KR101729285B1 - System for measuring and analyzing dynamic stiffness of structure - Google Patents

System for measuring and analyzing dynamic stiffness of structure Download PDF

Info

Publication number
KR101729285B1
KR101729285B1 KR1020150168207A KR20150168207A KR101729285B1 KR 101729285 B1 KR101729285 B1 KR 101729285B1 KR 1020150168207 A KR1020150168207 A KR 1020150168207A KR 20150168207 A KR20150168207 A KR 20150168207A KR 101729285 B1 KR101729285 B1 KR 101729285B1
Authority
KR
South Korea
Prior art keywords
hammer
stage
holder
holding member
dynamic stiffness
Prior art date
Application number
KR1020150168207A
Other languages
Korean (ko)
Inventor
최태묵
최용주
조주영
김국현
Original Assignee
(주)크리에이텍
동명대학교산학협력단
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by (주)크리에이텍, 동명대학교산학협력단 filed Critical (주)크리에이텍
Priority to KR1020150168207A priority Critical patent/KR101729285B1/en
Application granted granted Critical
Publication of KR101729285B1 publication Critical patent/KR101729285B1/en

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
    • G01N29/04—Analysing solids
    • G01N29/045—Analysing solids by imparting shocks to the workpiece and detecting the vibrations or the acoustic waves caused by the shocks
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
    • G01M7/00—Vibration-testing of structures; Shock-testing of structures
    • G01M7/08—Shock-testing
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
    • G01N29/22—Details, e.g. general constructional or apparatus details
    • G01N29/24—Probes
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
    • G01N3/30—Investigating strength properties of solid materials by application of mechanical stress by applying a single impulsive force, e.g. by falling weight
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
    • G01N3/30—Investigating strength properties of solid materials by application of mechanical stress by applying a single impulsive force, e.g. by falling weight
    • G01N3/303—Investigating strength properties of solid materials by application of mechanical stress by applying a single impulsive force, e.g. by falling weight generated only by free-falling weight
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/02—Viewing or reading apparatus
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
    • G01N2203/003—Generation of the force
    • G01N2203/0032—Generation of the force using mechanical means
    • G01N2203/0039—Hammer or pendulum
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2291/00—Indexing codes associated with group G01N29/00
    • G01N2291/26—Scanned objects
    • G01N2291/269—Various geometry objects

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • General Health & Medical Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Biochemistry (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Acoustics & Sound (AREA)
  • Optics & Photonics (AREA)
  • Investigating Strength Of Materials By Application Of Mechanical Stress (AREA)
  • Investigating Or Analyzing Materials By The Use Of Ultrasonic Waves (AREA)

Abstract

The present invention relates to a system to measure and analyze dynamic stiffness of a structure, capable of constantly setting an initial position of a hammer with motor control during consecutive hits by the hammer, so as to acquire reliable measurement and analysis data without intervention of incorrect manual work of a work. According to the present invention, the system comprises: a vibration device including a hammer vibrated by repeatedly hitting a structure; an accelerometer to measure a vibration response generated from the structure repeatedly hit by the vibration device upon each hit; a measurement environment setting unit to perform calibration of the accelerometer; a numeric setting unit to set the number of vibration, an initial position of the hammer, and a measurement time interval formed by the vibration device; a display unit to visualize and display a result measured by the accelerometer; and a dynamic stiffness evaluation unit to evaluate dynamic stiffness of the structure based on a vibration response value measured by the accelerometer. The vibration device comprises: a three-axis stage including Z-, Y-, and X-stages; a holding member installed along the X-stage to be able to move; and a hammer member to hit the structure by free fall while being held by the holding member. The Y- and X-stages, and the holding member are moved by driving of a motor.

Description

TECHNICAL FIELD [0001] The present invention relates to a dynamic rigidity measurement system for a ship,

The present invention relates to a system for measuring and analyzing dynamic stiffness of a structure for dynamic stiffness measurement. In particular, it is possible to set the initial position of a hammer constantly using a motor control in a continuous striking by a hammer, And more particularly, to a structure dynamic torsional stiffness measurement and analysis system capable of obtaining reliable measurement and analysis data.

Generally, noise and vibration caused by ship engines and pumps are generated. Such noise and vibration are transmitted through the equipment pedestal, affecting the stability of the ship itself, as well as being transmitted to the water through the outside of the hull and adversely affecting the marine ecosystem .

