JP7431585B2 - Compression test equipment - Google Patents

Description

The present invention relates to a compression testing device.

An aircraft includes a fuselage and a main wing, and can fly in the air by the lift generated by the main wing. When an aircraft is in flight, an upward force acts on the main wing due to lift force, and a downward force acts on the main wing at the connection with the fuselage due to the weight of the fuselage. Therefore, while an aircraft is in flight, the main wing is subjected to a force that causes it to warp upward as it moves away from the fuselage.

At this time, the upper outer skin of the main wing receives a compressive load, and the lower outer skin receives a tensile load. In general, the compressive strength of materials used for aircraft skins tends to be lower than the tensile strength. Therefore, a strength assurance test is conducted to check whether the upper outer skin of the main wing can withstand the target compressive load.

In the strength assurance test, a compression test device is used to apply a compressive load to the upper outer skin specimen of the main wing in a direction perpendicular to the thickness direction. When a compressive load is applied to the specimen using this compression testing device, depending on the condition of the end surface of the specimen and the contact surface of the compression testing device, unexpected out-of-plane deformation may occur in the specimen, resulting in edge fracture. There was a risk.

Here, Patent Document 1 discloses a compression test apparatus that applies a compressive load to a test object. Patent Document 1 discloses that when there is a gap between the end surface of the test object and the contact surface of the compression test device, in order to reduce the gap, there is a gap between the end surface of the test object and the contact surface of the compression test device. It is disclosed that a shim is installed.

Further, Patent Document 1 discloses that when there is a gap between the end face of the test object and the contact surface of the compression test device, a spherical compression plate is used to reduce the gap. The contact surface of the spherical compression plate with the end surface of the test object is configured to be tiltable with respect to the horizontal plane. Therefore, the spherical compression plate can match the parallelism with the end surface of the test object even if the end surface of the test object is inclined with respect to the horizontal plane. As a result, the spherical compression plate can reduce the gap between the end surface of the test object and the contact surface of the compression testing device.

Japanese Patent Application Publication No. 2013-142698

However, when installing a shim between the end surface of the test object and the contact surface of the compression test device as described in Patent Document 1, the gap between the end surface of the test object and the contact surface of the compression test device is adjusted. depends on the thickness of the shim, making it difficult to optimize the gap. In addition, to adjust the gap using shims, apply a pre-compression load that is less than the target compression load to the test object, measure the strain of the test object with a strain gauge, and then remove the pre-compression load from the shim plate. Adjustments are made by examining the thickness, installing shims, and repeatedly applying pre-compression loads. Therefore, there is a problem in that adjusting the gap using shims takes a lot of time and effort.

On the other hand, when using a spherical compression plate as described in Patent Document 1, the gap between the end surface of the test object and the contact surface of the compression test device can be easily adjusted, and the compression applied to the end surface of the test object can be easily adjusted. The stress can be made uniform in the width direction of the end face. However, if there is local deformation such as deflection, distortion, or twisting near the center of the test object in the loading direction, even if the compressive stress applied to the end face of the test object is uniform, the center of the test object ( For example, the compressive stress applied to the orientation section may not be uniform in the width direction. In that case, even if a spherical compression plate was used, it was difficult to apply compressive stress evenly near the center of the test object, making it impossible to accurately measure the strength properties near the center of the test object. .

Therefore, an object of the present invention is to easily and highly accurately adjust the compressive stress applied to the vicinity of the center of a specimen, regardless of the state of the end face or the state of the vicinity of the center of the specimen.

In order to solve the above problems, the compression test apparatus of the present invention includes a pair of compression plates that sandwich a specimen in a first direction, and a load that applies a compressive load in the first direction to the specimen through the compression plates. A device, a plurality of strain gauges attached to the orientation part of the specimen, which are set based on the results of strength analysis when simulating a state in which a compressive load is applied to the specimen , and at least one of a pair of compression plates. The part that comes into contact with the specimen in the first direction is divided into a plurality of movable pieces so as to be movable individually in the first direction, and a part that corresponds to the outputs of the plurality of strain gauges when a compressive load is applied to the specimen. an adjustment mechanism that can individually adjust the positions of the plurality of movable pieces in the first direction ; and a control device that controls the adjustment mechanism based on the outputs of the plurality of strain gauges . In a state where a pre-compression load that is less than the target compression load applied at The positions of the plurality of movable pieces in the first direction are individually adjusted .

