CN204903298U - Drawing - shearing preloads normal position indentation testing arrangement - Google Patents

Abstract

The utility model relates to a tension-shear preload in-situ indentation testing device, which belongs to the field of precision scientific instruments. The mechanical transmission module is composed of a servo motor, a two-stage worm gear and a lead screw and a lead screw nut, which can convert the rotation of the motor into a linear motion at a quasi-static rate to realize the stretching process; the tensile and shear composite loading module at any angle passes through The friction force of the bolt presses the movable device on the base, and the load force inclination angle of the specimen can be changed by changing the angle of the movable device; the cantilever indentation module passes the piezoelectric stack installed above the cantilever beam and parallel to it To achieve this, the indentation is achieved by squeezing the cantilever beam forcing it to bend when the piezoelectric stack is energized to generate actuation. In the tensile-shear composite test, the device can be placed under a microscope for in-situ observation. The utility model patent has reliable principle, compact structure, high practical value, and can accurately perform tensile shear indentation multi-load material mechanics test and in-situ observation.

Description

Tensile-shear preload in-situ indentation test device

technical field

The utility model relates to the field of precision scientific instruments, in particular to a tension-shear preload in-situ indentation testing device.

Background technique

For a long time, among the many mechanical performance parameters of material mechanics testing, parameters such as elastic modulus, yield limit, strength limit, elongation and shear modulus are the most important test objects. There are many kinds of performance parameters for the above materials Test methods such as tension/compression, bending, torsion, tympanometry, and nanoindentation. However, many of the methods mentioned above are aimed at a single load, that is, a single test can only obtain a single performance parameter of the material, and each test method requires specific experimental instruments for testing, which is very cumbersome.

In addition, because the existing testing instruments can only test a single mechanical property, it is impossible to perform a composite test on two or more stress situations, so that it is impossible to know the mechanical properties of the material under the influence of various factors in the process of composite loading. Whether the mechanical properties will change under the influence of a single factor in the performance and single loading process. And the test of only a single mechanical property is unfavorable to the applicability of the test results. Since the material is still subjected to composite loads in most cases under real service conditions, when we use the material performance data obtained under a single load to determine the When checking and calculating materials under real service conditions, it may not be accurate. For example, a material may have a decrease in its modulus of elasticity when subjected to shear, or a decrease in surface hardness when a material is subjected to tension, which will affect the accuracy of its calibration.

At present, there is no relatively mature multi-load test instrument integrating tensile, shear and indentation, and traditional tensile and shear instruments can only perform tests at specific angles. The main difficulties in the integration of the three types of loads are mainly reflected in the following aspects: 1. How to realize the locking of the specimen freely changing the angle; 2. How to ensure the reliability of the device locking under the condition of freely changing the angle, Rapidity and accuracy; 3. How to simplify the indentation module as much as possible without affecting the function because the tension-shear composite device has enough complexity.

To sum up, a set of multi-load material mechanics testing instruments that can integrate tensile, shear and indentation is of great significance for the testing of material mechanical properties.

Contents of the invention

The purpose of this utility model is to provide a tensile-shear preload in-situ indentation test device, which solves the above-mentioned problems in the prior art, especially solves the impact of different loads on the mechanical properties of materials under the condition that multiple loads act on the material at the same time. impact issues. It is a material mechanics testing device that integrates tension, shear and indentation, and can realize the common load of tension and shear indentation; it can freely change the clamping angle of the specimen; the cantilever structure greatly simplifies the indentation module device ; Two-stage piezoelectric stack is used to control the displacement of the indentation to realize coarse adjustment and fine adjustment respectively. The utility model has high test precision and can realize automation of measurement and data analysis.

Above-mentioned purpose of the utility model is realized through the following technical solutions:

Tensile-shear preload in-situ indentation test device, including a mechanical transmission module, an arbitrary-angle tensile-shear composite loading module, a cantilever indentation module, and a measurement module, wherein the mechanical transmission module drives arbitrary-angle tensile-shear composite loading The module, the cantilever indentation module and the measurement module move, and the measurement module measures the changes of the tensile-shear composite loading module and the cantilever indentation module at any angle;

