CN215727307U

CN215727307U - Temperature stress testing machine

Info

Publication number: CN215727307U
Application number: CN202121673513.0U
Authority: CN
Inventors: 王卫仑; 林志海; 胡晓泉
Original assignee: Shenzhen Qianhai Tongyuan Construction Technology Co ltd
Current assignee: Shenzhen Qianhai Tongyuan Construction Technology Co ltd
Priority date: 2021-07-21
Filing date: 2021-07-21
Publication date: 2022-02-01
Anticipated expiration: 2031-07-21

Abstract

The utility model belongs to the field of temperature stress tests, and particularly relates to a temperature stress testing machine which comprises a rack, a motor assembly, a first chuck, a second chuck and an engagement part, wherein the first chuck and the second chuck are respectively arranged at two ends of the engagement part, a containing cavity for containing a test piece is formed in the first chuck, the engagement part and the second chuck, the first chuck, the engagement part and the second chuck are respectively arranged in the rack, the first chuck is movably connected with the rack, the second chuck is fixedly connected with the rack, the motor assembly is fixedly arranged at one side of the rack, one end of the motor assembly penetrates through the rack and is connected with the first chuck so as to drive the first chuck to move on the rack, and the testing machine further comprises two displacement measuring rods which are respectively and fixedly arranged on the first chuck and the second chuck. In the testing machine, the defect that a measuring rod of a test piece is not stable and firm enough before hardening is avoided, and the measuring precision of the test piece in a liquid state is improved.

Description

Temperature stress testing machine

Technical Field

The utility model belongs to the field of temperature stress tests, and particularly relates to a temperature stress testing machine.

Background

The concrete temperature stress testing machine has the function of simultaneously measuring various material mechanical parameters of the concrete, such as elastic modulus, creep, relaxation, cracking stress, characteristic fracture temperature and the like, and can simulate different constraint conditions in a laboratory to establish the relation with an engineering structure. A concrete temperature stress tester is an effective test device for comprehensively evaluating the cracking resistance of concrete.

The existing concrete temperature stress testing machine has the following defects: firstly, the displacement measuring rod is directly inserted into the test piece for measurement, but the arrangement has the defect that the measuring rod is not stable and firm enough before the test piece is hardened, and the measurement precision of the test piece in a liquid state is influenced. Secondly, the existing concrete temperature stress testing machines are all devices with larger volume, and the side films and the bottom film of the concrete temperature stress testing machines are both made of stainless steel plates. Thirdly, when the existing concrete temperature stress testing machine is used for testing, the test piece is easy to deflect, and the testing effect is influenced.

Disclosure of Invention

In order to solve the above problems, a primary object of the present invention is to provide a temperature stress testing machine, which avoids the disadvantage that a measuring rod is not stable and firm enough before a test piece is hardened, and improves the measurement accuracy of the test piece in a liquid state.

Another object of the present invention is to provide a temperature stress testing machine having a better heat-insulating effect.

It is a further object of the present invention to provide a temperature stress testing machine that avoids deflection of the test piece during testing.

In order to achieve the above object, the present invention has the following technical means.

A temperature stress testing machine comprises a frame, a motor component, a first chuck, a second chuck and a joint part, wherein the first chuck and the second chuck are respectively arranged at two ends of the joint part, and a containing cavity for containing a test piece is formed in the first clamping head, the joint part and the second clamping head, the first chuck, the jointing part and the second chuck are all arranged in the frame, the first chuck is movably connected with the frame, the second chuck is fixedly connected with the frame, the motor component is fixedly arranged at one side of the frame, one end of the motor component penetrates through the frame to be connected with the first chuck so as to drive the first chuck to move on the frame, the testing machine is characterized by further comprising two displacement measuring rods, wherein the two displacement measuring rods are fixedly arranged on the first chuck and the second chuck respectively so as to measure the displacement change between the first chuck and the second chuck. In this testing machine, through with two displacement measurement poles respectively fixed setting on first chuck and second chuck, not directly insert when experimental and establish in the test piece, avoided the not firm shortcoming of measuring rod unstability before the sclerosis of test piece, improved the measurement accuracy when the test piece is in liquid. After the displacement measuring rod is fixed on the first chuck, the first chuck drives the displacement measuring rod on the first chuck to move after moving, and then deformation data of the test piece can be measured by measuring the distance change between the two displacement measuring rods.