Therefore, ship noise and vibration regulation is strengthened for structural safety of offshore structure, comfort of residence of crew, protection of marine life, and so, low vibration design technique is required.

In the past, vibration of equipment during ship operation was transmitted through the equipment support. Therefore, elastic mounts, damping materials, and acoustic shielding boxes were applied between the equipment and the pedestal for vibration reduction. To demonstrate, the equipment stand and substructure should be designed to have sufficient dynamic stiffness, and then assessed if the pedestal is designed and constructed to have sufficient dynamic stiffness performance during shipbuilding.

A method of evaluating dynamic rigidity of equipment in a ship using an impact hammer is used. The impact hammer has a hammer structure such as a general hammer, and a tip having a predetermined hardness is connected to a force sensor at an end of the hammer body .

The toughness of the pedestal is evaluated by using the impedance value of the pedestal, and is calculated by using the output value of the force sensor attached to the hammer and the sensor attached to the pedestal when the impact hammer strikes.

At present, the dynamic stiffness evaluation of the equipment pedestal is performed by manually hitting the designated position of the pedestal by the operator using the impact hammer. In order to increase the reliability of the measured value, the average value of the results of the three successive strikes, It is evaluated whether the coherence of the values becomes equal to or greater than the reference value.

However, when the operator hits the hammers, the sensor output and the force sensor output value attached to the object are different from each other when the operator applies the hammering force as well as the hammering position. That is, since the hitting force and the hitting position are changed, there is a problem that the matching rate of the resultant values successively hit three times does not satisfy the reference value.

Further, when the hammer is struck by the object, when the worker does not apply the force to the hammer in a direction opposite to the direction of hitting the object quickly, the hammer hits the object more than once and the secondary impact is applied to the object.

In addition, since the operator performs the hammering work until the reliable measurement data is obtained, not only a lot of time is required but also the worker's fatigue is increased.

Korean Patent Registration No. 1336560 (Dec. 3, 2013)

It is therefore an object of the present invention to provide a motor control apparatus and a hammer apparatus which can set an initial position of a hammer constantly using a motor control when a hammer is continuously hit by a hammer, The present invention is to provide a system for measuring and analyzing dynamic rigidity of a structure capable of obtaining reliable measurement and analysis data without manual intervention.

In order to accomplish the above object, the present invention provides a structure dynamic torsional stiffness measuring and analyzing system comprising: a vibrating device including a hammer for repeatedly hitting and vibrating a structure; An accelerometer for measuring a vibration response occurring at each hit from a structure repeatedly struck by the vibrating device; A calibration environment setting unit for calibrating the accelerometer; A numerical value setting unit for setting the number of excursions made by the vibrating device, the initial position of the hammer, and the measurement time interval; A display unit for visualizing and displaying results measured by the accelerometer; And a dynamic stiffness evaluating unit for evaluating dynamic stiffness of the structure based on the vibration response value measured by the accelerometer, wherein the vibrating apparatus comprises: a base frame supported on a surface of the structure; A three-axis stage including a Z stage, a Y stage provided movably along the Z stage and formed in the Y direction, and an X stage provided movably along the Y stage and formed in the X direction; And a hammering member which is held by the holding member and strikes the structure by free fall when the holding member releases the holding member. The Z stage, the Y stage, and the X stage, A first rail, a second rail, and a third rail formed in the longitudinal direction, wherein the Y stage, Not be the one to the holding member is moved by a motor-driven along the first rail, a second rail, the third rail, respectively, characterized on the technical configuration.

Here, before the dynamic stiffness evaluation unit evaluates the dynamic stiffness of the structure, the respective vibration response values measured repeatedly in the accelerometer are statistically processed according to the results of the frequency response analysis reflecting the coherence And a statistical processing unit.

The hammering member may include a guide bar formed to be long in the vertical direction and guided by the holding member, a hammer coupled to a lower end of the guide rod and hammering the structure with a hammer tip at a lower surface thereof, A guide tube for guiding the lifting and lowering of the guide rod in a state in which the guide rod passes through the holder, and a holder for holding the guide rod of the hammer member.

Also, the holder of the holding member may include a first holder and a second holder, which are opposed to each other with the guide rods therebetween and are spaced from each other by an electromagnetic force, while pressing and holding the guide rods . ≪ / RTI >

In addition, a seating groove corresponding to an outer circumferential surface of the guide rod may be formed on a surface of the first holder and the second holder facing each other.

