KR20060017666A - Fatigue measurement device for structure and method thereof - Google Patents

Abstract

The present invention is to automatically measure the fatigue strength and fatigue damage of building and construction structures made of metal or composite materials, and as a result of the fatigue life of the structure and to determine the residual life of the structure to display the residual life diagnostic device and It's about how. The present invention has two or more different areas of incision that are attached to the structure and form parallel bands having two or more different lengths, wherein fatigue failure when stress and strain are applied to the band and the structure member is prevented. An apparatus and method for diagnosing a structure by detecting a test coupon that is generated in the band earlier than the structure and is formed such that the fatigue by the band is generated at a percentage lower than the fatigue life of the member. Detecting a deformation state of the test coupon; Comparing and determining the deformation state of the test coupon detected in the sensing step with previously stored data to automatically measure the fatigue strength and fatigue damage of the structure, and as a result, determine the fatigue state and the remaining life of the structure; According to the determining step, characterized in that the diagnostic results for displaying the fatigue state of the structure and the remaining life of the structure.

Architecture, construction, structure, fatigue, strength, damage, measurement, judgment, marking, test coupon

Description

Residual Life Diagnosis Apparatus and Method Thereof According to Fatigue Measurement of Structures {FATIGUE MEASUREMENT DEVICE FOR STRUCTURE AND METHOD THEREOF}

Figure 1 is a block diagram showing a device for diagnosing residual life according to the fatigue measurement of the structure according to the present invention.

Figure 2 is a control flowchart showing a method for diagnosing residual life according to the fatigue measurement of the structure according to the present invention.

Figure 3 is a block diagram showing a test coupon detection unit through the image reading in accordance with the present invention.

Figure 4 is a block diagram showing a test coupon detection unit through the disconnection detection in accordance with the present invention.

5 is a control flowchart illustrating a method for diagnosing residual life according to fatigue measurement of a structure through image reading as an embodiment of the present invention.

Figure 6 is a plan view showing the shape of the fatigue test coupon consisting of bands having different length and surface area according to the present invention.

7 is a plan view showing the shape of a fatigue test coupon consisting of bands having the same length and surface area according to the present invention.

8A and 8B are plan and side views of a fatigue test coupon attached to a structure for measuring fatigue damage and fatigue strength along the applied stress axis according to the present invention.

9 shows a typical fatigue life curve commonly referred to as the S-N curve.

<Description of Symbols for Major Parts of Drawings>

1: test coupon 20: structure

100: test coupon detection unit 110: unmanned camera

120: image reading unit 130: matrix unit

140: disconnection detection sensor 150: analog-to-digital converter

160: feature extraction section 170: measurement result database

180: remaining life diagnosis unit 190: diagnosis result display unit

200: Diagnostic report output unit 210: Modem for transmitting the diagnostic results

The present invention relates to an apparatus for measuring fatigue of a structure and a method thereof, and more particularly, to an apparatus for diagnosing residual life according to fatigue measurement of a structure for measuring fatigue strength and fatigue damage of a building or construction structure made of a metal material or a composite material. And to a method thereof.

Architects should be able to predict the fatigue strength and life of materials if any material considered or used as a load bearing member is subjected to repeated or cyclic stress loads. The reason is that repeated stress on the structure will eventually lead to material destruction of the structure.

In addition, when a loading structure is subjected to repeated loads, building design engineers need to be able to detect the effects of the forces and determine the remaining life of the structure so that they can be removed or appropriately handled before failure occurs.

Technicians have extensively studied the fatigue life of structure materials to better understand the current state of structure fatigue damage and to more accurately predict the remaining life. From these studies, the technicians note that fatigue strength is the mechanical or metallic structure used in the experiment, how the materials are processed, the ambient temperature at which the structure is present or operating, the magnitude of the stress on the structure, or the stress of the tested structure. It was found to be related to the number of iterations. It was also found that the materials that make up the structures tested are inversely proportional to the force applied to a given structure, as repeated stresses of lower strength than those under extreme stress will cause fatigue failure of the structure. In other words, the higher the strength of the applied force, the shorter the life of the structure material.