The orientation portion may be a portion where the compressive stress is the largest when a compressive load is applied to the specimen.

The specimen may be an aircraft skin member made of fiber-reinforced plastic.

According to the present invention, it is possible to easily and accurately adjust the compressive stress applied to the vicinity of the center of the specimen, regardless of the state of the end face or the state of the vicinity of the center of the specimen.

1 is a schematic perspective view of an aircraft according to an embodiment of the present invention. 2 is a schematic cross-sectional view showing the main wing taken along line II-II in FIG. 1. FIG. FIG. 2 is a schematic perspective view of a specimen according to the same embodiment. It is a schematic block diagram of the compression test device concerning the same embodiment. It is a schematic perspective view of the compression plate based on the same embodiment. It is a schematic sectional view of the compression board concerning the same embodiment. FIG. 2 is a schematic configuration diagram of the compression testing apparatus during contact state adjustment processing according to the same embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in these embodiments are merely illustrative to facilitate understanding of the invention, and do not limit the invention unless otherwise specified. In this specification and the drawings, elements with substantially the same functions and configurations are given the same reference numerals to omit redundant explanation, and elements not directly related to the present invention are omitted from illustration. do.

[1. Overall configuration of the aircraft]
First, with reference to FIG. 1, the overall configuration of an aircraft 1 according to an embodiment of the present invention will be described. FIG. 1 is a schematic perspective view of an aircraft 1 according to an embodiment of the present invention.

As shown in FIG. 1, the aircraft 1 includes a fuselage 3, a main wing 5, a horizontal stabilizer 7, and a vertical stabilizer 9. Hereinafter, the main wing 5, horizontal stabilizer 7, and vertical stabilizer 9 will also be simply referred to as wings.

The fuselage 3 is a central structural member of the fuselage of the aircraft 1, and its length in the longitudinal direction (roll axis direction) is longer than the length in the left-right direction (pitch axis direction) and the vertical direction (yaw axis direction). Inside the fuselage 3, a boarding space is formed in which a passenger can board, and various devices such as a drive source such as an engine, a fuel tank, a driving device, and a measuring instrument are mounted.

A pair of main wings 5, 5 are provided on both left and right sides of the center portion of the fuselage 3. The pair of main wings 5, 5 are arranged so as to extend from the center of the fuselage 3 in the left-right direction. The main wing 5 generates upward lift on the aircraft 1.

A pair of horizontal stabilizers 7, 7 are provided on both left and right sides of the rear portion of the fuselage 3. The pair of horizontal stabilizers 7, 7 are arranged so as to protrude from the rear of the fuselage 3 in the left-right direction. The horizontal stabilizer 7 has a function of maintaining stability of the aircraft 1 around the pitch axis.

A vertical stabilizer 9 is provided above the rear part of the fuselage 3. The vertical stabilizer 9 is arranged so as to protrude upward from the rear part of the fuselage 3. The vertical stabilizer 9 has a function of maintaining stability of the aircraft 1 around the yaw axis.

[2. Internal configuration of main wing]
FIG. 2 is a schematic cross-sectional view showing the main wing 5 taken along line II-II in FIG. As shown in FIG. 2, the main wing 5 includes an outer plate (panel) 11, a stringer 13, and a box structure 15.

The cross-sectional shape of the outer plate 11 has, for example, a streamlined airfoil shape. The outer plate 11 has an outer surface exposed to an external space S1 and an inner surface forming an internal space S2. The stringer 13 is formed, for example, in an I-shape and is accommodated in the internal space S2. One end of the stringer 13 is connected to the outer panel 11, and the other end of the stringer 13 is connected to the box structure 15. In this embodiment, the stringer 13 is configured integrally with the outer panel 11. However, the stringer 13 may be configured separately from the outer panel 11 and may be attached to the outer panel 11.

The box structure 15 includes a spar of the main wing 5 (main wing spar). The box structure 15 is formed into a hollow rectangular shape and is accommodated in the internal space S2. The box structure 15 is supported by the stringer 13 while being spaced apart from the outer panel 11. A fuel storage space S3 is formed inside the box structure 15. In this embodiment, the box structure 15 functions as part of the fuel tank. Furthermore, the box structure 15 also functions as a reinforcing member that reinforces the main wing 5.

