Fully-graded concrete bending and tensile test device and test method

Abstract

The invention relates to the technical field of concrete flexural-tensile tests, in particular to a fully-graded concrete flexural-tensile test device and a test method.The fully-graded concrete flexural-tensile test device comprises an electro-hydraulic servo actuator used for applying pressure to a test piece, and a workbench is arranged below the electro-hydraulic servo actuator; the workbench is provided with a supporting assembly used for placing a test piece and an adjusting assembly used for adjusting the central axis of the test piece and the central axis of the pressure applying end of the electro-hydraulic servo actuator to be located on the same central axis. The supporting assembly comprises first movable plates which are symmetrically arranged; the adjusting assembly comprises baffles which are symmetrically arranged, the two first movable plates are arranged between the two baffles, and the baffles and the first movable plates are in sliding connection with the top face of the workbench. The central axis of the test piece placed on the supporting assembly and the central axis of the pressure applying end of the electro-hydraulic servo actuator can be located on the same central axis through the adjusting assembly, the centering precision of the test piece is effectively improved, and the data accuracy and the test efficiency are effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of flexural tensile tests of concrete, and particularly to a full-graded concrete flexural tensile test device and a test method. Background Art

[0002] Full-graded concrete uses continuously graded aggregates with a relatively large maximum aggregate size (usually exceeding 40 mm) and is widely used in large-volume structures such as hydraulic dams and bridges; its mechanical properties (especially flexural tensile strength) directly affect the crack resistance and durability of the structure.

[0003] However, before conducting the experiment with the existing device, manual centering of the concrete specimens is still required, resulting in poor centering accuracy of the concrete specimens, which affects the accuracy of data and the test efficiency; therefore, there is an urgent need for a full-graded concrete flexural tensile test device and a test method that can effectively improve the centering accuracy of the concrete specimens, improve the data accuracy, and at the same time improve the test efficiency. Summary of the Invention

[0004] The purpose of the present invention is to provide a full-graded concrete flexural tensile test device and a test method to solve the problems existing in the above-mentioned prior art.

[0005] To achieve the above purpose, the present invention provides the following solution: A full-graded concrete flexural tensile test device includes an electro-hydraulic servo actuator for pressing the specimen. A workbench is arranged below the electro-hydraulic servo actuator. A support assembly for placing the specimen and an adjustment assembly for adjusting the central axis of the specimen to be on the same central axis as the pressing end of the electro-hydraulic servo actuator are arranged on the workbench; the support assembly includes symmetrically arranged first movable plates; the adjustment assembly includes symmetrically arranged baffles. The two first movable plates are arranged between the two baffles, and the baffles, the first movable plates are slidably connected to the top surface of the workbench.

[0006] Preferably, a first chute is formed on the top surface of the workbench. A first lead screw and a second lead screw are rotatably connected in the first chute, and the first lead screw is arranged above the second lead screw.

[0007] Preferably, two first sliders are threadedly connected to the first lead screw, and the first sliders are arranged in one-to-one correspondence with the first movable plates. One end of the first slider extending out of the first chute is fixedly connected to the bottom of the first movable plate.

[0008] Preferably, two second sliders are threadedly connected to the second lead screw, the second sliders are arranged in one-to-one correspondence with the baffles, one end of the second slider extending out of the first chute is fixedly connected to the bottom of the baffle, and the second slider is sleeved on the first lead screw and is slidably connected to the first lead screw.

[0009] Preferably, a roller is arranged at one end of the first movable plate away from the first slider, and two first fixing plates are respectively rotatably connected to both ends of the roller, and the first fixing plates are fixedly connected to the first movable plate.

[0010] Preferably, a second chute is formed in the baffle, two third sliders are slidably connected in the second chute, one end of the third slider extending out of the second chute is fixedly connected to a third movable plate, and the other end of the third slider extending out of the second chute is threadedly connected to a third lead screw.

[0011] Preferably, the third movable plate is arranged on one side where the two baffles face each other, and the bottom surface of the third movable plate is higher than the top surface of the roller.