To determine the status of fatigue damage in these structures and to predict the life of the structure, analysts usually use fatigue detectors, fuses, gauges, indicators, monitors, and predictors that previously used techniques. ), They have relied on several types of fatigue monitoring devices, such as sensors, testers or transducers.

However, as these devices were attached on the structure so that they were in line with the direction of the maximum principal stress applied to the test structure, the fatigue damage could only be monitored in a fixed direction. In order to obtain the required value, there was a problem that the excessive experiments on the structure had to be inevitable or the excessive gauge was attached to the experimental apparatus.

In addition, the relationship between the stress applied to the material or member of a given structure and the service life is represented by the coordinates formed by N the number of stress repetitions until the material is damaged by the stress applied to the structural material or member. In order to obtain SN curves for new materials or composites that cannot be obtained, analyzers had to process new or composite materials into test coupons as suggested in the ASTM Handbook, which would cause the test coupons to be destroyed. Until a constant positive cyclic load is applied to the coupon, the process continues to apply different positive cyclic loads until another specimen breaks, which must be repeated on another coupon. There is a problem that the process is required but can not be automated and can be done by hand.

Accordingly, the present invention has been made to solve the above-mentioned problems, and automatically measures the fatigue strength and fatigue damage of building and construction structures made of metal or composite materials, and as a result the fatigue state and the remaining life of the structure An object of the present invention is to provide an apparatus and method for diagnosing residual life according to fatigue measurement of a structure to be determined and displayed.

Residual life diagnostic apparatus according to the fatigue measurement of the structure according to the present invention for achieving the above object, has a cutout of two or more different areas attached to the structure, forming a parallel band having two or more different lengths, When a stress and strain are applied to the band and the structural member, fatigue failure occurs in the band before the structure, and fatigue caused by the band fatigue occurs at a percentage lower than the fatigue life of the structural member. An apparatus for diagnosing a structure by detecting a coupon, the apparatus comprising: a test coupon detecting unit detecting a deformation state of the test coupon attached to the structure; A microprocessor for automatically determining the fatigue strength and fatigue damage of the structure by determining the deformation state of the test coupon detected by the test coupon detection unit with previously stored data, and determining the fatigue state and the remaining life of the structure as a result; And a diagnosis result display unit for displaying the fatigue state of the structure and the remaining life of the structure under the control of the microprocessor.

The test coupon detector; An unmanned camera photographing a deformation state of the test coupon attached to the structure; And an image reading unit which reads and processes an image of the test coupon photographed by the unmanned camera and transmits the image to the microprocessor of the present invention.

The test coupon detector; A matrix unit forming a plurality of thin film lines in the test coupon in horizontal and vertical directions; And a disconnection detecting sensor for detecting a disconnection state of the thin film line of the matrix unit, processing the resistance change signal, and transferring the resistance change signal to the microprocessor.

The microprocessor; A feature extractor extracting a vibration signal of the resonant frequency band capable of detecting the most sensitively among the data sensed by the test coupon detector; And a residual life diagnosis unit for determining a deformation state thereof based on the vibration signal of the structure to be extracted extracted by the feature extraction unit to diagnose the remaining life.

An analog / digital converter for converting analog data sensed by the test coupon detector into digital data; It further includes a basic data obtained by collecting the relationship between vibration and life in advance, and a measurement result database for collecting and preserving data on the load and the elapsed time of the structure to be diagnosed.

The apparatus may further include a transmission modem for easily estimating the remaining life of a specific structure at a remote location by connecting the waveform data and the diagnosis result output to the diagnosis result display unit to an Internet line.

More preferably, the test coupon detector detects a deformation state of the test coupon according to a predetermined condition for a predetermined time or a predetermined period.

The cutout of the test coupon has a rectangular shape with each interior angled 90 degrees and rounded corners so that the bands are all the same length and width.

The test coupon has two or more cutouts having the same cross-sectional area, and the cutout forms two or more bands having different elasticities and having the same length and shape.