The main wing 5 is assembled by fastening the stringer 13, which is integrally formed with the outer plate 11, to the box structure 15 using a fastening member (for example, a bolt).

As described above, during flight of the aircraft 1, the upper skin 11 of the main wing 5 receives a compressive load, and the lower skin 11 receives a tensile load. Generally, the compressive strength of the material used for the outer panel 11 tends to be lower than the tensile strength. Therefore, it is necessary to perform a strength guarantee test to check whether the upper outer plate 11 of the main wing 5 can withstand the target compressive load.

[3. Configuration of specimen]
In the strength assurance test, a part of the main wing 5 is used as a specimen 17. In this embodiment, for example, a part of the upper outer panel member of the main wing 5 is used as the specimen 17. However, the specimen 17 is not limited to this, and may be a part of the lower outer panel member of the main wing 5, or a part of the outer panel member of another wing such as the horizontal stabilizer 7 or the vertical stabilizer 9. or a part of the outer panel member of the fuselage 3. That is, the specimen 17 may just be a part of the outer panel member of the aircraft 1.

FIG. 3 is a schematic perspective view of the specimen 17 according to this embodiment. As shown in FIG. 3, the specimen 17 includes an outer panel 11, a stringer 13, and a pair of reinforcing plates 19, 19.

Below, the direction parallel to the thickness direction of the outer plate 11 is the front-rear direction X, the horizontal direction perpendicular to the front-rear direction X is the left-right direction Y, and the direction perpendicular to the front-rear direction X and the left-right direction Y is the up-down direction. This will be explained as direction Z. The front direction +X (hereinafter referred to as the front side) is the direction toward the side of the outer panel 11 where the stringer 13 is arranged, and the rear direction -X (hereinafter referred to as the rear side) is the direction toward the side of the outer panel 11 where the stringer 13 is arranged. The direction is towards the opposite side from the side you are facing. Left direction +Y (hereinafter referred to as left side) and right direction -Y (hereinafter referred to as right side) are directions toward the left and right sides, respectively, when the specimen 17 is viewed from the front side. The upward direction +Z (hereinafter referred to as upper side) and the lower direction -Z (hereinafter referred to as lower side) are directions toward the upper side and lower side, respectively, when the specimen 17 is viewed from the front side.

In FIG. 3, the outer panel 11 and stringer 13, which are outer panel members of the aircraft 1, are arranged upright so that the longitudinal direction perpendicular to the plate thickness direction corresponds to the vertical direction Z. The outer plate 11 and the stringer 13 are made of, for example, CFRP (Carbon Fiber Reinforced Plastics). However, the outer panel 11 and the stringer 13 may be made of other fiber-reinforced plastics such as GFRP (Glass-Fiber-Reinforced Plastics) or AFRP (Aramid-Fiber-Reinforced Plastics). Thereby, the specific strength can be increased and the weight can be reduced compared to when the outer plate 11 and the stringer 13 are made of metal materials.

The pair of reinforcing plates 19, 19 are each formed into a rectangular shape. However, the pair of reinforcing plates 19, 19 may be formed in a shape other than a rectangular shape, such as a polygonal shape or a circular shape. The pair of reinforcing plates 19, 19 are made of metal such as aluminum, for example. However, the pair of reinforcing plates 19, 19 may be made of the same material as the outer plate 11 and the stringer 13.

A pair of reinforcing plates 19, 19 are attached to both ends of the outer plate 11 and the stringer 13 in the vertical direction Z. The pair of reinforcing plates 19, 19 reinforces both upper and lower ends of the outer panel 11 and the stringer 13 so that compressive loads are evenly and stably applied to the outer panel 11 and the stringer 13 in the vertical direction Z during the strength guarantee test. It has the function of The movement of the outer plate 11 and the stringer 13 in the left-right direction Y and the front-back direction X is restricted by the pair of reinforcing plates 19, 19.

[4. Compression test equipment configuration]
With reference to FIG. 4, a compression test apparatus according to this embodiment will be described. FIG. 4 is a schematic configuration diagram of the compression testing apparatus 100 according to this embodiment. In FIG. 4, the stringer 13 of the specimen 17 is not shown in order to make the drawing easier to see.

In the strength assurance test according to the present embodiment, a compression testing apparatus 100 is used that applies a compressive load to the specimen 17 in the vertical direction Z. As shown in FIG. 4, the compression test apparatus 100 includes a pair of compression plates 101, 101, a load device 103, a first strain gauge 105a, a second strain gauge 105b, and a third strain gauge 105c (hereinafter referred to as strain gauge). ) and a control device 107.