[0012] Preferably, both ends of the third lead screw are respectively rotatably connected to second fixing plates, and the second fixing plates are fixedly connected to the baffles.

[0013] Preferably, the center line between the two baffles and the center line between the two rollers are perpendicular to and intersect with the central axis of the pressing end of the electro-hydraulic servo actuator.

[0014] A flexural tensile test method for fully graded concrete includes the following steps:

[0015] S1. Adjust the distance between the two first movable plates according to the length of the test piece;

[0016] S2. Then place the test piece on the support assembly;

[0017] S3. Then adjust the position of the test piece through the adjustment assembly;

[0018] S4. Check whether the support assembly supports the test piece at the designated position of the test piece;

[0019] S4.1. When the support position is incorrect, adjust the support position of the support assembly to the designated position of the test piece;

[0020] S4.2. When the support position of the support assembly is at the designated position of the test piece, the next step can be carried out;

[0021] S5. Apply a load to the test piece through the electro-hydraulic servo actuator to conduct a flexural tensile test.

[0022] The present invention discloses the following technical effects:

[0023] Through the adjustment component, the central axis of the specimen placed on the support component can be made to be on the same central axis as the pressure application end of the electro-hydraulic servo actuator, effectively improving the centering accuracy of the specimen and effectively improving the accuracy of data and the test efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0025] Figure 1 It is a front view structural schematic diagram of the whole of the present invention;

[0026] Figure 2 It is a top view structural schematic diagram of the electro-hydraulic servo actuator of the present invention;

[0027] Figure 3 It is a top view structural schematic diagram of the workbench of the present invention;

[0028] Figure 4 It is a structural schematic diagram of the workbench of the present invention;

[0029] Figure 5 It is a sectional view structural schematic diagram of the workbench of the present invention;

[0030] Figure 6 It is a front view structural schematic diagram of the baffle of the present invention;

[0031] Among them, 1, workbench; 2, roller; 3, baffle; 4, electro-hydraulic servo actuator; 11, first chute; 12, first lead screw; 13, first slider; 14, first motor; 15, second lead screw; 16, second slider; 17, second motor; 21, first movable plate; 22, first fixed plate; 31, second chute; 32, third lead screw; 33, third slider; 34, third movable plate; 35, third motor; 36, second fixed plate; 41, pressure application end. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0032] The embodiments that can be added to the present invention are as follows:

[0033] The flexural tensile test of concrete specimens is an important test to evaluate their flexural tensile strength, elastic modulus and deformation performance, and relevant standards (such as national standards, ASTM, JTG, etc.) and technical specifications need to be strictly followed. The following are its main test requirements and key control points:

[0034] 1. Requirements for specimen preparation

[0035] Specimen size:

[0036] Standard specimen: Common sizes are prisms (such as 150mm×150mm×550mm, 100mm×100mm×400mm).

[0037] Full-graded specimen: The actual aggregate gradation of the project needs to be retained (such as the maximum aggregate size ≥ 40mm), with a larger size (such as 450mm×450mm×1350mm), and wet screening treatment should be avoided during preparation.

[0038] Preparation method:

[0039] Vibrate layer by layer during pouring to ensure compaction and avoid segregation;

[0040] The specimen surface should be flat, and the parallelism error of both end faces ≤ 0.5mm;

[0041] Curing condition: Cure in a standard curing room (temperature 20±2°C, humidity ≥ 95%) for 28 days.

[0042] 2. Requirements for experimental equipment

[0043] Loading device:

[0044] Three-point bending: Single-point loading at the mid-span, suitable for small-sized specimens;

[0045] Four-point bending: Double-symmetric point loading to ensure a pure bending section and reduce the interference of shear stress;

[0046] Dynamic loading system: It should have a high-rigidity frame and closed-loop control, and support static, dynamic or cyclic loads (such as a servo-hydraulic system).