Another feature of the invention is that it has two or more different areas of cutout that are attached to the structure and form parallel bands having two or more different lengths, and are subjected to fatigue when a similar stress state and strain is applied to the band and the structure member. In the method of diagnosing a structure by detecting a test coupon formed so that the fracture is caused to occur earlier in the band than the structure, the fatigue caused by the fatigue of the band occurs at a percentage lower than the fatigue life of the member of the structure, the method attached to the structure Detecting a deformation state of the test coupon; Comparing and determining the deformation state of the test coupon detected in the sensing step with previously stored data to automatically measure the fatigue strength and fatigue damage of the structure, and as a result, determining the fatigue state and the remaining life of the structure; And a diagnosis result displaying step of displaying the fatigue state of the structure and the remaining life of the structure according to the determining step.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings.

1 is a block diagram showing a device for diagnosing residual life according to fatigue measurement of a structure according to the present invention.

As shown, the present invention, the test coupon detection unit 100, the analog / digital converter 150, the feature extraction unit 160, the measurement result database 170, the remaining life diagnosis unit 180 And a diagnosis result display unit 190, a check schedule and diagnosis report output unit 200, and a transmission modem 210.

The analog-to-digital converter 150 converts the analog data obtained by the image reading unit 120 or the disconnection detecting sensor 140 into digital data for the diagnosis structure 20 to be diagnosed with the remaining life described above.

The feature variable extracting unit 160 extracts the vibration signal of the resonant frequency band that can detect the highest sensitivity among the digital data converted by the analog-digital converter 150.

The measurement result database 170 collects and preserves the basic data which collected the relationship of vibration and lifespan in advance, and the data regarding the load and the elapsed time of the to-be-tested structure 20 which are trying to diagnose residual life.

The remaining life diagnosis unit 180 determines the deformation state based on the vibration signal of the diagnosis structure 20 extracted by the feature extraction unit 160 by using the data mounted in the measurement result database 170. Diagnose life.

The diagnosis result display unit 190 displays the result of the remaining life diagnosis unit 180. The inspection schedule diagnosis report output unit 200 outputs a report of the next inspection schedule and diagnosis result of the diagnosis structure 20 to a printer or the like based on the diagnosis result of the remaining life diagnosis unit 180.

As described above, according to the present invention, the lifetime of the structure 20 can be estimated by using the resonance frequency band signal or the high frequency signal, so that the lifetime of the structure can be detected at low cost, and the detected lifetime can be estimated with high accuracy.

The transmission modem 210 connects the waveform data and the diagnosis result to the Internet line. In this way, it is possible to easily estimate the remaining life of the specific structure 20 at a remote location by connecting to the Internet line.

2 is a control flowchart illustrating a method for diagnosing residual life according to fatigue measurement of a structure according to the present invention.

As shown, it is estimated whether the diagnosis structure 20 is in the early stage or the late stage by using the data obtained in the basic data collection means and the remaining life diagnosis preparation step. In this residual life diagnostic step, by calculating the tendency of the vibration to increase, it is determined whether the diagnosed structure 20 is in the initial or final state of deformation.

3 is a block diagram illustrating a test coupon detector through an image reading in accordance with the present invention.

As shown, the test coupon detector of the present invention includes an unmanned camera 110 and an image reader 120.

The test coupon 1 is attached to the structure 20 and has two or more different areas of incisions forming parallel bands having two or more different lengths, the bands having similar stress states and strains to the bands and the structural members. When applied, the fracture by fatigue occurs earlier in the strip than the structure, and the fatigue by the strip is formed such that it occurs at a percentage lower than the fatigue life of the structural member.

The unmanned camera 100 photographs the deformation state of the test coupon 1 attached to the structure 20, and the image reading unit 110 an image of the test coupon 1 photographed by the unmanned camera 100. Is read and passed to the microprocessor of the present invention.

The unmanned camera 100 may photograph the deformation state of the test coupon 1 according to a predetermined condition such as a predetermined time or a predetermined period.