The first holder may have a guide hole formed therein. The second holder may be formed with a bar-shaped guide inserted into the guide hole of the first holder, so that the distance between the first holder and the second holder It is possible to prevent mutual deviation when the spacing is changed.

Further, the genital hammer member may further include a load cell provided between the hammer and the guide bar.

The hammer member may further include a plurality of unit weights which are stacked on the upper side of the hammer in the form of a washer fitted to the guide bar to adjust the weight of the hammer member.

A support stand vertically installed on the other side of the base frame; And a camera installed at an upper end of the support so that the hammer can be photographed.

In addition, the camera may be configured to be tilted and rollable relative to the support.

In addition, the base frame may be a rectangular frame body formed with openings except for the circumferential portion, and the hammer member may fall through the opening portion to strike the structure.

In addition, a damping base for damping vibrations may be provided on the bottom surface of the base frame.

The structure dynamic toughness measuring and analyzing system according to the present invention can set the initial position of the hammer constant by using the motor control in the continuous striking by the hammer so that reliable measurement and analysis data can be obtained without the manual intervention of the operator Can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a diagram showing the entire construction of a structural rigidity measurement and analysis system according to an embodiment of the present invention
2 is a perspective view of a motor control vibrating apparatus in a system for measuring and analyzing dynamic rigidity of a structure according to an embodiment of the present invention.
3 is a partial perspective view for explaining a configuration of a holding member and a hammering member of a motor control vibrating apparatus in a system for measuring and analyzing dynamic rigidity of a structure according to an embodiment of the present invention.
4A and 4B are a series of reference drawings for explaining the operation and operation of the holding member of the motor control vibrating apparatus in the structure dynamic torsional stiffness measuring and analyzing system according to the embodiment of the present invention
5 is a partial perspective view for explaining the configuration of a camera of a motor control vibrating apparatus in a structure dynamic toughness measurement and analysis system according to an embodiment of the present invention.
6 is a flow chart of the dynamic stiffness measurement and analysis method using the structural dynamic toughness measurement and analysis system according to the embodiment of the present invention
7A to 7F are a series of reference drawings for explaining the operation and the operation of the apparatus in the structure dynamic toughness measurement and analysis system according to the embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described more fully with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown. The present invention is capable of various modifications and various forms, and specific embodiments are illustrated in the drawings and described in detail in the text. It is to be understood, however, that the invention is not intended to be limited to the particular forms disclosed, but on the contrary, is intended to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. Like reference numerals are used for like elements in describing each drawing. In the accompanying drawings, the dimensions of the structures are enlarged to illustrate the present invention, and are actually shown in a smaller scale than the actual dimensions in order to understand the schematic structure.

Also, the terms first and second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component. On the other hand, unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the contextual meaning of the related art and are to be interpreted as either ideal or overly formal in the sense of the present application Do not.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a structural dynamic toughness measurement and analysis system according to an embodiment of the present invention; FIG.

As shown in the drawings, the structure dynamic toughness measuring and analyzing system according to an embodiment of the present invention includes a three-axis stage (XYZ-stage) and a holding member for moving and dropping a hammer to hammer the structure repeatedly, A vibrator controller for processing various signals in the middle while controlling the vibrator, including a vibrator having a camera for setting a position, a vibrator having a load cell, An acceleration sensor (vibration sensor) for evaluating the acceleration, a numerical value setting unit, a display unit, a statistical processing unit, and a dynamic stiffness evaluating unit.

In the case of the apparatus for measuring and analyzing the dynamic stiffness of the structure, the apparatus of the present invention plays a pivotal role of setting the initial position of the hammer to be constant by using the motor control in the continuous striking by the hammer in the embodiment of the present invention. This enables continuous hitting of the hammer on the structure without operator's inaccurate manual intervention, thereby enabling a reliable evaluation of dynamic stiffness.

Hereinafter, the vibrating device will be described in detail.

FIG. 2 is a perspective view of a motor control vibrating apparatus in a system for measuring and analyzing dynamic rigidity of a structure according to an embodiment of the present invention, and FIG. 3 is a perspective view FIGS. 4A and 4B are diagrams for explaining the operation and operation of the holding member of the motor control vibrating apparatus in the structure dynamic torsional stiffness measuring and analyzing system according to the embodiment of the present invention. It is a series of reference diagrams. And FIG. 5 is a partial perspective view for explaining a configuration of a camera of a motor control vibrating apparatus in a structure dynamic toughness measurement and analysis system according to an embodiment of the present invention.