[0047] Load control:

[0048] The accuracy of the load sensor ≤ ±1%, and the range covers 20% - 80% of the expected failure load;

[0049] Loading rate: Usually 0.05 - 0.1MPa / s for static tests, and adjusted according to frequency requirements for dynamic tests (such as 1 - 10Hz).

[0050] Data acquisition system:

[0051] Measure the mid-span deflection with a displacement sensor (LVDT) or an extensometer;

[0052] Monitor the surface strain with strain gauges or fiber optic sensors;

[0053] Record the load-displacement curve with a high-speed data acquisition card (sampling frequency ≥ 100Hz).

[0054] 3. Experimental process control

[0055] Specimen installation:

[0056] Place the specimen in the center to ensure that the loading axis coincides with the geometric center of the specimen;

[0057] Use a level to calibrate the support rollers and loading rollers to avoid eccentric loading;

[0058] Pad the contact surface with rubber sheets or thin steel plates to reduce local stress concentration.

[0059] Loading procedure:

[0060] Preload to 10% of the ultimate load to eliminate the gap between the specimen and the device;

[0061] Load continuously and uniformly until the specimen fails, and record the peak load and failure mode;

[0062] For dynamic tests, the load waveform (such as sine wave, square wave), amplitude, and frequency need to be set.

[0063] Environmental conditions:

[0064] Room temperature test: Temperature 20 ± 5°C, humidity ≤ 70%;

[0065] Special environment test (such as freeze-thaw, chloride salt erosion): It is necessary to apply flexural tensile load synchronously in a specific environmental chamber.

[0066] Standard specification reference

[0067] Chinese standards:

[0068] "Test Regulations for Cement and Cement Concrete in Highway Engineering" (JTG E30 - 2005);

[0069] "Test Regulations for Hydraulic Concrete" (SL / T 352 - 2020).

[0070] International standards:

[0071] ASTM C78 / C78M: Standard Test Method for Flexural Strength of Concrete;

[0072] ISO 1920 - 7: Testing of concrete - Part 7: Determination of flexural strength.

[0073] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0074] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0075] Embodiment 1

[0076] Reference Figures 1-6 The present invention provides a full-graded concrete bending and tension testing device, including an electro-hydraulic servo actuator 4 for applying pressure to a specimen, a workbench 1 is arranged below the electro-hydraulic servo actuator 4, and a supporting assembly for placing the specimen and an adjusting assembly for adjusting the central axis of the specimen and the central axis of a pressure-applying end 41 of the electro-hydraulic servo actuator 4 to be on the same central axis are arranged on the workbench 1; the supporting assembly includes symmetrically arranged first movable plates 21; the adjusting assembly includes symmetrically arranged baffles 3, two first movable plates 21 are arranged between the two baffles 3, and the baffles 3 and the first movable plates 21 are slidably connected to the top surface of the workbench 1.

[0077] The electro-hydraulic servo actuator 4 is a hydraulic actuator that can convert the hydraulic energy from the hydraulic source into mechanical energy, and can also be servo-controlled through the displacement sensor or travel switch provided in the product as needed; it is used to execute the commands of the main controller to control the speed, direction, displacement and force of the load.

[0078] The electro-hydraulic servo actuator 4 is an important component of the hydraulic servo control; it is mainly composed of hydraulic servo valves, hydraulic actuators, displacement sensors, pressure sensors, load sensors, shock absorbers and other components.

[0079] The electro-hydraulic servo actuator 4 is a high-precision drive device that combines electrical control, hydraulic power and closed-loop feedback, and is widely used in fields that require high power, high response and precise control.

[0080] In test equipment, the electro-hydraulic servo actuator 4 is mainly used for high-precision force / displacement control of material testing machines and vibration tables.

[0081] The present invention can make the central axis of the test piece placed on the support assembly and the central axis of the pressure end 41 of the electro-hydraulic servo actuator 4 on the same central axis by adjusting the assembly, thereby effectively improving the centering accuracy of the test piece, and effectively improving the accuracy of data and test efficiency.