Furthermore, cover plates are fixedly arranged on the first chuck and the second chuck respectively to cover the accommodating cavity at the first chuck and the accommodating cavity at the second chuck. The setting of apron can push down test piece both ends department for this testing machine can avoid the test piece to appear deflecting when experimental.

Furthermore, the two displacement measuring rods are respectively and fixedly arranged on the cover plate of the first chuck and the cover plate of the second chuck. After the displacement measuring rods are fixed on the cover plate of the first chuck, the first chuck drives the displacement measuring rods on the cover plate to move after moving, and deformation data of a test piece can be measured by measuring the distance change between the two displacement measuring rods.

Furthermore, the joint part comprises two side films and a bottom film, the two side films are respectively fixed on two sides of the bottom film, and the accommodating cavity at the joint part is formed by encircling the two side films and the bottom film; the two side films and the bottom film are both glass fiber heat insulation plates. The glass fiber heat insulation plate has the advantages of good flatness, smooth surface and no pits, and has better heat insulation effect compared with a stainless steel plate, so that the testing machine has better heat insulation effect.

Furthermore, a sliding rail and sliding block structure is arranged between the first chuck and the rack, and the first chuck and the rack are movably connected in a sliding manner through the sliding rail and sliding block structure. The concrete temperature stress testing machine with large size realizes the relative movement between the first chuck and the rack through the universal ball, and adopts a slide rail and slide block structure (a slide block and a guide rail are adopted, the slide block can be fixed on the first chuck, and a slide rail is fixed on the rack), so that the first chuck can be ensured to move along a straight line, and then the two ends of the test piece are ensured to move along the straight line.

Further, the detachable upper cover that is provided with in the frame, the upper cover corresponds the displacement measuring stick and is provided with the displacement through-hole, the displacement measuring stick passes the displacement through-hole and shows outside the upper cover, just upper cover department is provided with two displacement sensor, and two displacement sensor correspond with two displacement measuring sticks respectively to measure the distance between two displacement measuring sticks.

Furthermore, a temperature control system for heating or refrigerating is arranged in the rack. Temperature control systems are known in the art.

Furthermore, three temperature sensors are arranged in the rack, two of the temperature sensors are respectively arranged in the accommodating cavity of the connecting piece and the accommodating cavity of the first chuck/the second chuck, and the other temperature sensor is positioned outside the accommodating cavity. During testing, the two sensors are respectively arranged in the accommodating cavity of the connecting piece and the accommodating cavity of the first chuck/the second chuck, and the positions of the two sensors are respectively located in the middle and the end of the test piece so as to measure the temperature of the test piece. Another temperature sensor, located outside the receiving cavity, is located outside the test piece for measuring the air temperature. When the air temperature and the temperature inside the test piece exceed set values, the temperature control system is started to heat or cool the air, and the purpose of semi-adiabatic maintenance is achieved.

Further, a force sensor is arranged at the second chuck. The stress of the test piece is measured by the force sensor at the second chuck.

Furthermore, fixed clamping plates are fixed on two sides of the rack, the motor assembly is fixedly arranged on the fixed clamping plates, and one end of the motor assembly sequentially penetrates through the fixed clamping plates and the rack to be connected with the first chuck so as to drive the first chuck to move on the rack; more than two fixed shafts are arranged between the two fixed clamping plates, and two ends of each fixed shaft are respectively fixed with the two fixed clamping plates. Above-mentioned fixed grip block and the setting of fixed axle for this testing machine overall structure intensity is higher, so that its life is longer.

