81 results about "Extensometer" patented technology

Systems and methods for materials testing include mage devices employing camera based image capture (e.g., vision or video) for measurement of strain on the test specimen. Such systems and methods collect multiple images of the specimen under test (i.e. during a testing process), with the images being synchronized with other signals of interest for the test (such as specimen load, machine actuator and / or crosshead displacement, etc.). The images of the specimen are analyzed (e.g., in real-time and / or post-test) by algorithms to locate and track specific specimen characteristics as the test progresses.

The invention discloses a method for testing compression performance through a testing machine, which comprises the following specific steps: placing a sample on the upper end surface of a compression main body, and enabling two end surfaces of the sample to be parallel; after the extensometer is fixed, the testing machine is reset, and the extensometer is reset; starting the testing machine for compression, synchronously acquiring sample load data and average deformation data on two sides by the extensometer, transmitting the data into the testing machine, generating a stress-strain curve by the testing machine, and reading the compression yield strength, the compression elastic modulus and the compression strength from the curve. The extensometers on the two sides are directly hung between the upper cover and the compression main body to form a closed symmetrical measurement chain, so that knife edges on the two sides are located in the same rigid frame, bending deformation is offset, the reading difference is reduced to one tenth of the original value, meanwhile, a load line and a measurement line coincide, a secondary force transmission path is avoided, and the measurement accuracy is improved. And the flexibility of the rack only affects the overall displacement without changing the relative deformation in the gauge length of the extensometer, so that the repeatability of the elastic modulus is remarkably improved.

The utility model discloses a metal material constant load testing device suitable for a hydrogen environment, which comprises a high-pressure gas storage bin, the high-pressure gas storage bin is hermetically connected with an upper bin cover and a lower bin cover, the upper bin cover is provided with a gas inlet pipeline, the lower bin cover is provided with a gas outlet pipeline, the high-pressure gas storage bin is filled with hydrogen, the upper bin cover is provided with an upper loading rod, and the lower bin cover is provided with a lower loading rod. The upper end of an upper loading rod is connected with a loading head, the lower end of the loading rod extends into the high-pressure gas storage bin, a load sensor is installed on the upper loading rod, a lower loading rod is arranged on the lower bin cover, the upper end of the lower loading rod extends into the high-pressure gas storage bin, the lower end of the lower loading rod is connected with a base, the lower end of the upper loading rod is provided with an upper connector, and the upper connector is connected with a lower connector. A lower connector is arranged at the upper end of the lower loading rod, a constant-load sample is connected between the upper connector and the lower connector, an extensometer is mounted on the constant-load sample, and a temperature sensor and a pressure sensor are mounted in the high-pressure gas storage bin. According to the utility model, a high-pressure hydrogen test environment can be effectively provided, and the performance test of a metal material under a constant load is realized.

The application discloses a kind of coal rock nonlinear fracture propagation length quantitative determination method based on multiple parameters, comprising: preparation of coal rock sample containing notch;Spray black and white speckle on the surface of sample, install acoustic emission sensor, clip type extensometer and displacement sensor;Carry out three-point bending peak after cycle loading and unloading fracture experiment, record load, crack opening, force point displacement, acoustic emission waveform and DIC image;Through COD-P and LPD-P curve calculation mechanics flexibility, back calculation to solve stress constraint crack length;From acoustic emission positioning, obtain the spatial distribution histogram of breakage dissipation energy, combined with DIC horizontal displacement gradient threshold cloud picture, determine equivalent crack tip and length;Further calculate coal rock fracture process zone length, and intuitively show nonlinear fracture propagation path.The application provides a kind of crack dynamic change quantitative determination method based on mechanics flexibility-displacement gradient-energy dissipation distribution multiple physical parameters, reduce the influence of human subjective consciousness, and the measurement result is accurate and reliable.

