Experimental system for directly measuring anisotropy coefficient in any direction in panel

Abstract

The invention belongs to the field of plate plastic processing, and discloses an experimental system for directly measuring anisotropy coefficient in any direction in a plate surface, which comprises an experimental sample, an experimental mold, a press machine, a data acquisition unit, a clamp, a data processing unit and a rotary table. According to the experimental system provided by the invention, the experimental result can directly reflect the plastic deformation condition of the plate in any direction, the anisotropy coefficient in any direction in an experimental sample plane is obtained through one-time experiment, and the defect that only discrete experimental data in a certain specific direction can be obtained in the current uniaxial tension experiment is overcome.

Description

Technical Field

[0001] The invention belongs to the field of plate plastic processing, and in particular relates to an experimental system for directly measuring anisotropy coefficients in any direction within a plate surface. Background Art

[0002] Complex thin-walled parts have excellent properties such as good bending and torsion resistance and significant weight reduction effects, and are widely used in aviation, aerospace, automobile and other fields. Such components often undergo a complex deformation process during forming, and defects such as fractures and wrinkles often occur in the forming area, which increases the difficulty of manufacturing parts. In order to reduce manufacturing costs and optimize the process flow, it is necessary to predict the forming results through accurate numerical simulation. At present, thin-walled metal sheets are usually formed by rolling. During the forming process, the material will undergo severe deformation, resulting in preferential orientation of the grains inside the material, thus showing obvious in-plane anisotropy. The in-plane anisotropic properties of the material will significantly affect the deformation behavior of the material during the forming process. In order to optimize the manufacturing process and reduce manufacturing costs, it is necessary to accurately measure the in-plane anisotropic properties of the material.

[0003] At present, the mechanical properties of the sheet are usually measured by unidirectional tensile test according to the national standard GBT 228.1-2021. The sheet is cut in different directions to obtain unidirectional tensile specimens, and then the unidirectional tensile test is carried out to obtain the mechanical properties parameters of the material in different directions. This method can only obtain discrete experimental data, and it is difficult to ensure that the experimental conditions and experimental processes of each independent experiment are completely consistent. In addition, anisotropy means a property that changes continuously with the change of loading direction. The most appropriate description of anisotropic plastic flow should be the continuously changing material property data. Therefore, the existing test methods will inevitably lead to errors, resulting in large deviations between the numerical simulation results and the experimental results. For example, the article "The influence of material property data on the accuracy of forming simulation (Part 1) - Experimental data and its application" by Lian Changwei, Lv Chao and Hu Weilong and the article "The influence of material property data on the accuracy of forming simulation (Part 2) - Improvement of experimental methods" by Han Fei, Lian Changwei and Hu Weilong both analyze the errors that may be caused by unreasonable experimental data.

[0004] In order to solve the above problems, the present invention provides an experimental system for directly measuring the anisotropy coefficient of a plate in any direction within the surface of the plate. The experimental results can directly reflect the plastic deformation in any direction within the surface of the plate, laying an experimental foundation for measuring the anisotropy coefficient of a plate in any direction within the surface of the plate. Summary of the invention

[0005] The purpose of the present invention is to provide an experimental system for directly measuring the anisotropy coefficient of a plate in any direction within the plane, so as to solve the problems existing in the above-mentioned prior art. The experimental results can directly reflect the plastic deformation in any direction within the plane of the plate, and can be used to directly measure the anisotropy coefficient of the plate in the plane, and can also be used to experimentally verify the material constitutive model.

[0006] The technical solution of the present invention:

[0007] An experimental system for directly measuring the anisotropy coefficient of a plate in any direction within a plate surface, comprising an experimental specimen, an experimental die, a press, a data acquisition unit, a fixture, a data processing unit and a rotary table;

[0008] The experimental sample is cut from the plate to be tested, and the center of the experimental sample has a closed hole. The experimental sample undergoes plastic deformation through an experimental mold, which is required for directly measuring the anisotropy coefficient of the plate to be tested in any direction within the surface.