Compared with the prior art, the utility model has the advantages that the two displacement measuring rods are respectively and fixedly arranged on the first chuck and the second chuck, and are not directly inserted into the test piece during the test, so that the defect that the measuring rods are not stable and firm enough before the test piece is hardened is avoided, and the measurement precision of the test piece in the liquid state is improved.

Drawings

Fig. 1 is a schematic structural view of the present invention.

Fig. 2 conceals the structural schematic diagram of the upper cover and the cover plate.

Fig. 3 conceals the structural schematic diagram of the upper cover, the cover plate and part of the frame.

Fig. 4 is a schematic view showing the structure of the motor assembly.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the utility model and are not intended to limit the utility model.

Referring to fig. 1-4, a temperature stress testing machine, the testing machine includes a frame 1, a motor assembly 2, a first chuck 3, a second chuck 4 and an engaging portion 5, the first chuck 3 and the second chuck 4 are respectively disposed at two ends of the engaging portion 5, a containing cavity 6 for containing a test piece is formed in the first chuck 3, the engaging portion 5 and the second chuck 4, the first chuck 3, the engaging portion 5 and the second chuck are all disposed in the frame 1, the first chuck 3 is movably connected with the frame 1, the second chuck 4 is fixedly connected with the frame 1, the motor assembly 2 is fixedly disposed at one side of the frame 1, and one end of the motor assembly 2 passes through the frame 1 and is connected with the first chuck 3 to drive the first chuck 3 to move on the frame 1, the testing machine is characterized in that the testing machine further includes two displacement measuring rods 7, the two displacement measuring rods 7 are respectively fixedly disposed on the first chuck 3 and the second chuck 4, to measure the variation in displacement between the first jaw 3 and the second jaw 4. Wherein, the motor component 2 is the prior art, if a motor 21, a speed reducer 22, a belt, two belt pulleys 23, a first connecting piece 24 with external threads and a second connecting piece 25 with internal threads are adopted, the two belt pulleys 23 are both engaged with the belt and are connected with each other through belt transmission, the motor 21 is connected with the speed reducer 22, the speed reducer 22 is connected with one belt pulley 23, the other belt pulley 23 is connected with the first connecting piece 24, the first connecting piece 24 and the second connecting piece 25 are sleeved through the matching of the internal threads and the external threads, the second connecting piece 25 is fixed with the first chuck 3, wherein the motor 21 drives the belt pulley 23 to work through the speed reducer 22, the belt pulley 23 drives the first connecting piece 24 to rotate, when the first connecting piece 24 rotates, the second connecting piece 25 moves on the first connecting piece 24 based on the matching of the threads of the first connecting piece 24 and the second connecting piece 25, thereby moving the first chuck 3.

Further, a cover plate 8 is fixedly arranged on each of the first chuck 3 and the second chuck 4 to cover the accommodating cavity 6 at the first chuck 3 and the accommodating cavity 6 at the second chuck 4.

Further, two displacement measuring rods 7 are respectively fixedly arranged on the cover plate 8 of the first chuck 3 and the cover plate 8 of the second chuck 4.

Further, the joint part 5 comprises two side films 51 and a bottom film 52, the two side films 51 are respectively fixed on two sides of the bottom film 52, and the accommodating cavity 6 at the joint part 5 is formed by surrounding the two side films 51 and the bottom film 52; both the two side films 51 and the one bottom film 52 are glass fiber insulation panels.

Further, a sliding rail and sliding block structure 11 is arranged between the first chuck 3 and the frame 1, and the first chuck and the frame are movably connected in a sliding manner through the sliding rail and sliding block structure 11. Wherein, a slide rail/slide block is arranged on the frame 1, and a slide block/slide rail is arranged on the first chuck 3.

