22 results about "Gauge length" patented technology

The invention relates to the technical field of material mechanical property testing, and provides an ultralow-temperature slow strain mechanical tensile test platform which comprises a vacuum Dewar unit, a liquid helium temperature control unit, a slow strain tensile unit, a measuring unit and a control unit, the vacuum Dewar unit comprises a vacuum Dewar body and is used for providing a closed low-temperature test environment; the liquid helium temperature control unit comprises a direct injection module and a recovery module, the direct injection module is used for directly injecting liquid helium to the gauge length section of the sample for cooling, and the recovery module is used for recovering and recycling unevaporated liquid helium; the slow strain stretching unit is used for stretching a sample arranged in the vacuum Dewar body at a low strain rate; the measuring unit is arranged in the vacuum Dewar body and is used for monitoring the temperature, the force value and the strain data of the sample in real time. Liquid helium is used as a cold source, the liquid helium is directly aligned to the gauge length section of the sample through the direct injection module, and compared with a traditional liquid helium steam natural convection heat exchange mode, the heat exchange coefficient is increased, and automatic precise temperature control is achieved.

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 simple device for drawing a gauge length of an aluminum alloy circular performance sample, which belongs to the technical field of gauge lengths of aluminum alloy samples, solves the problems that the operation is difficult and the marking is easy to generate errors when the gauge length of the aluminum alloy circular performance sample is manually made at present, and comprises a caliper bracket, a sample bracket and a caliper, a sliding rail is arranged on a caliper support bottom plate, vertical groove-shaped caliper support supporting rods are symmetrically arranged on the two sides of the bottom plate, spring columns are arranged at the bottoms in grooves of the caliper support supporting rods, and springs are arranged on the spring columns. A left sample holder supporting rod and a right sample holder supporting rod of the sample bracket are arranged on the slide rail in a sliding manner; the caliper is provided with a fixed measuring claw and a caliper outer measuring claw in a sliding mode, two sides of the caliper are lengthened to be provided with blank caliper bodies, and two ends of the blank caliper bodies are clamped in the caliper support supporting rod grooves in a sliding mode and abut against the tops of the springs. The marking of various scale distances is accurately realized, and the efficiency and the accuracy of marking the scale distances are greatly improved.

The application provides a prestressed steel strand anchoring performance nondestructive detection method, and belongs to the technical field of steel strand performance detection, and comprises the following steps: applying a pre-tension force to a steel strand to be detected, unloading to zero after load preservation, so as to eliminate initial disturbance; applying a preset axial tensile load to the steel strand to be detected, the axial tensile load enabling the steel strand to be in an elastic stress state; under the condition of maintaining the axial tensile load, measuring a torsion angle generated by the steel strand within a gauge length; according to the torsion angle, determining a characteristic parameter representing a tensile-torsion coupling characteristic of the steel strand; comparing the characteristic parameter with a preset qualified judgment threshold value, and judging whether the anchoring performance of the steel strand to be detected is qualified based on a comparison result. The prestressed steel strand anchoring performance nondestructive detection method provided by the application realizes nondestructive detection and root-by-root screening of the steel strand.

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 relates to a line drawing device and method for a center line and a scale distance of a dumbbell-shaped tensile sample, and the device comprises a base which is provided with a groove for placing the dumbbell-shaped tensile sample; the fool-proof device is an arc-shaped protrusion arranged on the inner wall of the groove, and the arc-shaped protrusion is matched with the dumbbell-shaped tensile sample in outline and used for preventing a non-dumbbell-shaped sample from being placed in the groove; the limiting assembly comprises a longitudinal length positioning frame and a transverse width positioning frame which are respectively arranged along the length direction and the width direction of the groove and are used for limiting the displacement of the sample in the groove; the positioning line drawing assembly comprises a scale distance line blocking edge and a center line positioning blocking edge, the scale distance line blocking edge is arranged in the scale distance length direction of the sample, the center line positioning blocking edge is arranged in the middle in the width direction of the sample, and the scale distance line blocking edge and the center line positioning blocking edge perpendicularly intersect to form a cross-shaped positioning structure. By adjusting the length and the width of the groove and the curvature of the arc section, the device can adapt to various standard dumbbell-shaped samples and has wide applicability.