To this end, the unmanned camera 100 may be applied to a black and white or a color camera for a normal CCTV, it is possible to transmit the captured image in a wired or wireless manner.

In addition, by applying the concept of the unmanned camera 100, a vibration sensor, a pressure sensor and an infrared sensor may be directly attached to the test coupon 1 of the structure 20 to detect a deformation state of the structure.

4 is a block diagram illustrating a test coupon detector through disconnection detection according to the present invention.

As illustrated, the test coupon detector of the present invention includes a matrix unit 130 and a disconnection sensor 140.

The matrix unit 130 forms a plurality of thin film wires (conductor tape, other thin wires, etc.) in the horizontal and vertical directions of the test coupon 1.

The disconnection sensor 140 detects a disconnection state of the thin film line of the matrix unit 130, processes the resistance change signal, and transmits the resistance change signal to the microprocessor of the present invention.

According to the disconnection state, the fatigue strength and the fatigue damage of the building and construction structure 20 made of a metal material or a composite material can be measured automatically.

5 is a control flowchart illustrating a method for diagnosing residual life according to fatigue measurement of a structure through image reading as an embodiment of the present invention.

As shown, the remaining life diagnostic method according to the fatigue measurement of the structure according to the present invention, the step of attaching a test coupon formed to the structure of the failure caused by the fatigue of the band is lower than the fatigue life of the structural member to the structure (S101) ); Photographing a deformation state of the test coupon attached to the structure with an unmanned camera (S102); Reading an image of the test coupon photographed by the unmanned camera by an image reading unit (S103); Comparing the image of the test coupon read by the image reading unit with an image previously stored in a memory in a microprocessor to automatically measure the fatigue strength and the damage of the structure, and as a result determine the fatigue state and the remaining life of the structure (S104); And displaying (S105) the fatigue state of the structure and the remaining life of the structure under the control of the microprocessor in the display unit.

In the unmanned camera photographing step (S102), the deformation state of the test coupon 1 may be photographed and transmitted to the microprocessor according to a preset condition such as a predetermined time or a predetermined period.

6 is a plan view showing the shape of a fatigue test coupon consisting of bands having different lengths and surface areas according to the present invention, Figure 7 is a plan view showing the shape of a fatigue test coupon consisting of bands of the same length and surface area according to the present invention. .

FIG. 6 is a device for measuring fatigue life and fatigue stress for a monitored structure made of a known component, and is most suitable as a test coupon 1 to be attached to a test structure 20 selected for a stress fatigue test and a stress damage test. It is well described.

The test coupon 1 may be made of a cutting device capable of programming thin sheets of paper of uniform composition and of uniform thickness with suitable materials such as aluminum, titanium, stainless steel or copper. Examples of such cutting devices are, without limitation, cutouts (hereinafter referred to as 'slots') forming perforations, cutting lines, electrical discharge cutters, laser cutters or ligaments 7, 8, 9 and 10. Slots (2) (3) (4) (5) (6), such as cutting devices programmed to measure and cut. Computer software, usually associated with a programmable cutting device, can calculate specific values for slots (2) (3) (4) (5) (6) based on the material from which the test coupon (1) is made. Can be.

As already mentioned, this fatigue measuring device, unlike the previous one, can be made of any suitable material, which presents a significant advantage over the previous technique, which shows a measuring device that must be made of the same material as the structure to be tested. will be.

The appropriate values for the slots 2, 3, 4, 5 and 6 will depend on the material from which the test coupon 1 is made, which can be calculated by hand and entered into the cutting device. It may also be calculated using computer software associated with the cutting device.

