KR20230078224A - 3-point bending test system and 3-point bending test method - Google Patents

Abstract

The present invention relates to a 3-point bending test system and a 3-point bending test method capable of accurately detecting and measuring fractures occurring in a specimen in a 3-point bending test, which can perform a 3-point bending test of a specimen formed elongated in the longitudinal direction. A bending tester including a support part for supporting both sides of the lower surface of the specimen and a pressing part located on the center line of the support part and installed to be able to move up and down with respect to the support part to press the upper surface of the specimen, and one side of the specimen A first sensor unit installed on the pressurizing unit to sense sound generated from the specimen being pressed by the pressurizing unit, and installed on one side of the supporting unit so as to be positioned on the center line of the supporting unit, and pressurized by the pressing unit. A second sensor unit for capturing an image of a pressurized portion of the specimen to be applied, and a third sensor unit installed on one side of the pressurization unit and measuring a movement displacement of the pressurization unit that descends toward the support unit and presses the specimen; A fourth sensor unit installed on the pressurizing unit so as to be located on the center line of the support unit and measuring a load applied to the pressurizing unit, a sound signal of the first sensor unit, and an image signal of the second sensor unit; An analyzer configured to match and analyze a displacement signal of the third sensor unit and a load signal of the fourth sensor unit to determine a fracture occurrence time point of the specimen and output a load value at the fracture occurrence time point.

Description

3-point bending test system and 3-point bending test method

The present invention relates to a three-point bending test system and a three-point bending test method, and more particularly, to a three-point bending test system capable of accurately detecting and measuring fractures occurring in a specimen in a three-point bending test and a three-point bending test It's about how.

In general, the bending test of a horizontal frame, horizontal bar, etc. is performed to determine the ductility or strength of a material by measuring the deformation resistance or breaking strength when a bending moment acts on the material. ), thin plate, thick plate, drawn, extruded bar, angle bar and welding material, etc. to evaluate the mechanical properties. Types of bending tests include a bending resistance test to determine the material's resistance to bending (bending strength), the elastic modulus and elastic energy of the material, and a bending fracture test to test the malleability, ductility, and fracture of the material. there is. The bending fracture test is a test for evaluating and determining the appropriateness and soundness of processing.

The bending test may be divided into a three-point bending test and a four-point bending test according to the number of support points and points of application, and the three-point bending test indicates a case in which two points of support and one point of application of a load are applied. For example, in the 3-point bending test, both ends of a test specimen (hereinafter referred to as "specimen") manufactured in the form of a bar are supported from below and a load is applied from above at the center to measure the applied load and the amount of deformation or fracture of the specimen. Strength is measured. means how to measure

However, in the 3-point bending test system and 3-point bending test method for the 3-point bending test of the conventional specimen, when the specimen is formed of a high-toughness material, it is difficult to accurately measure the fracture point because fracture does not occur in the specimen. However, there was a problem that it was difficult to accurately detect the time point of breakage. Accordingly, there is a problem in that it is difficult to accurately test the strength of the specimen, such as the breaking strength at which fracture occurs in the specimen.

The present invention is to solve various problems, including the above problems, to provide a three-point bending test system and a three-point bending test method that can accurately detect and measure the fracture occurring in the specimen in the three-point bending test aims to However, these tasks are illustrative, and the scope of the present invention is not limited thereby.

According to one embodiment of the present invention, a three-point bending test system is provided. The 3-point bending test system is located on the center line of the support part and the support part for supporting both sides of the lower surface of the specimen so that the 3-point bending test of the specimen formed long in the longitudinal direction can be raised and lowered based on the support part. a bending tester including a pressurizing unit installed so as to press the upper surface of the specimen; a first sensor unit installed on one side of the specimen and detecting sound generated from the specimen pressed by the pressurizing unit; a second sensor unit installed on one side of the support unit so as to be located on the center line of the support unit, and taking an image of a pressurized portion of the specimen pressed by the pressurization unit; a third sensor unit installed at one side of the pressing unit and measuring a movement displacement of the pressing unit that descends toward the support unit and presses the specimen; a fourth sensor unit installed on the pressing unit to be positioned on the center line of the support unit and measuring a load applied to the pressing unit; and matching and analyzing the sound signal of the first sensor unit, the image signal of the second sensor unit, the displacement signal of the third sensor unit, and the load signal of the fourth sensor unit to determine the time point at which fracture of the specimen occurs, It may include; an analysis unit that outputs a load value at the time of occurrence of the fracture.

According to one embodiment of the present invention, the first sensor unit may include an acoustic sensor installed on one side of the specimen, detecting the sound generated from the specimen and outputting the sound signal as the sound signal; and an amplifier for amplifying the acoustic signal output by the acoustic sensor.

According to an embodiment of the present invention, the second sensor unit is installed on one side of the support part so as to face a direction perpendicular or inclined to the lifting direction of the pressing part, and the specimen pressed by the pressing part. a camera sensor that photographs the pressurized portion and outputs the image signal; a reflector installed under the specimen supported by the support and illuminating the pressurized portion of the specimen toward the camera sensor; and a driving body for sliding and moving the camera sensor.