3, the vibrating apparatus 100 includes a base frame 110, a three-axis stage 120, a holding member 130, a hammer 130, A member 140, and a camera 150.

The base frame 110 of the vibrating device 100 includes the three-axis stage 120 and supports other components. To this end, the base frame 110 is formed of a rectangular frame having an opening 111a except for the periphery thereof, and the hammer member 140 is dropped through the opening 111a to be able to strike the structure 111). The base frame 110 is provided taking into account the structural stability of the impact force of up to 450 - 4500kg f applied to the apparatus 100 has. Damping bases 112 for attenuating vibrations are provided on the bottom surface of the base frame 110, respectively. When the damping base 112 is installed, the influence of the vibrations received by the base frame 110 in a state where the structure is excited by the hitting of the hammer 142 can be minimized.

The three-axis stage 120 of the vibrating device 100 plays a pivotal role in setting the initial position where the hammer 142 continuously falls down constantly. To this end, the three-axis stage 120 includes a Z stage 121 vertically installed on one side of the base frame 110, a Y stage 121 installed movably along the Z stage 121 and formed in the Y direction, And an X stage 123 which is installed to move along the Y stage 122 and is formed in the X direction. The Z stage 121, the Y stage 122 and the X stage 123 are provided with a first rail 121a, a second rail 122a and a third rail 123a formed in the longitudinal direction thereof, The Y stage 122, the X stage 123 and the holding member 130 move along the first rail 121a, the second rail 122a, and the third rail 123a, respectively, by motor driving. The Y stage 122 and the Y stage 123 are disposed along the first rail 121a, the second rail 122a and the third rail 123a formed on the Z stage 121, the Y stage 122 and the X stage 123, The configuration in which the X stage 123 and the holding member 130 are moved by motor driving applies a general LM guide configuration.

Meanwhile, the Z stage 121 receives a load due to the holding member 130 and the hammering member 140, unlike the other stages, and thus needs to be more firmly supported with respect to the base frame 110. A reinforcing plate 124 which is joined to the side surface of the base frame 110 and supports the rear side of the Z stage 121 as shown in FIG. 2, and a reinforcing plate 124 which is provided on the left and right sides of the lower end of the Z stage 121 And a pair of triangles 125 for stably supporting the lower end of the reinforcing plate 124 to the base frame 110 while being positioned.

According to such a configuration of the three-axis stage 120, the hammering member 140 can be repeatedly moved to the initial position without the manual operation of the operator. When the operator hits the hammering member 142 using the hammer 142, It is possible to completely solve the problem that the output value of the accelerometer attached to the structure is different, reliable measurement data can be obtained, and the time and labor required for the operator to perform the hammering operation can be saved.

The holding member 130 of the vibrating device 100 holds the hammer member 140 and moves along the X stage 123 to drop the hammer member 140. 3, the holding member 130 includes a guide tube 132 guiding the guide bar 141 of the hammering member 140 to move up and down in a state of passing through the guide rod 141, And holders 133 and 134 for holding the guide rod 141 of the hammer member 140 between the upper body 131a and the lower body 131b. 4A and 4B, the holders 133 and 134 are spaced apart from each other with the guide rod 141 therebetween, and are spaced apart from each other by an electromagnetic force, And a first holder 133 and a second holder 134 for pressing and holding the first holder 133 and the second holder 134, respectively. Each of the first holder 133 and the second holder 134 has a square bar shape and seating grooves 133b and 134b corresponding to the outer circumferential surface of the guide rod 141 are formed on the surfaces facing each other. 4A is a state in which the first holder 133 and the second holder 134 are pressing the guide rod 141 of the hammering member 140 while narrowing the distance between them, 133 and the second holder 134 are spaced apart from each other so that the guide rod 141 of the hammering member 140 can be freely dropped. The first holder 133 is formed with a guide hole 133a and the second holder 134 is formed with a rod that is inserted into the guide hole 133a of the first holder 133, Shaped guides 134a are formed to guide the first holder 133 and the second holder 134 so that they do not deviate from each other when the spacing between the first holder 133 and the second holder 134 is changed.