[0009] The experimental mold adopts a split design, and the punch can be replaced according to needs during the experiment; the experimental mold includes an upper connecting plate, a support column, a punch, a blank holder connecting plate, a blank holder, a die and a die pad, and during the installation process, the centers of the upper connecting plate, the punch, the blank holder connecting plate, the blank holder, the die and the die pad are ensured to be on the same axis; the upper connecting plate is directly connected to the slider of the press, and moves up and down along the axis direction of the mold with the slider of the press, and there is a through hole in the center of the upper connecting plate, the size of the through hole is larger than the size of the punch, and the punch can pass through the through hole when moving up and down, ensuring that the movement of the punch is not affected by the upper connecting plate;

[0010] The support columns are distributed between the upper connecting plate and the blank holder connecting plate and between the die and the die pad. The connecting line of the support columns is rectangular or circumferentially distributed around the axis of the punch, so that the blank holder connecting plate and the die are subjected to more uniform force, thereby making the blank holder force on the test specimen more uniform during the mold closing process.

[0011] There are two types of punches, and the sizes and shapes of the two punches are different. During the experiment, the two different punches are used to respectively realize the flanging forming and calendering forming of the experimental sample; the punch is directly connected to the slide of the press, and is driven by the slide of the press to move up and down along the axis direction of the experimental mold;

[0012] The blank holder ring connecting plate is directly connected to the support column and the blank holder ring. During the experiment, the force transmitted by the support column is evenly transmitted to the blank holder ring through the blank holder ring connecting plate. There is a through hole in the middle of the blank holder ring connecting plate. The size of the through hole is larger than the size of the punch. The punch can pass through the through hole when moving up and down, ensuring that the movement of the punch is not affected by the blank holder ring connecting plate.

[0013] There is a through hole in the center of the blank holder, and the size of the through hole is larger than the size of the punch used in the forming process; the blank holder is divided into two freely detachable parts, which are used for flanging forming and calendering forming respectively; there are draw ribs on the blank holder, which can increase the deformation of the straight wall area of ​​the experimental sample during the calendering forming process, so that all positions of the straight wall area enter the plastic deformation state during the experiment; the blank holder is directly connected to the bottom of the blank holder connecting plate. During the experiment, the blank holder moves along the axis of the experimental mold together with the blank holder connecting plate. When reaching a certain position, the bottom of the blank holder contacts the top surface of the experimental sample to transmit the clamping force;

[0014] The die is located below the blank holder, and there is a through hole in the center of the die, the size of which is larger than the size of the punch used in the forming process; the die is also divided into two freely detachable parts, which are used for flanging forming and calendering forming respectively; there are grooves on the surface of the die that match the shape and size of the draw ribs on the blank holder, which cooperate with the draw ribs during the forming process to increase the deformation of the straight wall area of ​​the experimental sample, so that all positions of the straight wall area enter the plastic deformation state during the experiment; the die is directly connected to the die pad through a support column;

[0015] The die pad is connected to the die through a support column, and the bottom is fixed on the workbench of the press machine to prevent the die from moving due to external forces during the experiment, which may lead to inaccurate measurement results.

[0016] The press provides the required pressure for the plastic deformation of the test specimen; the press has two movable slides, one of which is directly connected to the upper connecting plate of the test die, and the other is directly connected to the punch of the test die;

[0017] The data acquisition unit is used to measure the deformation characteristics of the straight wall area of ​​the sample during the experiment, including strain and strain increment; the data acquisition unit is fixed on the turntable by a clamp, and can be moved on the turntable track by the clamp as needed to realize real-time automatic collection of deformation characteristic information at any position of the straight wall area of ​​the sample; the distance and height relationship between the data acquisition unit and the experimental sample must meet the requirements for reliable and accurate measurement of the deformation characteristic information of the straight wall area of ​​the sample; N sets of data acquisition units can be arranged, where N is a positive integer; when the number of data acquisition units N=1, deformation characteristic information in different directions can be automatically collected by moving the position of the data acquisition units; when the number of data acquisition units N>1, data acquisition units can be arranged simultaneously at different positions required for observation to realize simultaneous measurement of deformation characteristic information at different positions. If the number of data acquisition units is sufficient, simultaneous measurement of deformation characteristic information in any direction of the straight wall area of ​​the sample can be realized.