According to an embodiment of the present invention, the third sensor unit may include a laser sensor installed on one side of the pressing unit, measuring a distance from the pressing unit to the support unit, and outputting the displacement signal as the displacement signal.

According to an embodiment of the present invention, the drive body is linked with the laser sensor so that the focal distance between the pressurized portion of the specimen pressed downward by the pressurization unit and the camera sensor can be maintained constant The camera sensor may be slid and moved by a descending distance of the pressing unit according to the displacement signal output by the laser sensor.

According to an embodiment of the present invention, the analysis unit may include: a first data collection unit for collecting and converting the sound signal output from the first sensor unit and the displacement signal output from the third sensor unit into data; a first analysis unit that matches and analyzes the acoustic signal and the displacement signal, which are data-generated by the first data collection unit, and displays and lists the acoustic signal for each displacement of the pressing unit according to the displacement signal; a second data collection unit for collecting and converting the image signal output from the second sensor unit and the displacement signal output from the third sensor unit into data; a second analysis unit that matches and analyzes the video signal and the displacement signal, which are data-generated by the second data collection unit, and displays and lists the video signal for each displacement of the pressing unit according to the displacement signal; and checking the predetermined displacement of the pressing unit at the position where the sound signal is displayed in the first analysis unit and the image signal of the second analysis unit at the same displacement as the predetermined displacement to determine whether the specimen is fractured. and a comparison determination unit configured to determine the sound signal at the predetermined displacement of the first analysis unit as a signal at the time of occurrence of fracture of the specimen when fracture occurrence is confirmed in the video signal.

According to an embodiment of the present invention, the first data collection unit collects the load signal output from the fourth sensor unit and converts it into data together with the acoustic signal and the displacement signal, and the first analysis unit collects the displacement signal. For each displacement of the pressing unit according to the signal, changes in the load value of the pressing unit according to the load signal together with the sound signal may be displayed and arranged.

According to an embodiment of the present invention, the comparison and determination unit sets the load value corresponding to the predetermined displacement equal to the acoustic signal at the time of fracture of the specimen of the first analysis unit at the time of fracture of the specimen. It can be output as a load.

According to one embodiment of the present invention, the specimen is formed of a material with high toughness, and a notch portion may be concavely formed in a width direction of the specimen on a lower surface of a pressurized portion pressed by the pressurization unit.

According to another embodiment of the present invention, a three-point bending test method is provided. The three-point bending test method includes a specimen seating step of seating the specimen on a support of a bending tester capable of performing a three-point bending test of a specimen formed long in the longitudinal direction; a specimen test step of performing a bending test on the specimen by pressing an upper surface of the specimen seated on the support part with a pressurizing part; and a test termination step of terminating the bending test when a fracture occurs in the specimen to be subjected to the bending test, wherein the specimen testing step is a first sensor unit installed on one side of the specimen, which is pressed by the pressing unit. Acoustic signal extraction step of detecting the sound generated from the specimen; An image signal extraction step of capturing an image of a pressurized portion of the specimen pressed by the pressurization unit with a second sensor unit installed on one side of the support unit so as to be located on the center line of the support unit; a displacement signal extraction step of measuring a moving displacement of the pressing unit that presses the specimen by descending toward the support unit with a third sensor unit installed at one side of the press unit; a load signal extraction step of measuring a load applied to the pressing unit with a fourth sensor unit installed in the pressing unit so as to be positioned on the center line of the support unit; And matching and analyzing the sound signal output from the sound signal extraction step, the video signal output from the image signal extraction step, the displacement signal output from the displacement signal extraction step, and the load signal output from the load signal extraction step. Thus, an analysis step of determining a fracture occurrence time point of the specimen and outputting a load value at the fracture occurrence time point; may include.

According to another embodiment of the present invention, the analyzing step may include a first data collection step of collecting and converting the sound signal output from the sound signal extraction step and the displacement signal output from the displacement signal extraction step into data; A first analysis step of matching and analyzing the sound signal and the displacement signal, which are data-data in the first data collection step, and displaying and listing the sound signal for each displacement of the pressing part according to the displacement signal; a second data collection step of collecting and converting the image signal output from the image signal extraction step and the displacement signal output from the displacement signal extraction step into data; a second analysis step of matching and analyzing the image signal converted into data in the second data collection step and the displacement signal, and displaying and listing the image signal for each displacement of the pressing part according to the displacement signal; And checking the predetermined displacement of the pressing part at the position where the sound signal is displayed in the first analysis step and the image signal in the second analysis step at the same displacement as the predetermined displacement to determine whether or not the specimen is broken. and a comparison and determination step of determining the sound signal at the predetermined displacement in the first analysis step as a signal at the time of occurrence of fracture of the specimen when the occurrence of fracture is confirmed in the video signal. there is.

According to another embodiment of the present invention, in the first data collection step, the load signal output from the load signal extraction step is collected and converted into data together with the acoustic signal and the displacement signal, and in the first analysis step, For each displacement of the pressing part according to the displacement signal, a change in the load value of the pressing part according to the load signal together with the sound signal may be displayed and listed.

According to another embodiment of the present invention, in the comparison and determination step, the load value corresponding to the predetermined displacement equal to the acoustic signal at the time of fracture of the specimen in the first analysis step is the occurrence of fracture of the specimen It can be output with the load of the hour.