This invention provides a method and apparatus for testing the mechanical properties of bolted composite materials in a single shear test, relating to the field of material testing and analysis. The method includes: calculating pixel equivalents and establishing a displacement conversion relationship between image displacement and actual physical displacement; adjusting the front and rear positions of the first extensometer clip and / or the second extensometer clip using positioning screws based on the spot deviation; activating the extensometer and high-speed camera to acquire extensometer displacement data sequences and tracer point sequence images, performing image displacement conversion processing on the sequence images to obtain a high-speed camera displacement data sequence; calculating the displacement deviation between the extensometer displacement data sequence and the high-speed camera displacement data sequence to generate a corrected extrusion deformation; and calculating the mechanical property parameters using real-time load, the corrected extrusion deformation, and preset specimen geometric parameters. This achieves high-precision measurement of extrusion deformation and automatic calculation of multi-dimensional mechanical property parameters in a single shear test.

Described are opto-mechanical tower extensometers having opposing carriages whose vertical positions relative to each other are actively motor controlled so that deformation of a strain test specimen held between the grips of a mechanical testing system in a test area can be tracked and measured. Upper and lower arm assemblies are used to position optical heads within the specimen test area. Each optical head carries one or more camera assemblies, spot lighting, and optional alignment lasers. Such a system presents a compact design in which the optics can be maintained in close proximity to the test specimen throughout testing.

The invention belongs to the field of mechanical property detection of metal materials, and particularly relates to a method for measuring a stiffness coefficient of a tensile testing machine, which comprises the following steps of: 1) room-temperature tensile test: measuring the value of elastic modulus E1 of a tensile sample according to the scale length by using an extensometer; stopping the test at the proportional elasticity stage of the tensile sample; unloading the tensile sample; (2) the tensile testing machine adopts the cross beam platform to carry out the room-temperature tensile test again by using the tensile sample according to the scale distance length, and the elastic modulus E2 is measured; and 3) calculating the stiffness coefficient K of the tensile testing machine according to the elasticity modulus values measured twice. The method has the advantages that the stiffness coefficient of the high-rigidity tensile testing machine can be accurately, simply and conveniently measured, and quantitative separation and measurement of linear deformation of the testing machine are realized through twice elastic tensile tests of the same sample.

The invention provides a damping steel tensile test method, which relates to the technical field of metal material performance detection, and comprises the following steps: a testing machine adopts automatic program control, the initial tensile speed is set to be 1-5mm / min, a displacement control mode is adopted, hysteresis loop method cyclic tensile is performed for the first time, the target strain point of a first extensometer is set to be 1%, and the target strain point of a second extensometer is set to be 1%; the lower reverse point of the lag loop is 5-10 MPa, and the load holding time is 10-20 s; the strain is accumulated in sequence, the target strain point of the extensometer in each cyclic stretching is increased by 1%, the stress is unloaded to 5-10 MPa after the target strain point is reached each time, and loading is carried out again after the load is kept for 10-20 s until the sample is fractured; extracting stress-strain original data of each time of cyclic stretching, and performing data superposition on the original data extracted each time to form a stress-strain curve of cyclic stretching; and according to the stress-strain curve, analyzing the mechanical property and damping property change of the damping steel under cyclic loading.

A method of laser-based high temperature mechanical property characterization comprising the steps of providing a mechanical test frame and chamber, loading a specimen in the mechanical test frame in the chamber, providing a laser, aligning the laser, sealing the chamber, evacuating 5 the chamber and optionally backfilling with a prescribed atmosphere, turning on the laser, applying mechanical loading to the specimen in the mechanical test frame, utilizing a load cell and a non-contact video extensometer, synchronizing the output of the load cell and non-contact video extensometer, and tracking the strain in the specimen. A device for laser-based high temperature mechanical property characterization comprising a vacuum chamber with a laser 10 transmissible window and viewing window, a vacuum pump, a uniaxial tensile system inside the vacuum chamber, a thermocouple inside the vacuum chamber, laser optics inside the vacuum chamber, a function generator, a laser source, an IR camera, and a video camera.