The mechanical transmission module is: the first-stage worm wheel 23 cooperates with the first-stage worm 22, the second-stage worm wheel 26 cooperates with the second-stage worm 28, and the second-stage worm 28 passes through the second-stage worm support frame a27, the second-stage worm support frame b30, The auxiliary support frame 25 is connected on the main frame 11; because the secondary worm gear protrudes too long, its rigidity is increased through the auxiliary support frame 25; the DC servo motor 19 is fixed on the motor base 21 through the reducer 20; the rotary motion is converted into a straight line The two ends of the moving ball screw 13 are respectively installed on the main frame 11 through the bearing seat a12 and the bearing seat b29, and the nut pairs matched with the ball screw 13 are fixed on the mobile platform a9 and the mobile platform b33, respectively driving the mobile platform a9, Moving the platform b33 so as to realize linear motion;

The arbitrary-angle tension-shear composite loading module includes: mobile platforms a, b9, 33, 90-degree scales a, b8, 31 for determining the clamping angle of the specimen, a clamping unit, and the 90-degree scales a, b8, 31 are respectively arranged on the mobile platforms a, b9, 33, and the clamping unit is that the pressing block a6 and the bearing block a34 press the two ends of the test piece on the pressing block b7 and the bearing block b32 respectively by screws, and the two The clamping unit is connected to the auxiliary pressure plate 38 under the mobile platform through screws, and the clamping unit will approach the auxiliary pressure plate by tightening the screws, and the two will be respectively pressed on both sides of the mobile platform, thereby realizing the clamping of the specimen;

The cantilever indentation module is: the indentation adjustment plate 42 is fixed on the side of the main frame 11, and the overall height of the cantilever indentation module is adjusted, and will not change once adjusted; the cantilever beam 1 is fixed on the column 3 by screws, and the cantilever beam 1 There are two flexible grooves in series to facilitate displacement loading in the vertical direction; the piezoelectric stack 37 is fixedly connected to the top block 36, and the other end is pushed against the cantilever beam 1 to facilitate displacement in the vertical direction load;

Described measurement module is: encoder 18 is installed on the DC servo motor 19 of mechanical transmission module; LVDT linear displacement sensor 16 is fixed on the mobile platform b33 by LVDT fixed block 17, and LVDT block 15 is fixed on the mobile platform a9 and with The LVDT linear displacement sensor 16 cooperates; the tension/tension sensor 10 is installed on the main frame 11 to measure the tensile force borne by the test piece; The sensors 35 are not in contact, leaving a certain distance for measuring the distance between the two.

The encoder 18 is used to measure the motor rotation angle to estimate the displacement of the two mobile platforms; the LVDT linear displacement sensor 16 is used to accurately measure the relative displacement of the two mobile platforms; the capacitive displacement sensor 4 and the baffle 2 are used to measure the pressing depth; The indentation sensor 35 is used to measure the pressure exerted by the indenter during the indentation process; when the indentation process is not in progress, it is used to observe the tensile shear deformation of the material in situ with a microscope.

The inside of the auxiliary support frame 25 communicates with the secondary worm support frames a, b27, and 30, all of which are provided with supporting rolling bearings. Because the overall size of the device is relatively wide, the primary worm wheel stretches out longer, in order to ensure the stability of the transmission parts This component is added due to its performance. The secondary worm support frame a, b27, 30 is fixed on the side of the main frame 11 by screws, as close as possible to the primary worm wheel.

The action of the cantilever indentation module is divided into two stages, that is, the coarse adjustment of the piezoelectric stack far away from the end of the cantilever beam 1 and the fine adjustment of the piezoelectric stack near the end of the cantilever beam 1. , as shown in Figure 4, wherein the right side of each piezoelectric stack 37 is fixedly connected to the cantilever beam 1, and the left side is fixedly connected to the top block 36; 1, the cantilever beam at the contact point has a certain inclination angle so as to be easy to bear force and prevent the top block 36 from sliding out from above.

The arbitrary-angle tensile-shear composite loading module is to determine the clamping angle of the specimen through the 90-degree scales a, b8, and 31, and through the auxiliary pressing plate 38 fixed below the mobile platform a, b9, and 33, and the pressing block a above , b6, 7 and bearing blocks a, b34, 32 to achieve accurate and rapid positioning process.

The tensile-shear preload in-situ indentation test device cooperates with the microscope, the indentation module is removed when the indentation process is not performed, and the entire device is placed under the microscope for in-situ observation of the tension-shear process .