The hammering member 140 of the vibrating device 100 directly hits and excites the structure. The hammer member 140 is vertically extended and is guided by the holding member 130. The hammer member 140 is coupled to the lower end of the guide rod 141 and has a hammer tip And a load cell (not shown) installed between the guide rod 141 and the hammers 142. The hammers 142 are installed in the hammers 142, According to the configuration of the hammering member 140, the guide rod 141 is maintained in a state of passing through the guide pipe 132 until the hammers 142 fall free in a state of being raised and strike the structure, The first holder 133 and the second holder 134 of the holding member 130 can hold the guide rod 141 in such a manner that the guide rod 141 can be lifted and lowered freely. The first holder 133 and the second holder 134 hold the guide rods 141 by the electromagnetic force and brakes them by the brakes immediately after the hammer 142 hits the structure, A problem that a car shock occurs can be prevented.

The hammer member 140 further includes a plurality of unit weights 143 stacked on the hammer 142 in the form of a washer fitted to the guide rod 141. When the plurality of unit weights 143 are provided, the weight of the hammers 140 can be easily increased by increasing the number of the unit weights 143 stacked when the structure needs to be hit with a larger load.

The camera 150 of the vibrating device 100 is provided at an upper end of a support base 160 erected on the opposite side of the Z stage 121 to capture the hammer 142. The support base 160 includes a vertical portion 161 erected on the other side of the base frame 110 and a horizontal portion 162 extending from the upper end of the vertical portion 161 toward the Z stage 121 And the camera 150 is installed so as to be tilted and rollable in such a manner that it slants downwardly to the horizontal part 162. 5, the body 151 of the camera 150 is formed in a spherical shape so that the camera 150 can be tilted and rolled with respect to the support base 160, and the horizontal portion 162 of the support base 160 It is possible to form a receiving portion 162a capable of receiving the body 151 of the camera 150 in a simple manner as in the case of a universal joint, but the tilting and rolling operations of the camera 150 can be combined have. Of course, in order to tilt and roll the camera 150, a rotation axis for supporting the body 151 of the camera 150 in a vertically tilting manner is provided, and a rotation body for rotating the rotation axis in the left and right direction is provided It is somewhat complicated, but various configurations are conceivable.

If the tilting and rolling camera 150 is installed at the upper end of the support member 160, it is helpful to accurately set the initial position for freely dropping the hammer 142 through the image analysis. Particularly, when setting the initial position of the hammer 142, the camera 150 sets the XY axis coordinates through image analysis and the Y axis coordinates are set to the Y stage 122 with respect to the fixed Z stage 121, And the initial position is set correctly by performing the control in such a manner as to control.

The accelerometer measures a vibration response generated at each hit from a structure repeatedly struck by the vibrating device 100 installed on a structure to be excited.

The measurement environment setting unit performs pre-measurement calibration for the accelerometer each time to increase the reliability of the measurement.

The numerical value setting unit serves to set signal processing parameters, and the number of excursions performed by the vibrating device 100, the initial position of the hammer 142, and the measurement time interval are included in the objects to be set. In addition, the operation of marking the structure and the display line of the vibrating device 100 preceded by the points and measurement points preceding the elements set through the numerical value setting section is preceded.

The display unit serves to visualize and display the measurement result of the accelerometer.

The statistical processing unit may calculate the vibration response values repeatedly measured in the accelerometer before evaluating the dynamic stiffness of the structure in the dynamic stiffness evaluating unit according to a frequency response function result reflecting the coherence, Thereby generating more accurate data for the dynamic stiffness evaluation. In order to evaluate the dynamic stiffness of the structure with high reliability and effectiveness, it is common to evaluate the dynamic stiffness by direction and position by performing repetitive test with different impact force position and vibration response measurement position on the structure. And the dynamic stiffness of the structure is evaluated using the linear average value. Additionally, as a value close to two C xy correlation of the signal for the impact time signal x (t) and the structure vibration response time signal y (t) of a has a value of xy 0≤C ≤1, C xy 1 , The coherence between x (t) and y (t) measured by each test order is evaluated for reliable high toughness evaluation with low test error. Only a measurement result having a correlation level equal to or higher than a certain level is regarded as a valid result.