The present application relates to the field of fatigue test, in particular to a kind of tubular sample dynamic liquid lead bismuth alloy loop corrosion fatigue test device and use method.Tubular sample is installed between upper and lower base, the lower end of tubular sample is sequentially communicated with the through hole in lower base, liquid lead bismuth alloy inlet pipe, the upper end of tubular sample is sequentially communicated with the through hole in upper base, liquid lead bismuth alloy outlet pipe.Tubular sample outer paste thermocouple real-time monitoring and control liquid lead bismuth temperature, outer surface installation extensometer strain measurement.Liquid lead bismuth is driven by electromagnetic pump through storage tank, enters reaction kettle and is heated and oxygen is controlled, after flow rate is measured by flowmeter, it flows into tubular sample, then backflow to storage tank and forms loop.The outer wall of loop pipeline is equipped with armored electric heating and thermal insulation cotton, to ensure temperature control.The present application realizes the accurate control of high-temperature liquid lead bismuth temperature, dissolved oxygen and flow rate, supports dynamic strain control fatigue test, and evaluates the corrosion fatigue performance of material in flowing high-temperature liquid lead bismuth environment.

A method for measuring the deformation displacement of a high-temperature tensile test specimen belongs to the field of experimental mechanics high-temperature testing technology, and solves the problem of electronic components being unable to withstand high temperatures and having low precision in deformation displacement measurement in high-temperature environments. The method of the present invention is implemented through a high-temperature displacement measurement module, a normal-temperature displacement measurement module, and a connection module. A pair of high-temperature resistant sliders are provided in the high-temperature box, each connected to a retractable high-temperature contact, and can slide along a guide rod parallel to the axis of the specimen; each slider is staggeredly connected to the lower and upper normal-temperature sliders on the same axis outside the high-temperature box through a high-temperature resistant and inelastic silk thread, converting the high-temperature environment displacement to a normal-temperature environment; then, the dynamic relative displacement of the two normal-temperature sliders is measured by a normal-temperature extensometer and introduced into the tensile test system. The method of the present invention breaks through the limitations of high-temperature environments on electronic components for displacement measurement, has the characteristics of a wide range of applications, high measurement precision, and low cost, and is suitable for deformation displacement measurement in metal tensile tests over a large temperature range.

The utility model discloses a steel bar residual stress deformation detection device which comprises a detection box, temperature adjusting mechanisms used for adjusting the internal temperature of the detection box are arranged on the two corresponding inner walls of the detection box, a box door is arranged on the surface of the detection box, and a first fixing mechanism is arranged at the bottom of the inner wall of the detection box. A hydraulic cylinder is fixedly installed at the top of the detection box, the end of a piston rod of the hydraulic cylinder extends into the detection box to be connected with a second fixing mechanism, a to-be-detected steel bar is arranged between the first fixing mechanism and the second fixing mechanism, and an extensometer used for detecting residual stress deformation is arranged on the outer side of the to-be-detected steel bar. Mounting boxes are symmetrically fixed to the bottom of the inner wall of the detection box, the temperature in the detection box can be adjusted through combination of the semiconductor chilling plate and the two-way fan, temperature adjustment can be achieved by controlling the fan at the refrigerating end or the heating end, the detection process can be conducted in different temperature environments, and the detection efficiency is improved. The stress deformation performance in the actual working condition is simulated.

The present application relates to a kind of calibration device for strain extensometer calibration, including device support, lower clamping structure for clamping the lower end of strain extensometer and upper clamping structure for clamping the upper end of strain extensometer are provided on device support, device support also includes cross slide that the action output end can be left and right movement adjustment and front and back movement adjustment, lower clamping structure is fixed on the action output end of cross slide, upper clamping structure, lower clamping structure all include a pair of clamping block that can be moved along the radial opposite of strain extensometer and opposite movement, upper clamping structure, lower clamping structure also include the clamping block drive mechanism of driving corresponding pair of clamping block synchronous opposite movement and synchronous opposite movement.The purpose of the present application is to provide a kind of calibration device and the calibration method using the calibration device, which can realize the calibration of strain extensometer.

