KR100903560B1 - Apparatus for providing impact test - Google Patents

Abstract

The present invention relates to an impact tester, and its object is to provide a repeated impact tester capable of measuring stress and strain.

The present invention for achieving the above object and the first and second strain measuring sensor for fixing both ends of the specimen required to test; An impact load measuring sensor connected to an end of the first strain measuring sensor; An impactor connected to one end of the second strain measuring sensor to transmit an impact load to the specimen; It is composed of a drive unit connected to the other side of the impactor to move the impactor to apply an impact load to the specimen, it can give a repeated impact load of shear, tensile and compressive impact load test of small materials or products, resulting in strain and The technical gist of an impact tester capable of measuring strain velocity or acceleration is defined.

 Impact tester, electromagnetic coil, impact load, strain, strain rate, solder, impact, fatigue.

Description

Impact Tester {APPARATUS FOR PROVIDING IMPACT TEST}

1 is an exemplary view according to a preferred embodiment of the present invention,

2 is a detailed view of a grip part and a specimen according to a preferred embodiment of the present invention;

3 is a schematic diagram of an LVDT;

4 is a simple illustration of a general gap sensor;

5 is an exemplary diagram in which a gap sensor is applied to an impact tester.

6 is an exemplary diagram in which a laser displacement sensor is applied to an impact tester.

7 is a detailed view of a grip for applying a tensile impact load,

8 is a detailed view of a grip for applying a shear impact load;

9 is a front view of a grip for applying a compressive shock load,

10 is an exemplary view in which an electronic component or a small specimen is fixed to a grip;

11 is an exemplary view at different angles of grip for fixing an electronic component or a small specimen;

12 is a correlation diagram of a control device for controlling each sensor and a drive unit.

<Description of the symbols for the main parts of the drawings>

1: drive unit 10: electromagnetic coil

11 magnet 12 elastic body

20: first strain measurement sensor (LVDT) 21: second strain measurement sensor

22: upper core 23: lower core

24, 24a: Grip 25: Tightening bolt

200: gap sensor 201: gap sensor reaction unit

210: laser displacement sensor 211: reflector

3: impact load measuring sensor 30: alignment adjustment unit

4: shocker

4a: Impactor for tensile / shear (clasp) 4b: Impactor for compression (hammer)

40: impact transfer bar

40a: impact / transfer bar for tension / shear 40b: impact transfer bar for compression

41: shock transfer pin

5: frame 50: mainframe

51: first crossbar 52: second crossbar

53: height adjuster 54: linear bushing

6: sensor support 60: support cylinder

61: upper connector 62: lower connector

7: Specimen 70: Solder Ball Joint

71: pad 72: copper plate

73: solder

The present invention relates to a repetitive impact tester capable of measuring stress and strain, and more particularly, to evaluate the material properties such as impact load, strain, strain rate, and shock absorption amount for a small specimen such as an electronic component. It relates to an impact test apparatus for product reliability test.

Conventionally impact tests can be divided into material property evaluation and actual product evaluation. Material property evaluation is a method of evaluating the impact properties using a specimen of a particular shape in the material and product development stages, using the data obtained here to select materials, determine the shape of the product. In general, Hopkinson bar is used for high strain rate experiments, and Charpy impact tester is mainly used for measuring the amount of impact. In addition, there is an impact tester using dropping heavy materials or using a gas gun. . Detailed descriptions of these test methods are detailed in the KS Test Specification or the American Society for Testing and Materials Handbook.

In addition, the impact test of the actual product is also performed, which is a verification step after the design is completed, and the impact test is performed on the actual product or a part of the product. This is usually done using a drop impact tester or a product specific impact tester.