[0018] The clamp can clamp the data acquisition unit and can freely move along the circular track on the turntable through the spherical ball, thereby changing the position of the data acquisition unit; the height of the clamp can be adjusted by the screw rod, thereby ensuring that the data acquisition unit can accurately collect deformation information of the straight wall area of ​​the sample during the experiment;

[0019] The data processing unit is placed on the workbench of the press, connected to the data acquisition unit by cables or wirelessly, receives and processes in real time the deformation information of the straight wall area of ​​the sample collected by the data acquisition unit during the experiment, automatically calculates the anisotropy coefficient in any direction within the plate surface based on the measured deformation information, and displays it intuitively on the data processing unit.

[0020] The turntable is placed on the workbench of the press, the center of the turntable and the center of the experimental mold are located on the same axis, and the turntable has a circular track. The distance between the turntable circular track and the sample must meet the requirements of reliable and accurate measurement of the deformation characteristic information of the straight wall area of ​​the sample. The turntable is divided into four parts, which are connected into a whole by a mortise and tenon structure.

[0021] Preferably, after the flanging forming is completed, the flange forming part of the pressure ring and the die can be directly removed.

[0022] Preferably, the data processing unit can intuitively display the determined anisotropy coefficient results in the form of graphs or tables.

[0023] Beneficial effects of the present invention:

[0024] (1) The experimental system proposed in the present invention can directly reflect the plastic deformation of the plate in any direction. The anisotropy coefficient in any direction within the surface of the experimental sample can be obtained through one experiment, which solves the shortcoming that the current unidirectional tensile test can only obtain discrete experimental data in a specific direction.

[0025] (2) The special design of the experimental mold ensures that the straight wall area of ​​the specimen does not contact the mold during the experiment, ensuring that it is not affected by external forces during the forming process and is in a completely free state. This ensures that the stress state of the straight wall area of ​​the specimen during the deformation process meets the requirements for the determination of the material anisotropy coefficient.

[0026] (3) The design of the drawbead ensures that the straight wall area of ​​the specimen undergoes greater plastic deformation during the forming process, which facilitates the collection of deformation characteristic information and improves the accuracy and reliability of the determination of the anisotropy coefficient of the plate.

[0027] (4) The experimental system proposed in the present invention can obtain the anisotropy coefficients in all directions within the surface of the experimental sample through a single forming experiment, thereby ensuring that the experimental data obtained are continuous deformation data under the same experimental conditions.

[0028] (5) It is convenient to automatically and in real time collect the deformation information of the straight wall area in a specific direction during the entire experiment, and it can also simultaneously collect the deformation information of the straight wall area in any direction during the experiment.

[0029] (6) It can automatically and accurately determine the anisotropy coefficient of the plate in any direction in real time online, and can display it intuitively.

[0030] (7) The design of the circular guide rail of the turntable ensures the consistency of the deformation of the sample observed at different positions on the circular guide rail, avoiding the experimental error introduced by the change in the distance between the observation position and the sample, while facilitating the operation of observing the deformation information of the sample at different positions.

[0031] (8) The fixture has a simple structure, which reduces the difficulty of data collection and allows convenient data collection as needed.

[0032] (9) The experimental system of the present invention can be used to measure the anisotropy coefficient of the plate in any direction within the plane, and can also be used to experimentally verify the material constitutive model.

[0033] (10) The experimental system of the present invention can be used to determine the in-plane anisotropy coefficient of various metal material plates, such as aluminum alloy, titanium alloy, magnesium alloy, high-strength steel and other pipes, and has a wide range of applications.

[0034] (11) The experimental mold has a simple structure and is easy to assemble and use. It can realize two forming methods, flanging and calendering, through a set of molds, and has the advantages of low manufacturing and use costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 Schematic diagram of the experimental system for directly measuring the anisotropy coefficient of a plate in any direction in the plane proposed by the present invention;

[0036] Figure 2 (a) is a schematic diagram of a punch used for flanging in an experimental system for directly measuring anisotropy coefficient of a sheet material in any direction in the plane proposed by the present invention, and (b) is a schematic diagram of a punch used for calendering;

[0037] Figure 3 A schematic diagram of the relationship between the flange forming part and the calendering forming part of the blank holder in the experimental system for directly measuring the anisotropy coefficient of the sheet material in any direction in the plane proposed by the present invention;

[0038] Figure 4 A schematic diagram of the relationship between the flange forming part and the calendering forming part of the concave die in the experimental system for directly measuring the anisotropy coefficient of the sheet material in any direction in the surface of the sheet material proposed by the present invention;