According to another embodiment of the present invention, in the image signal extraction step, the second sensor unit is installed on one side of the support unit so as to face a direction perpendicular to or inclined to the direction of elevation of the pressing unit, and the pressing unit a camera sensor for photographing the pressurized portion of the specimen pressed by and outputting the image signal; a reflector installed under the specimen supported by the support and illuminating the pressurized portion of the specimen toward the camera sensor; and a driving body for sliding and moving the camera sensor.

According to another embodiment of the present invention, the specimen seating step includes a reflector angle adjusting step of adjusting an angle of the reflector so that the pressurized portion of the specimen seated on the support portion is projected toward the camera sensor, , The image signal extraction step is interlocked with the third sensor unit to maintain a constant focal distance between the pressurized portion of the specimen pressed downward by the pressurization unit and the camera sensor, and the third sensor A camera sensor movement step of sliding and moving the camera sensor by a descending distance of the pressing unit according to the displacement signal output from the unit.

According to another embodiment of the present invention, the sound signal extraction step may include a sound signal detection step of detecting the sound generated from the specimen and outputting the sound signal as the sound signal by an acoustic sensor installed on one side of the specimen; and an amplification step of amplifying the sound signal output in the sound signal sensing step.

According to another embodiment of the present invention, in the displacement signal extraction step, a laser sensor installed on one side of the pressing part may measure a distance from the pressing part to the support part and output the displacement signal as the displacement signal.

According to another embodiment of the present invention, in the specimen seating step, the specimen is formed of a high-toughness material, and a notch portion is formed concavely in the width direction of the specimen on the lower surface of the pressurized portion pressed by the pressurization unit. can

According to one embodiment of the present invention made as described above, in a specimen formed of a high-toughness material, by forming a notch on the lower surface of the pressurized portion where the upper surface is pressed by the pressurization unit, the initiation of fracture can be easily achieved, The location of breakage can also be accurately controlled.

In addition, during the bending test of the specimen, the sound generated from the specimen collected using the acoustic sensor and the camera sensor and the image of the pressurized part of the specimen are matched and compared for each pressurized displacement of the specimen so that fracture occurring in the specimen can be detected during the bending test. By doing so, it is possible to accurately detect the point of occurrence of fracture of the specimen and output the load value at this time.

Accordingly, a three-point bending test system having the effect of increasing the efficiency and reliability of a three-point bending test of a specimen formed of a high-toughness material by accurately testing the strength of the specimen, such as the breaking strength at which fracture occurs in the specimen, and 3 A point bend test method can be implemented. Of course, the scope of the present invention is not limited by these effects.

1 and 2 are cross-sectional views schematically showing front and side views of a three-point bending test system according to an embodiment of the present invention.
3 and 4 are cross-sectional views schematically showing front and side views of a specimen subjected to a bending test in the three-point bending test system of FIG. 1 .
5 is a schematic diagram schematically illustrating an analysis unit of the 3-point bending test system of FIG. 1;
6 is a process flow chart showing a three-point bending test method using the three-point bending test system of FIG. 1 in order.

Hereinafter, several preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art, and the following examples may be modified in many different forms, and the scope of the present invention is as follows It is not limited to the examples. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the spirit of the invention to those skilled in the art. In addition, the thickness or size of each layer in the drawings is exaggerated for convenience and clarity of explanation.

Hereinafter, embodiments of the present invention will be described with reference to drawings schematically showing ideal embodiments of the present invention. In the drawings, variations of the depicted shape may be expected, depending on, for example, manufacturing techniques and/or tolerances. Therefore, embodiments of the inventive concept should not be construed as being limited to the specific shape of the region shown in this specification, but should include, for example, a change in shape caused by manufacturing.

1 and 2 are cross-sectional views schematically showing front and side views of a three-point bending test system 1000 according to an embodiment of the present invention, and FIGS. 3 and 4 are three-point bending test systems 100 of FIG. 1 are cross-sectional views schematically showing the front and side surfaces of the specimen 1 subjected to the bending test, and FIG. 5 is a schematic diagram schematically showing the analysis unit 600 of the three-point bending test system 1000 of FIG. 1.

First, as shown in FIGS. 1 and 2, the three-point bending test system 1000 according to an embodiment of the present invention includes a bending tester 100, a first sensor unit 200, and a first It may include a second sensor unit 300 , a third sensor unit 400 , a fourth sensor unit 500 and an analysis unit 600 .

As shown in FIGS. 1 and 2, the bending tester 100 supports both sides of the lower surface of the specimen 1 so that a three-point bending test of the specimen 1 formed in the form of a long bar in the longitudinal direction can be performed. It may include a support part 110 and a pressurizing part 120 located on the centerline (C) of the support part 110 and installed to be able to go up and down with respect to the support part 110 to press the upper surface of the specimen 1 .

For example, the support part 110 of the bending tester 100 may be formed in a “c” shape to support both sides of the lower surface of the specimen 1 so that the specimen 1 can be supported by two supporting points. The support part 110 may be a kind of frame structure capable of supporting the specimen 1 with two support points. For example, the support 110 may be an integral injection structure, a casting, or a frame structure formed by welding or connecting various shapes of plates, wires, pipes, vertical members, horizontal members, and inclined members to each other.