For impact loads, the behavior of the material varies with strain rate and strain. Therefore, it can be applied to all products except specific products or conditions for which the physically meaningful physical quantity should be measured. In addition, the height of the falling object and the acceleration change at the time of impact are not important, but the stress, strain rate, strain, and shock absorption energy caused by the impact load should be measured. Since these physical quantities are not independent and interdependent, all physical quantities must be considered at the same time. However, many commonly used impact testers do not measure all these physical quantities. In the case of the Charpy impact tester, only the shock absorbing energy can be measured, and in the case of the drop impact tester, only the drop load can be measured. The impact test using the Hopkinson bar can measure all of the strain rate, strain, and load, but it is not widely used due to its complicated structure, space, and cost.

Here, 'material behavior' refers to the behavior referred to in material behavior, which refers to the behavior of a machine or the like.

The term 'engineeringly significant physical quantity' refers to the 'stress and strain velocity' in the following sentence, and the field of measurement in many impact testers is 'drop height, acceleration change during impact', and so on. Although it is applicable to, the measured value cannot be applied when the shape or material changes. Therefore, it is emphasized that stress or strain rate should be measured.

The impact load acts in various directions, and the behavior of the material changes according to the direction of the impact load. However, current testers, that is, Hopkinson bar and drop impact tester can only test for compressive impact load, and Charpy impact tester has a problem that it can only test for complex load.

In addition, there is a test in which the impact load is applied only once, and there are tests in which the impact load is repeatedly repeated. The study of the cyclic impact load is very important in the reliability evaluation. Accordingly, there is a need for a mechanism capable of repeatedly applying a load. Most Hopkinson bars use heavy gas guns to fire heavy objects, making it difficult to repeat. In addition, the Charpy impact tester or drop impact tester has been repeatedly performed using a motor, etc., but the complexity of the structural system increases, resulting in frequent failures.

In addition, in order to perform the impact test on small materials or components, such as electronic components or MEMS (Micro Electro Mechanical Systems), the precision of the conventional impact tester is significantly reduced. In the case of the drop impact tester, rotation occurs during the dropping process, and thus the accurate shock wave is not generated. This effect is even greater for small materials. In the case of the Charpy impact tester, the energy loss is generated by the frictional force of the hammer operation part, so that the accurate shock absorption energy cannot be measured. Hopkinson bar tests using strain gages also require higher performance strain gages because of less strain. Therefore, there is a need for a method capable of precisely measuring strain and load on small specimens.

In order to measure the strain of small specimens, a high resolution displacement measuring device is required. In addition, when the displacement measuring device makes contact, the frictional effect may occur, so it is necessary to use a non-contact sensor. Therefore, LVDT which can have infinite resolution according to the performance of amplifier is used. An example of using LVDT is `` Soldering & Surface Mount Technology Vol.18, No.2, 2006 K.T. Tsai, F-L. Liu, E. H. Wong and R. Rajoo pp 12-17 '' is a tester that uses electromagnets for impact tests on micromaterials. In more detail, it accelerates hammers by regulating current in electromagnets and The load cell was mounted on the impact area of the hammer for measurement, and the LVDT sensor was attached to measure the position of the hammer. This does not apply to testing machines or other tensile and compressive impact loads that can only apply shear impact force. In addition, although LVDT was used to know the position of hammer, it could not be used as a displacement measuring device.

The present invention was created in order to solve the conventional problems as described above, the object of which is to give a repeated impact load for shear, tensile and compressive impact load test of small materials or products, the resulting strain and strain rate (B) providing an impact tester capable of measuring acceleration.

In order to achieve the object as described above, the impact tester according to the present invention includes a first and second strain measuring sensor for fixing both ends of the specimen to be tested at each end; An impact load measuring sensor connected to an end of the first strain measuring sensor; An impactor connected to one end of the second strain measurement sensor to transmit an impact load to the specimen; It is characterized in that it comprises a drive unit connected to the other side of the impactor to move the impactor to apply an impact load to the specimen.

In addition, the driving unit may be composed of an electromagnetic coil and a magnet so that the impactor can repeatedly operate the impact load.