[0039] Figure 5 Schematic diagram of the sample before and after the experiment for directly measuring the anisotropy coefficient of the plate in any direction in the plane proposed by the present invention;

[0040] Figure 6 This is a schematic diagram of the fixture structure in the test system for directly measuring the anisotropy coefficient of a plate in any direction in the plane proposed by the present invention;

[0041] Figure 7 A schematic diagram of the structure of a turntable in a test system for directly measuring anisotropy coefficients in any direction within the surface of a rolled plate proposed by the present invention;

[0042] In the figure: 1 upper connecting plate, 2 supporting column, 3 punch, 4 blank holder connecting plate, 5 blank holder, 6 fixture, 7 die pad, 8 turntable, 9 experimental specimen, 10 die, 11 data acquisition unit, 12 data processing unit, 13 draw rib, 14 groove, 15 straight wall area, 16 screw, 17 spherical ball, 18 annular track, 19 mortise and tenon structure. DETAILED DESCRIPTION

[0043] Next, the experimental system for directly measuring the anisotropy coefficient of the rolled plate in any direction in the plane proposed by the present invention will be specifically explained in conjunction with the drawings of the specification. The examples explained are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments proposed by the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the protection scope of the present invention.

[0044] The experimental system for directly measuring the anisotropy coefficient of a plate in any direction proposed in the present invention solves the problem that the existing plate anisotropy coefficient testing method can only obtain discrete experimental data in one direction, and provides a feasible technical method for directly measuring the anisotropy coefficient of a plate in any direction through experiments.

[0045] In order to make the advantages and implementation methods of the technical solution proposed in the present invention more understandable, the experimental system for directly measuring the anisotropy coefficient of rolled plate in any direction in the plane proposed in the present invention will be introduced in detail in conjunction with the drawings in the specification.

[0046] In conjunction with the accompanying drawings, the specific implementation of the invention is as follows:

[0047] The present invention proposes an experimental system for directly measuring the anisotropy coefficient of a plate in any direction within the surface. The system includes an experimental sample 9, an experimental mold, a press, a data acquisition unit 11, a fixture 6, a data processing unit 12, and a turntable 8.

[0048] The experimental sample 9 is cut from the plate to be tested, and has a closed hole in the center of the sample. The experimental sample undergoes plastic deformation through an experimental mold, which can be used to directly measure the anisotropy coefficient of the plate in any direction.

[0049] The experimental mold includes an upper connecting plate 1, a support column 2, a punch 3, a blank holder connecting plate 4, a blank holder 5, a die 10, and a die pad 7. The experimental mold adopts a split design, and the punch 3 can be freely replaced during the experiment. During the installation of the experimental mold, it should be ensured that the centers of the upper connecting plate 1, the punch 3, the blank holder connecting plate 4, the blank holder 5, the die 10, and the die pad 7 are on the same axis.

[0050] The upper connecting plate 1 is directly connected to the slider of the press and can move up and down along the axis of the mold with the slider of the press. There is a through hole in the center of the upper connecting plate 1. The size of the through hole is larger than the size of the punch 3. The punch 3 can pass through the through hole when moving up and down, ensuring that the movement of the punch 3 is not affected by the upper connecting plate.

[0051] The support columns 2 are distributed between the upper connecting plate 1 and the blank holder connecting plate 4 and between the die 10 and the die pad 7. The connecting line of the support columns 2 is rectangular or circumferentially distributed around the axis of the punch 3, so that the blank holder connecting plate 4 and the die 10 are subjected to more uniform force, thereby making the blank holder force applied to the experimental sample 9 more uniform during the mold closing process.

[0052] The punch 3 has two types, namely, a punch for flanging forming ( Figure 2 (a)) and the punch used for calendering ( Figure 2 (b)), the two punches have different sizes and shapes. During the experiment, the two different punches are used to respectively realize the flanging and rolling forming of the experimental sample 9. The punch 3 is directly connected to the slide of the press and can move up and down along the axis of the mold driven by the slide of the press.