FIG. 6 shows a test coupon 1 consisting of various slots 2, 3, 4, 5, 6 defining the strips 7, 8, 9, 10. The number of slots shown in 1) can vary according to the situation, which increases the efficiency of the experiment, while increasing the number of bands for the analyzer and thus reducing the number of cyclic stress experiments necessary to obtain sufficient data. Provide an opportunity to

FIG. 6 shows a test coupon 1 consisting of various slots 2, 3, 4, 5, 6 with different arrangements or shapes, with slots 2, 3, 4, 5 (6) will each have a different surface area. Therefore, the strips 7, 8, 9, and 10 of the test coupon 1 shown in FIG. 6 have different surface areas (SSA2, SSA3, SSA4, SSA5, SSA6) and different lengths (l 7, l8, l9, 10), which will have different cross-sectional areas (LCSA7, LCSA8, LCSA9, LCSA10), and due to the diversity of these values, the bands (7) (8) (9) (10) are stress fatigues in order of weakest to strongest. Will be destroyed by

In this arrangement, the bands 7, 8, 9 and 10 are stressed when the test coupon 1 and the test structure 20 are generally subjected to the same test history. It is calculated in such a way as to ensure that the bands 7, 8, 9 and 10 are sequentially destroyed by stress fatigue before being destroyed by fatigue. In other words, it is calculated in such a way as to ensure that each band 7, 8, 9, 10 is broken by applying a cyclic stress load of known or predetermined magnitude to the test coupon 1. By applying a cyclic stress load of known or pre-determined magnitude to the test coupon 1, each of the bands 7, 8, 9 and 10 exhibits the same elongation or contraction as experienced by the test structure 20. Will be felt, and because each strip (7) (8) (9) (10) has a different length, different surface area, and different cross sectional area, each strip (7) (8) (9) (10) The stress б and strain ε that will be subjected to the same applied force depends on the length and cross-sectional area of the bands (7) (8) (9) (10).

The weakest band will feel the greatest amount of stress б and strain ε exerted by the applied force and will be destroyed before the other bands in the test coupon (1) and the test coupon (1) and the test structure (20). Repeated application of additional load will destroy the next weaker band.

FIG. 7 shows another form for the fatigue measuring device in that all of the slots 11 have the same surface area by having the same shape or arrangement. Likewise, the strips 12 all have the same length, surface area, and cross sectional area. Since the composition of the test coupon 1 in the arrangement shown in FIG. 7 may vary, the elastic modulus of each band 11 may have a different value.

As such, higher elastic modulus causes higher stress on a particular band so that the band exhibiting the highest modulus will break due to cyclic stress before other bands with lower modulus. The test coupon 1 may be used for the fatigue strength test and the fatigue damage test under the scenario that more strain is needed for the test structure 20. The test coupon 1 may also be used to provide a warning or other indication that the test structure 10 has reached a predetermined milestone in its service life.

The fatigue measurement device shown in FIG. 7 can also be made of any suitable material, which can present important advantages over the prior art, and the apparent values for the slots 11 and the band 12 are given in the test coupon (1). Depending on the material from which) is made, these values can also be calculated by using computer software associated with the device or part thereof used to dig out the slot 11.

8A and 8B are a plan view and a side view of a fatigue test coupon attached to a structure for measuring fatigue damage and fatigue strength along an applied stress axis according to the present invention, and FIG. 9 shows a typical fatigue life curve generally referred to as an SN curve. Drawing.

FIG. 8A is a plan view of the test coupon 1 attached to the test structure 20, and FIG. 8B is a cross-sectional view of the test coupon 1 attached to the test structure 20. The test coupon 1 and the test structure 20 are shown in FIG. ) Can create a bond 21. Suitable bonding techniques herein include, without limitation, methods of welding or the use of adhesive bonding compounds.

9 shows the degree of stress applied to Si and Si + 1 and shows the typical fatigue life, commonly referred to as the S-N curve, by indicating the number of stress repetitions until Ni and Ni + 1 are destroyed.

Any material used to make the structural members or devices of the present invention will have a unique fatigue life curve that provides a frequency for the number of repeated stresses that will cause fatigue failure as a function of the stress applied. Therefore, the material to which the S-N curve shown in FIG. 9 is applied will be destroyed by the fatigue stress if the stress Si degree is applied by the repetition number Ni.

Similarly, this same material will be destroyed because of fatigue stress if it is applied with a different degree of stress Si + 1 and a different number of Ni + 1. Thus, as analyzers can use more data points, the shape of the S-N curve more accurately reflects the fatigue life of the tested material as the number of different values of stresses caused increases.