[0082] In a further optimized solution, a first slide groove 11 is provided on the top surface of the workbench 1, and a first lead screw 12 and a second lead screw 15 are rotatably connected in the first slide groove 11, and the first lead screw 12 is arranged above the second lead screw 15. By arranging the first lead screw 12 above the second lead screw 15, the first lead screw 12 and the second lead screw 15 can effectively rotate in the first slide groove 11.

[0083] To enable the baffle 3 to effectively push the test piece and the first movable plate 21 to effectively support the test piece, the widths of the baffle 3 and the first movable plate 21 are greater than the width of the first chute 11 and less than the width of the top surface of the workbench 1.

[0084] One end of the first lead screw 12 extending outside the first chute 11 is drivingly connected to a first motor 14, and one end of the second lead screw 15 extending outside the first chute 11 is drivingly connected to a second motor 17. The first motor 14 and the second motor 17 are fixedly connected to the outer wall of the workbench 1.

[0085] The first lead screw 12 and the second lead screw 15 are bidirectional lead screws.

[0086] In a further optimized solution, two first sliders 13 are threadedly connected to the first lead screw 12. The first sliders 13 are arranged in one-to-one correspondence with the first movable plate 21. One end of the first slider 13 extending outside the first chute 11 is fixedly connected to the bottom of the first movable plate 21.

[0087] The first motor 14 drives the first lead screw 12 to rotate. The first lead screw 12 drives the two first sliders 13 to approach or move away synchronously. The first sliders 13 drive the first movable plates 21 to approach or move away from each other.

[0088] In a further optimized solution, two second sliders 16 are threadedly connected to the second lead screw 15. The second sliders 16 are arranged in one-to-one correspondence with the baffle 3. One end of the second slider 16 extending outside the first chute 11 is fixedly connected to the bottom of the baffle 3. The second slider 16 is sleeved on the first lead screw 12 and is slidably connected to the first lead screw 12.

[0089] The first slider 13 and the second slider 16 move along the first chute 11.

[0090] The second motor 17 drives the second lead screw 15 to rotate. The second lead screw 15 drives the two second sliders 16 to approach or move away synchronously. The second sliders 16 drive the baffle 3 to approach or move away from each other synchronously.

[0091] In a further optimized solution, rollers 2 are arranged at one end of the first movable plate 21 away from the first slider 13. Both ends of the rollers 2 are rotatably connected to first fixing plates 22. The first fixing plates 22 are fixedly connected to the first movable plate 21.

[0092] By driving the rollers 2 to approach or move away from each other synchronously through the first movable plate 21, the rollers 2 can effectively support the bottom of the test piece.

[0093] For a further optimized solution, a second chute 31 is formed in the baffle 3. Two third sliders 33 are slidably connected in the second chute 31. One end of the third slider 33 extending out of the second chute 31 is fixedly connected with a third movable plate 34, and the other end of the third slider 33 extending out of the second chute 31 is threadedly connected with a third lead screw 32. The third slider 33 moves along the second chute 31.

[0094] The third lead screw 32 is a bidirectional lead screw. By rotating the third lead screw 32, the two third sliders 33 are driven to approach or move away from each other synchronously.

[0095] For a further optimized solution, the third movable plate 34 is arranged on the opposite side of the two baffles 3, and the bottom surface of the third movable plate 34 is higher than the top surface of the roller 2.

[0096] The third movable plate 34 can effectively adjust the position of the test piece placed on the roller 2.

[0097] When the width of the test piece is smaller than the width of the roller 2, since the bottom surface of the third movable plate 34 is higher than the top surface of the roller 2, the two third movable plates 34 can move above the roller 2, and the two third movable plates 34 can effectively adjust the position of the test piece on the roller 2.

[0098] For a further optimized solution, both ends of the third lead screw 32 are respectively rotatably connected with second fixing plates 36, and the second fixing plates 36 are fixedly connected with the baffle 3. One end of the third lead screw 32 extending out of the second fixing plate 36 is drivingly connected with a third motor 35, and the third motor 35 drives the third lead screw 32 to rotate between the two second fixing plates 36.