The beneficial effects of the utility model are that: the common load of stretching and shearing indentation can be realized; the clamping angle of the specimen can be changed freely; the indentation module device is greatly simplified by adopting the cantilever structure; The displacement control of the indentation can realize coarse adjustment and fine adjustment respectively; the compact structure has high practical value, and can accurately carry out tensile shear indentation multi-load material mechanics test and in-situ observation.

Description of drawings

The accompanying drawings described here are used to provide a further understanding of the utility model and constitute a part of the application. The schematic examples and descriptions of the utility model are used to explain the utility model and do not constitute improper limitations to the utility model.

Fig. 1 is the overall appearance schematic diagram of the utility model;

Fig. 2 is the lower axonometric schematic diagram of the mobile platform of the present utility model;

Fig. 3 is the back view of the utility model;

Fig. 4 is the right view of the utility model;

Fig. 5 is a schematic structural view of the auxiliary platen of the present invention;

Fig. 6 is a structural schematic diagram of the indentation adjustment plate of the present invention;

Fig. 7 is the principle diagram of the tensile shear composite deformation of the present utility model;

Fig. 8 is the schematic diagram of realizing the in-situ observation of the utility model;

Fig. 9 is a load-displacement schematic diagram of a typical press-in test of the present invention.

In the figure: 1. cantilever beam; 2. baffle; 3. column; 4. capacitive displacement sensor; 5. fixed block of capacitive sensor; 6. pressing block a; 7. pressing block b; , mobile platform a; 10, tension/compression/tension sensor; 11, main frame; 12, bearing seat a; 13, ball screw; 14, guide rail; 15, LVDT stopper; 16, LVDT linear displacement sensor; 17, LVDT fixed block; 18, encoder; 19, DC servo motor; 20, reducer; 21, motor base; 22, primary worm; 23, primary turbine; 24, connecting rod; 25, auxiliary support frame; 26, Secondary worm wheel; 27. Secondary worm support frame a; 28. Secondary worm; 29. Bearing seat b; 30. Secondary worm support frame b; 31. 90-degree scale b; 32. Bearing block b; 33. Mobile Platform b; 34. Bearing block a; 35. Tension pressure/indentation sensor; 36. Top block; 37. Piezoelectric stack; 38. Auxiliary pressure plate; 39. Slider block; 40. Nut mobile platform connection block; 41. Nut; 42, indentation palette.

Detailed ways

Further illustrate the detailed content of the utility model and its specific implementation below in conjunction with accompanying drawing.

Referring to Fig. 1 to Fig. 9, the tension-shear preload in-situ indentation test device of the present invention consists of a mechanical transmission module, an arbitrary-angle tension-shear compound loading module, a cantilever indentation module and a measurement module. Partial composition.

The mechanical transmission module includes a main frame 11, a primary worm gear 23 and a primary worm 22 provide a primary deceleration, a connecting rod 24, a secondary worm gear 26, and a secondary worm 28 provide a secondary deceleration, a secondary worm support frame a27, and a secondary worm The first-stage worm support frame b30, because the second-stage worm gear protrudes too long, the auxiliary support frame 25, the motor support frame 21 to increase its rigidity, the reducer 20 placed to obtain the quasi-static loading rate, and the drive device for stretching motion DC servo The motor 19, the lead screw 13 that converts the rotary motion into linear motion, the bearing seat a12 and the bearing seat b30 that provide support for the lead screw. The nut mobile platform connecting block 40 and the nut 41 matched with the lead screw are fixedly connected on the mobile platform a9, which drives the mobile platform a9 to move in a straight line, and the mobile platform b33 also moves in the same way. The sliders 39 are fixedly connected under the two mobile platforms, and the sliders 39 are placed on the guide rails 14 to provide degrees of freedom in the linear direction.

The arbitrary-angle tensile-shear composite loading module includes mobile platforms a, b9, and 33 responsible for carrying and driving most of the devices, and 90-degree scales a, b8, and 31 for determining the fixed angle of the specimen. The clamping unit for directly clamping the test piece includes pressing blocks a, b6, 7 and bearing blocks a, b34, 32, wherein the pressing block a6 and the bearing block a34 respectively press the two ends of the test piece on the On the pressing block b7 and the bearing block b34, in addition, the two clamping units are connected to the auxiliary pressing plate 38 below the mobile platform through screws, and the clamping unit will approach the auxiliary pressing plate by tightening the screws, and the two will be respectively pressed against the moving platform. Both sides, and then realize the clamping of the specimen. Among them, as shown in Figure 5, the auxiliary pressure plate has three threaded holes at corresponding positions on a fan-shaped flat plate, and the positions are matched with the three through holes on the bearing block.