This application discloses a testing method for nickel-based superalloys, belonging to the field of material purity testing and evaluation. The testing method includes sample preparation: processing the nickel-based superalloy raw material into cylindrical tensile specimens with a gauge length diameter of 6–15 mm, and polishing the surface; room temperature tensile testing: stretching the tensile specimen at room temperature until it fractures; fracture surface analysis: after fracture, observing the fracture surface using an optical microscope and / or scanning electron microscope, measuring the size of non-metallic foreign matter on the fracture surface, and analyzing its composition to complete the detection. This application has the following advantages: high sensitivity: it can detect micro-non-metallic foreign matter with a maximum Feret diameter of less than 10 μm; high efficiency: the fracture surface can be obtained through room temperature tensile testing, eliminating the need for a high-temperature environment and complex fatigue testing; the segmented tensile process can significantly shorten the testing cycle; for a specimen with a working section of approximately 50 mm, the test can be completed in only about 3 hours.

The application belongs to the technical field of inspection and detection, and particularly relates to a metal tensile specimen gauge length measurement auxiliary device, which comprises a bottom plate base, a fixing module, an electromagnetic module, a movable clamping module and a clamping module for driving the clamping module to move to clamp a specimen are arranged on the bottom plate base, the fixing module and the clamping module clamp two ends of the specimen respectively, the electromagnetic module adsorbs to fix the specimen, and the fixing module, the electromagnetic module, the clamping module and the clamping module are arranged on the same straight line; wherein the clamping module comprises a lead screw and a seat plate, the seat plate is fixed vertically on the bottom plate base, the lead screw is threadedly connected with the seat plate, and the end of the lead screw is rotationally connected with the clamping module. The application effectively reduces the measurement error by combining the electromagnetic fixing and mechanical fixing, and improves the reliability and accuracy of the measurement result.

The invention discloses a method, a device, equipment, a medium and a product for testing the percentage elongation after fracture of a metal material through a small punch test, and relates to the technical field of material mechanical property testing. The method comprises the following steps: acquiring a small punch sample set of a target metal material; performing small punch test treatment on the small punch sample set to obtain test information of the target metal material; based on the finite element model of the notched small punch sample, according to the true stress-strain curve and the load-displacement curves corresponding to the small punch samples of various different notched configurations, determining the fracture criterion of the target metal material in the multi-axial stress state; and inputting the true stress-strain curve and the fracture criterion into a preset finite element model of a standard uniaxial tensile sample, simulating a tensile test to measure the gauge length of the fractured tensile sample, and determining the percentage elongation after fracture. According to the method, the standard percentage elongation after fracture of the material can be simply, conveniently and accurately determined.

The invention relates to the technical field of material mechanical property testing, in particular to a multi-rate tensile test method based on speed correction and self-adaptive adjustment. The method comprises the following steps: firstly, determining a theoretical tensile speed according to collision regulations, and obtaining a real strain rate of a material through a primary test; and correcting the theoretical speed in combination with the scale distance of the sample. Starting from the corrected speed, by comparing the change of the maximum stress of the material at the adjacent rates, adaptively selecting different proportions to adjust the subsequent test speed step by step, and iteratively carrying out until a preset span ratio termination condition is met. Through speed planning and feedback adjustment of the system, an effective stress-strain curve which covers a wide strain rate range and is free of data redundancy can be efficiently obtained with the least test times, the test efficiency and the data validity are remarkably improved, and accurate and reliable material model input is provided for vehicle collision simulation.

The invention belongs to the field of metal material testing, and particularly relates to a room-temperature tensile testing method for replacing an extensometer, the position of a cross beam platform is changed, so that the distance between clamps is larger than the actual distance between the clamps, and the rigid strain of a testing machine in the loading process is counteracted by using the difference between the two. The method has the advantages that the dependence on the extensometer is completely eliminated through mathematical modeling and rigidity compensation of the testing machine; firstly, a shoulder-free strip-shaped sample is combined with high-precision milling or grinding, so that the size consistency of the sample is ensured; secondly, setting the distance between clamps to be equal to the gauge length of the sample and introducing a beam platform position correction formula to accurately offset the elastic deformation of the testing machine in the loading process, so that the real strain of the sample is reversely deduced by directly utilizing beam displacement data, and a stress-strain curve is drawn according to the real strain; therefore, various parameters related to linear deformation and overall deformation can be accurately measured.