An embodiment of the present invention configured as described above will be described in detail with reference to FIGS. 3 and 5.

The test coupon 1 is attached to the structure 20 so that the fracture due to the fatigue of the band is generated at a percentage lower than the fatigue life of the structure member (S101).

Here, the test coupon (1) is attached to the experimental structure 20 in a manner that can feel the same strain and environment as the experimental structure 20, the attachment of the test coupon (1) to the experimental structure 20 nail needles, It can be done by means of adhesive or welding, and unlike most test coupons presented in the prior art, the test coupon 1 does not need to be attached to any important position of the experimental structure 20. However, the test coupon (1) is attached to the experimental structure 20 in a manner that can feel the tensile strain and the environment, such as the experimental structure (20) and its portion should be determined. In general, the axis of the test coupon 1 is aligned in the direction of the maximum principal tensile strain to be expected in the test structure 20.

Thereafter, the deformation state of the test coupon 1 attached to the structure 20 is photographed by the unmanned camera 110, and the test coupon 1 photographed by the unmanned camera 110 in the image reader 120. ) Is read out (S102 to S103).

At this time, the unmanned camera 110 transmits the image taken by applying a black and white or color camera for CCTV in a wired or wireless manner.

In addition, in the unmanned camera photographing step (S102), the deformation state of the test coupon 1 may be photographed and transmitted to the microprocessor according to a preset condition such as a predetermined time or a predetermined period.

The microprocessor compares the image of the test coupon 1 read by the image reading unit 120 with the image stored in the database 170 in advance to automatically measure the fatigue strength and fatigue damage of the structure 20, As a result, the fatigue state and the remaining life of the structure is determined (S104).

That is, when a cyclic stress load of known or predetermined magnitude is applied to the test coupon 1, each of the bands 7, 8, 9, and 10 causes the same amount of elongation or contraction as the test structure 20. Will be. Since each strip (7) (8) (9) (10) has a different length and cross-sectional area, each strip (7) (8) (9) (10) has a different amount of load at the same applied load. You will feel the stress б and strain ε.

These different amounts of stress б and strain ε vary as a function of the length and cross sectional area of the bands 7, 8, 9, 10. The weakest band will feel the highest amount of stress б and strain ε of the applied load and will break before the remaining bands.

As additional load is cyclically applied to the test coupon 1 and the test structure 20, the next weaker band will be destroyed. As a constant cyclic load is applied to the test coupon 1 and the test structure 20, each band will be destroyed from the weakest to the next weakest and eventually all of them.

For example, when comparing two strips 7 and 10 of the test coupon 1 described in FIG. 6, the total length l7 of the strip 7 is the upper part l7u and the bottom of the strip 7. The portion l7l is summed up, and the other strip 10 will also be the same. Likewise, the cross-sectional area CSA7 of the band 7 can be divided into two parts, the cross-sectional area CSA7u of the upper part of the band 7 and the cross-sectional area CSA7l of the lower part.

When the band 7 and the band 10 have the same displacement δ, the strain or stress ratio of the band 7 and the band 10 is expressed by Equation 1 below.

[Equation 1]

Ε7u is the strain of the upper part of the band 7, silver ε7u is the strain of the band 10, б7u is the stress of the upper part of the band 7, and б10 is the stress of the band 10.

If L7u = L7l = L10 / 2 and CSA7u = CSAn / 2, the strain and stress at the top of the band 7 are 1.3 times greater than that shown in the band 10. Therefore, the strip 7 will break before the strip 10 because it has higher strain and stress. Thus, the stress and strain ratios caused by the bands 7, 8, 9, 10 can be determined by a suitable combination of the property parameters of the bands 7, 8, 9, 10.

In general, each of the strips 7, 8, 9, 10 may be of various parts having different lengths and cross sections. The ability to adjust the length and cross-sectional area at this time will allow the analyzer to have the desired stress and strain ratio for each strip (7) (8) (9) (10).