The pair of compression plates 101, 101 are each formed into a rectangular shape. However, the pair of compression plates 101, 101 may be formed in a shape other than a rectangular shape, such as a polygonal shape or a circular shape. The pair of compression plates 101, 101 are arranged to face each other in the up-down direction Z, and are arranged on both sides of the specimen 17 in the up-down direction Z. The pair of compression plates 101, 101 have contact surfaces 101a that can respectively contact end surfaces 17a, 17a of the specimen 17 in the vertical direction Z. The lower surface of the upper compression plate 101 and the upper surface of the lower compression plate 101 serve as the contact surface 101a. The pair of compression plates 101, 101 sandwich the specimen 17 in the first direction (vertical direction Z) and hold the specimen 17.

The load device 103 is connected to the upper compression plate 101 of the pair of compression plates 101, 101. However, the load device 103 may be connected to the lower compression plate 101 of the pair of compression plates 101, 101, or may be connected to both of the pair of compression plates 101, 101.

The loading device 103 applies a compressive load to the specimen 17 in a first direction via the compression plate 101 . In this embodiment, the first direction in which the compressive load is applied is the vertical direction Z. However, the first direction in which the compressive load is applied may be a direction different from the up-down direction Z, such as the left-right direction Y or the front-back direction X.

The strain gauge 105 detects strain in the orientation section 109 of the specimen 17. In this embodiment, for example, three strain gauges 105a, 105b, and 105c are attached to the specimen 17, but the number of strain gauges installed may be two, or four or more. The strain gauge 105 is attached to the orientation section 109 located near the center of the specimen 17 in the vertical direction, for example. These strain gauges 105 are arranged at intervals in the width direction (horizontal direction Y) of the specimen 17. In the example of FIG. 4, three strain gauges 105 are arranged on the front side (side surface in the +X direction) of the specimen 17, but in order to check whether the specimen 17 is bent during the compression test, the rear side A plurality of strain gauges 105 may be attached to the (side surface in the −X direction) side. These strain gauges 105 measure strain in the orientation section 109 of the specimen 17.

The orientation section 109 is set at a portion of the specimen 17 that is to be measured in the strength assurance test. For example, the orientation portion 109 may be a portion (severe portion) where the compressive stress is greatest as a result of strength analysis when a state in which a compressive load is applied to the specimen 17 is simulated. That is, the orientation part 109 is a part of the specimen 17 that is predicted to have the weakest strength, and may be a part to be destroyed in the strength assurance test. In this embodiment, for example, the vicinity of the center of the specimen 17 in the vertical direction Z is set as the orientation section 109. However, the setting position of the locating unit 109 is not limited to this example, and the locating unit 109 can set any position of the specimen 17 where measurement is desired, for example, the area between the end surface 17a and the center of the specimen 17. You can also set it as .

In this embodiment, the width of the orientation section 109 in the left-right direction Y is larger than the width in the up-down direction Z, and is set to be horizontally long. However, the width of the orientation section 109 in the left-right direction Y may be smaller than the width in the up-down direction Z, or may be set vertically. Further, the height of the leftmost end of the orientation section 109 is approximately equal to the height of the rightmost end of the orientation section 109. However, the height of the leftmost end of the orientation section 109 may be higher or lower than the height of the rightmost end of the orientation section 109, and is set to be inclined with respect to the left-right direction Y. may be done.

The first strain gauge 105a is arranged on the leftmost side of the orientation section 109. The third strain gauge 105c is arranged on the rightmost side of the orientation section 109. The second strain gauge 105b is arranged between the first strain gauge 105a and the third strain gauge 105c, and is arranged at the center of the orientation section 109.

The control device 107 is composed of a microcomputer including a central processing unit (CPU), a ROM in which programs and the like are stored, and a RAM as a work area, and controls the entire compression testing device 100. In FIG. 4, signals input and output to the control device 107 are shown by dashed lines. The control device 107 is electrically connected to the load device 103 and controls the compressive load applied to the specimen 17. Further, the control device 107 is electrically connected to the pair of compression plates 101, 101, and controls an adjustment mechanism 115, which will be described later.