[0053] The blank holder ring connecting plate 4 is directly connected to the support column 2 and the blank holder ring 5. During the experiment, the force transmitted by the support column 2 is evenly transmitted to the blank holder ring 5 through the blank holder ring connecting plate 4. There is a through hole in the middle of the blank holder ring connecting plate 4. The size of the through hole is larger than the size of the punch 3 used in the forming process. The punch 3 can pass through the through hole when moving up and down, ensuring that the movement of the punch 3 is not affected by the blank holder ring connecting plate 4.

[0054] There is a through hole in the center of the blank holder 5, and the size of the through hole is larger than the size of the punch 3 used in the forming process. The blank holder 5 is divided into two freely detachable parts ( Figure 3 ), which are used for flanging and calendering, respectively. There are draw ribs 13 on the blank holder 5. During the calendering process, this part can increase the deformation of the straight wall area 15 of the experimental sample, so that all positions of the straight wall area 15 enter the plastic deformation state during the experiment. The blank holder 5 is directly connected to the bottom of the blank holder connecting plate 4. During the experiment, the blank holder 5 moves along the axis of the mold together with the blank holder connecting plate 4. When it reaches a certain position, the bottom of the blank holder 5 contacts the top surface of the experimental sample 9 to transmit the clamping force.

[0055] The die 10 is located below the blank holder 5. There is a through hole in the center of the die 10. The size of the through hole is larger than the size of the punch 3 used in the forming process. The die 10 is also divided into two freely detachable parts ( Figure 4 ), which are used for flanging and calendering respectively. The surface of the die 10 has a groove 14 that matches the shape and size of the draw rib 13 on the blank holder 5. During the forming process, it cooperates with the draw rib 13 to increase the deformation of the straight wall area 15 of the experimental sample, so that all positions of the straight wall area 15 enter the plastic deformation state during the experiment. The die 10 is directly connected to the die pad 7 through the support column 2.

[0056] The die pad 11 is connected to the die 6 through the support column 2, and the bottom is fixed on the workbench of the press to prevent the die from moving due to external forces during the experiment, which would lead to inaccurate measurement results.

[0057] The press provides the required pressure for the plastic deformation of the test specimen 9. The press has two movable slides, one of which is directly connected to the upper connecting plate 1 of the test die, and the other is directly connected to the punch 3 of the test die.

[0058] The data acquisition unit 11 is used to measure the deformation characteristics of the straight wall area 15 of the sample during the experiment, including strain and strain increment. The data acquisition unit 11 is fixed on the turntable 8 by the clamp 6, and can be moved on the turntable track 18 by the clamp 6 as needed to realize the real-time automatic acquisition of deformation characteristic information at any position of the straight wall area 15 of the sample. The distance and height relationship between the data acquisition unit 11 and the sample 9 must meet the requirements of reliable and accurate measurement of the deformation characteristic information of the straight wall area 15 of the sample. The data acquisition unit 11 can be arranged in N sets, where N is a positive integer. When the number of data acquisition units 11 N=1, the deformation characteristic information in different directions can be automatically collected by moving the position of the data acquisition unit 11. When the number of data acquisition units 11 N>1, the data acquisition units 11 can be arranged at the same time at different positions to be observed to realize the simultaneous measurement of deformation characteristic information at different positions. If the number of data acquisition units 11 is sufficient, the deformation characteristic information in any direction of the straight wall area 15 of the sample can be measured simultaneously.

[0059] The fixture 6 can clamp the data acquisition unit 11, and can freely move along the circular track 18 on the turntable 8 through the spherical ball 17, thereby changing the position of the data acquisition unit 11. The height of the fixture 6 can be adjusted by the screw 16, so as to ensure that the data acquisition unit 11 can accurately collect the deformation information of the straight wall area 15 of the sample during the experiment.

[0060] The data processing unit 12 is placed on the workbench of the press, and is connected to the data acquisition unit 11 via a cable or wirelessly, and receives and processes in real time the deformation information of the straight wall area 15 of the sample collected by the data acquisition unit 11 during the experiment, and automatically calculates the anisotropy coefficient in any direction within the plate surface according to the measured deformation information, and intuitively displays it on the data processing unit 12.

[0061] The turntable 8 is placed on the workbench of the press, the center of the turntable and the center of the experimental mold are located on the same axis, and the turntable 8 has a circular track 18. The distance between the turntable circular track 18 and the sample must meet the requirements of reliably and accurately measuring the deformation characteristic information of the straight wall area 15 of the sample.