The dynamic stiffness evaluating unit evaluates the dynamic stiffness of the structure based on the vibration response value obtained by machining the statistical processing unit. The dynamic stiffness Z (ω) of the structure is evaluated by the vibration response y (t) of the structure with frequency ω in the case where the structure is excited by a unit force. Z (ω) is the frequency spectrum Y (t) of the vibration time response y (t) corresponding to the frequency spectrum X (ω) of the impact force time signal x (t) input to the structure and the displacement, ω) / X (ω), and can also be evaluated as the reciprocal of Y (ω) / X (ω). The reliability of the dynamic stiffness evaluation depends on the auto-spectral density function G xx of the impact force time signal x (t) input to the structure and the magnetic spectral density function G (x) of the vibration time response y the correlation between the input signal x (t) and the output signal y (t), which is calculated as the magnitude | G xy | of the cross-spectral density function G xy of yy and x (t) and y coherence G xy (= | G xy | / G xx G xy) .

The dynamic stiffness measurement and analysis method of the dynamic stiffness measurement and analysis system according to the embodiment of the present invention will be described in detail with reference to the accompanying drawings. 6A to 6F are flow charts of the dynamic stiffness measurement and analysis method using the dynamic stiffness measurement and analysis system of the structure according to the embodiment of the present invention. Figs. 7A to 7F are diagrams illustrating the dynamic stiffness measurement and analysis Fig. 2 is a set of reference diagrams for explaining the operation and operation of the apparatus in the system. Fig.

As shown in FIG. 6, the dynamic stiffness measurement and analysis method of the structural dynamic torsional stiffness measuring and analyzing system according to the embodiment of the present invention can be broadly divided into a test preparation stage and a test stage.

First, the test preparation step will be described with reference to FIG.

First, mark the points, measurement points, and vibrating device display lines on the structure to be measured with respect to the dynamic rigidity.

Then, the base frame 110 of the vibrating device 100 is installed in a corresponding area of the target structure to accurately position the vibrating device 100.

Then, it is photographed by the camera 150 and transmitted to the controller of the apparatus 100 having the measurement point and the image information about the vibrating apparatus 100.

Then, the calibration environment setting unit calibrates the accelerometer.

Thereafter, the number of times that the numerical value setting section has been performed and the initial position of the hammer 142 are set, and the measurement time interval is set.

Thereafter, the vibrating device 100 is operated to continuously apply a blow to the structure, and details of the vibrating device 100 are as follows.

7A shows a state in which the hammers 142 of the hammering member 140 are in contact with the surface of the structure in a state where the base frame 110 of the vibrating device 100 is supported on the structure. At this time, the Y-stage 122 moves to a proper height and holds the guide rod 141 of the hammering member 140 using the holding member 130. At this time, the primary height information of the Y stage 122 with respect to the Z stage 121 is transmitted to the controller for storage.

7B, the Y stage 122 is lifted along the Z stage 121 while the holding member 130 catches the hammer member 140. The height information of the Y stage 122 is transmitted to the controller for storage . Here, the height (Y-axis coordinate) at which the hammer 142 ascends from the structure is determined, which corresponds to a height increase from the secondary height of the above-mentioned Y stage 122 by subtracting the first height, Z coordinate of the initial position of the Z axis.

When the camera 150 mounted on the opposite side of the Z stage 121 photographs the position of the hammer 142 and transmits the image information to the controller in the state where the hammer 142 is raised as described above, Allows you to set axis coordinates.

Thereafter, a work for hitting and hitting the structure with the hammer 142 is performed. The first holder 133 and the second holder 134 of the holding member 130 release the electromagnetic force applied to the first holder 133 and the second holder 134 to widen the gap between the first holder 133 and the second holder 134, The hammers 142 are released and hit the structure as shown in FIG. 7C. The vibration response y (t) of the structure due to impact impact can be measured using an accelerometer installed in the structure, and the moment load applied using the load cell installed in the hammer member 140 can be measured .

At this time, the hammer 142 instantly hitting the structure jumps upward due to the repulsive force. As shown in FIG. 7D, an electromagnetic force is applied to the first holder 133 and the second holder 134 of the holding member 130 By holding the guide rod 141, the projected hammer 142 drops down to the structure so that the secondary impact is not applied.