The application discloses a kind of test device and test method for measuring the deformation of plate specimen by displacement meter, the device includes displacement meter, mounting frame and connecting device;Mounting frame is composed of upper U-shaped component and lower "I" shaped component, and is connected with the plate specimen to be measured by C-shaped clamp;Displacement meter is symmetrically bound on U-shaped component by rubber band, and top rod is pre-pressed against "I" shaped component.The application adopts separate fixing mode, effectively fixes displacement meter along the force direction, solves the problems that extensometer of plate specimen is not easy to fix and magnetic table base is easy to slide.The device can adapt to plate pieces of different lengths, is easy to disassemble and assemble, symmetrical arrangement can reduce error, improve the accuracy and efficiency of plate specimen tension and compression deformation test.

To provide a video type non-contact extensometer that can easily and accurately adjust a position of a camera so that a distance between the camera and a specimen is a predetermined distance regardless of an operator.SOLUTION: A video type non-contact extensometer comprises a camera that photographs a specimen marked with marked lines at predetermined intervals. The video type non-contact extensometer measures the elongation of the specimen from the displacement of the marked lines based on photographic data photographed by the camera in a state where the position of the camera is adjusted so that a distance to the specimen becomes a predetermined distance. The video type non-contact extensometer comprises a rangefinder that is provided integrally with the camera and measures the distance to the specimen in a non-contact manner.SELECTED DRAWING: Figure 3

This invention belongs to the field of strain measurement technology and discloses an automatic calibration device and method for single-axis and dual-axis extensometers. The device includes a cross-shaped guide rail mounted on a base plate. The two straight tracks of the cross-shaped guide rail are divided into a first section and a second section by their perpendicular intersection. The first section is equipped with a closed-loop stepper motor, a motor connecting shaft, a moving slider, and a moving extensometer connecting shaft. The second section is equipped with a fixed slider, a locking bolt, and the extensometer connecting shaft. The fixed extensometer connecting shaft cooperates with the moving extensometer connecting shaft to fix the extensometer. The closed-loop stepper motor is connected to a host computer for signal transmission. When working synchronously, it can calibrate dual-axis extensometers; when working independently, it can calibrate single-axis extensometers. The two closed-loop stepper motors can work together in both phases and opposite phases, and can also calibrate dual-axis extensometers in proportional or non-proportional conditions. Therefore, this invention has the characteristics of high accuracy, strong adaptability, simple operation, and flexible application.

The invention discloses a hydrogen environment metal material constant load testing device and a CTOD-based testing method.The high-pressure gas storage bin in the device is connected with an upper bin cover and a lower bin cover in a sealed mode, the upper bin cover is provided with a gas inlet pipeline, the lower bin cover is provided with a gas outlet pipeline, the high-pressure gas storage bin is filled with hydrogen, the upper bin cover is provided with an upper loading rod, and the upper loading rod is provided with a lower loading rod; the upper end of the upper loading rod is connected with a mechanical testing machine loading head, the lower end of the loading rod extends into the high-pressure gas storage bin, a load sensor is installed on the upper loading rod in the high-pressure gas storage bin, a lower loading rod is arranged on the lower bin cover, the upper end of the lower loading rod extends into the high-pressure gas storage bin, and the lower end of the lower loading rod is connected with a mechanical testing machine base. A constant-load sample is connected between the upper loading rod and the lower loading rod, an extensometer is mounted on the constant-load sample, and a temperature sensor and a pressure sensor are mounted in the high-pressure gas storage bin. The device can effectively provide a high-pressure hydrogen test environment, the method is not limited by the wall thickness of the pipe, and the fracture toughness value of the sample in the hydrogen environment is obtained.