[0062] Preferably, after the flanging forming is completed, the flange forming parts of the blank holder 5 and the die 10 can be directly removed.

[0063] Preferably, the data processing unit 12 can intuitively display the determined anisotropy coefficient results in the form of graphs or tables.

[0064] Specifically, the material of the experimental sample 9 is metal, such as aluminum alloy, low carbon steel, magnesium alloy, high strength steel, and high temperature alloy.

[0065] Specifically, during the experiment, when the punch 3 moves downward, the experiment can be completed by uniform loading or pulse loading.

[0066] Specifically, the data acquisition unit 11 may use digital image correlation (DIC) to measure the strain or strain increment data of the straight wall region 15 of the experimental sample 9 in real time.

[0067] Specifically, the data acquisition unit 11 and the data processing unit 12 can be connected via a network cable or WI FI.

[0068] Specifically, the data acquisition unit 11 may be a measurement unit composed of four DICs, which can realize automatic simultaneous real-time measurement of strain or strain increment data in any direction of the straight wall area 15 of the sample.

[0069] The experimental system for directly measuring the anisotropy coefficient in any direction in the plate surface proposed by the present invention can realize the direct measurement of the anisotropy coefficient in any direction in the plate surface. The system can realize the flanging-calendering forming of the experimental sample 9, and ensure that the straight wall area 15 of the sample after flanging forming is always in a free deformation state in the subsequent deformation process. The deformation information of the straight wall area 15 of the sample during deformation is obtained in real time through the data acquisition unit 11 in the system, and the deformation information of the straight wall area 15 is processed through the data processing unit 12, so as to realize the direct measurement of the anisotropy coefficient in any direction in the surface of the rolled plate, thereby providing a reference for the process determination and process parameter formulation in the actual forming of the parts.

[0070] The specific implementation examples proposed in the present invention are only used to help understand the method and core ideas of the present invention. For those skilled in the art, according to the ideas of the present invention, there will be some differences in the specific implementation methods and application scopes. In short, the content of this specification should not be understood as limiting the present invention.

