KR101213752B1 - Active mass damper system for controlling vibration of vertical direction - Google Patents

Abstract

PURPOSE: An AMD(Active Mass Damper) system for controlling vibration a vertical direction is provided to generate the vertical reciprocating motion of a movable mass body, thereby proving the vibration control performance of an AMD by performing a vibration control with respect to the vertical direction. CONSTITUTION: An AMD system for controlling vibration a vertical direction comprises an AMD(20), a plurality of displacement meters(30), and a controller. The AMD comprises a jig, a ball screw, a movable mass body, a driving motor, and a driver. The jigs are fixed to both side ends and a central portion of the bridge testing model and the ball screw is vertically installed in the jig. The movable mass body is installed in the ball screw, thereby vertically moving by the rotation of the ball screw. The driving motor is rotated and reversely rotated according to external driving signals. The driver generates the driving signals depending on an external control, thereby rotating the driving motor. The displacement meter measures the displacement of the bridge testing model. The controller generates vertical reciprocating motion by operating the AMD according to offset oscillation frequency which phase is opposite to natural frequency after extracting oscillation frequency to the vertical direction of the bridge testing model by using the signals measured by the displacement meter.

Description

ACTIVE MASS DAMPER SYSTEM FOR CONTROLLING VIBRATION OF VERTICAL DIRECTION}

The present invention relates to an AMD system for vertical vibration damping. Specifically, AMD is installed at both ends of a bridge experimental model mounted on a wind tunnel tester, and the magnitude of vertical vibration of the bridge experimental model generated by wind is measured by a laser displacement meter. After extracting the vertical vibration frequency using the measured signal, input the signal to the AMD drive motor according to the offset vibration frequency which is in phase opposite to the natural frequency to generate the vertical reciprocating motion of the moving mass. The present invention relates to an AMD system for vertical vibration damping that can perform damping to demonstrate AMD's damping performance.

The bridge, which plays an important role as a means of transportation, consists of a bridge and a top plate installed on the top of the bridge. Such bridges are constructed by installing bridges at regular intervals along the length and placing top plates between the bridges.

The recent construction trend of bridges is in the direction of minimizing the obstacles caused by the flow velocity while providing aesthetics and symbolism.

Therefore, in view of the above point of view, it is often constructed in the form of a cable bridge such as a long cable-stayed bridge or a suspension bridge between bridges and bridges.

As long bridges are preferred for long bridges, it is possible to minimize floating in the bridge even if heavy rain occurs during the rainy season. This is because the aesthetics are excellent.

However, as described above, long bridges between bridges are disadvantageously affected by wind loads, and thus, bridges manufactured by incorrect designs may be collapsed by typhoons and strong winds.

In particular, in recent years, a huge typhoon caused by global warming is frequently occurring around the world, and as mentioned above, the bridge is also a bridge to be constructed in the design stage before constructing an expensive bridge in the reality that the construction of the long bridge is increasing. It is very important to be able to know wind loads generated by the test in advance in order to secure the wind resistance of the bridge.

For this reason, it is a reality that large construction companies, which are receiving orders for large-scale bridges all over the world, possess their own wind tunnel test facilities or rent wind tunnel test facilities from test institutes. Wind loads are measured and reflected in the design to design and construct a safe bridge with wind safety.

Wind tunnel test of the bridge is to make a model in which the bridge is reduced to a certain ratio, install the reduced model inside the wind tunnel, and apply wind pressure to the model to observe the wind load and deformation of the model.

Representative examples of wind tunnel tests include dynamic response measurement and static aerodynamic force coefficient measurement. The dynamic response measurement measures the vibration displacement of the cross section for each angle, and the static aerodynamic force coefficient is the static load and moment of the cross section according to the angle of attack. By measuring, drag, lift, and moment coefficients are calculated.

The above experiments require a separate tester different from each other due to the characteristics of the test, and thus, the wind tunnel laboratory may have a wind tunnel test smoothly only if it is provided with a suitable tester for each test.

In addition, the scale model of the bridge to be tested also continues to deform as the bridge is designed to change, and in order to attach the deformed scale model to the tester, there is a difficulty that the tester must be partially modified to fit the scale model.

In addition, attaching the scale model to the tester inside the wind tunnel for the wind tunnel test has a problem that the wind tunnel test cannot be performed while the scale model is installed.

In addition, an unexpected turbulence may occur during the wind tunnel test due to the shape of the tester, and the turbulence has a problem in that accurate data cannot be obtained because the error range is enlarged in the experimental data.

In order to solve the above problems, a tester for the wind tunnel test was filed and registered by the present applicant, Korean Patent Registration No. 10-0969242 (mobile wind tunnel tester for bridge).