In addition, the drive unit may be configured as an actuator for creating an impact load, such as an electromagnet or an acceleration device such as a hydraulic pneumatic gun or a gas gun, so that the repeated impact may be possible because the force is removed after the impact.

In addition, an elastic body such as a coil spring or a leaf spring or a leaf spring installed on the electromagnetic coil or the driver side may be further included in order to enhance the restoring force of the electromagnetic coil or the driver of the driving unit.

In addition, the first and second strain sensors may be configured as an LVDT attached to the grips at both ends of the specimen to calculate the strain by measuring the displacement.

In addition, the first and second strain measurement sensors may measure the displacement through a displacement transmission mechanism using a gap sensor response or a laser displacement sensor.

In addition, the impact load measuring sensor has a fast reaction speed and can be configured as a load cell of the appropriate capacity according to the specimen material of the impact test.

The apparatus may further include a frame configured to constrain the outer shapes of the respective measuring sensors and the driving unit to form an integrated body.

In addition, at least one linear bushing may be formed on the frame for alignment and linearity of the driver to guide the impactor to move up and down without departing.

In addition, the frame includes a main frame constituting the entire outline, a first crossbar provided on one side of the main frame and having an alignment adjusting unit for connecting the impact load measuring sensor and aligning the specimen and the grip with the driving unit; It may be formed as a second crossbar provided on the other side of the frame and having a sensor support portion mounted to guide the first and second strain sensors.

In addition, the main shaft corresponding to the drive shaft is installed on one end of the main axis may be provided with a height adjuster for fastening the specimen and height adjustment.

In addition, the height adjuster may be manually driven using a handle for height adjustment, or may be automatically driven by installing a motor or a pneumatic system.

The shock absorber may further include a shock transmission bar connected to the other side of the impactor and one side of the driving unit to transfer the force generated by the driving unit to the impactor.

The apparatus may further include a control device for controlling driving of the respective measuring sensors and the driving unit.

In addition, the impactor may be formed in a clasp or hammer shape according to the tensile and shear impact load or the compressive impact load.

In addition, the first and second strain measurement sensors may include a grip for fixing the specimen to change the angle of the grip surface for fixing the specimen to a predetermined angle according to the direction of the impact load required for the test.

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

Prior to the entry, in describing the present invention, even if the embodiments are different, the same reference numerals are used for the same configuration, and the description thereof may be omitted as necessary.

1 is an exemplary view according to a preferred embodiment of the present invention, Figure 2 is a detailed view of the grip portion and the specimen according to a preferred embodiment of the present invention.

1 and 2, the impact tester according to the preferred embodiment of the present invention, the driving unit 1, the first and second strain measurement sensors (20, 21), and the upper and lower grips 24, 24` ), An impact load measuring sensor 3, an impactor 4, and a frame 5.

The driving unit 1 is composed of an electromagnetic coil 10 surrounded by a magnet 11 around the force generated by the interaction with the magnet 11 by the law of Fleming as a current flows in the electromagnetic coil 10. Done.

In other words, when a current is generated, the electromagnetic coil 10 generates a repulsive force due to the magnetic field formation of the magnet 11 and the electromagnetic coil 10 to perform the driven movement.

In other words, it uses an energy conversion device that converts electrical energy into kinetic energy.

Here, since the electromagnetic coil 10 can be moved freely, it is connected to the elastic body 12 and fixed to float in the air to maintain the position.

The magnet 11 may use an electromagnet or a permanent magnet, it is preferable to use a permanent magnet.

The elastic body 12 may use an elastic force restoring device such as a thick paper or a thin metal or coil spring, leaf spring, leaf spring.

Another example of the drive unit 1 is a driver for making an impact load, it may be composed of an accelerator such as an electromagnet or a hydraulic or gas gun.

The first and second strain measurement sensors 20 and 21 measure the strain and strain rate of the specimen 7 which is required to be tested, and in this embodiment, an LVDT sensor is used.