The cantilever indentation module is: the indentation adjustment plate 42 is fixed on the side of the main frame to adjust its height to adjust the overall height of the cantilever indentation module. Once adjusted, it will not change, and the length can be changed by passing an electric current and then used as a piezoelectric module. The piezoelectric stack 37 of the drive device supports the column 3 of the cantilever beam, which is used to place the piezoelectric stack and cantilever beam 1 that can be bent and deformed. It is fixed on the column by two screws above and below. A series of flexible grooves, through which the cantilever beam will be easier to bend, the top block 36 is fixedly connected with the piezoelectric stack, and the other end is pushed against the cantilever beam, so that it is easier to realize displacement loading in the vertical direction.

The measurement module includes: an encoder 18 used to measure the motor rotation angle to estimate the displacement of the two mobile platforms, an LVDT linear displacement sensor used to accurately measure the relative displacement of the two mobile platforms, and a linear displacement sensor used to measure the tension and compression of the test piece. The sensor 10 is used in conjunction with the capacitive displacement sensor 4 and the baffle plate 2 to measure the indentation depth, the pressure sensor 35 used to measure the pressure applied by the indenter during the indentation process, and the capacitive sensor fixing block 5 is used to fix the sensor 35 and fix it. Connected to the mobile platform a; a microscope used to observe the tensile and shear deformation of materials in situ when the indentation process is not in progress.

Described auxiliary supporting frame 25, its interior is the same as secondary worm screw supporting frame a, b27, 30, is provided with the rolling bearing that supports, because the whole size of device is wider, and primary worm wheel stretches out longer, in order to ensure transmission parts This component is added for stability. This bracing frame is by two screws on the side of main frame 11, as far as possible near one-stage worm gear.

The action of the cantilever indentation module is divided into two stages, that is, the coarse adjustment performed by electrifying the piezoelectric stack far from the end of the cantilever beam and the fine adjustment performed by electrifying the piezoelectric stack near the end of the cantilever beam. . As shown in Figure 4, the right side of each piezoelectric stack is fixedly connected to the cantilever beam, and the left side is fixedly connected to the top block. The top block is in the shape of a semi-cylindrical, and the side of the busbar is connected with the cantilever beam. The cantilever beam at the contact point is designed to have a certain inclination angle, which is easy to bear force and prevents the top block from sliding out from above.

The arbitrary-angle tensile-shear composite loading module is characterized in that the clamping angle of the specimen is determined by a 90° angle scale, and the two are separated by screws on the upper and lower sides through the auxiliary pressure plate below and the bearing block above the mobile platform. The side is pressed onto the mobile platform to achieve accurate and fast positioning.

The utility model is realized together with a microscope. When the indentation process is not performed, the indentation module is removed, and the whole device is placed under the microscope to observe the drawing and shearing process in situ.

Next, the test principles of tensile-shear composite and indentation will be described in detail.

Pull-shear composite

As shown in Figure 6, the original length (parallel length) of the specimen is l _g , width b, and thickness h. The fixture moves along the vertical direction in the figure, and the relative movement distance is l _d . The angle of the specimen when it is initially fixed is θ, The midline angle of the two states after stretching is γ.

After derivation, the following formula can be obtained:

${\mathrm{<span\; class="notranslate">\; \&Delta;l</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}<span\; class="notranslate">\; =</span>\sqrt{{\mathrm{<span\; class="notranslate">\; l</span>}}_{\mathrm{<span\; class="notranslate">\; g</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; l</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 2</span>}{\mathrm{<span\; class="notranslate">\; l</span>}}_{\mathrm{<span\; class="notranslate">\; g</span>}}{\mathrm{<span\; class="notranslate">\; l</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}\mathrm{<span\; class="notranslate">\; c</span>}\mathrm{<span\; class="notranslate">\; o</span>}\mathrm{<span\; class="notranslate">\; the\; s</span>}\mathrm{<span\; class="notranslate">\; \&theta;</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; l</span>}}_{\mathrm{<span\; class="notranslate">\; g</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$