Thereafter, the hammer 142 is returned to the initial position set at the time of the first excitation for the secondary excitation to the structure. The hammer 142 is first brought into contact with the surface of the structure as shown in FIG. 7E by releasing the electromagnetic force of the holding member 130 holding the guide rod 141 of the hammer member 140, The Y stage 122 is lowered to reach the primary height of the Y stage 122 stored at the time of primary excitation. 7f, the guide bar 141 of the hammering member 140 is held and lifted up to the second height of the Y stage 122 stored at the time of the first excitation, 122). Thus, the Y-axis coordinate of the hammer 142 is positioned at the initial Y-axis coordinate.

Then, the X stage 123 and the holding member 130 of the hammer 142 are moved according to the image information of the camera 150 stored at the time of first excitation to move to the initial X-Y axis coordinates. As a result, the hammer 142 is accurately positioned at the initial position where the hammer 142 was located at the time of the primary impact. Thereafter, the hammer 142 is freely dropped to carry out secondary excitation, and excitation is performed by the same number of excitation times set by the numerical value setting unit. At this time, the numerical value setting unit resets the initial set point, the measurement point, and the initial position of the hammer 142 if it is not proper, and if appropriate, enters the full-scale test step by considering that the test preparation step is completed.

In the test step, a new measurement position is selected, and the structure is struck successively in the manner of the above-described test preparation step. Then, based on the vibration response y (t) of the structure measured at each excitation of the structure, the statistical processing unit and the dynamic stiffness evaluation unit calculate the dynamic stiffness of the structure, and confirm the results and report the results. This completes the dynamic stiffness measurement and analysis for the structure.

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 clear that the present invention can be suitably modified and applied in the same manner. Therefore, the above description does not limit the scope of the present invention, which is defined by the limitations of the following claims.

110: Base frame 120: 3-axis stage
130: holding member 140: hammer member
150: camera 160: support

Claims (11)

In a dynamic stiffness measurement and analysis system for a structure having a support base of a ship as a measurement target structure,
An excitation device having a hammer for repeatedly striking and vibrating a structure;
An accelerometer for measuring a vibration response occurring at each hit from a structure repeatedly struck by the vibrating device;
A calibration environment setting unit for calibrating the accelerometer;
A numerical value setting unit for setting the number of excursions made by the vibrating device, the initial position of the hammer, and the measurement time interval;
A display unit for visualizing and displaying results measured by the accelerometer;
And a dynamic stiffness evaluation unit for evaluating dynamic stiffness of the structure based on the vibration response value measured by the accelerometer,
The vibrating device includes a base frame supported on a structure surface, a Z stage vertically installed on one side of the base frame, a Y stage movably installed along the Z stage and formed in the Y direction, Stage, which is movably installed along the X-axis, and an X-stage formed in the X-direction, a holding member movably installed along the X-stage, and a holding member holding the holding member at an initial position held by the holding member. The Y stage, and the X stage, the first rail, the second rail, and the third rail are formed in the longitudinal direction of the Z stage, the Y stage, and the X stage, respectively. , The Y stage, the X stage, and the holding member are moved along the first rail, the second rail, and the third rail, respectively, So that the hammer, which has fallen freely without manual operation of the operator, is returned to the initial position, so that the same impact can be repeatedly applied to the structure,
The hammer member includes a guide rod formed to be long in the vertical direction and guided by the holding member, a hammer coupled to a lower end of the guide rod and having a hammer tip on the lower surface thereof for hitting the structure, Further comprising a plurality of unit weights laminated on the upper side of the hammer in the form of a lag washer so as to control the weight,
Wherein the holding member includes a guide tube for guiding the lifting and lowering of the guide rod in a state where the guide rod is passed through the guide tube and a guide tube which is opposed to each other with the guide rod therebetween, By momentarily shortening the distance between them by moment of electromagnetic force immediately after the vehicle is struck by the recoil, the hammering member is prevented from dropping again to prevent the secondary impact from being applied to the structure, A first holder and a second holder having a seating groove corresponding to the outer circumferential surface of the guide rod,
The first holder is formed with a guide hole. The second holder is formed with a rod-like guide inserted into the guide hole of the first holder, and is spaced apart from the first holder and the second holder. It is possible to prevent deviation from each other when changing,
A support frame vertically erected on the other side of the base frame, and a camera mounted on the upper end of the support frame so as to be able to tilt and roll,
Wherein the base frame is a rectangular frame body formed with openings except for the periphery thereof, and the hammer member falls through the opening to strike the structure, and a damping base Wherein the hammering member is capable of striking the structure while the base frame is mounted on the structure. The method according to claim 1,
A statistical processor for statistically processing each of the vibration response values measured repeatedly in the accelerometer according to a frequency response function reflecting coherence before the dynamic stiffness evaluation unit evaluates the dynamic stiffness of the structure, Further comprising: a structural rigidity measurement and analysis system. delete delete delete The method according to claim 1,
Wherein the elastic hammer member further comprises a load cell provided between the hammer and the guide rod. delete delete delete delete delete
KR1020150168207A 2015-11-30 2015-11-30 System for measuring and analyzing dynamic stiffness of structure KR101729285B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
KR1020150168207A KR101729285B1 (en) 2015-11-30 2015-11-30 System for measuring and analyzing dynamic stiffness of structure