[0099] For a further optimized solution, the center line between the two baffles 3 and the center line between the two rollers 2 are perpendicular and intersect with the central axis of the pressing end 41 of the electro-hydraulic servo actuator 4. When the opposite sides of the two baffles 3 are respectively abutted against the outer wall of the test piece, and the opposite sides of the two third movable plates 34 are respectively abutted against the outer wall of the test piece, the central axis of the test piece and the central axis of the pressing end 41 of the electro-hydraulic servo actuator 4 are on the same central axis.

[0100] A flexural test method for fully graded concrete includes the following steps:

[0101] S1. Adjust the distance between the two first movable plates 21 according to the length of the test piece; that is, first adjust the distance between the two rollers 2 according to the length of the test piece. Turn on the first motor 14 to drive the first lead screw 12 to rotate. The first lead screw 12 drives the two first sliders 13 to approach or move away from each other synchronously. The first slider 13 drives the first movable plate 21 to approach or move away from each other. The first movable plate 21 drives the rollers 2 to approach or move away from each other, so that the distance between the two rollers 2 is at the required distance.

[0102] S2. Then place the test piece on the support assembly; that is, place the test piece on the roller 2.

[0103] S3. Then adjust the position of the test piece through the adjustment assembly; turn on the second motor 17 to drive the second lead screw 15 to rotate. The second lead screw 15 drives the two second sliders 16 to approach synchronously. The second sliders 16 drive the baffles 3 to approach each other. When the opposite sides of the two baffles 3 are respectively in contact with the outer wall of the test piece, turn off the second motor 17 and turn on the third motor 35. The third motor 35 drives the third lead screw 32 to rotate. The third lead screw 32 drives the two third sliders 33 to approach each other. The third sliders 33 drive the third movable plates 34 to approach each other, so that the third movable plates 34 can effectively adjust the position of the test piece placed on the roller 2. When the opposite sides of the two third movable plates 34 are respectively in contact with the outer wall of the test piece, the central axis of the test piece and the central axis of the pressure application end 41 of the electro-hydraulic servo actuator 4 are on the same central axis.

[0104] S4. Check whether the support assembly supports the test piece at the specified position of the test piece; that is, whether the position where the roller 2 contacts the test piece meets the requirements.

[0105] S4.1. When the support position is incorrect, adjust the support position of the support assembly to the specified position of the test piece; that is, turn on the first motor 14 to adjust the positions of the two rollers 2. When the rollers 2 reach the specified positions at the bottom surface of the test piece, the rollers 2 can effectively support the bottom of the test piece.

[0106] S4.2. When the support position of the support assembly is at the specified position of the test piece, the next step can be carried out; that is, the position where the roller 2 contacts the test piece meets the requirements, and the roller 2 can effectively support the bottom of the test piece.

[0107] After the position where the roller 2 contacts the test piece meets the requirements, turn off the first motor 14, and then turn on the second motor 17 and the third motor 35 to separate the baffles 3 and the third movable plates 34 from the outer wall of the test piece, ensuring that the test piece has enough deformation space during the test.

[0108] S5. Apply a load to the test piece through the electro-hydraulic servo actuator 4 for a flexural tension test; that is, apply a load to the test piece through the pressure application end 41 of the electro-hydraulic servo actuator 4 for a flexural tension test.

[0109] Embodiment 2

[0110] In order to record the test data of the test piece more accurately, two rows of 3 strain gauges with an effective length of 100 mm are arranged on the top and bottom surfaces of the test piece parallel to the beam axis direction respectively; three rows of 3 strain gauges with an effective length of 100 mm are arranged on the two side surfaces of the test piece parallel to the beam axis direction respectively. There are a total of 30 channels for the strain measurement points. The full-scale flexural test measurement signals include: system time, load, displacement, load command or displacement command, 30-channel strain and maximum strain, a total of 35-channel signals.

[0111] The bearing capacity of the full-scale concrete flexural test piece is very low, so a 2.5 MN load sensor is used to measure the load; the load sensor is installed at the end of the pressure application end 41 of the electro-hydraulic servo actuator 4, effectively improving the measurement accuracy.