The utility model discloses a hydrogen fuel cell carbon paper deformation detection device which comprises a universal testing machine, an experiment pressing block, an experiment cushion block, a polar plate carbon paper stacking structure, a video extensometer, a concentrated light source and a microscope, the polar plate carbon paper stacking structure is arranged between the experiment pressing block and the experiment cushion block, and the universal experiment machine is configured to provide continuously changing packaging force and uniformly transmit the packaging force to the polar plate carbon paper stacking structure through the experiment pressing block and the experiment cushion block, namely, the mechanical environment of carbon paper in a galvanic pile is simulated; the concentrated light source is configured to provide brightness, and the video extensometer and the microscope are configured to observe the form change of the carbon paper in the polar plate carbon paper stacking structure after continuous stress. The device simulates the in-pile mechanical environment through the universal testing machine, and directly observes the real form change of the carbon paper in the flow channel through the optical detection technology, thereby being beneficial to improving the cognition on the internal structure of the electric pile and guiding the design of the electric pile.

The invention discloses a hyperelastic material large strain visual measurement method based on surface grid deformation identification, which comprises the following steps: processing a hyperelastic material to be measured into a dumbbell-shaped sample, and constructing uniformly distributed regular grid lines on the surface of a scale distance section of the sample; stretching the sample at a preset stretching rate, and continuously collecting surface grid deformation images of the sample while stretching; identifying the position of each grid line in each frame of image; and according to the position change condition of the corresponding grid lines in the two adjacent frames of images, determining the strain condition of the hyperelastic material at each moment under the preset stretching rate. The invention aims to solve the problems that a traditional measurement method is inaccurate in measurement under the condition of large strain of the hyperelastic material, for example, speckles chapped and deformed in a random speckle sample laying method are difficult to recover, an extensometer cannot obtain local strain and results have uncontrollable factors, and a traditional DIC method is large in measurement error under large strain.

The invention belongs to the technical field of pipeline tests, and particularly relates to a high-temperature stress endurance testing device for an aviation pipeline connecting piece. The device comprises a tensile testing machine, a high-temperature environment box and a video extensometer, the tensile testing machine comprises a stand column and an upper moving platform sliding on the stand column, the upper moving platform is connected with an upper straight-through connector of a pipeline test piece through an upper switching unit, and a transverse plate at the bottom end of the stand column is connected with a lower straight-through connector of the pipeline test piece through a lower switching unit. Hydraulic oil flow channels are arranged in the upper adapter unit and the lower adapter unit, one end of each hydraulic oil flow channel is connected with a pipeline of the pipeline test piece, and the other end is connected with the pump set unit; the high-temperature environment box sleeves the pipeline test piece and is used for providing a high-temperature environment; the video extensometer is located outside the high-temperature environment box and collects deformation data of the pipeline test piece in the test process through a transparent temperature-resistant glass window of the high-temperature environment box. The application can more accurately simulate and reproduce the use condition of the aviation pipeline piece in the high-temperature environment.

This invention provides a convenient temperature-resistant installation device for a dynamic extensometer, relating to the field of material mechanical property testing technology. It includes: a hollow, fixed housing with a first mounting hole on its first side wall and rectangular slots on its opposite second and third side walls; an extensometer blade with a second mounting hole to fix the fixed housing and the blade to both sides of the extensometer; and a spring clip formed from a single-piece, heat-resistant, elastic metal plate, comprising a V-shaped fixing arm, a U-shaped clamping arm, and a transition section. The V-shaped opening of the fixing arm is opposite to the U-shaped opening of the clamping arm, and they are smoothly connected by the transition section to form the spring clip. The fixing arm is inserted into the rectangular slot of the fixed housing, and the clamping arm is used to clamp the test piece. This invention achieves reliable installation of the extensometer at different test temperatures. The device is easy to operate, highly stable, safe to use, and has high measurement accuracy and versatility.