The resulting stress and strain ratio will depend on when each of the bands 7, 8, 9 and 10 will break under fatigue load. The belt with the highest stress will be destroyed first, followed by the belt with the highest stress.

The image reader 120 reads the bands (7) (8) (9) (10) appearing in the test coupon (1), and makes it possible to clearly know the existing service life of the test structure (20), and the test coupon ( If there are more bands in 1), the microprocessor can find out the service life within a more accurate range.

In laboratory operation, analyzers usually use the apparatus shown in Fig. 1 to obtain the data points needed for the SN curve table of the new material, whereby the test coupon (1) was manufactured using the new material and the cyclic load test was performed. Is applied. That is, a given stress amplitude ("S") is marked on the longitudinal axis of the S-N curve, while the number of repetitions ("N") until broken by a given stress condition is plotted on the horizontal axis. Next, the second stress amplitude ("S + 1") forms a vertical axis, and the number of times until breakage ("N + 1") forms a horizontal axis. The analyzer will curve with enough data points necessary to determine the service life of the stressed state in any of the predicted ranges of use of the experimental material.

Using the test coupon (1) shown in FIG. 6, it is necessary to specify that only one fatigue cycling test gives the analyzer various data points on the SN curve, and the number of data points on the SN curve obtained here is the band of the test coupon. Matches the number of

Increasing the number of bands will increase the number of data points on the S-N curve and increase the usefulness over a wide range. This aspect of the invention is an improvement on the previous technique that allowed the experiment to perform excessive fatigue load tests to obtain sufficient data points for the S-N curve.

Otherwise, the experimental structure 20 may be selected or confirmed for stress fatigue test and stress damage test, and the stress strength of the experimental structure 20 is input to the S-N curve appropriate for the material constituting the structure 20. For example, if the experimental structure 20 is made of aluminum, the stress repetition frequency (N) applied by the experimental structure 20 by the experimental data will be input to the horizontal axis of the S-N curve for aluminum. The number of repetitions remaining (“NR”) under any load condition is found at a point on the aluminum SN curve that matches the defined or expected load conditions, and the horizontal axis at the point that matches the number of repetitions (NA) at which breakage occurs. The difference between "NA" and "N" is the remaining service life of the experimental structure (20).

Therefore, as described above, the microprocessor inputs the image of the test coupon 1 read by the image reading unit 120 at an hourly or several minute interval and stores it in the database 170 for several days or months, The deformation state is determined by continuously comparing with the previously photographed image.

As described above, the fatigue strength and the fatigue damage of the structure 20 are automatically measured, and as a result, the fatigue state and the remaining life of the structure are determined (S104).

In addition, as described above, the fatigue state of the structure and the remaining life of the structure, which are determined under the control of the microprocessor, are displayed on the diagnosis result display unit 180 configured as a monitor screen such as a CRT or LCD (S105).

The display method of this result may use a display method configured with various user interfaces such as a text table or a graph.

In addition, the present invention can be applied not only to structures such as buildings, buildings, bridges, but also to moving structures such as large aircraft and ships.

Although the preferred embodiments of the present invention have been illustrated and described above, the present invention is not limited to the above-described embodiments, and the present invention is not limited to the above-described embodiments without departing from the spirit of the present invention as claimed in the claims. Various modifications can be made by those skilled in the art, and such modifications are intended to fall within the scope of the appended claims.

As described above, according to the apparatus for evaluating the residual life according to the fatigue measurement of the structure according to the present invention and the method thereof, the fatigue strength and fatigue damage of the building and construction structures made of metal or composite materials are automatically measured, and as a result the fatigue By determining and displaying the condition and the remaining life of the structure, the actual degree of fatigue can be measured more accurately and efficiently than suggested in the prior art.

In addition, the number of experiments to graph the SN curve of any material or composite material to be tested can be drastically reduced, and there is no need to artificially weaken the experimental elements, and it is possible to reliably predict the service life remaining in the test structure. This saves analyzers time and money.

In addition, it is also possible to easily estimate the remaining life of a specific structure in a remote location by connecting the waveform data and the diagnosis result output to the internet line through the transmission modem to the Internet line.