3 is a schematic diagram of an LVDT, where a linear variable differential transformer (LVDT) basically consists of a movable core and three coils. When the AC excitation voltage is supplied to the main winding, the core moves, resulting in a change in magnitude and phase of the output voltage at the secondary winding terminal.

The magnitude of the output voltage is proportional to the position of the core away from the center and the polarity is determined by the direction of movement of the core.

One embodiment of the LVDT consists of a coiler, a coiler, a core, a support rod for supporting the core, and a case. Since the LVDT has no substantial contact between the core and the coil in structure, No mechanical wear occurs Therefore, since the friction that affects the output is small, the response characteristic can be enhanced, and there is no influence by overload. In high temperature and low temperature conditions, and in environments containing bases, the life of LVDT is shortened and it is difficult to expect normal operation. Considering these matters, there are ceramics that are strong in strength, corrosion resistance, humidity, etc., and have excellent straightness, parallelism, etc., but this is difficult to process, and it is difficult to readjust the dimensional error generated during the process and friction between ceramic former and core It is larger than other materials, so wear is easy. Synthetic resin system is used for LVDT former because the former's straightness and warpage are less than that of ceramic, but the impact, heat and cold resistance are high and the friction between the former and core is not bad enough to affect the output. Materials used as cores should be selected from magnetic materials with high permeability, which are less affected by environmental changes, reduce the eddy currents occurring between the primary and secondary coils, and reduce the influence of external magnetic fluxes on the LVDT. Shielding case should be used.

Such LVDTs are generally used for small displacement measurements and are therefore preferred for use in the present invention.

However, the first and second strain measurement sensors 20 and 21 may measure the displacement through a displacement transfer mechanism using a gap sensor or a laser displacement sensor, but the apparatus is not limited thereto.

Figure 4 is a simple illustration of a general gap sensor, Figure 5 is an illustration of applying the gap sensor to the impact tester, Figure 6 is an illustration of applying the laser displacement sensor to the impact tester.

The gap sensor 200 may measure the displacement according to the movement of the gap sensor reaction unit 201. When the position of the specimen is changed as shown in FIG. 5, the relative position of the gap sensor and the gap sensor reaction unit may be changed. Able to know.

The laser displacement sensor 210 can check the displacement according to the laser irradiation position reflected by the reflector 211 attached to the grip 24. When the position of the specimen 7 is changed as shown in FIG. 6, the reflector 211 is used. As the position of is changed, the laser irradiation position is changed so that the displacement can be known.

As shown in FIG. 2, the first and second strain measurement sensors 20 and 21 attach grips 24 and 24` to both ends of the specimen 7 that require a test, and the tightening bolt 25). An adhesive or welding may be used instead of the tightening bolt 25.

The grips 24 and 24 ′ of both ends are coupled to the upper core 22 and the lower core 23, respectively, and the upper core 22 and the lower core 23 are first and second strain measuring sensors. It is inserted into the LVDT.

The LVDT is preferably connected as close to the specimen as possible. The closer you are to the specimen, the smaller the error in strain measurement caused by the deformation of the grip. Therefore, it is desirable to process the LVDT core in the form of a tube and connect it with the grip on the side close to the specimen.

The impact load measuring sensor 3 connects one side to the grip 24 at the top to directly measure the impact load.

The impact load measuring sensor 3 preferably uses a load cell capable of changing the capacity depending on the target of the impact test.

The load cell is a load sensing sensor using an elastic body that is proportionally changed by an external force and a strain gauge that converts it into an electrical signal.

7 is a detailed view of a grip for applying a tensile impact load, FIG. 8 is a detailed view of a grip for applying a shear impact load, and FIG. 9 is a front view of a grip for applying a compressive impact load.

The impactor 4 is a unit that is connected to the end of the grip (24`) of the lower end by the impact transfer pin 41, and transmits the impact to the specimen (7).

A shock transfer bar 40 is connected to one side of the driving unit 1 and the other side of the impactor 4 to transmit the force generated by the driving unit 1 to the impactor 4.