The control device 107 is electrically connected to the first strain gauge 105a, the second strain gauge 105b, and the third strain gauge 105c. The control device 107 acquires outputs corresponding to the strain at each position of the orientation section 109 from the first strain gauge 105a, the second strain gauge 105b, and the third strain gauge 105c. Based on the acquired output, the control device 107 derives the stress applied to each portion of the orientation unit 109 to which each of the strain gauges 105a, 105b, and 105c is attached. The control device 107 displays the derivation result on the display unit.

[5. Compression plate configuration]
Next, with reference to FIGS. 5 and 6, the configuration of the compression plate 101 included in the compression testing apparatus 100 will be described in detail. FIG. 5 is a schematic perspective view of the compression plate 101 according to this embodiment. FIG. 6 is a schematic cross-sectional view of the compression plate 101 of this embodiment. 5 and 6 show the lower compression plate 101 of the pair of compression plates 101, 101, and the configuration of the lower compression plate 101 will be described in detail below. Of the pair of compression plates 101, 101, the upper compression plate 101 has the same configuration as the lower compression plate 101, so detailed description thereof will be omitted.

As shown in FIGS. 5 and 6, the compression plate 101 includes a plurality of movable pieces 111, a housing section 113, and an adjustment mechanism 115.

The plurality of movable pieces 111 are configured by dividing a portion of the compression plate 101 that contacts the specimen 17 into a grid pattern in the front-rear direction X and the left-right direction Y. Each movable piece 111 has, for example, a rectangular parallelepiped shape, but is not limited to this example, and may have a cubic shape, a polygonal column shape, or the like.

The upper surface of the plurality of movable pieces 111 becomes a contact surface 111a that contacts the lower surface of the specimen 17. In the state shown in FIG. 5, the contact surface 111a of each movable piece 111 is flush with the upper surface of the compression plate 101. The plurality of movable pieces 111 are configured to be individually movable in the vertical direction Z. That is, the plurality of movable pieces 111 can be individually moved in the direction of the load on the load device 103. As a result, each movable piece 111 is placed in a protruding position, flush position, or retracted position with respect to the upper surface (contact surface 101a) of compression plate 101. The protruding position is the position of the movable piece 111 in a state where the contact surface 111a of the movable piece 111 protrudes upward from the upper surface of the compression plate 101. The flush position is a position of the movable piece 111 in a state where the contact surface 111a of the movable piece 111 is flush with the upper surface of the compression plate 101. The retracted position is the position of the movable piece 111 in a state where the contact surface 111a of the movable piece 111 is retracted downward from the upper surface of the compression plate 101.

The accommodating portion 113 is, for example, a rectangular recess that is formed by recessing from the upper surface of the compression plate 101 to the lower surface side. The plurality of movable pieces 111 are accommodated in the accommodation portion 113 . For example, when each movable piece 111 is in the protruding position, the accommodating portion 113 accommodates a part of the lower side of each movable piece 111. On the other hand, when each movable piece 111 is in the retracted position, the accommodating portion 113 accommodates all of the movable pieces 111.

The adjustment mechanism 115 has a function of individually moving each movable piece 111 in the vertical direction Z and adjusting the height position of each movable piece 111 individually. The adjustment mechanism 115 includes a plurality of ball screws 117 and a plurality of motors 119. The number of installed ball screws 117 and multiple motors 119 corresponds to the number of installed movable pieces 111. Each ball screw 117 is threadedly engaged with each movable piece 111. The upper end of each ball screw 117 is connected to each movable piece 111, and the lower end of each ball screw 117 is connected to each motor 119.

Each motor 119 is connected to each ball screw 117. Each motor 119 is connected to an end of each ball screw 117 opposite to the side connected to each movable piece 111 . Each motor 119 rotates each ball screw 117 around its central axis. As a result, each movable piece 111 screwed into each ball screw 117 moves in the vertical direction Z. Each motor 119 is electrically connected to the control device 107, and the control device 107 controls the amount and direction of rotation of each motor shaft.

[6. Operation of movable piece and adjustment mechanism]
With reference to FIG. 6, the operations of the movable piece 111 and the adjustment mechanism 115 of the compression testing apparatus 100 according to this embodiment will be described. In FIG. 6, the output signal output from the control device 107 to each motor 119 is shown by a chain line.