Claims

1. An experimental system for directly measuring the anisotropy coefficient of a plate in any direction within the plane, characterized in that: The experimental system for directly measuring the anisotropy coefficient of a plate in any direction in a plane comprises an experimental specimen, an experimental die, a press, a data acquisition unit, a fixture, a data processing unit and a rotary table; The experimental sample is cut from the plate to be tested, and the center of the experimental sample has a closed hole. The experimental sample undergoes plastic deformation through an experimental mold, which can be used to directly measure the anisotropy coefficient of the plate to be tested in any direction within the surface. The experimental mold includes an upper connecting plate, a support column, a punch, a blank holder connecting plate, a blank holder, a die and a die pad. During the installation process, the centers of the upper connecting plate, the punch, the blank holder connecting plate, the blank holder, the die and the die pad are ensured to be on the same axis; the upper connecting plate is directly connected to the slider of the press, and moves up and down along the axis direction of the mold with the slider of the press. There is a through hole in the center of the upper connecting plate, and the size of the through hole is larger than the size of the punch. The punch can pass through the through hole when moving up and down, ensuring that the movement of the punch is not affected by the upper connecting plate; The support columns are distributed between the upper connecting plate and the blank holder connecting plate and between the die and the die pad; There are two types of punches, and the sizes and shapes of the two punches are different. During the experiment, the two different punches are used to respectively realize the flanging forming and calendering forming of the experimental sample; the punch is directly connected to the slide of the press, and is driven by the slide of the press to move up and down along the axis direction of the experimental mold; The blank holder ring connecting plate is directly connected to the support column and the blank holder ring. During the experiment, the force transmitted by the support column is evenly transmitted to the blank holder ring through the blank holder ring connecting plate. There is a through hole in the middle of the blank holder ring connecting plate. The size of the through hole is larger than the size of the punch. The punch can pass through the through hole when moving up and down, ensuring that the movement of the punch is not affected by the blank holder ring connecting plate. There is a through hole in the center of the blank holder, and the size of the through hole is larger than the size of the punch used in the forming process; the blank holder is divided into two freely detachable parts, which are used for flanging forming and calendering forming respectively; there are draw ribs on the blank holder, which can increase the deformation of the straight wall area of ​​the experimental sample during the calendering forming process, so that all positions of the straight wall area enter the plastic deformation state during the experiment; the blank holder is directly connected to the bottom of the blank holder connecting plate. During the experiment, the blank holder moves along the axis of the experimental mold together with the blank holder connecting plate. When reaching a certain position, the bottom of the blank holder contacts the top surface of the experimental sample to transmit the clamping force; The die is located below the blank holder, and a through hole is present in the center of the die, the size of the through hole being larger than the size of the punch used in the forming process; The die is also divided into two freely removable parts, which are used for flanging and calendering respectively; there are grooves on the die surface that match the shape and size of the draw ribs on the blank holder, which cooperate with the draw ribs during the forming process to increase the deformation of the straight wall area of ​​the test specimen, so that all positions of the straight wall area enter the plastic deformation state during the experiment; the die is directly connected to the die pad through a support column; The die pad is connected to the die through a support column, and the bottom is fixed on the workbench of the press to prevent the die from moving due to external forces during the experiment, which may lead to inaccurate measurement results. The press provides the required pressure for the plastic deformation of the test specimen; the press has two movable slides, one of which is directly connected to the upper connecting plate of the test die, and the other is directly connected to the punch of the test die; The data acquisition unit is used to measure the deformation characteristics of the straight wall area of ​​the sample during the experiment, including strain and strain increment; the data acquisition unit is fixed on the turntable by a clamp, and can be moved on the turntable track by the clamp as needed to realize the real-time automatic acquisition of deformation characteristic information at any position of the straight wall area of ​​the sample; the distance and height relationship between the data acquisition unit and the experimental sample must meet the requirements of reliable and accurate measurement of the deformation characteristic information of the straight wall area of ​​the sample; The clamp can clamp the data acquisition unit and can freely move along the circular track on the turntable through the spherical ball, thereby changing the position of the data acquisition unit; the height of the clamp can be adjusted by the screw rod, thereby ensuring that the data acquisition unit can accurately collect deformation information of the straight wall area of ​​the sample during the experiment; The data processing unit is placed on the workbench of the press, connected to the data acquisition unit by cables or wirelessly, receives and processes the deformation information of the straight wall area of ​​the sample collected by the data acquisition unit during the experiment in real time, automatically calculates the anisotropy coefficient in any direction within the plate surface according to the measured deformation information, and displays it intuitively on the data processing unit; The turntable is placed on the workbench of the press, the center of the turntable and the center of the experimental mold are located on the same axis, and the turntable is provided with a circular track; the distance relationship between the circular track of the turntable and the sample must meet the requirements of reliably and accurately measuring the deformation characteristic information of the straight wall area of ​​the sample; the turntable is divided into four parts, which are connected into a whole by a mortise and tenon structure.

2. The experimental system for directly measuring the anisotropy coefficient of a plate in any direction according to claim 1, characterized in that: The experimental mold adopts a split design, and the punch can be replaced according to needs during the experiment.

3. The experimental system for directly measuring the anisotropy coefficient of a plate in any direction according to claim 1, characterized in that: The connecting line of the support columns is rectangular or circumferentially distributed around the axis of the punch, so that the blank holder connecting plate and the die are subjected to more uniform force, thereby making the blank holder force on the test specimen more uniform during the mold closing process.

4. The experimental system for directly measuring the anisotropy coefficient of a plate in any direction according to claim 1, characterized in that: N sets of data acquisition units can be arranged, where N is a positive integer; when the number of data acquisition units N=1, the deformation characteristic information in different directions can be automatically collected by moving the data acquisition unit position; when the number of data acquisition units N>1, the data acquisition units can be arranged simultaneously at different positions required for observation to achieve simultaneous measurement of deformation characteristic information at different positions. If the number of data acquisition units is sufficient, the deformation characteristic information in any direction of the straight wall area of ​​the specimen can be measured simultaneously.

5. The experimental system for directly measuring the anisotropy coefficient of a plate in any direction according to claim 1, characterized in that: After the flanging is completed, the flange forming parts of the pressure ring and the die can be directly removed.

6. The experimental system for directly measuring the anisotropy coefficient of a plate in any direction according to claim 1, characterized in that: The data processing unit intuitively displays the determined anisotropy coefficient results in the form of graphs and tables.

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