The impactor 4 of FIG. 7 is a versatile unit that can be used for tensile / shear and compressive impact loads.

As illustrated in FIG. 7, the shock delivery bar 40 is inserted into the shock absorber 4, and when the shock transport bar 40 rises, the shock transporter 40 lifts up the shock transporter 4 and the shock transport bar 40. ) Pulls the impactor (4) by the locking portion when descending.

The impactor 4 and the impact transfer bar 40 can be replaced by a unit whose structure and shape are specialized according to the tensile / shear and compressive impact load tests.

In the tensile / shear impact load test, as shown in FIG. 8, a tension / shear for shock 4a formed in a clasp shape and a tension / shear formed in the nail / shear for shock 4a are provided. It is composed of a molten impact transmission bar (40a), the tension / shear impact transmission bar (40a) is pulled down to extend the specimen 7 is pulled down across the lower guide line for the tension / shear shock impactor (4a) formed in the form of a latch do.

At this time, the grips (24a, 24a`) is installed by replacing the grips (24a, 24a`) formed with a tracer to attach the specimen (7) vertically.

In the compression shock load test, as shown in FIG. 9, the compression impactor 4b formed in the form of a hammer, and the compression impact delivery bar 40b formed in a shape corresponding to the compression impactor 4b similarly. Compression shock transmission bar 40b is configured to strike and press the compression shock impactor (4b) to transfer the force to the specimen (7).

The frame 5 includes a main frame 50 forming an overall appearance, a first crossbar 51 disposed on the main frame 50, and a second cross bar 52 disposed below the main frame 50. The drive unit 1 is installed at the bottom of the frame 5.

The main frame 50 preferably has at least two cylinders 501 coupled to the flat plate support 500 as a main shaft.

The main frame 50 is preferably made of a stainless steel group.

At this time, the two cylinders 501 are guided to each crossbar (51, 52) to reduce the strain.

Therefore, it is preferable that each crossbar is at least 1 or more.

The first crossbar 51 is connected to the other side of the impact load measuring sensor 3 and is provided with an alignment adjusting unit 30 for aligning the specimen 7 and the grips 24, 24 ′ with the driving unit 1. .

The second cross bar 52 is provided with a sensor support 6 to fix the first and second strain sensors 20 and 21 to the central axis based on the driving unit 1.

The sensor support part 6 includes a support cylinder 60 vertically installed on the second crossbar 52, one side of which is fixed to the support cylinder 60, and the first and second strain measuring sensors 20 on the other side. 21 is composed of an upper connecting portion 61 and a lower connecting portion 62 for fixing the drive unit 1 to be aligned with the central axis driven (see FIG. 7).

In addition, a height adjuster 53 for fastening the specimen and adjusting the height is installed at one end of the main shaft 50 of the flat plate support 500.

The height adjuster 53 may be driven manually using a handle for height adjustment or fully automatic using a motor or a pneumatic system. The handle driving of the height adjuster 53 or the driving of the motor or the pneumatic system is a conventional driving method, so detailed description thereof will be omitted.

On the other hand, the center of the second cross bar 52, the impact transmission bar 40 penetrates, and the linear bushing for inducing the impact transmission bar 40 to be driven in a linear movement to the drive of the drive unit ( It is preferable to further include 54).

In addition, the first and second crossbars 51 and 52 may move up and down along the cylinder 501 of the main frame 50.

In the present embodiment, the height of the first crossbar 51 can be adjusted by the height adjuster 53.

Hereinafter, the operation according to the embodiment of the present invention will be described in connection with the accompanying drawings.

Here, the first and second strain measurement sensors 20 and 21 are LVDT sensors, and the impact load measurement sensor 3 will be described based on a load cell.