In addition, the pressing part 120 is located on the center line (C) of the support part 110 from above the support part 110, and a linear drive device (not shown) such as a hydraulic cylinder, a pneumatic cylinder, or an electric cylinder By being installed to be able to move up and down in a direction approaching the support part 110 or in a direction away from the support part 110, the upper surface of the center of the specimen 1 supported by the support part 110 as two support points is pressed as one action point. can do.

Here, the specimen 1 subjected to the 3-point bending test by the bending tester 100 may be formed of a high-toughness material, and when the upper surface in the center is pressed by the pressing unit 120, fracture easily occurs, and fracture occurs. A notch portion N may be formed concavely in the width direction of the specimen 1 on the bottom surface of the center pressed by the pressing unit 120 so that the location of occurrence of the specimen 1 may be guided to the central portion of the specimen 1. .

It may be preferable that the notch portion N be formed in a triangular cross section so that the stress applied to the specimen 1 is concentrated in one place so that fracture can be easily initiated.

As shown in FIGS. 1 and 2 , the first sensor unit 200 is installed on one side of the specimen 1 to detect sound generated from the specimen 1 being pressed by the pressing unit 120. can

More specifically, the first sensor unit 200 is installed on one side of the specimen 1, detects the sound generated in the specimen 1 and outputs the acoustic signal as the acoustic sensor 210 and the acoustic sensor ( 210) may include an amplifier 220 that amplifies the sound signal detected as a fine sound and output.

The first sensor unit 200 may accurately detect the sound that may be generated according to the start of fracture of the specimen 1 during a bending test of the specimen 1, so that the notch part (N) of the specimen 1 ), it may be desirable to install it in a position as close as possible to

As shown in FIGS. 1 and 2 , the second sensor unit 300 is installed on one side of the support unit 110 so as to be positioned on the center line C of the support unit 110, and the pressing unit 120 The pressurized portion of the specimen 1 pressed by the can be captured as an image.

More specifically, the second sensor unit 300 is installed on one side of the support unit 110 so as to face a vertical direction or an inclined direction with the elevating direction of the pressing unit 120, by the pressing unit 120. A camera sensor 310 for photographing the lower surface of the pressurized portion of the pressurized specimen 1 and outputting the image signal, and a camera sensor 310 installed below the specimen 1 supported by the support part 110, the specimen 1 It may include a reflector 320 that shines the pressurized portion of the camera sensor 310 toward the camera sensor 310 and a driving body 330 that slides the camera sensor 310 .

For example, the camera sensor 310 of the second sensor unit 300 is installed so as to face the support unit 110 in a direction perpendicular to the elevating and descending direction of the pressing unit 120, and a notch portion N is formed. The lower surface of the pressurized portion of the specimen 1 may be photographed.

In addition, the lower surface of the pressurized portion of the specimen 1 having the notch portion N toward the camera sensor 310 installed in a direction perpendicular to the direction in which the notch portion N of the sample 1 is formed can be reflected, A reflector 320, which is a kind of mirror, may be inclinedly installed below the specimen 1 at a position corresponding to the pressurized portion of the specimen 1. At this time, it may be preferable that the reflector 320 is installed such that the inclination angle is adjustable so that the lower surface of the pressurized portion of the specimen 1 can be easily reflected according to the installation direction of the camera sensor 310 .

In addition, the driving body 330 is a linear driving unit such as a hydraulic cylinder, a pneumatic cylinder, or an electric cylinder, and can slide the camera sensor 310 in a direction closer to or farther from the support unit 110 .

More specifically, as shown in FIGS. 3 and 4, during the bending test of the specimen 1, the pressurized portion of the specimen 1 pressed downward by the pressurization unit 120 and the camera sensor 310 In order to keep the focal distance constant, the driving body 330 interlocks with the laser sensor 410 of the third sensor unit 400 to be described later, and presses according to the displacement signal output from the laser sensor 410. The camera sensor 310 may be slid and moved by the descending distance of the unit 120 .

For example, in order for the camera sensor 310 to accurately detect fracture occurring in the notch portion N of the specimen 1, the notch portion N must be clearly photographed, and thus the pressurized portion of the specimen 1 and the camera sensor The focal distance between (310) can act as a very important factor.

Therefore, when setting the initial specimen 1, if the user appropriately moves the camera sensor 310 to set the focal length, during the bending test of the specimen 1, the driving body 330 is applied to the pressing part 120. By sliding the camera sensor 310 in a direction away from the support 110 as much as the deflection distance of the pressurized portion of the specimen 1 pressed downward by being pressed by the force, the focal length continues during the bending test of the specimen 1 can be kept constant.

As shown in FIGS. 1 and 2 , the third sensor unit 400 is installed on one side of the pressing unit 120 and descends toward the support unit 110 to press the specimen 1 . ) can measure the movement displacement. The third sensor unit 400 is a laser sensor 410 installed on one side of the pressing unit 120 and measuring the distance from the pressing unit 120 to the support unit 110 and outputting the displacement signal. can

However, the third sensor unit 400 is not necessarily limited thereto, and is one side of the pressing unit 120, such as an ultrasonic sensor that measures a distance by generating ultrasonic waves or a contact-type distance sensor that can measure a distance using a probe. All types of sensors that are installed on and can measure the distance from the pressing part 120 to the support part 110 can be used.

