KR20150006934A - A method and device of for generating vibration with intensive pulsed light - Google Patents

Abstract

The present invention relates to an apparatus for excitation using intensive pulsed light, which comprises: a generating unit (100) which generates light; a radiating unit (200) which is mounted at one side of the generating unit, in order to excite a specimen by radiating the light generated by the generating unit (100); and a measuring unit (300) which is placed at one side of the specimen in order to measure responses of the specimen, changing by the light. In addition, suggested in the present invention is a method for exciting a specimen using the excitation apparatus, which comprises: a step of generating light in an intensive pulsed shape; a step of radiating the light to a specimen; and a step of measuring excitation responses of the specimen by light or heat energy of the light.

Description

TECHNICAL FIELD The present invention relates to an apparatus and a method for vibrating with intense pulsed light emission,

[0001] The present invention relates to an apparatus and a method using an enhanced pulsed light emission, and more particularly, to an apparatus and a method using an enhanced pulse-type light emission, which irradiates a specimen with light energy or heat energy, Apparatus and method.

Representative devices of the vibrating device are shaker and impulse hammer. Shakers are typically excited using electromagnetic forces, and the device is small and has the advantage that the magnitude of the force can be easily controlled using control feedback.

However, in the case of a large structure test, a hydraulic shaker is used, in which case the size of the vibrating device becomes large. The signal of the oscillator is given as a harmonic function, a random function, or some other appropriate form. The harmonic function is the most widely used, increasing the frequency from the lower frequency and looking at the dynamic characteristics of the system over a range of frequencies. In addition, the reaction is measured by excitation with time from a specific frequency to a steady state. The electromagnetic shaker usually receives an AC voltage as input and generates a linear excitation force accordingly. When testing with a shaker, considerable care is required with respect to the attachment of the structure under test and the shaker. The reason for this is that when the mass is attached to the structure for the excitation of the shaker, it changes the vibration characteristics due to the mass increase.

The impulse hammer is a widely used swing device because it has no mass problem with the shaker and simple experiment. However, the impulse hammer is mainly used for vibration testing of relatively small structures due to the limit of its excitation force. The impulse hammer has a force transducer at its head and applies the force of the impact function by tapping the target structure. The force generated at this time has a maximum size proportional to the mass and the price of the hammer, and the shape is similar to the Half sine function. Therefore, the Fourier transform of this function is not a constant size value which is a transformation of the Delta function but a sine function in which the wavelength is very short and the amplitude is reduced.

Vibrating vibrations using shakers or hammers can be of limited size or may damage the product in a contact manner. Also, when it is attached to the structure, it is a factor of the characteristic change and there is a limit of the excitation force depending on the size. Small objects on the micro scale are difficult to hold, and therefore non-contact, non-destructive vibrational excitation is needed.

Ultrasonic method is one of the most similar methods for nondestructive testing in the field of fault detection, but it has a disadvantage in that it has to measure a single point. As a prior art related thereto, there has been disclosed an apparatus for measuring vibration of a specimen by applying vibration to a specimen using ultrasonic waves in US Pat. No. 5,623,307 and Korean Patent Publication No. 2010-0092233 have.

The present invention intends to excavate a specimen which is susceptible to damage due to small or contactless contactlessly by using the excitation apparatus and method using the intensified pulse light radiation according to one embodiment.

According to one embodiment, there is provided an excitation apparatus and method using enhanced pulsed light emission capable of minimizing a change in state of a specimen before and after excitation.

According to another aspect of the present invention, there is provided a vibrating device including a generator for generating light, a light source for emitting light generated by the generator, and a measuring unit disposed on one side of the specimen and measuring a response of the specimen changed by the light.

According to one aspect of the present invention, the light generated by the generation portion can be irradiated to the specimen in the form of a reinforced pulsed wave.

According to one aspect, the generator may generate a reinforcing pulse wave.

According to one aspect of the present invention, the irradiation unit can control a time interval for irradiating light to 0.2 ms or less.

According to one aspect of the present invention, the irradiating unit is capable of irradiating the specimen with the specimen and adjusting the irradiation area of the irradiated specimen.

According to one aspect, the specimen may be spaced apart from the generator, and the specimen may be spaced apart from the irradiator, so that the specimen may be insulated in a noncontact state.

According to one aspect, the measuring unit may include an acceleration sensor attached to one end of the specimen to measure the dynamic characteristics of the specimen.

According to one embodiment, there is provided a method of exciting a specimen using light, comprising the steps of generating light in the form of a reinforcing pulse wave, irradiating the specimen with light, irradiating the specimen with light energy or heat energy And measuring a dynamic response according to the excitation of the specimen.

According to one aspect, the step of measuring the dynamic response may further include obtaining natural frequency, frequency, and phase information from the dynamic response of the measured specimen.

According to one aspect of the present invention, the method may further include determining whether the specimen has an internal abnormality based on the natural frequency, frequency, and phase information of the specimen.

   According to the excitation apparatus and method using the enhanced pulse light emission according to the embodiment, the specimen which is likely to suffer damage due to small or back-to-back contact can be excited non-contactly.