The utility model relates to composite material detection technical field especially is related to a kind of fiber tensile modulus test tool, including base, vertical moving mechanism is equipped on base, and the moving part of vertical moving mechanism is installed with horizontal mounting bracket;Horizontal mounting bracket includes the first mounting bracket slidable connection with the moving part of vertical moving mechanism, and the first mounting bracket one end extends with second mounting bracket, and extensometer is slidably installed on second mounting bracket;The top surface and bottom surface of second mounting bracket are both equipped with inserting slot, further including the telescopic plate installed in the outer side of second mounting bracket, and the top and bottom of telescopic plate are respectively fixed with multiple inserting rods, and each inserting rod is slidably inserted with each inserting slot;Further including compression spring, and the both ends of compression spring are respectively fixed with the outer side of second mounting bracket and the inner side of telescopic plate;The utility model installs extensometer on horizontal mounting bracket, and the weight of extensometer is supported using tool body, avoid the influence of extensometer deadweight on detection result.

The utility model belongs to the technical field of geological disaster early warning, and discloses a geological disaster early warning monitoring device which comprises a lock floor, a corner base is fixedly mounted at the top of the lock floor, a rotating shaft is rotatably mounted above the corner base through a bearing, a detection rod is fixedly mounted at the top of the rotating shaft, and a support is fixedly mounted on the inner side of the top of the lock floor. The top of the support is fixedly provided with the landslide extensometer, the connecting rod drives the pull rope to swing up and down through the sleeve damage, and ice and snow attached to the pull rope are shaken off, so that the weight of the pull rope is reduced, the detection rod is prevented from being pulled by the inner side to restore to the original shape, the landslide extensometer does not give out early warning at the moment, and when the detection rod does not return to the original position, the landslide extensometer gives out early warning. Or when the air temperature detector does not detect the air temperature in a cold season in winter and the detection rod is subjected to the tension of the inner side to generate a corner, it is indicated that the two locking plates located on the two sides of the landslide crack are likely to be away from each other, and at the moment, the landslide extensometer gives out an early warning.

The present disclosure describes systems and methods to compensate for error in a video extensometer system, including noise, perspective variations, and / or component placement and / or operation.

The invention relates to the technical field of rock mechanics, in particular to a real-time measurement and prediction device and method for thermal expansion force and deformation of high-temperature rock. The real-time measurement and prediction device comprises a base, a computer control system and a prediction machine. The high-temperature-resistant resistance stress ring, the differential axial extensometer and the differential circumferential extensometer upload measured data to the resistance-type strain tester in real time, the resistance-type strain tester synchronously transmits the received data to the computer control system, and the computer control system transmits the collected data to the prediction machine. The prediction machine extracts predictive characteristics in various data, a prediction result is output to the computer control system through the prediction model, the computer control system calculates the thermal expansion force and deformation of the rock in real time based on the prediction result, by adopting the structure, the thermal expansion force and deformation of the rock can be automatically, synchronously and accurately measured in real time in a real high-temperature environment, and the rock thermal expansion force and deformation measurement accuracy is improved. And large difference between a measurement result and an actual working condition is avoided.

This invention proposes a method for testing the compressive strength of carbonized seawater sand concrete, comprising: preparing seawater sand concrete specimens and carbonizing them until fully carbonized; preloading and then unloading the specimens on a testing machine, followed by displacement-controlled loading; collecting data through strain gauges during the ascending phase, and switching to a displacement extensometer to collect deformation during the descending phase when the load reaches 70-80% of the peak load, while simultaneously reducing the loading rate until the specimen is completely destroyed; performing dimensionless processing on the two data segments, and using a two-segment model of polynomial ascending phase and rational fractional descending phase for least squares fitting to construct a full-curve constitutive relationship, effectively solving the data discontinuity problem caused by strain gauge detachment during the descending phase of highly brittle materials; the obtained model has a high goodness of fit and the physical meaning of the parameters is clear.