As shown in FIGS. 1 and 2 , the fourth sensor unit 500 is installed in the pressing unit 120 so as to be located on the center line C of the support unit 110, and presses the specimen 1. A load applied to the pressing part 120 can be measured as a reaction force by . For example, the fourth sensor unit 500 may be a load cell.

In addition, as shown in FIGS. 1 and 2 , the analysis unit 600 includes the sound signal of the first sensor unit 200, the video signal of the second sensor unit 300, and the third sensor unit 400. ) and the load signal of the fourth sensor unit 500 are matched and analyzed to determine the time point of breakage of the specimen 1, and output the load value at the time of breakage.

More specifically, as shown in FIG. 5 , the analyzer 600 analyzes the acoustic signal output from the first sensor unit 200 through the first data collection unit 610 and the third sensor unit 400. The output displacement signal is collected and converted into data, and the acoustic signal converted into data in the first data collection unit 610 through the first analyzer 620 and the displacement signal are matched and analyzed to apply pressure according to the displacement signal. The acoustic signals may be displayed and arranged in a graph form for each displacement of the unit 120 .

Here, the first data collection unit 610 collects the load signal output from the fourth sensor unit 500 and converts it into data together with the sound signal and the displacement signal, and the first analysis unit 620 For each displacement of the pressing unit 120 according to the displacement signal, changes in the load value of the pressing unit 120 according to the load signal together with the sound signal may be displayed and listed in a graph form.

Accordingly, the analysis result output from the first analysis unit 620 in the form of a graph is the displacement of the pressing unit 120 on the X axis, and the sound level of the sound signal (in dB) and the magnitude of the load value on the Y axis. It can be output in graph form.

In addition, the analysis unit 600 collects the image signal output from the second sensor unit 300 and the displacement signal output from the third sensor unit 400 through the second data collection unit 630 and turns them into data. and by matching and analyzing the image signal and the displacement signal converted into data in the second data collection unit 630 through the second analyzer 640, the image for each displacement of the pressing unit 120 according to the displacement signal. Signals can be displayed in graph form and listed.

Accordingly, the analysis result output from the second analysis unit 640 in the form of a graph takes the displacement of the pressing unit 120 as the X-axis, and the pressurized portion of the specimen 1 photographed at the corresponding displacement along the X-axis ( Notch portion) may be output in the form of a graph in which the image signals are sequentially arranged.

Therefore, as shown in FIG. 5, the analysis unit 600 finally determines the predetermined position of the pressing unit 120 at the position where the sound signal is displayed in the first analysis unit 620 through the comparison and determination unit 650. By checking the displacement of and the video signal of the second analysis unit 640 at the same displacement as the predetermined displacement, whether or not fracture of the specimen 1 has occurred is confirmed, and in the video signal corresponding to the predetermined displacement, When fracture occurs, the acoustic signal at the predetermined displacement of the first analyzer 620 may be determined as a signal at the time of fracture of the specimen 1 .

Subsequently, by outputting the load value corresponding to the same predetermined displacement as the acoustic signal at the time of fracture of the specimen 1 of the first analysis unit 620 as the load at the time of fracture of the specimen 1, The fracture time of the specimen 1 formed of the high-toughness material can be accurately detected, and the fracture strength of the specimen 1 can also be accurately calculated.

Therefore, according to the three-point bending test system 1000 according to an embodiment of the present invention, in the specimen 1 formed of a high-toughness material, the lower surface of the pressurized portion, the upper surface of which is pressed by the pressurization unit 120, By forming the notch portion N, initiation of fracture can be easily achieved due to stress concentration occurring in the specimen 1, and the occurrence location of fracture can also be accurately controlled.

In addition, during the bending test of the specimen 1, the acoustic sensor 210 and the camera sensor 310 are used to detect the fracture occurring in the specimen 1, and the sound and By matching and comparing the image of the pressurized part of the specimen 1 for each pressurized displacement of the specimen 1, it is possible to accurately detect the point of occurrence of fracture of the specimen 1 and output the load value at this time.

Therefore, by accurately testing the strength of the specimen 1, such as the breaking strength at which fracture occurs in the specimen 1, the effect of increasing the efficiency and reliability of the three-point bending test of the specimen 1 formed of a high-toughness material can have

Hereinafter, a three-point bending test method capable of performing a bending test of the specimen 1 using the above-described three-point bending test system 1000 will be described in detail.

6 is a process flow chart showing a three-point bending test method using the three-point bending test system 1000 of FIG. 1 in order.

First, referring to FIG. 6 , the three-point bending test method according to another embodiment of the present invention may proceed in the order of a specimen seating step (S100), a specimen testing step (S200), and a test termination step (S300).

For example, as shown in FIG. 6, in the specimen seating step (S100), the specimen 1 formed in the form of a long bar in the longitudinal direction is placed on the support 110 of the bending tester 100 capable of performing a three-point bending test. The specimen (1) can be seated.