Further, frame 1 is last detachably to be provided with upper cover 12, and upper cover 12 corresponds displacement measuring stick 7 and is provided with displacement through-hole 121, displacement measuring stick 7 passes displacement through-hole 121 and shows outside upper cover 12, just upper cover 12 department is provided with two displacement sensor 122, and two displacement sensor 122 correspond with two displacement measuring sticks 7 respectively to measure the distance between two displacement measuring sticks 7. The displacement measuring rod 7 can move left and right at the displacement through hole 121.

Further, a temperature control system for heating or refrigerating is arranged in the rack 1. The temperature control system is prior art.

Furthermore, three temperature sensors are arranged in the frame 1, wherein two temperature sensors are respectively arranged in the accommodating cavity 6 of the connecting piece and the accommodating cavity 6 of the first chuck 3/the second chuck 4, and the other temperature sensor is positioned outside the accommodating cavity 6. Temperature sensors are known in the art.

Further, a force sensor is arranged at the second chuck 4. Force sensors are known in the art.

Further, fixed clamping plates 13 are fixed on two sides of the rack 1, the motor assembly 2 is fixedly arranged on the fixed clamping plates 13, and one end of the motor assembly 2 sequentially penetrates through the fixed clamping plates 13 and the rack 1 to be connected with the first chuck 3 so as to drive the first chuck 3 to move on the rack 1; more than two fixed shafts 14 are arranged between the two fixed clamping plates 13, and two ends of each fixed shaft 14 are respectively fixed with the two fixed clamping plates 13.

Further, a load sensor is arranged at the first chuck.

The working principle is as follows: the second chuck of the temperature stress tester is fixed in the frame, and the first chuck can freely move in the frame. Two test modes were used in the test: free deformation and fully constrained mode. The test piece of the free deformation test is regarded as a parallel test piece, and the full-constraint test mode is regarded as a main test piece. The parallel test pieces were the same size as the master test piece, and were all 50mm 350 mm. When the test is carried out, the stirred concrete mixture is directly poured into the containing cavity, and the temperature control system is used for heating or cooling according to the test requirement. The stress of the test piece is measured by the force sensor at one side of the second chuck. The first chuck and the second chuck at two ends of the test piece are provided with displacement measuring rods, and the distance between the two displacement measuring rods is measured through the two displacement sensors, so that the real-time displacement of the concrete test piece can be measured. The testing machine can automatically record the temperature, stress and deformation of the test piece through the temperature sensor, the load sensor and the displacement sensor. The data are measured by a sensor, the signals are amplified and then are processed by a computer to be used as display signals and control signals, and the heating and the refrigeration of a temperature control system are controlled, so that the temperature of maintenance air tracks the central temperature of the concrete test piece; and controlling a motor to contract and stretch the test piece. In the test process, the room temperature is always controlled to be (20 +/-2) DEG C so as to reduce the influence of the temperature on mechanical deformation. In the full-constraint mode, when the displacement of the first chuck exceeds a set value (such as 1um), the computer system starts to control the motor (such as a stepping motor) to work, so that the concrete specimen restores to the original length, and the strain of the effective length part is 0 again. The system repeats the working cycle until the concrete sample is broken. When the free deformation test is carried out, the parallel test piece adopts the same maintenance mode as the main test piece. When the stress value measured by the force sensor exceeds a set value (such as 0.01MPa), the motor is started to force the test piece to displace, so that the test piece is restored to the stress level of 0.