1 and 2, 7, 8 and 9, the present invention is a pair of grips (24, 24`; 24a, 24a) formed by processing the shape according to the tensile, shear, compressive impact load test `) Are respectively coupled to the upper core 22 and the lower core 23, and the upper core 22 and the lower core 23 are inserted into the first and second strain measurement sensors 20 and 21.

The first strain measurement sensor 20 is fixed to the upper connection portion 61, and the second strain measurement sensor 21 is fixed to the lower connection portion 62.

Here, the grip 24 of the first strain measuring sensor 20 is connected to the impact load measuring sensor 3, the impact load measuring sensor 3 is precisely aligned, and then the first crossbar 51. Fix it with the alignment adjusting unit 30.

In addition, the lower grip 24 ′ is fixed to the impactor 4 and the impact transfer pin 41.

Here, the impactor (4, 4a, 4b) and the impact transfer bar (40, 40a, 40b) can be replaced by a specialized unit according to the characteristics of the tensile, shear, compressive impact load test.

In addition, since the position of the first crossbar 51 is adjusted by turning the height adjuster 53, the mounting and detaching of the specimen 7 is easy.

The principle of impact load is explained as follows.

First, when the tensile shock load and the shear impact load are applied, referring to FIGS. 7 and 8, the impact transfer bars 40 and 40a connected to the driving unit 1 rise and fall from the reference position, and then the impactor 4 and 4a. ), Or collides with the impactor (4, 4a) while lowering. Impact load generated in the impactor (4, 4a) is to be transmitted to the grip (24 ') of the lower end via the impact transfer pin (41). To this end, the impact transmission bars 40 and 40a form hammer heads shaped like nails at the ends, and the impactor 4 and 4a is empty inside so that the hammer can accelerate and collide, and the part where the hammer collides It will be blocked. The upper end of the impactor 4, 4a is formed with a hole into which the impact transfer pin 41 can be inserted. Therefore, the impact transfer pin 41 passes through the holes of the impactor 4, 4a and the grip 24 'at the same time, and serves as the impact load transfer.

In order to apply the shear impact load, the lower grip 24a` and the upper grip 24a are formed by vertical machining as shown in FIG.

Referring to FIG. 9 in relation to the case where the compressive shock load is applied, the shock delivery bar 40 is replaced with the compression shock delivery bar 40b, and the impactor 4, 4a is replaced with the compression shocker 4b. Replace with and use. In this case, the compression shock delivery bar 40b moves up or down immediately after descending from the reference position, thereby transmitting the compression shock to the compression shock absorber 4b.

In addition, since the impactor 4 and the impact transmission bar 40 in FIG.

Shockwaves can be sized in several ways. For example, the magnitude and waveform of the shock waveform may be determined by changing the speed of the shock transmission bar 40 by adjusting the magnitude and time of the current applied to the electromagnetic coil 10 of the driving unit 1. In addition, the impactor (4) and tension / shear shock (4a), compression shock (4b), impact transmission bar 40 and tension / shear impact transmission bar (40a), compression shock transmission bar ( 40b), the material of the impact transfer pin 41 and the grips 24, 24 '; 24a, 24a' can be changed to determine the magnitude and waveform of the impact load. As the material, it is desirable to use a metal material that does not exhibit viscoelastic properties, and the size and shape of the waveform can be determined by attaching a specific material to the inside and outside of the impactor 4 or processing it into a suitable shape.

Using the signals of the first and second strain measurement sensors 20 and 21, the strain and the strain rate of the specimen may be obtained through Equations 1 and 2 below.

As an embodiment of the present invention, a case of testing an electronic component or a small specimen such as a PCB has been described. FIG. 10 is an exemplary view in which an electronic component or a small specimen is fixed to a grip, and FIG. 11 is a fixing of the electronic component or the small specimen. This is an exemplary view with different grip angles.

 A test piece composed of at least one solder ball joint 70, a pad 71 in contact with both sides of the solder ball joint 70, a copper plate 72 in contact with the pads 71, and solder 73 Is carried out with the grip (24) fixed.