At this time, in the specimen seating step (S100), through the reflector angle adjustment step (S100), the reflector 320 so that the pressurized portion of the specimen 1 seated on the support 110 can be projected toward the camera sensor 310. The angle of may be adjusted, and in this process, the user may appropriately move the camera sensor 310 to adjust the focal distance between the pressurized portion of the specimen 1 and the camera sensor 310.

The specimen 1 used in the specimen seating step (S100) is formed of a high-toughness material and has a notch concave in the width direction of the specimen 1 on the lower surface of the pressurized portion pressurized by the pressurization unit 120. (N) can be formed.

Subsequently, in the specimen testing step (S200), the specimen 1 may be subjected to a bending test by pressing the upper surface of the specimen 1 seated on the support part 110 with the pressing part 120.

At this time, in the course of the specimen testing step (S200), a sound signal extraction step (S210), an image signal extraction step (S220), and a displacement signal so that the fracture occurrence time and breaking load of the specimen 1 can be measured. An extraction step (S230), a load signal extraction step (S240), and an analysis step (S250) may be executed.

For example, in the sound signal extraction step (S210), the first sensor unit 200 installed on one side of the specimen 1 may detect sound generated from the specimen 1 pressed by the pressing unit 120. .

More specifically, in the sound signal extraction step (S210), the acoustic sensor 210 installed on one side of the specimen 1 detects the sound generated in the specimen 1 and outputs the sound signal as the sound signal detection step. (S211) and an amplification step (S212) of amplifying the sound signal output in the sound signal detection step (S211) may be executed in order.

In addition, in the image signal extraction step (S220), the second sensor unit 300 installed on one side of the support unit 110 to be positioned on the center line (C) of the support unit 110, by the pressing unit 120 The pressurized portion of the specimen 1 to be pressed may be captured as an image.

In the image signal extraction step (S220), the camera sensor is moved so that the focal distance between the pressurized portion of the specimen 1 pressed downward by the pressurization unit 120 and the camera sensor 310 can be kept constant Through step S221, the camera sensor 310 is interlocked with the third sensor unit 400 to move the camera sensor 310 to the support unit 110 as much as the descending distance of the pressing unit 120 according to the displacement signal output from the third sensor unit 400. ) and can be moved by sliding in a direction away from it.

In addition, in the displacement signal extraction step (S230), the third sensor unit 400 installed on one side of the pressing unit 120 descends toward the support unit 110 and presses the specimen 1. Movement displacement can be measured. In the displacement signal extraction step (S230), the laser sensor 410 installed on one side of the pressing unit 120 can measure the distance from the pressing unit 120 to the support unit 110 and output it as the displacement signal. there is.

In addition, in the load signal extraction step (S240), the fourth sensor unit 500 installed in the pressing unit 120 so as to be located on the center line (C) of the support unit 110, applied to the pressing unit 120 load can be measured.

The above-described sound signal extraction step (S210), image signal extraction step (S220), displacement signal extraction step (S230), and load signal extraction step (S240), in the specimen testing step (S200), support part 110 It can be performed simultaneously while the specimen 1 seated on is pressed by the pressing unit 120, and the sound signal, video signal, displacement signal, and load signal output in each step are followed by an analysis step (S250). ), by matching and analyzing each other, it is possible to determine the time of occurrence of fracture of the specimen 1 and to output the load value at the time of occurrence of fracture.

More specifically, in the analysis step (S250), the sound signal output from the sound signal extraction step (S210) and the displacement signal output from the displacement signal extraction step (S230) are collected through the first data collection step (S251). and data, through the first analysis step (S252), by matching and analyzing the acoustic signal and the displacement signal data-data in the first data collection step (S251), the displacement of the pressing unit 120 according to the displacement signal The acoustic signals may be displayed and listed for each.

At this time, in the first data collection step (S251), the load signal output from the load signal extraction step (S240) is collected and converted into data together with the sound signal and the displacement signal, and in the first analysis step (S252), the For each displacement of the pressing unit 120 according to the displacement signal, changes in the load value of the pressing unit 120 according to the load signal may be displayed and arranged along with the sound signal.

In addition, in the analysis step (S250), the video signal output from the image signal extraction step (S220) and the displacement signal output from the displacement signal extraction step (S230) are collected through the second data collection step (S253), data, and through the second analysis step (S254), by matching and analyzing the image signal and the displacement signal, which are data-data in the second data collection step (S253), and each displacement of the pressing part 120 according to the displacement signal The video signals may be displayed and listed.

Therefore, as shown in FIG. 6, in the analysis step (S600), through the final comparison and determination step (S255), in the first analysis step (S252), the predetermined position of the pressing part 120 at the position where the sound signal is displayed is determined. By checking the displacement of and the video signal of the second analysis step (S254) at the same displacement as the predetermined displacement, whether or not fracture of the specimen 1 occurs, and if fracture occurs in the video signal, The acoustic signal at the predetermined displacement in the first analysis step (S252) may be determined as a signal at the time of occurrence of the fracture of the specimen 1.

Subsequently, by outputting the load value corresponding to the predetermined displacement equal to the acoustic signal at the time of fracture of the specimen 1 in the first analysis step (S252) as the load at the time of fracture of the specimen 1, The fracture time of the specimen 1 formed of the high-toughness material can be accurately detected, and the fracture strength of the specimen 1 can also be accurately calculated.