1 and 2, the movable wind tunnel tester 1 for the bridge includes a main frame 100 and a moving frame 200 which is moved to both sides within the main frame 100, and the moving frame 200. Wheel 300 is installed on the side of the wheel and the wheel rotating device 400 for rotating the wheel 300, the width adjusting device 500 for moving the moving frame 200 to both sides of the main frame 100 and In the wind tunnel test, turbulence is generated by the moving frame 200 and the wheel 300, and the duct 600 prevents an error from occurring in the experimental data.

However, in recent years, as the bridge becomes longer and longer, the application of various vibration damping devices for vibration control has been examined. In fact, it is required to increase the performance through a scaled-up model experiment.

Domestic Patent Registration No. 10-0969242

The present invention is to meet the above requirements, the AMD is installed in each of the center of both ends of the bridge experimental model mounted on the wind tunnel tester, and the vertical size of the bridge experimental model generated by the wind is measured by a laser displacement meter, After extracting the vertical vibration frequency by using the measured signal, the input signal is given to the AMD drive motor according to the offset vibration frequency opposite to the natural frequency and generates vertical reciprocating motion of the moving mass to perform vibration damping in the vertical direction. The aim is to provide an AMD system for vertical vibration damping that can demonstrate the vibration damping performance.

According to an aspect of the present invention,

1. A wind tunnel tester for installing a wind tunnel test by installing a bridge model, each of which is installed at the centers of both ends of the bridge model to generate damping force by using a vertical reciprocating motion; A plurality of displacement measuring means installed in the wind tunnel tester so as to be spaced apart from each other at adjacent positions of the bridge test model to measure the displacement of the bridge test model; And a control means for generating vertical reciprocating motion by extracting the vertical vibration frequency of the bridge experimental model using the signal measured by the displacement measuring means, and then driving the AMD according to the offset vibration frequency opposite to the natural frequency. Characterized in that made.

Here, the AMD is a jig fixedly installed in the bridge experimental model; A ball screw installed in the vertical direction from the jig; A moving mass installed on the ball screw and moving up and down according to its rotation; A drive motor installed at an upper end of the ball screw and rotating forward and backward according to an external driving signal; And a driver for generating a drive signal and rotating the drive motor according to the control of the control means.

Here, the ball screw is further provided with a limit switch at both ends, the moving mass is provided with a stopper in contact with the limit switch, when the stopper of the moving mass is in contact with the limit switch to operate the drive motor Stop it.

Here, the plurality of moving masses may be combined to set different moving masses.

Here, the displacement measuring means is a laser displacement device.

Here, the control means stores the offset vibration frequency corresponding to the extracted vibration frequency in the form of a look-up table.

According to the AMD system for vertical direction vibration damping of the present invention constituted as described above, AMD is respectively installed at the center of both ends of the bridge experimental model mounted on the wind tunnel tester, and the laser displacement meter is used to determine the vertical size of the bridge experimental model generated by the wind. After the vertical vibration frequency is extracted by using the measured signal, it is inputted to the AMD drive motor according to the offset vibration frequency that is out of phase with the natural frequency to generate vertical reciprocating motion of the moving mass. We can demonstrate the damping performance of AMD.

1 and 2 are views showing the configuration of a mobile wind tunnel tester for a general bridge.
Figure 3 is a perspective view schematically showing the appearance of the AMD system for vertical vibration damping according to the present invention applied to the mobile wind tunnel tester for the bridge.
4 is a perspective view showing the configuration of AMD in FIG.
FIG. 5 is a schematic diagram schematically illustrating FIG. 3.
6 is a block diagram schematically illustrating the configuration of an AMD system for vertical direction vibration suppression according to the present invention.

Hereinafter, the configuration of the AMD system for vertical direction vibration isolation according to the present invention will be described in detail with reference to the accompanying drawings.

In the following description of the present invention, detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. The following terms are defined in consideration of the functions of the present invention, and may be changed according to the intentions or customs of the user, the operator, and the like. Therefore, the definition should be based on the contents throughout this specification.

FIG. 3 is a perspective view schematically showing a state in which the AMD system for vertical direction vibration isolation according to the present invention is applied to a mobile wind tunnel tester for a bridge, and FIG. 4 is a perspective view showing the configuration of AMD in FIG. 3, and FIG. 6 is a schematic diagram illustrating a configuration of an AMD system for vertical vibration suppression according to the present invention, and FIG. 7 is a graph for explaining the vibration frequency and the offset vibration frequency.

3 to 7, the AMD system 10 for vertical vibration damping according to the present invention includes an AMD 20, a displacement measuring means 30, and a control means 40.