Specimens of the electronic components vary their angles according to tensile or composite and shear impact tests. As shown in FIG. 11, (a) maintains the grip angle at 0 degrees during the tensile test, and (b) The grip angle is maintained at 45 degrees, which is useful in complex tests. (C) is installed by machining the grip angle at 90 degrees during shear test.

12 is a correlation diagram of each sensor and a controller for controlling the driver.

In order to control the drive unit 1 of the impact tester of the present invention and to measure the first and second strain sensors 20 and 21 and the impact load measuring sensor 3, a control device is required.

The configuration of the control device shown in FIG. 12 is a diagram for referring to this, and thus a detailed description thereof will be omitted.

As described above, the detailed description of the present invention has been made by the embodiments with reference to the accompanying drawings, but the above-described embodiments are only described with reference to the preferred examples of the present invention, and thus the present invention is limited to the above embodiments. It should not be understood as. Therefore, a person having ordinary knowledge in the technical field to which the present invention pertains may easily implement other forms of the present invention within the same scope as the above-described embodiments, or the present invention only by the description of the embodiments of the present invention. It will be possible to practice the invention in the same and equal range.

As described above, the present invention is a repeated impact tester capable of measuring stress and strain, and can simultaneously perform an impact test while simultaneously measuring an impact load, a strain, and a strain rate for various impact loads, and easily perform a repeated impact test. have.

As a result, various studies on impact loads are possible, and thus the impact characteristics of materials subjected to impact loads such as electronic parts and mobile devices can be further matured, and furthermore, the reliability of products can be evaluated by performing repeated impact load tests. Useful invention with the invention is an invention that is expected to use greatly in the industry.

Claims (16)

First and second grips which fix both ends of the specimen to be tested at each end; First and second strain measuring sensors for measuring the displacement of the first and second grips and then measuring the strain of the specimen using the difference; An impact load measuring sensor connected to an end portion of the first grip which is not connected to the specimen; An impactor having one side connected to an end portion of the second grip which is not connected to the specimen to transmit an impact load to the specimen; And a drive unit connected to the other side of the impactor to move the impactor so that an impact load is applied to the specimen via the second grip. The method of claim 1, The first and second grips, the impact tester, characterized in that the angle of the grip surface for fixing the specimen to a predetermined angle in accordance with the direction of the impact load required in the test. The method of claim 1, The first and second strain measuring sensors are characterized by using an LVDT having a core connected to each grip and a measuring unit for measuring displacement of the core. The method of claim 1, The first and second strain measuring sensors are impact tester, characterized in that for measuring the displacement through a displacement transmission mechanism using a gap sensor or a laser displacement sensor. The method of claim 1, The impact load measuring sensor is a shock tester, characterized in that using the load cell having a suitable capacity according to the material of the specimen. The method of claim 1, The driving unit is a shock tester, characterized in that consisting of a magnet to form a magnetic field, and an electromagnetic coil to follow the movement in the magnetic field. The method of claim 6, The impact tester further comprises an elastic body for supporting the electromagnetic coil in order to increase the restoring force of the electromagnetic coil of the drive unit. The method of claim 1, The driving unit is an impact tester, characterized in that consisting of an accelerator using an electromagnet, a pneumatic pressure or a gas gun. The method of claim 1, And a control device for controlling the driving of the drive unit. The method of claim 1, And an impact transfer bar connected to the other side of the impactor and one side of the driving unit to transfer the force generated by the driving unit to the impactor. The method of claim 1, The impactor impact tester, characterized in that it has a clasp or hammer shape, respectively, corresponding to the tensile and shear impact load or compressive impact load. The method of claim 1, Impact tester further comprises a frame to constrain the outer shape of each measuring sensor and the drive unit to form an integrated. The method of claim 12, And at least one linear bushing provided in the frame for linearity and alignment of the actuator to guide the shock transfer bar to move up and down without departing from side to side. delete delete delete

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