The invention discloses a tensile fixture of a universal testing machine, and relates to the field of sample clamping devices in material testing. The clamp comprises clamp bodies which are oppositely arranged, clamping faces are arranged on the opposite surfaces of the clamp bodies, main anti-skid teeth and auxiliary anti-skid teeth are arranged on the clamping faces, and the distance between the tooth tops of the main anti-skid teeth and the clamping faces is larger than the distance between the tooth tops of the auxiliary anti-skid teeth and the clamping faces. The tooth top angle E of each main anti-skid tooth is 80-100 degrees, the tooth height H of each main anti-skid tooth is 0.6-1.0 mm, and the tooth top of each main anti-skid tooth is provided with a transition arc; the included angle between the front tooth surface of each auxiliary antiskid tooth and the clamping surface datum line is smaller than that between the rear tooth surface of each auxiliary antiskid tooth and the clamping surface datum line; the tooth tops of the auxiliary anti-skid teeth are provided with transition arcs. According to the device, the local pressure stress and damage to the sample are greatly reduced while effective piercing is guaranteed, slippage caused by material stress relaxation is effectively resisted through the synergistic effect of the main teeth and the auxiliary teeth, it is guaranteed that the sample is broken at the gauge length section, and therefore a stable and accurate test result is obtained.

This invention provides a tensile plate-shaped specimen for testing the strain rate impact fatigue properties of materials, relating to the field of material mechanical property testing technology. The plate-shaped specimen includes, along its axial direction: a gauge length section located in the middle of the specimen; both ends of the gauge length section are connected to one end of a square limiting section via transition sections; the other end of the square limiting section is connected to a threaded section. The gauge length section has a cuboid structure, and the cross-section of the square limiting section is a rounded rectangle or a square. The transition section connects the square limiting section and the gauge length section, achieving a smooth transition from the rounded rectangle or square cross-section to the rectangular cross-section of the gauge length section. The threaded section, located at the end of the specimen, is a threaded cylinder used for fixing with a specimen clamp. The plate-shaped specimen of this invention can stably cooperate with impact tensile testing devices, achieve anti-torsional clamping, and meet the testing requirements for different stress concentration factors.

The invention relates to a high-throughput mechanical testing device and method based on a DIC technology, and the method comprises the following steps: installing a clamp matched with a to-be-tested material sample on the device, and connecting a clamping mechanism with a strain mechanism; respectively fixing a plurality of material samples to be detected on the clamp; configuring strain parameters and image acquisition parameters; an actuator or a driving system is started to drive the cross beam to move, and tension is synchronously applied to the multiple to-be-tested material samples for synchronous strain; measuring a force value in real time through a force sensor while carrying out strain on the plurality of to-be-measured material samples, and collecting images of scale distance sections of the plurality of to-be-measured material samples through a camera; after the to-be-tested material samples are snapped, performing DIC processing on the acquired images, and calculating strain data of gauge length sections of the to-be-tested material samples; and generating a stress-strain curve of the material sample by combining strain data according to a force value measured in the strain acquisition process, so as to realize high-throughput mechanical test.

The application discloses a kind of TPU multi-filament harness performance test equipment and method thereof, including outer frame, vertical frame fixed on the outer frame and roll rack fixedly installed on the outer wall of vertical frame;Steel roller is installed in the roll rack, and a plurality of annular isolation grooves are arranged on the circumference of steel roller along the axial direction, each annular isolation groove is used to independently accommodate a TPU silk line and pass in V-shaped type;Stage is movably arranged on the vertical frame, and lifting assembly is installed on the outer wall of vertical frame above the roll rack, and the driving end of lifting assembly is connected with stage.The application utilizes the structure of steel roller, annular isolation groove, lifting assembly, stage, S-type tension sensor and multi-thread single-cylinder compression assembly etc., to complete the real limit tensile test of TPU multi-filament harness in the stroke of short gauge length equipment.

The invention relates to the technical field of metal material tensile tests, in particular to a parallel test and minimum spacing compensation method for uniaxial tensile elongation after fracture of a plate. The method comprises the following steps: preparing a sample with a gauge length of L, and carrying out equal-interval marking; through at least two parallel tensile tests, the key mark distance at the fracture is measured; selecting a minimum value of key spacing in all tests as a compensation reference value; and for a to-be-tested sample, after the to-be-tested sample is tested under the same marking condition, the corrected percentage elongation after fracture is calculated by utilizing the compensation reference value and a corresponding formula. Through the core means of determining the reference value through the parallel test and performing model compensation, on the premise that an existing efficient marking technology is not changed, system errors caused by mark damage are corrected fundamentally, the accuracy and authenticity of a measurement result are remarkably improved, and the method can be conveniently integrated to an existing test system and has very high engineering practical value.

The invention discloses a concrete box girder nonlinear damage identification method considering a shear hysteresis effect, and the method comprises the steps: estimating the position of a neutral axis of a box girder through long gauge length strain and material performance, and then determining the curvature distribution, bending rigidity and deflection. A simulation result shows that the evaluation parameter (bending rigidity) can clearly and quantitatively reflect the degradation process of the box girder. Meanwhile, the long gauge length strain can reflect global response and can also capture local changes, and the structural response obtained through inversion is highly consistent with the actual measurement result. Compared with a finite element model correction method, the method does not need a finite element model, and can consider nonlinear and shear hysteresis effects; meanwhile, the method is suitable for the whole process of structure failure.