First, as shown in FIGS. 3 and 4, the AMD 20 is vertically fixed to the jig 21 and the jig 21 fixedly installed at the centers of both ends of the bridge experimental model 3 fixedly installed in the wind tunnel tester 1. A ball screw 23 installed in the direction, a moving mass 25 installed on the ball screw 23 and moving up and down according to the rotation thereof, and a driver installed on the upper end of the ball screw 23 to be described below. A drive motor 27 which is rotated forward and backward according to the drive signal of 29 and a driver 29 which generates a drive signal and rotates the drive motor 27 according to the control of the control means 40 to be described below. . Here, the ball screw 23 is further provided with a limit switch 23a at both ends, the moving mass 25 is provided with a stopper 25a in contact with the limit switch 23a, the moving mass 25 is constant When the stopper 25a of the moving mass 25 comes into contact with the limit switch 23a by moving more than the displacement, the operation of the drive motor 27 is stopped to protect the device. Here, the moving mass 25 may also be coupled to a plurality of moving masses 25 to set different moving masses.

The displacement measuring means 30 is a laser displacement machine, which is installed in the wind tunnel tester 1 so as to be spaced apart from each other at an adjacent position of the bridge test model 3 to measure the vertical displacement of the bridge test model 3.

In addition, the control means 40 extracts the vertical vibration frequency of the bridge experimental model 3 by using the signal measured from the displacement measuring means 30, as shown in FIG. The drive motor 27 of the AMD 20 is operated in accordance with the frequency to generate a vertical reciprocating motion through the moving mass 25. Here, the control means 40 stores the offset vibration frequency corresponding to the extracted vibration frequency in the form of a look-up table, and the look-up table may obtain respective data through an iterative experiment. In this case, the control means 40 may be applied to a desktop computer, a notebook computer, a tablet PC, a smartphone, or the like, and may be set to enable remote control.

Hereinafter, the operation of the AMD system for vertical direction vibration isolation according to the present invention will be described in detail with reference to the accompanying drawings.

First, the bridge experimental model 3 is installed in the wind tunnel tester 1, and the AMD 20 is fixedly installed at the center of both ends of the bridge experimental model 3.

In this state, the position of the displacement measuring means 30 is adjusted so that the vertical displacement of the bridge experimental model 3 can be measured.

Then, the AMD 20 and the displacement measuring means 30 are electrically connected to the control means 40.

When all the settings are completed, vibration is generated in the bridge experimental model 3 by wind in the wind tunnel or the like. At this time, when the vertical natural frequency of the bridge experimental model (3) is matched with the frequency of the wind, the vibration occurs in the vertical direction.

Then, the control means 40 extracts the vertical vibration frequency of the bridge experimental model 3 using the signal measured from the displacement measuring means 30.

When the vertical vibration frequency is extracted, the control means 40 searches for the offset vibration frequency whose phase is opposite to the natural frequency in the look-up table through the value (amplitude, period, etc.) of the vertical vibration frequency.

Then, the control means 40 operates the drive motor 27 of the AMD 20 according to the offset vibration frequency matched with the natural frequency to generate the vertical reciprocating motion through the moving mass 25.

Then, the vibration in the vertical direction is attenuated by the vertical reciprocating motion of the moving mass 25.

Therefore, after attaching AMD to the bridge model, it is possible to prove the vibration damping performance through the experiment.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. It is to be understood, however, that the invention is not to be limited to the specific forms thereof, which are to be considered as being limited to the specific embodiments, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims. .

20: AMD 21: Jig
23 ball screw 25 moving mass
27: drive motor 29: driver
30: displacement measuring means 40: control means

Claims (6)

In the wind tunnel tester where a bridge test model is installed to perform a wind tunnel test,
Jig is installed in each of the center of both ends of the bridge experimental model, the ball screw is installed in the vertical direction from the jig, the moving mass is installed on the ball screw is moved up and down according to its rotation, installed on the top of the ball screw outside An AMD comprising a drive motor which is rotated forward and backward according to a drive signal of a driver and a driver which generates a drive signal under external control to rotate the drive motor;
A plurality of displacement measuring means installed in the wind tunnel tester so as to be spaced apart from each other at adjacent positions of the bridge test model to measure the displacement of the bridge test model; And
Control means for generating vertical reciprocating motion by extracting the vertical vibration frequency of the bridge experimental model using the signal measured by the displacement measuring means and then driving the AMD according to the offset vibration frequency opposite in phase with the natural frequency. AMD system for vertical direction damping, characterized in that. delete The method of claim 1,
The ball screw,
Limit switches are further provided at both ends,
The moving mass is provided with a stopper in contact with the limit switch,
And the stopper of the moving mass stops the operation of the driving motor when the stopper of the moving mass contacts the limit switch. The method of claim 1,
The moving mass is
AMD system for vertical vibration damping, characterized in that a plurality of can be combined to set the moving mass differently. The method of claim 1,
The displacement measuring means,
AMD system for vibration suppression in the vertical direction, characterized in that the laser displacement. The method of claim 1,
Wherein,
AMD system for vertical vibration damping, characterized in that the offset vibration frequency corresponding to the extracted vibration frequency is stored in the form of a look-up table.

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