sensor.

detailed description

Specific embodiments will be described with reference to the accompanying drawings.

Example 1: Comprehensive test device for ultra-low frequency simple harmonic vibration displacement and tensile-bending composite strain

As shown in Figure 1 and Figure 2, the steel frame structure with certain quality and solid foundation is composed of outrigger 4, lower beam 5, bottom plate 6, upper bracket 3, and upper reinforcement beam 2. The steel frame structure with stable foundation hangs the test workpiece 7 vertically on an upper beam 1 with only one fixed plate hook 8 at one end, and configures weight accessories (including weight hook 9 and weight support rod 11) on the test workpiece and weight tray 12), the lower end of the test workpiece is connected to the top of the long optical axis 20, as shown in Figure 1, the simple harmonic vibration mechanism II and the second adjustable motor 17 are arranged on the frame bottom plate, and the output shaft of the second adjustable motor The upper beam 1 is parallel to the two upper beams at the same distance, and the output shaft is connected to the crank 18, as shown in Figure 5. The crank is connected to the short optical axis frame 28 through a linear bearing 26 and a short optical axis 27. The middle and long optical axis 20 is fixedly connected, the short optical axis frame 28 is supported by the guide rail bracket 15 and the guide rail slider 21 on the guide rail 16, and the long optical axis 20 is supported by a bracket and a linear bearing 19, and is connected with the test workpiece 7. The magnetic axis 24 of the displacement sensor of the magnetostrictive displacement sensor 25 is placed parallel to the long optical axis 20, and the magnetic ring is installed through the sensor bracket 22 at the top of the long optical axis to form a closed loop. The low-frequency acceleration sensor 23 and the capacitive acceleration sensor 36 are fixedly connected to the sensor bracket 22 at the axial end of the long optical axis 20 . The laser sensor 10 is placed parallel to the second adjustable motor 17 , corresponding to the reflector on the crank 18 . As shown in Fig. 1, the slider crank mechanism 1 and the first adjustable motor 35 are arranged on the frame bottom plate of the steel frame structure with solid foundation, and the first adjustable motor 35 is supported by the motor bracket 14 and is opposite to the second adjustable motor 17 Arrangement, the first motor spindle 13 is parallel to the upper beam 1, the first motor spindle 13 is connected to the disc (crank) 34, and the disc (crank) 34 is connected to the slider 32 on the guide rail seat (including the guide rail) 29 through the connecting rod 33 The slide block is connected with the test workpiece through the push rod 31 and the fastening device 30 .

Embodiment 2: Two-axis acceleration signal synchronous measurement device

Simple harmonic vibration mechanism II and the second adjustable motor 17 are arranged on the frame base plate as shown in Figure 1, the output shaft of the second adjustable motor 17 is parallel to the upper beam 1, and the output shaft is connected with the crank 18, as shown in Figure 5. The short optical axis frame 28 is connected, the short optical axis frame 28 is fixedly connected with the long optical axis 20, the short optical axis frame 28 is supported by the guide rail slider 21 on the guide rail 16, the long optical axis 20 is supported by a bracket and a linear bearing 19, and Connect with the sensor mounting frame 22 as shown in FIG. 5 .

Describe the usage of specific functions.

Usage 1: Comprehensive test of ultra-low frequency simple harmonic vibration displacement and tensile bending composite strain

According to embodiment one, at first as shown in Figure 2, the test workpiece 7 is suspended on the crossbeam by the plate hook 8, and its lower end is connected with the top of the long optical axis 20, and the test workpiece is adjusted so that it is perpendicular to the ground, and then the test workpiece 7 shown in Figure 5 The medium and low frequency acceleration sensor 23 and the capacitive acceleration sensor 36 in Fig. 1 are installed and fixed on the sensor mounting frame 22 in Fig. 5, the magnetostrictive displacement sensor 25 in Fig. 5 is placed in the effective range, and the laser sensor 10 in Fig. 2 is aligned , install the strain gauge on the test workpiece, and connect the test equipment. After setting the relevant parameters in the software, start the second adjustable motor 17 in Figure 1 to drive the crank 18 to rotate, and the crank 18 drives the short optical axis frame 28 and the long optical axis 20 to move together through the linear bearing 26 in Figure 5 connected to it , a simple harmonic vibration signal is generated in the axis direction of the long optical axis, and at the same time, the test workpiece 7 undergoes forced simple harmonic vibration under the push of the long optical axis 20 to generate a composite tension-bending strain signal. If the motor speed is below 60r/min, the test device can provide ultra-low frequency displacement simple harmonic vibration below 1Hz. The amplitude of the displacement vibration can be controlled by adjusting the connection point between the crank 18 and the connecting rod. The test device provides three levels of amplitude, which are 2cm, 4cm and 6cm. In this way, the test device can provide simple harmonic vibrations of different frequencies and amplitudes and dynamic composite strain signals of different sizes.