should be

$\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; I</span>}\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&Delta;l</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}<span\; class="notranslate">\; /</span>{\mathrm{<span\; class="notranslate">\; l</span>}}_{\mathrm{<span\; class="notranslate">\; g</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; I</span>}\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; (</span>\sqrt{{\mathrm{<span\; class="notranslate">\; l</span>}}_{\mathrm{<span\; class="notranslate">\; g</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; l</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 2</span>}{\mathrm{<span\; class="notranslate">\; l</span>}}_{\mathrm{<span\; class="notranslate">\; g</span>}}{\mathrm{<span\; class="notranslate">\; l</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}\mathrm{<span\; class="notranslate">\; c</span>}\mathrm{<span\; class="notranslate">\; o</span>}\mathrm{<span\; class="notranslate">\; the\; s</span>}\mathrm{<span\; class="notranslate">\; \&theta;</span>}}<span\; class="notranslate">\; /</span>{\mathrm{<span\; class="notranslate">\; l</span>}}_{\mathrm{<span\; class="notranslate">\; g</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>$

then the angle

$\mathrm{<span\; class="notranslate">\; \&gamma;</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; r</span>}\mathrm{<span\; class="notranslate">\; c</span>}\mathrm{<span\; class="notranslate">\; c</span>}\mathrm{<span\; class="notranslate">\; o</span>}\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; \&lsqb;</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; l</span>}}_{\mathrm{<span\; class="notranslate">\; g</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; l</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}\mathrm{<span\; class="notranslate">\; c</span>}\mathrm{<span\; class="notranslate">\; o</span>}\mathrm{<span\; class="notranslate">\; the\; s</span>}\mathrm{<span\; class="notranslate">\; \&theta;</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; /</span>\sqrt{{\mathrm{<span\; class="notranslate">\; l</span>}}_{\mathrm{<span\; class="notranslate">\; g</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; l</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 2</span>}{\mathrm{<span\; class="notranslate">\; l</span>}}_{\mathrm{<span\; class="notranslate">\; g</span>}}{\mathrm{<span\; class="notranslate">\; l</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}\mathrm{<span\; class="notranslate">\; c</span>}\mathrm{<span\; class="notranslate">\; o</span>}\mathrm{<span\; class="notranslate">\; the\; s</span>}\mathrm{<span\; class="notranslate">\; \&theta;</span>}}<span\; class="notranslate">\; \&rsqb;</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; )</span>$

If the coefficient

k ² =l _g /(l _g +△l _d )(4)

The tensile stress and shear stress are respectively

σ _t =F _l cos(θ-γ)/(k ² bh)(5)

σ _t =F _l sin(θ-γ)/(k ² bh)(6)

From this, the relationship curves of tensile stress and tensile strain, shear stress and shear strain can be obtained.

indentation

The solution is solved with the classical test principle based on elastic contact theory proposed by Oliver and Pharr.

P＝a(hh _f ) ^m (7)

where P is the load, h is the displacement, h _f is the residual depth after unloading, and a and m are fitting parameters.

According to the relevant knowledge of contact mechanics and combined with the above formula, the contact stiffness S can be calculated:

S=(dP/dh) _h=hmax ＝am(h _max -h _f ) ^m-1 (8)

Among them, dP/dh represents the slope of the Ph curve at the maximum indentation depth _hmax .

by contact depth

${\mathrm{<span\; class="notranslate">\; h</span>}}_{\mathrm{<span\; class="notranslate">\; c</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; h</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; x</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}\frac{{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; x</span>}}}{\mathrm{<span\; class="notranslate">\; S</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 9</span>}<span\; class="notranslate">\; )</span>$

Among them, h _c is the contact depth, ε is a constant related to the shape of the indenter. For a conical indenter, ε=0.72, P _max is the maximum pressure.

And according to the area function A=f(h _c ), the contact area can be calculated. For the ideal Bosch indenter,

Then the indentation hardness H of the material can be expressed as:

$\mathrm{<span\; class="notranslate">\; h</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; x</span>}}}{\mathrm{<span\; class="notranslate">\; A</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 10</span>}<span\; class="notranslate">\; )</span>$

The above descriptions are only preferred examples of the utility model, and are not intended to limit the utility model. For those skilled in the art, the utility model can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made to the utility model shall be included in the protection scope of the utility model.