In this way, when fracture occurs in the specimen 1 to be subjected to the bending test during the specimen testing step (S200), the bending test may be terminated through the test termination step (S300) after the above-described steps are completed.

Therefore, according to the three-point bending test method according to another embodiment of the present invention, in the specimen 1 formed of a high-toughness material, the notch portion ( By forming N), the initiation of fracture can be easily achieved due to the stress concentration occurring in the specimen 1, and the location of fracture occurrence can also be accurately controlled.

In addition, during the bending test of the specimen 1, the acoustic sensor 210 and the camera sensor 310 are used to detect the fracture occurring in the specimen 1, and the sound and By matching and comparing the image of the pressurized part of the specimen 1 for each pressurized displacement of the specimen 1, it is possible to accurately detect the point of occurrence of fracture of the specimen 1 and output the load value at this time.

Therefore, by accurately testing the strength of the specimen 1, such as the breaking strength at which fracture occurs in the specimen 1, the effect of increasing the efficiency and reliability of the three-point bending test of the specimen 1 formed of a high-toughness material can have

Although the present invention has been described with reference to the embodiments shown in the drawings, this is merely exemplary, and those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. Therefore, the true technical scope of protection of the present invention should be determined by the technical spirit of the appended claims.

1: Psalms
100: bending tester
110: support
120: pressing part
200: first sensor unit
210: acoustic sensor
220: amplifier
300: second sensor unit
310: camera sensor
320: reflector
330: driving body
400: third sensor unit
410: laser sensor
500: fourth sensor unit
600: analysis unit
610: first data collection unit
620: first analysis unit
630: second data collection unit
640: second analysis unit
650: comparison judgment unit
N: notch
1000: 3-point bending test system

Claims (18)