As shown in FIG. 6, the plurality of movable pieces 111 can individually move in the vertical direction with respect to the upper surface of the compression plate 101. For example, by rotating each ball screw 117 clockwise, each movable piece 111 can be moved upward. Moreover, by rotating each ball screw 117 counterclockwise, each movable piece 111 can be moved downward.

The amount of movement of each movable piece 111 in the vertical direction Z changes depending on the amount of rotation of each ball screw 117. As the amount of rotation of each ball screw 117 increases, the amount of movement of each movable piece 111 in the vertical direction Z increases. In FIG. 6, the amount of rotation in the clockwise direction increases in order from the ball screw 117 located on the rightmost side to the ball screw 117 located on the leftmost side. Therefore, the amount of upward movement increases in order from the movable piece 111 located on the rightmost side to the movable piece 111 located on the leftmost side. In this way, by rotating each ball screw 117 in the forward and reverse directions using each motor 119, each movable piece 111 can be moved in the vertical direction Z, and the height of each movable piece 111 can be adjusted.

By the way, in the strength assurance test, when a compressive load is applied to the specimen 17 by the compression testing apparatus 100, depending on the contact state between the end surface 17a of the specimen 17 and the contact surface 101a of the compression plate 101, the specimen 17 may be Out-of-plane deformation may occur and end fracture may occur.

Therefore, before performing the strength assurance test (main test), the compression test apparatus 100 of the present embodiment loads a pre-compression load to the extent that it does not affect the specimen 17, and uses a plurality of strain gauges attached to the orientation section 109. Signs of out-of-plane deformation are confirmed by the outputs 105a, 105b, and 105c.

Specifically, before performing a strength guarantee test using the compression testing apparatus 100, a preliminary compression work is performed in which a pre-compression load is applied. In this preliminary compression work, a pre-compression load that is less than the target compression load applied in the strength assurance test is applied to the specimen 17. At this time, the control device 107 acquires the outputs of the plurality of strain gauges 105a, 105b, and 105c, and determines whether the output values of the plurality of strain gauges 105a, 105b, and 105c roughly match. Here, even if the output values of the plurality of strain gauges 105a, 105b, and 105c do not completely match, if the deviation amount of the output values is less than a predetermined threshold value, the control device 107 determines that they roughly match. judge. That is, the control device 107 determines whether the output values of the plurality of strain gauges 105a, 105b, and 105c are approximately equal within a predetermined range.

The control device 107 determines that when all the output values of the plurality of strain gauges 105a, 105b, and 105c are approximately the same, the compressive stress applied to the orientation section 109 is approximately equal in the width direction, and the specimen 17 is subjected to unexpected stress. Out-of-plane deformation is unlikely to occur, and the strength assurance test is judged to be practicable. On the other hand, when the output value of any one of the plurality of strain gauges 105a, 105b, 105c does not roughly match the other output values, the control device 107 controls the compressive stress applied to the orientation section 109 to be shifted depending on the portion in the width direction. Therefore, unexpected out-of-plane deformation is likely to occur in the specimen 17, and it is determined that the strength guarantee test cannot be performed. In this case, the control device 107 controls the plurality of motors 119 and executes a contact state adjustment process for adjusting the contact state between the end surface 17a of the specimen 17 and the contact surface 101a of the compression plate 101.

FIG. 7 is a schematic configuration diagram of the compression testing apparatus 100 during the contact state adjustment process according to the present embodiment. In FIG. 7, the magnitude of the compressive stress applied to each part of the specimen 17 is indicated by solid line arrows, and the output signals output from each strain gauge 105a, 105b, 105c to the control device 107 and the output signal from the control device 107 to each motor 119 are shown by solid arrows. The output signal to be outputted is shown by a dashed line.

As shown in FIG. 7, the control device 107 obtains outputs corresponding to the strain in the orientation section 109 from the plurality of strain gauges 105a, 105b, and 105c while a pre-compression load is applied to the specimen 17. Then, the control device 107 controls the adjustment mechanism 115 so that the output values of the plurality of strain gauges 105a, 105b, and 105c substantially match each other. In other words, the control device 107 controls the adjustment mechanism 115 so that the compressive stresses applied to the portions of the orientation section 109 where the strain gauges 105a, 105b, and 105c are located are approximately the same.