Claims (5)

1. A tensile-shear preload in-situ indentation test device, characterized in that: it includes a mechanical transmission module, an arbitrary-angle tensile-shear composite loading module, a cantilever indentation module and a measurement module, wherein the mechanical transmission module drives The movement of the tensile-shear composite loading module at any angle, the cantilever indentation module and the measurement module, and the measurement module measures the changes of the tensile-shear composite loading module at any angle and the cantilever indentation module; The mechanical transmission module is: the primary worm gear (23) cooperates with the primary worm (22), the secondary worm gear (26) cooperates with the secondary worm (28), and the secondary worm (28) is supported by the secondary worm Frame a (27), secondary worm support frame b (30), and auxiliary support frame (25) are connected to the main frame (11); since the secondary worm gear protrudes too long, its rigidity is increased through the auxiliary support frame (25) ; The DC servo motor (19) is fixed on the motor base (21) through the reducer (20); the two ends of the ball screw (13), which converts the rotary motion into linear motion, respectively pass through the bearing seat a (12), the bearing seat b (29) Installed on the main frame (11), the nut pair matched with the ball screw (13) is fixed on the mobile platform a (9) and the mobile platform b (33), respectively drive the mobile platform a (9), mobile platform b (33) to achieve linear motion; The arbitrary-angle tensile-shear composite loading module includes: mobile platforms a, b (9, 33), 90-degree scales a, b (8, 31) for determining the clamping angle of the specimen, and a clamping unit. The 90-degree scales a, b (8, 31) are set on the mobile platforms a, b (9, 33) respectively, and the clamping unit is the pressing block a (6) and the bearing block a (34) respectively screwed together The two ends of the specimen are pressed tightly on the pressing block b (7) and the bearing block b (32), and the two clamping units are connected with the auxiliary pressing plate (38) under the mobile platform through screws, and the clamping unit will move toward The auxiliary pressure plate is close, and the two will be respectively pressed on both sides of the mobile platform, so as to realize the clamping of the specimen; The cantilever indentation module is as follows: the indentation adjustment plate (42) is fixed on the side of the main frame (11), and the overall height of the cantilever indentation module is adjusted. Once adjusted, it will not change; the cantilever beam (1) is fixed on the column ( 3) On the cantilever beam (1), there are two flexible grooves in series to facilitate displacement loading in the vertical direction; the piezoelectric stack (37) is fixedly connected to the top block (36), and the other end is on the The cantilever beam (1) is easy to realize displacement loading in the vertical direction; The measurement module is: the encoder (18) is installed on the DC servo motor (19) of the mechanical transmission module; the LVDT linear displacement sensor (16) is fixed on the mobile platform b (33) through the LVDT fixed block (17), and the LVDT The block (15) is fixed on the mobile platform a (9) and cooperates with the LVDT linear displacement sensor (16); the tension/tension sensor (10) is installed on the main frame (11) to measure the The baffle (2) is fixedly connected to the capacitive displacement sensor (4), and is not in contact with the tension/indentation sensor (35), leaving a certain distance for measuring the distance between the two. 2. The tension-shear preload in-situ indentation test device according to claim 1, characterized in that: the inside of the auxiliary support frame (25) is connected with the secondary worm support frame a, b (27, 30 ) are connected, and are provided with rolling bearings for support, and the secondary worm support frames a, b (27, 30) are fixed on the side of the main frame (11) by screws. 3. The tension-shear preload in-situ indentation test device according to claim 1, characterized in that: the action of the cantilever indentation module is divided into two stages, that is, away from the end of the cantilever beam (1) Coarse adjustment by energizing the piezoelectric stack of the cantilever beam (1) and fine adjustment by energizing the piezoelectric stack near the end of the cantilever beam (1), wherein the right side of each piezoelectric stack (37) is connected to the cantilever beam (1 ), the left side is fixedly connected with the jacking block (36); the jacking block (36) is in the shape of a semi-cylindrical, and the side close to the busbar is in contact with the cantilever beam (1). And prevent top block (36) from sliding out from above. 4. The tension-shear preload in-situ indentation test device according to claim 1, characterized in that: the arbitrary angle tension-shear composite loading module is passed through 90 degree scales a, b (8, 31) Determine the clamping angle of the specimen, through the auxiliary pressure plate (38) fixed below the mobile platform a, b (9, 33), the upper pressure block a, b (6, 7) and the bearing block a, b (34 , 32), to achieve accurate and fast positioning process. 5. The tensile-shear preload in-situ indentation test device according to claim 1, characterized in that: the tensile-shear preload in-situ indentation test device cooperates with a microscope, During the indentation process, the indentation module was removed, and the whole device was placed under a microscope to observe the tension-shear process in situ.