The utility model discloses a device for measuring the scale distance length of a tensile sample after fracture, which comprises a positioning platform, a plurality of measuring devices are arranged on the positioning platform, the measuring devices are detachably arranged on the positioning platform, and each measuring device comprises a base with a U-shaped groove structure. The measuring device comprises a base, frame structures are detachably connected to the base, the frame structures are symmetrically arranged on the two sides of the base, door-type frame structures are formed through the frame structures, a space for measuring the gauge length of a broken circular or plate-shaped tensile sample is formed between the door-type frame structures, and the measuring device further comprises a moving assembly. The measuring device comprises a frame structure and a moving assembly, the moving assembly is detachably provided with a circular or plate-shaped tensile sample, the upper portion of the moving assembly is detachably connected with the circular or plate-shaped tensile sample, the measuring device further comprises a measuring scale detachably connected to the frame structure, and the two sides of the measuring scale are connected to an L-shaped positioning plate through bolts.

The invention relates to the technical field of strength prediction, in particular to a continuous strength prediction method and device for an engineering size irradiation material. The method comprises the following steps: acquiring first strength data obtained by a non-irradiation tensile test of a first tensile sample at different size points under different size spectrum systems; inputting the cross sectional area of the scale distance section in the first tensile sample and the first intensity data into a non-irradiation intensity prediction model to obtain a first parameter set; obtaining second strength data obtained by a tensile test after irradiation of a second tensile sample at different size points; inputting the cross sectional area of the scale distance section in the second tensile sample, the first parameter set and the second intensity data into the post-irradiation intensity prediction model to obtain a second parameter set; and inputting the cross sectional area of the engineering size irradiation material into the fitted post-irradiation intensity prediction model to obtain predicted intensity data of the engineering size irradiation material. According to the technical scheme, the strength of the engineering size irradiation material can be continuously predicted.

The invention relates to a thin plate tensile property testing method and a clamp tool, and belongs to the technical field of material mechanical property testing. The invention discloses a method for testing the tensile property of a thin plate. The method comprises the following steps: preparing a sample, wherein the sample comprises an effective gauge length section and clamping sections positioned at two ends of the effective gauge length section; preparing a pair of clamp tools; respectively fixing the clamping sections on a clamp tool by using an adhesive; then the clamp tool is fixedly connected with an upper chuck and a lower chuck of detection equipment respectively; applying an axial tensile load to the sample through detection equipment until the sample is fractured, and recording load-displacement data; and calculating the tensile property parameters of the sample according to the data. Through mutual cooperation of the clamp tool and the adhesive, the device is suitable for tensile tests in different temperature environments such as room temperature, high temperature and low temperature, the problem that an ultrathin sample is prone to slipping, buckling or breaking in advance is solved, a complete and real stress-strain curve can be obtained, data discreteness is small, and repeatability is extremely high.

The invention discloses a novel cable tension testing device and method for cable material processing, and belongs to the technical field of cable testing. The method comprises the following steps: evaluating the precision of a system through an equipment capability model; quantifying initial condition deviation of the sample through the sample state influence model; evaluating operation normativity through an operation efficiency model; dynamically evaluating process control quality through a process matching model and introducing state dependence sensitivity; finally, through a scale distance optimization model, according to the sample state coefficient and the process matching degree, the optimal target measurement scale distance is calculated and adjusted in a self-adaptive mode. According to the invention, comprehensive quantitative evaluation and dynamic parameter optimization of multiple factors such as equipment, samples, operation and processes are realized, and the precision, reliability and intelligent level of cable tension testing are remarkably improved. The corresponding device is used for executing the method.

The present application relates to the technical field of strength prediction, in particular to a method and device for continuously predicting the strength of engineering size irradiated materials. The method comprises: obtaining first strength data of first tensile samples of different size points in different size spectra obtained through unirradiated tensile test; inputting the cross-sectional area of the gauge length section in the first tensile sample and the first strength data into an unirradiated strength prediction model to obtain a first parameter set; obtaining second strength data of second tensile samples of different size points obtained through tensile test after irradiation; inputting the cross-sectional area of the gauge length section in the second tensile sample, the first parameter set and the second strength data into an irradiated strength prediction model to obtain a second parameter set; and inputting the cross-sectional area of the engineering size irradiated material into the fitted irradiated strength prediction model to obtain predicted strength data of the engineering size irradiated material. The above technical solution can continuously predict the strength of the engineering size irradiated material.