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
KR1020150168207A KR101729285B1 (en) 2015-11-30 2015-11-30 System for measuring and analyzing dynamic stiffness of structure

Publications (1)

Publication Number Publication Date
KR101729285B1 true KR101729285B1 (en) 2017-04-24

Family

ID=58704175

Family Applications (1)

Application Number Title Priority Date Filing Date
KR1020150168207A KR101729285B1 (en) 2015-11-30 2015-11-30 System for measuring and analyzing dynamic stiffness of structure

Country Status (1)

Country Link
KR (1) KR101729285B1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11579059B2 (en) * 2018-06-26 2023-02-14 Mitsubishi Heavy Industries, Ltd. Inspection apparatus and inspection method for inspection target
CN116429603A (en) * 2023-06-14 2023-07-14 四川恒迪新材料集团有限公司 SPC floor free falling impact resistance detection device and method

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006284340A (en) * 2005-03-31 2006-10-19 Fuji Heavy Ind Ltd Rigidity measuring device and rigidity measuring method

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006284340A (en) * 2005-03-31 2006-10-19 Fuji Heavy Ind Ltd Rigidity measuring device and rigidity measuring method

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11579059B2 (en) * 2018-06-26 2023-02-14 Mitsubishi Heavy Industries, Ltd. Inspection apparatus and inspection method for inspection target
CN116429603A (en) * 2023-06-14 2023-07-14 四川恒迪新材料集团有限公司 SPC floor free falling impact resistance detection device and method
CN116429603B (en) * 2023-06-14 2023-08-29 四川恒迪新材料集团有限公司 SPC floor free falling impact resistance detection device and method

Similar Documents

Publication Publication Date Title
KR101739075B1 (en) Motor control vibration exciter for measuring dynamic stiffness of structure
JP7346462B2 (en) A method for determining the spatial configuration of multiple transducers in relation to a target object
KR101904197B1 (en) Drop testing apparatus and drop testing method of using the same
KR101729285B1 (en) System for measuring and analyzing dynamic stiffness of structure
JP2007040781A (en) Blow inspection device and blow inspection method
JP2017138115A (en) Preload inspection method applied to linear slide
CN108414178A (en) Percussion mechanism with pooling feature and its application process
CN104977218B (en) Micro-elastic detail rigidity detection device and method
JP2003043019A (en) Condition measuring instrument for concrete
KR102033506B1 (en) Rebound Check Device for Dynamic Loading Test and Measuring bearing capacity of soil of Pile
JP2019168389A (en) Crack angle determination device and crack angle determination method
KR20210081722A (en) Rebound Check Device
KR101942555B1 (en) In plane Pyro Shock Tester
CN116202900A (en) Detection instrument and detection method for detecting hardness of valve based on rebound parameters after impact
KR102250490B1 (en) System for the measurement of strength and physical parameters of concrete structures using impulse forces applied by hitting instrument mounted on drones
CN113530522B (en) Demolition blasting blasthole drilling quality acceptance device and use method
JP6340711B2 (en) Impact applying device and impact applying method
CN113390504A (en) Low-frequency vibration sensor calibration system and calibration method
JP4863796B2 (en) Pile bearing capacity measurement method
RU163680U1 (en) Exciter Not Attachable to Construction
JP7244832B2 (en) Condition evaluation device for inspection objects
JPH0915129A (en) Method and apparatus for measuring coefficient of restitution
KR20160128208A (en) Impact-energy measuring device at a tip of billiards cue shaft
JP3843108B2 (en) Specimen reaction force estimation device
JP2017083329A (en) Hammering inspection system, hammering inspection method, and program

Legal Events

Date Code Title Description
E701 Decision to grant or registration of patent right
GRNT Written decision to grant