The utility model discloses a protection structure of an extensometer, which relates to the technical field of extensometers and comprises a first fixing rod, a hydraulic clamp, a sensor fixing plate, a first pipe clamp, a second fixing rod, a second pipe clamp, a third pipe clamp, a photoelectric switch, a full-automatic extensometer device, a movable cross beam and an electronic universal testing machine main body, the movable cross beam and the hydraulic clamp are arranged on the inner side of the electronic universal testing machine main body, and the full-automatic extensometer device is arranged on the outer side of the electronic universal testing machine main body. By adopting the structure, the lower tool bit is moved to a fixed position, and when the electronic universal testing machine main body works and the main machine moving cross beam moves to the upper tool bit to prevent the two photoelectric switches from transmitting photoelectric signals, the main machine moving cross beam stops moving, so that an effect of protecting the full-automatic extensometer device is achieved; and the first pipe clamp and the second pipe clamp are connected and fixed with the second fixing rod, so that the function of arranging the circuit of the photoelectric switch can be achieved.

The application provides a lightweight multi-axis extensometer support. The lightweight multi-axis extensometer support comprises a support column, a connecting plate is slidably arranged on the side wall of the support column, magnetic attraction blocks are fixedly connected to both ends of the front side of the connecting plate, a rotating shaft is fixedly connected to the front side of the connecting plate, and a self-locking L-shaped cantilever frame is rotatably arranged on the surface of the rotating shaft through a first locking structure. The lightweight multi-axis extensometer support provided by the application can realize quick movement in three directions of rotation, height lifting and forward and backward movement, and can be locked and fixed after reaching the position, so that displacement does not occur in the use process. The lightweight multi-axis extensometer support has a rotation angle positioning and adjusting function, and the L-shaped cantilever frame can be tightly fixed through the magnetic attraction blocks after reaching the position. The integrated fine adjustment function cooperates with the reliable locking device, so that the quick, accurate alignment and stable fixation of the space position of the extensometer mechanism can be realized.

The invention relates to a photoelectric sensor-based high-precision tension-torsion extensometer calibration instrument, which comprises a base and a stand column mounted on the base, a cross beam is transversely and fixedly mounted at the top end of the stand column, a tension calibration unit is arranged on the cross beam and the stand column, and a torsion calibration unit is arranged on the base. According to the extensometer calibration instrument, a measurement mode of combining the grating ruler and the encoder is adopted, so that the axial measurement precision and the torsion measurement precision respectively reach 0.04 mu m and 0.001 degree and are far higher than those of other extensometer calibration instruments for tension-torsion combination, and meanwhile, the measurement range meets the range of a general extensometer; meanwhile, the calibration instrument is simple in structure, light in self weight and convenient to carry and maintain, and the applicability in various environments is improved.

The invention discloses an in-situ pre-deformation high-temperature fatigue testing method for powder high-temperature alloy, and belongs to the field of metal material performance testing. The in-situ pre-deformation high-temperature fatigue test method for the powder high-temperature alloy comprises the following steps: placing a sample on a scanning electron microscope sample table for pre-stretching treatment, and photographing the sample in the pre-stretching process to obtain a pre-deformation curve of the sample changing along with time; carrying out processing treatment on the pre-stretched sample; and after the processing treatment is completed, carrying out fatigue load loading treatment on the sample, and photographing the sample in the loading treatment process. In the invention, in-situ fatigue and in-situ prestretching control are integrated in a scanning electron microscope system, which is simple, convenient and efficient, and reliable in control; compared with a DIC test deformation control method of a digital image correlation method, the SEM video extensometer deformation control method is more efficient, simpler and more convenient, does not need a related high-speed camera and the like, is higher in accuracy, and controls the error within 0.05%.