In addition, the test coupon detection unit has an effect of detecting the deformation state of the test coupon in accordance with a predetermined condition for a predetermined time or a predetermined period.

Claims (10)

Two or more different areas of cutout that are attached to the structure and form parallel bands having two or more different lengths, and fatigue failures when stress and strain are applied to the band and the structural member are greater than those of the structure. In the apparatus for diagnosing a structure by detecting a test coupon that is first generated in the band, the fatigue caused by the fatigue of the band is generated at a percentage lower than the fatigue life of the structural member, A test coupon detector for detecting a deformation state of the test coupon attached to the structure; A microprocessor for automatically determining the fatigue strength and fatigue damage of the structure by determining the deformation state of the test coupon detected by the test coupon detection unit with previously stored data, and determining the fatigue state and the remaining life of the structure as a result; And a diagnostic result display unit for displaying the fatigue state of the structure and the remaining life of the structure under the control of the microprocessor. The method of claim 1, The test coupon detector; An unmanned camera photographing a deformation state of the test coupon attached to the structure; Residual life diagnosis apparatus according to the fatigue measurement of the structure, characterized in that it comprises an image reading unit for reading and processing the image of the test coupon photographed by the unmanned camera and transmitted to the microprocessor of the present invention. The method of claim 1, The test coupon detector; A matrix unit forming a plurality of thin film lines in the test coupon in horizontal and vertical directions; Residual life diagnosis apparatus according to the fatigue measurement of the structure comprising a disconnection detection sensor for detecting the disconnection state of the thin film line of the matrix portion, and processing the resistance change signal according to this to the microprocessor. The method of claim 1, The microprocessor; A feature extractor extracting a vibration signal of the resonant frequency band capable of detecting the most sensitively among the data sensed by the test coupon detector; Residual life diagnosis apparatus according to the fatigue measurement of the structure characterized in that it comprises a residual life diagnosis unit for determining the deformation state based on the vibration signal of the structure to be extracted extracted by the feature extraction unit for diagnosing the remaining life. The method of claim 1, An analog / digital converter for converting analog data sensed by the test coupon detector into digital data; Fatigue measurement of the structure, characterized in that it further comprises a basic data obtained by collecting the relationship between vibration and life in advance, and a measurement result database for collecting and preserving data on the load and the elapsed time of the structure to be diagnosed remaining life Residual Life Diagnosis Device The method of claim 1, According to the fatigue measurement of the structure characterized in that it further comprises a transmission modem for easily estimating the remaining life of a specific structure by remotely connecting the waveform data and the diagnosis result output to the diagnosis result display unit to the Internet line Residual Life Diagnostics. The method of claim 1, The test coupon detection unit, the remaining life diagnostic device according to the fatigue measurement of the structure, characterized in that for detecting a deformation state of the test coupon in accordance with a predetermined condition in a predetermined time or a predetermined period. The method of claim 1, The cutout of the test coupon, the fatigue measuring apparatus of the structure, characterized in that each of the inner angle is 90 degrees and rounded corners rectangular shape so that all the same length and width of the bands. The method of claim 1, The test coupon has two or more incisions having the same cross-sectional area, the incision is fatigue measuring apparatus of the structure, characterized in that to form two or more bands having the same length and shape with different elasticity. Two or more different areas of cutout that are attached to the structure and form parallel bands having two or more different lengths, and fatigue failures when stress and strain are applied to the band and the structural member are greater than those of the structure. In a method for diagnosing a structure by detecting a test coupon that is first generated in the strip, and the fatigue caused by the fatigue of the strip is formed at a percentage lower than the fatigue life of the structural member, Detecting a deformation state of the test coupon attached to the structure; Comparing and determining the deformation state of the test coupon detected in the sensing step with previously stored data to automatically measure the fatigue strength and fatigue damage of the structure, and as a result, determining the fatigue state and the remaining life of the structure; And a diagnosis result displaying step of displaying the fatigue state of the structure and the remaining life of the structure according to the determining step.

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