[0112] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0113] The above-described embodiments are only descriptions of the preferred embodiments of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. A fully graded concrete bending and tension test device, characterized in that: The invention comprises an electro-hydraulic servo actuator (4) for applying pressure to a test piece, wherein a workbench (1) is arranged below the electro-hydraulic servo actuator (4), and the workbench (1) is provided with a support component for placing the test piece and an adjustment component for adjusting the central axis of the test piece and the central axis of the pressure-applying end (41) of the electro-hydraulic servo actuator (4) to be on the same central axis; The support assembly comprises a symmetrically arranged first movable plate (21); the adjustment assembly comprises a symmetrically arranged baffle plate (3), two of the first movable plates (21) are arranged between the two baffle plates (3), and the baffle plate (3) and the first movable plate (21) are slidably connected to the top surface of the workbench (1).

2. The fully graded concrete bending and tension test device according to claim 1 is characterized in that: The top surface of the workbench (1) is provided with a first slide groove (11), in which a first lead screw (12) and a second lead screw (15) are rotatably connected, and the first lead screw (12) is arranged above the second lead screw (15).

3. The fully graded concrete bending tensile test device according to claim 2 is characterized in that: Two first sliders (13) are threadedly connected to the first lead screw (12), and the first sliders (13) are arranged in a one-to-one correspondence with the first movable plate (21). One end of the first slider (13) extending out of the first slide groove (11) is fixedly connected to the bottom of the first movable plate (21).

4. The fully graded concrete bending tensile test device according to claim 3 is characterized in that: The second lead screw (15) is threadedly connected with two second sliders (16), and the second sliders (16) are arranged one-to-one with the baffle (3). One end of the second slider (16) extending out of the first slide groove (11) is fixedly connected to the bottom of the baffle (3), and the second slider (16) is sleeved on the first lead screw (12) and is slidably connected to the first lead screw (12).

5. The fully graded concrete bending tensile test device according to claim 3 is characterized in that: A roller (2) is provided at one end of the first movable plate (21) away from the first sliding block (13), and both ends of the roller (2) are rotatably connected to first fixed plates (22), and the first fixed plate (22) is fixedly connected to the first movable plate (21).

6. The fully graded concrete bending tensile test device according to claim 5, characterized in that: The baffle plate (3) is provided with a second slide groove (31), and two third sliders (33) are slidably connected in the second slide groove (31); one end of the third slider (33) extending out of the second slide groove (31) is fixedly connected to a third movable plate (34), and the other end of the third slider (33) extending out of the second slide groove (31) is threadedly connected to a third lead screw (32).

7. The fully graded concrete bending tensile test device according to claim 6 is characterized in that: The third movable plate (34) is arranged on a side opposite to the two baffles (3), and the bottom surface of the third movable plate (34) is higher than the top surface of the roller (2).

8. The fully graded concrete bending and tension testing device according to claim 6, characterized in that: The two ends of the third lead screw (32) are rotatably connected to second fixing plates (36), and the second fixing plates (36) are fixedly connected to the baffle (3).

9. The fully graded concrete bending and tension testing device according to claim 6, characterized in that: The center line between the two baffles (3) and the center line between the two rollers (2) are perpendicular to and intersect with the center axis of the pressure end (41) of the electro-hydraulic servo actuator (4).

10. A method for bending and tensile testing of fully graded concrete, based on the bending and tensile testing device for fully graded concrete according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1. Adjusting the distance between the two first movable plates (21) according to the length of the specimen; S2. The specimen is then placed on the support assembly; S3. Then adjust the position of the specimen by adjusting the assembly; S4. Check whether the support assembly supports the specimen at the designated position of the specimen; S4.

1. When the support position is incorrect, adjust the support position of the support assembly to the specified position of the specimen; S4.

2. When the support position of the support assembly is at the designated position of the specimen, the next step can be performed; S5. Apply a load to the specimen through the electro-hydraulic servo actuator (4) to perform a bending and tension test.

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