Specifically, the control device 107 individually controls the position of each movable piece 111 in the vertical direction Z by controlling the amount and direction of rotation of each motor 119 based on the output of the strain gauge 105. For example, if the compressive stress applied to the first strain gauge 105a of the orientation unit 109 is smaller than the compressive stress applied to the second strain gauge 105b and the third strain gauge 105c, the leftmost motor 119 is controlled, and the leftmost movable piece 111 to the upper side. As a result, the pressing force with which the leftmost movable piece 111 presses the end surface 17a of the specimen 17 increases, and the compressive stress applied to the first strain gauge 105a portion of the orientation section 109 increases.

Further, when the compressive stress applied to the third strain gauge 105c of the orientation unit 109 is larger than the compressive stress applied to the second strain gauge 105b and the first strain gauge 105a, the rightmost motor 119 is controlled, and the rightmost movable piece Move 111 downward. As a result, the pressing force with which the rightmost movable piece 111 presses the end surface 17a of the specimen 17 becomes smaller, and the compressive stress applied to the third strain gauge 105c becomes smaller.

In FIG. 7, the compressive stress applied to the upper end surface 17a of the specimen 17 is approximately equal in the width direction (horizontal direction Y) of the specimen 17, and the compressive stress applied to the lower end surface 17a increases toward the left side. An example of this is shown below. Further, an example will be shown in which the compressive stress applied to the orientation portion 109 near the center of the specimen 17 is approximately equal in the width direction (left-right direction Y) of the specimen 17.

In this way, by controlling the adjustment mechanism 115, the control device 107 can control the compressive stress applied to the orientation portion 109 to be approximately uniform in the width direction of the specimen 17.

As described above, the compression testing apparatus 100 of this embodiment includes a plurality of movable pieces 111 and an adjustment mechanism 115. As a result, the gap between the end surface 17a and the contact surface 101a is filled without installing a shim between the end surface 17a of the specimen 17 and the contact surface 101a of the compression plate 101, and a good contact state between the two can be achieved. Can be adjusted.

Here, when adjusting the contact state between the end surface and the contact surface by installing a shim between the end surface of the specimen and the contact surface of the compression plate as in the conventional technology, the amount of adjustment is the thickness of the shim. Therefore, it was difficult to optimize the contact condition. In addition, adjustment of the contact state using shims involves applying a pre-compression load, measuring strain using multiple strain gauges, unloading the pre-compression load, considering the thickness of the shim, installing the shim, and applying the pre-compression load. It was necessary to repeatedly perform tasks such as overloading. Therefore, there is a problem in that adjusting the contact state using shims takes a lot of time and effort.

On the other hand, according to the compression testing apparatus 100 of the present embodiment, the adjustment mechanism 115 moves the plurality of movable pieces 111 individually while the pre-compression load is applied, and the end surface 17a and the contact surface 101a are brought into contact with each other. Conditions can be adjusted easily and quickly.

Furthermore, the length of each side of each movable piece 111 is smaller than the length of each side of the shim. For example, the length of each side of each movable piece 111 is less than 3 cm. Further, the minimum amount of movement of each movable piece 111 in the load direction by each ball screw 117 is smaller than the minimum plate thickness of a conventional shim. For example, the minimum amount of movement of each movable piece 111 in the load direction is less than 0.1 mm. Thereby, the adjustment of the contact state between the end surface 17a and the contact surface 101a by the adjustment mechanism 115 can be finely adjusted with higher precision than the adjustment of the contact state between the end surface 17a and the contact surface 101a using the shim.

In addition, since the contact state between the end surface 17a and the contact surface 101a can be adjusted while a pre-compression load is applied, time and labor are reduced compared to adjusting the contact state between the end surface 17a and the contact surface 101a using shims. can do. For example, adjusting the contact state using a conventional shim requires repeatedly applying and unloading a pre-compression load, whereas adjusting the contact state using the adjustment mechanism 115 requires repeatedly applying and unloading a pre-compressive load. is not necessary. In this embodiment, the adjustment of the contact state by the adjustment mechanism 115 can be performed by applying a pre-compression load only once, and after the adjustment of the contact state, a strength guarantee test (main test) is performed continuously. be able to.

According to the compression testing apparatus 100 of this embodiment, the positions of the plurality of movable pieces 111 in the load direction can be adjusted individually according to the outputs of the plurality of strain gauges 105a, 105b, and 105c attached to the orientation section 109. be. As a result, even if there is local deformation such as bending, distortion, or twisting in the orientation section 109 near the center of the specimen 17, the specimen 17 can be Compressive stress can be evenly applied to the 17 orientation sections 109. Therefore, according to the present embodiment, the compressive stress applied to the orientation section 109 of the specimen 17 can be adjusted easily and with high precision, regardless of the state of the end surface 17a of the specimen 17 or the local deformation state of the orientation section 109. be able to.