In addition, according to the apparatus and method using the reinforced pulsed light emission according to the embodiment, it is possible to minimize the change in state of the specimen before and after the excitation.

1 is a perspective view schematically showing a vibrating device using light.
FIG. 2 is a front view schematically showing how light and heat are generated when light is irradiated on a specimen. FIG.
3 (a) is a graph showing a response measured with an acceleration sensor when there is no excitation using light, and Fig. 3 (b) is a graph showing a response measured with an acceleration sensor when excited using light to be.
In FIG. 4, 4 (a) is a graph showing the time response when the light irradiation time is 5 ms, and FIG. 4 (b) is a graph showing the frequency response when the light irradiation time is 5 ms Graph.
5 (a) is a graph showing the time response when the light irradiation time is 0.2 ms, FIG. 5 (b) is a graph showing the frequency response when the light irradiation time is 0.2 ms Fig.
FIG. 6 shows the step of analyzing the response after excitation using light.

Hereinafter, configurations and applications according to embodiments of the present invention will be described in detail with reference to the accompanying drawings. The following description is one of many aspects of the claimed invention and the following description forms part of a detailed description of the present invention.

In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted to avoid obscuring the subject matter of the present invention. The same parts are used throughout the drawings for the parts having similar functions and functions.

Incidentally, throughout the specification, when a part is referred to as being "attached" to another part, it includes not only a direct part but also an indirect part with another part interposed therebetween. Also, to "include" an element means that it may include other elements, rather than excluding other elements, unless specifically stated otherwise.

1 is a perspective view schematically showing a vibrating device using light. The vibrating device 10 includes a generating unit 100 for generating light, an irradiating unit 200 for concentrating the light generated from the generating unit into a part of the specimen S, and a measuring unit 300) for analyzing the response measured by the measurement unit 300, and an analysis unit 400 for analyzing the response measured by the measurement unit 300.

The generator 100 may be connected to a power source and convert the supplied energy into light. The wavelength of the light generated by the generating unit 100 should be adjustable to a level that does not change the characteristics of the specimen S. [

The generating unit 100 may generate an " enhanced pulse type ". "Enhanced pulsed" light is a strong light that is applied to a certain area for a short time.

The irradiating unit 200 may be attached to one side of the generating unit 100 to irradiate pulsed light enhanced toward the specimen. For example, as shown in FIG. 1, the irradiating unit 200 may be provided between the generating unit 100 and the specimen so that the time when the enhanced pulsed light from the generating unit 100 is irradiated to the specimen S or Area can be controlled.

The irradiation unit 200 not only can collect light in a certain area, but also can adjust the irradiation range. For example, as shown in FIG. 1, the irradiation unit 200 may adjust the irradiation region to the first irradiation region Z1 or the second irradiation region Z2 according to the specimen S. If the specimen is not small or flat, it is preferable to adjust it to the first irradiation zone Z1. If the specimen S has a large and relatively even profile, it is preferable to adjust it to the second irradiation zone Z2 will be.

The measuring unit 300 may be attached to one side of the specimen S. The measurement unit 300 may include an acceleration sensor for measuring the vibration response due to the enhanced pulsed light irradiated on the specimen S. [ The measurement unit 300 may be configured as one or more acceleration sensors to increase the accuracy of the response and the measurement unit 300 is not limited to the acceleration sensor as long as it can measure the vibration response of the specimen S. [

The analysis unit 400 is connected to the measurement unit 300 and can analyze the dynamic characteristics from the vibration response of the sample S acquired by the measurement unit 300. [ The analysis unit 400 may include a PC having an analysis program installed therein, and may include various other vibration response measurement equipment. The specimen S may be spaced apart from the generating unit 100 and the irradiating unit 200 by a predetermined distance H and may be placed in an insulated state. The test piece S is insulated from the generating part 100 and the irradiating part 200, thereby avoiding a shock due to direct contact for vibration generation. For this reason, the vibrating device 10 according to one embodiment is also capable of measuring the dynamic characteristics of a small or loose specimen.

 FIG. 2 schematically shows how light and heat are generated when light is irradiated on the specimen S. FIG. When strengthened pulsed light is applied to a certain region of the specimen from the irradiation unit 200, light energy and heat energy are generated in the specimen S. Such light energy and thermal energy cause instantaneous vibration in the specimen, and these vibrations spread out from the irradiation point. And the vibration spreading through the specimen S is measured by the measuring unit 300.

 3 (a) is a graph showing a response measured by an acceleration sensor when there is no excitation using light, and FIG. 3 (b) is a graph showing a response measured by an acceleration sensor when excited by using the excitation device 10 according to an embodiment The graph shows the measured responses. 3 (a), no response is measured by the acceleration sensor because there is no external excitation. In FIG. 3 (b), even when only light is applied using the vibrator 10, And the response is measured by the acceleration sensor. In other words, it shows that the specimen can be excited by using pulsed light without physical blow.