In order to perform a three-point bending test of a specimen formed long in the longitudinal direction, a support part supporting both sides of the lower surface of the specimen and a support part located on the center line of the support part are installed to be able to move up and down with respect to the support part, and the upper surface of the specimen A bending tester including a pressing unit for pressing;
a first sensor unit installed on one side of the specimen and detecting sound generated from the specimen pressed by the pressurizing unit;
a second sensor unit installed on one side of the support unit so as to be located on the center line of the support unit, and taking an image of a pressurized portion of the specimen pressed by the pressurization unit;
a third sensor unit installed at one side of the pressing unit and measuring a movement displacement of the pressing unit that descends toward the support unit and presses the specimen;
a fourth sensor unit installed on the pressing unit to be positioned on the center line of the support unit and measuring a load applied to the pressing unit; and
The sound signal of the first sensor unit, the video signal of the second sensor unit, the displacement signal of the third sensor unit, and the load signal of the fourth sensor unit are matched and analyzed to determine the time point of fracture of the specimen, Analysis unit for outputting a load value at the time of fracture;
Including, three-point bending test system. According to claim 1,
The first sensor unit,
an acoustic sensor installed on one side of the specimen, detecting the sound generated from the specimen and outputting the sound signal; and
an amplifier that amplifies the sound signal output from the sound sensor;
Including, three-point bending test system. According to claim 1,
The second sensor unit,
a camera sensor installed on one side of the support part in a direction perpendicular to or inclined to the ascending and descending direction of the pressing part, and photographing the pressed portion of the specimen pressed by the pressing part and outputting the image signal;
a reflector installed under the specimen supported by the support and illuminating the pressurized portion of the specimen toward the camera sensor; and
a driving body for sliding and moving the camera sensor;
Including, three-point bending test system. According to claim 3,
The third sensor unit,
a laser sensor installed on one side of the pressing part, measuring a distance from the pressing part to the support part and outputting the displacement signal;
Including, three-point bending test system. According to claim 4,
The driving body,
The pressing part according to the displacement signal output by the laser sensor in conjunction with the laser sensor so that the focal distance between the pressing part of the specimen pressed and pressed downward by the pressing part and the camera sensor can be kept constant A three-point bending test system that slides the camera sensor by a falling distance. According to claim 1,
The analysis unit,
a first data collection unit that collects and converts the sound signal output from the first sensor unit and the displacement signal output from the third sensor unit into data;
a first analysis unit that matches and analyzes the acoustic signal and the displacement signal, which are data-generated by the first data collection unit, and displays and lists the acoustic signal for each displacement of the pressing unit according to the displacement signal;
a second data collection unit for collecting and converting the image signal output from the second sensor unit and the displacement signal output from the third sensor unit into data;
a second analysis unit that matches and analyzes the video signal and the displacement signal, which are data-generated by the second data collection unit, and displays and lists the video signal for each displacement of the pressing unit according to the displacement signal; and
In the first analysis unit, the predetermined displacement of the pressing unit at the position where the sound signal is displayed and the image signal of the second analysis unit at the same displacement as the predetermined displacement are checked to determine whether the specimen is broken, , a comparison determination unit for determining the sound signal at the predetermined displacement of the first analysis unit as a signal at the time of occurrence of fracture of the specimen when fracture occurrence is confirmed in the video signal;
Including, three-point bending test system. According to claim 6,
The first data collection unit,
The load signal output from the fourth sensor unit is collected and converted into data together with the sound signal and the displacement signal,
The first analysis unit,
For each displacement of the pressing part according to the displacement signal, a change in the load value of the pressing part according to the load signal together with the sound signal is displayed and listed. According to claim 7,
The comparison judgment unit,
A three-point bending test system that outputs the load value corresponding to the predetermined displacement equal to the acoustic signal at the time of fracture of the specimen of the first analysis unit as the load at the time of fracture of the specimen. According to claim 1,
The psalm,
A three-point bending test system formed of a high-toughness material and having a concave notch formed in the width direction of the specimen on the lower surface of the pressurized portion pressed by the pressurization unit. A specimen seating step of seating the specimen on a support of a bending tester capable of performing a three-point bending test on a specimen formed long in the longitudinal direction;
a specimen test step of performing a bending test on the specimen by pressing an upper surface of the specimen seated on the support part with a pressurizing part; and
Including; a test termination step of terminating the bending test when fracture occurs in the specimen to be subjected to the bending test;
The specimen test step,
a sound signal extraction step of detecting sound generated from the specimen pressed by the pressurizing unit with a first sensor unit installed on one side of the specimen;
An image signal extraction step of capturing an image of a pressurized portion of the specimen pressed by the pressurization unit with a second sensor unit installed on one side of the support unit so as to be located on the center line of the support unit;
a displacement signal extraction step of measuring a moving displacement of the pressing unit that presses the specimen by descending toward the support unit with a third sensor unit installed at one side of the press unit;
a load signal extraction step of measuring a load applied to the pressing unit with a fourth sensor unit installed in the pressing unit so as to be positioned on the center line of the support unit; and
Matching and analyzing the sound signal output from the sound signal extraction step, the video signal output from the image signal extraction step, the displacement signal output from the displacement signal extraction step, and the load signal output from the load signal extraction step , an analysis step of determining a fracture occurrence time point of the specimen and outputting a load value at the fracture occurrence time point;
Including, three-point bending test method. According to claim 10,
The analysis step is
a first data collection step of collecting and converting the sound signal output from the sound signal extraction step and the displacement signal output from the displacement signal extraction step into data;
A first analysis step of matching and analyzing the sound signal and the displacement signal, which are data-data in the first data collection step, and displaying and listing the sound signal for each displacement of the pressing part according to the displacement signal;
a second data collection step of collecting and converting the image signal output from the image signal extraction step and the displacement signal output from the displacement signal extraction step into data;
a second analysis step of matching and analyzing the image signal converted into data in the second data collection step and the displacement signal, and displaying and listing the image signal for each displacement of the pressing part according to the displacement signal; and
Checking the predetermined displacement of the pressing part at the position where the sound signal is displayed in the first analysis step and the image signal in the second analysis step at the same displacement as the predetermined displacement to determine whether the specimen is fractured and a comparison and determination step of judging the acoustic signal at the predetermined displacement in the first analysis step as a signal at the time of occurrence of fracture of the specimen when fracture occurrence is confirmed in the video signal;
Including, three-point bending test method. According to claim 11,
In the first data collection step,
The load signal output from the load signal extraction step is collected and converted into data together with the sound signal and the displacement signal,
In the first analysis step,
For each displacement of the pressing part according to the displacement signal, a change in the load value of the pressing part according to the load signal along with the sound signal is displayed and listed. According to claim 12,
In the comparison judgment step,
Three-point bending test method for outputting the load value corresponding to the predetermined displacement equal to the acoustic signal at the time of fracture of the specimen in the first analysis step as the load at the time of fracture of the specimen. According to claim 10,
In the image signal extraction step, the second sensor unit,
a camera sensor installed on one side of the support part in a direction perpendicular to or inclined to the ascending and descending direction of the pressing part, and photographing the pressed portion of the specimen pressed by the pressing part and outputting the image signal;
a reflector installed under the specimen supported by the support and illuminating the pressurized portion of the specimen toward the camera sensor; and
a driving body for sliding and moving the camera sensor;
Including, three-point bending test method. 15. The method of claim 14,
The specimen seating step,
A reflector angle adjusting step of adjusting an angle of the reflector so that the pressurized portion of the specimen seated on the support is projected toward the camera sensor;
The video signal extraction step,
According to the displacement signal output by the third sensor unit in conjunction with the third sensor unit, to maintain a constant focal distance between the pressurized portion of the specimen pressed by the pressurization unit and pressed downward and the camera sensor. a camera sensor movement step of sliding and moving the camera sensor by the descending distance of the pressing unit;
Including, three-point bending test method. According to claim 10,
The sound signal extraction step,
a sound signal sensing step of detecting the sound generated from the specimen and outputting the sound signal as the sound signal, with an acoustic sensor installed on one side of the specimen; and
an amplification step of amplifying the sound signal output in the sound signal sensing step;
Including, three-point bending test method. According to claim 10,
In the displacement signal extraction step,
With a laser sensor installed on one side of the pressing part, the distance from the pressing part to the support part is measured and output as the displacement signal, a three-point bending test method. According to claim 10,
In the specimen seating step, the specimen,
A three-point bending test method in which a notch is formed of a high-toughness material and is formed concavely in the width direction of the specimen on the lower surface of the pressing portion pressed by the pressing portion.

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