According to the compression testing apparatus 100 of this embodiment, the control device 107 that can control the plurality of motors 119 is provided. Thereby, the control device 107 can automatically adjust the stress applied to the orientation section 109 to be equal by controlling the plurality of motors 119 based on the outputs of the plurality of strain gauges 105a, 105b, and 105c. .

Although preferred embodiments of the present invention have been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to these embodiments. It is clear that those skilled in the art can come up with various changes and modifications within the scope of the claims, and it is understood that these naturally fall within the technical scope of the present invention. be done.

In the above embodiment, an example has been described in which a plurality of movable pieces 111 and adjustment mechanisms 115 are provided on both of the pair of compression plates 101, 101. However, the present invention is not limited thereto, and the plurality of movable pieces 111 and adjustment mechanism 115 may be provided only on one of the pair of compression plates 101, 101.

In the embodiment described above, an example in which the specimen 17 includes a pair of reinforcing plates 19, 19 has been described. However, the present invention is not limited to this, and a specimen 17 consisting only of the outer plate 11 and the stringer 13 may be used without providing the pair of reinforcing plates 19, 19 on the specimen 17.

In the above embodiment, an example in which the adjustment mechanism 115 includes a plurality of motors 119 has been described. However, the present invention is not limited thereto, and the adjustment mechanism 115 may not include the plurality of motors 119. For example, the operator may manually rotate the ball screw 117 of the adjustment mechanism 115 while checking stress information on the orientation section 109 displayed on the display section of the control device 107.

In the above embodiment, an example in which the adjustment mechanism 115 includes a plurality of ball screws 117 and a plurality of motors 119 has been described. However, the adjustment mechanism 115 is not limited thereto, and instead of these, the adjustment mechanism 115 may be configured with any drive mechanism such as a linear actuator or a hydraulic cylinder connected to each movable piece 111.

In the above embodiment, an example was described in which the strain gauge 105 is attached to the orientation section 109 of the specimen 17. However, the present invention is not limited thereto, and the strain gauge 105 may be attached to the intermediate portion of the specimen 17 between the end surface 17a and the orientation section 109.

In the above embodiment, an example has been described in which the specimen 17 is composed of an outer panel member of the aircraft 1 made of fiber-reinforced plastic. However, the present invention is not limited thereto, and the specimen may be a member other than the outer panel 1 of the aircraft 1, or may be a member made of a material different from fiber-reinforced plastic.

INDUSTRIAL APPLICATION This invention can be utilized for a compression test device.

11 Outer panel 13 Stringer 17 Specimen 100 Compression test device 101 Compression plate 103 Loading device 105a First strain gauge 105b Second strain gauge 105c Third strain gauge 107 Control device 109 Orientation section 111 Movable piece 115 Adjustment mechanism

Claims (3)

a pair of compression plates that sandwich the specimen in a first direction;
a loading device that applies a compressive load in the first direction to the specimen through the compression plate;
a plurality of strain gauges attached to the orientation part of the specimen, which are set based on the results of strength analysis when simulating the state in which the compressive load is applied to the specimen ;
a plurality of movable pieces that are portions of at least one of the pair of compression plates that contact the specimen and are divided so as to be movable individually in the first direction;
an adjustment mechanism that can individually adjust the positions of the plurality of movable pieces in the first direction according to the outputs of the plurality of strain gauges while the compressive load is applied to the specimen;
a control device that controls the adjustment mechanism based on outputs of the plurality of strain gauges;
Equipped with
When the control device applies a pre-compression load that is less than the target compression load applied in the strength guarantee test to the specimen, and the amount of deviation of the output values of the plurality of strain gauges is equal to or more than a predetermined threshold value, individually adjusting the positions of the plurality of movable pieces in the first direction so that the output values match;
Compression test equipment. The compression testing apparatus according to claim 1 , wherein the orientation section is a region where compressive stress becomes the largest when the compressive load is applied to the specimen. 3. The compression test apparatus according to claim 1 , wherein the specimen is an aircraft skin member made of fiber-reinforced plastic.

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