The test process comprises the following steps: (1) and (5) preparing. Before the test, the accommodating cavity is firstly polished through a steel brush, sand paper and a dust collector, so that the influence of friction force is reduced. And then adjusting the bottom die and the side die to enable the accommodating cavity to be flat. Then, in order to reduce the friction between the containing cavity and the test piece, two layers of plastic films are laid in the containing cavity. In addition, the plastic film can seal the poured test piece, the sealed test piece is not subjected to moisture exchange with the outside, the influence of drying shrinkage is eliminated, and the deformation of the test piece only comprises self-shrinkage and temperature deformation. Finally, the raw materials are put into a constant temperature and humidity laboratory at 20 ℃ 24 hours in advance. (2) Tests were carried out. And directly pouring the prepared clean slurry into the accommodating cavity, and uniformly vibrating by using a vibrating spear. Temperature sensors are placed in the middle and the end of the test piece. And sealing the surface of the test piece by using a preservative film, wrapping the test piece by using two pre-laid plastic films, and sealing by using an adhesive tape. Therefore, the evaporation of water in the test piece can be prevented, and the influence of drying deformation on the test can be eliminated. And selecting a test mode and a temperature maintenance mode for testing. And after the test is started for 24 hours, the test piece is demoulded, and the influence of the friction force of the containing cavity on the deformation of the test piece is eliminated. (3) The test was terminated. In the fully constrained mode, the test was terminated after the test piece broke. In the free deformation mode, the test was terminated after the temperature of the test piece had dropped to room temperature. And (5) storing the test data after the test is ended, and taking out the test piece.

The present invention is not limited to the above preferred embodiments, and any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A temperature stress testing machine comprises a frame, a motor component, a first chuck, a second chuck and a joint part, wherein the first chuck and the second chuck are respectively arranged at two ends of the joint part, and a containing cavity for containing a test piece is formed in the first clamping head, the joint part and the second clamping head, the first chuck, the jointing part and the second chuck are all arranged in the frame, the first chuck is movably connected with the frame, the second chuck is fixedly connected with the frame, the motor component is fixedly arranged at one side of the frame, one end of the motor component penetrates through the frame to be connected with the first chuck so as to drive the first chuck to move on the frame, the testing machine is characterized by further comprising two displacement measuring rods, wherein the two displacement measuring rods are fixedly arranged on the first chuck and the second chuck respectively so as to measure the displacement change between the first chuck and the second chuck.

2. The temperature stress testing machine of claim 1, wherein a cover plate is fixedly arranged on each of the first chuck and the second chuck to cover the accommodating cavity at the first chuck and the accommodating cavity at the second chuck.

3. The temperature stress tester of claim 2, wherein the two displacement measuring rods are fixedly arranged on the cover plate of the first chuck and the cover plate of the second chuck respectively.

4. The temperature stress testing machine according to claim 1, wherein the joint part comprises two side films and a bottom film, the two side films are respectively fixed on two sides of the bottom film, and the accommodating cavity at the joint part is formed by surrounding the two side films and the bottom film; the two side films and the bottom film are both glass fiber heat insulation plates.

5. The temperature stress testing machine according to claim 1, wherein a sliding rail and sliding block structure is arranged between the first chuck and the frame, and the first chuck and the frame are movably connected in a sliding manner through the sliding rail and sliding block structure.

6. The temperature stress testing machine according to claim 1, wherein the frame is detachably provided with an upper cover, the upper cover is provided with a displacement through hole corresponding to the displacement measuring rod, the displacement measuring rod passes through the displacement through hole and is exposed outside the upper cover, and the upper cover is provided with two displacement sensors, the two displacement sensors respectively correspond to the two displacement measuring rods so as to measure the distance between the two displacement measuring rods.

7. The temperature stress testing machine according to claim 1, wherein a temperature control system for heating or cooling is arranged in the frame.

8. The temperature stress testing machine according to claim 7, wherein three temperature sensors are further arranged in the frame, two of the three temperature sensors are respectively arranged in the accommodating cavity of the connecting piece and the accommodating cavity of the first chuck/the second chuck, and the other temperature sensor is positioned outside the accommodating cavity.

9. The temperature stress testing machine of claim 1, wherein a force sensor is disposed at the second chuck.

10. The temperature stress testing machine according to claim 1, wherein fixed clamping plates are fixed on both sides of the frame, the motor assembly is fixedly arranged on the fixed clamping plates, and one end of the motor assembly sequentially penetrates through the fixed clamping plates and the frame to be connected with the first chuck so as to drive the first chuck to move on the frame; more than two fixed shafts are arranged between the two fixed clamping plates, and two ends of each fixed shaft are respectively fixed with the two fixed clamping plates.