Figs. 4 (a) and 4 (b) are graphs showing the time response and the frequency response when the light irradiation time is 5 ms. In the case of the time response, the amplitude of the acceleration measurement is greatly increased when the first excitation starts, and the amplitude becomes smaller as the excitation end. In the case of the frequency response, background noise appears at a large amplitude at a low frequency, primary resonance frequency is observed at a higher frequency, and when the excitation time is 5 ms, the peak point of the first resonance frequency response Is not clearly observed.

 5 (a) and 5 (b) are graphs showing the time response and the frequency response when the light irradiation time is 0.2 ms. In the case of the time response, the excitation time is very short, so that the amplitude does not increase again after the excitation, and the amplitude of the acceleration measurement is increased again after the excitation is finished. In the case of the frequency response, the peak point of the first-order resonant frequency response is clearly observed, unlike the case in which background noise appears with a large amplitude at low frequencies and the excitation time is 5 ms. Through this, it can be seen that the resonance frequency measurement result is better observed when the excitation time is shortened to 0.2ms or less. Therefore, from Figs. 4 and 5, dynamic characteristics can be obtained from the vibration response of the specimen when the irradiation time is 0.2 ms or less.

Hereinafter, a method of exciting a specimen using the vibrating device 10 will be described.

FIG. 6 shows the step of analyzing the response after making the specimen with the reinforced pulsed light.

First, the generating unit 100 generates enhanced pulse-type light (S110). Specifically, the generating unit 100 may convert energy supplied to the power source into enhanced pulse-type light energy.

The reinforced pulsed light generated in the generating unit 100 is irradiated to the specimen S through the irradiating unit 200 (S120). Specifically, the irradiating unit 200 can concentrate the light generated by the generating unit 100 onto the specimen.

When light is irradiated to the specimen S from the irradiating unit 200, the specimen due to light energy or heat energy is excited by the irradiated light, and the dynamic response depending on the excitation of the specimen S can be measured (S130) . Specifically, an acceleration sensor or the like may be attached to one end of the specimen S to measure the vibration response.

After measuring the dynamic response, the natural frequency, frequency, and phase information may be obtained from the dynamic response of the measured specimen S (S140). Specifically, as shown in FIGS. 4 and 5, a graph analysis according to the acceleration sensor response can be performed.

The internal abnormality of the specimen (S) can be determined based on the natural frequency, frequency, and phase information of the obtained specimen (S150). Specifically, if the natural frequency, frequency, and phase information of the specimen S in the steady state are known, it is compared with the newly measured result to determine whether there is an internal abnormality.

According to the above-described vibrating device, it is possible to carry out micro-units such as semiconductors and MEMS which have not been able to be impulse hammers or shakers, and to measure the dynamic characteristics of a product which is highly deformed or damaged by the nondestructive vibration method . In addition, since the method itself is non-contact type, there is an effect that there is no change in dynamic characteristics such as a shaker or a hammer to be attached to a target.

Therefore, the above-described vibrating device can be applied to a dynamic characteristic testing device, a device for measuring natural frequency, frequency, and phase information through vibration by shaking or impacting an object, checking the condition of the object, It can be applied to experiment and mode analysis, fault detection and soundness monitoring, vibration signal measuring instrument, measuring instrument, modal test, and fault diagnosis.

The present invention may be embodied in other specific forms without departing from the spirit or essential characteristics of the invention.

Devices with: 10
Generation: 100
Investigation department: 200
Measurement part: 300
Analysis Department: 400

Claims (9)

A generating unit 100 for generating light;
An irradiating unit 200 mounted between the generator and the specimen to irradiate the specimen with the light generated in the generator 100 to apply the specimen to the specimen; And
A measuring unit 300 disposed at one side of the specimen for measuring a response of the specimen changed by the light;
Lt; / RTI >
And an analyzer for analyzing the dynamic characteristics of the specimen from the excitation response.
The method according to claim 1,
Wherein the generator is capable of generating a reinforcing pulse wave.
The method according to claim 1,
Wherein the irradiation unit is capable of controlling a time interval for irradiating light to 0.2 ms or less.
The method according to claim 1,
Wherein the irradiating unit is capable of irradiating the specimen with the light irradiating area irradiated to the specimen.
The method according to claim 1,
Wherein the generating part is spaced apart from the specimen and the specimen is spaced apart from the irradiating part so that the specimen is insulated in a noncontact state.
The method according to claim 1,
Wherein the measuring unit includes an acceleration sensor attached to one end of the specimen to measure a dynamic characteristic of the specimen.
Generating light in the form of a reinforcing pulsed wave;
Irradiating the specimen with the light;
Measuring a dynamic response of the specimen due to the light energy or heat energy of the light, the dynamic response depending on the excitation of the specimen;
≪ / RTI >
8. The method of claim 7,
Obtaining the natural frequency, frequency, and phase information from the dynamic response of the measured specimen after the step of measuring the dynamic response;
≪ / RTI >
9. The method of claim 8,
Further comprising the step of determining whether there is an internal abnormality of the specimen based on the natural frequency, frequency and phase information of the specimen.

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