Usage 2: Synchronous measurement of two-axis acceleration signals

According to the second embodiment, the test workpiece 7 is first removed, and two acceleration sensors are arranged on the sensor mounting frame 22, one is located in the axial direction of the long optical axis 20, and the other is located in the radial direction of the long optical axis 20, and the second adjustable motor 17 is turned on. The axial and radial vibration acceleration signals of the long optical axis of the simple harmonic vibration mechanism can be measured synchronously.

Usage three: ultra-low frequency simple harmonic vibration displacement test.

Using Example 1, first release the fastening device of the test workpiece and place it aside. Then install and fix the low-frequency acceleration sensor 23 and the capacitive acceleration sensor 36 on the sensor mounting frame 22, place the magnetostrictive displacement sensor 25 in the effective range, align the laser sensor 10, and connect the test equipment. After setting the relevant parameters in the software, start the second adjustable motor 17 to drive the crank 18 to rotate, and the crank drives the short optical axis frame 28 and the long optical axis 20 to move together through the linear bearing connected to it, in the axial direction of the long optical axis Generate a simple harmonic vibration signal. The simple harmonic vibration signal can be measured by the sensor installed on the sensor mounting frame at the top of the long optical axis. The frequency of simple harmonic vibration is achieved by changing the speed of the motor. The amplitude of the displacement vibration can be controlled by adjusting the connection point of the crank and the connecting rod. In this way, the test device can provide simple harmonic vibration signals of different frequencies and different amplitudes, and the simple harmonic vibration signals can be collected and analyzed by the test equipment.

Usage 4: Synchronously compare the test signals of two vibration devices

Using Embodiment 1 and as shown in Figure 1 and Figure 4, arrange the centering crank slider mechanism 1 on the frame bottom plate, then remove the test workpiece 7, and fix each sensor at the corresponding position, connect the test equipment, and set it up corresponding parameters. Turn on the first adjustable motor 35 and the second adjustable motor 17 at the same time, and adjust the motor speed to be consistent. At this time, the physical signals of simple harmonic vibration and crank slider vibration can be obtained at the same frequency for synchronous comparison.

Usage 5: Calibration of acceleration sensor under ultra-low frequency simple harmonic vibration

Using Embodiment 1, the test workpiece is removed first, and then the acceleration sensor to be calibrated is installed and fixed on the sensor mounting frame 22. At the same time, the magnetostrictive displacement sensor 25 is placed in the effective range, and the test equipment is connected. After setting the relevant parameters in the software, start the motor. The displacement is calculated by the measured acceleration signal, and then compared with the measured displacement signal, so as to realize the calibration of the acceleration sensor.

Claims (2)

1. a kind of ultralow frequency simple harmonic oscillation displacement and stretch bending composite strain comprehensive test device, it is characterised in that with certain mass And the firm steel framework structure in basis, on its two entablatures, a plate-girder hook is fixed at an entablature two ends respectively, Another entablature only fixes a plate-girder hook at one end, what two plate-girders positioned at same end on different entablatures were linked up with Line is orthogonal with entablature；Liang Tao mechanisms are arranged on chassis base；A set of mechanism is by two groups of centric slider-crank mechanisms With the first adjustable speed motor composition, the output shaft of the first adjustable speed motor is parallel with entablature, and with two distances of entablature Equal, under initial position, two groups of centric slider-crank mechanisms export axial symmetry on the first adjustable speed motor；It is another set of Second adjustable speed motor of the mechanism by simple harmonic oscillation mechanism and parameter as the first adjustable speed motor is constituted, and second is adjustable Speed motor is positioned opposite with the first adjustable speed motor, and its output shaft is equally parallel with entablature；First adjustable speed motor and second Adjustable speed motor is fixed by the screw on chassis base；Simple harmonic oscillation mechanism for testing is by the second adjustable speed motor, crank, straight line Bearing, short optical axis framework and optical axis long, sliding block and track, magnetostrictive displacement sensor, low-frequency acceleration sensor, electric capacity add Velocity sensor, laser sensor, sensor mount and some supports are constituted；The output shaft of the second adjustable speed motor and upper horizontal stroke Liangping row, and it is equal with the distance of two entablatures, output shaft is connected with crank, and crank is connected by bearing with short optical axis framework Connect, short optical axis framework is fixedly connected with optical axis long, short optical axis framework by the slider support on track, optical axis long by a support and Linear bearing is supported, and optical axis long can be connected with test piece；Magnetostrictive displacement sensor is placed in parallel with optical axis long, by length The sensor stand on optical axis top installs magnet ring, forms closed loop；Low-frequency acceleration sensor and capacitance acceleration sensor Sensor stand with optical axis long axial direction top is mutually fixedly connected；Laser sensor placement parallel with the second adjustable motor, with Reflecting piece on crank is corresponding.

2. ultralow frequency simple harmonic oscillation displacement as claimed in claim 1 and stretch bending composite strain comprehensive test device, its feature exist In in optical axis radial arrangement acceleration transducer long.