60 results about "Fracture Toughness Testing" patented technology

The invention discloses a test-based crystal plasticity and cohesion model coupling hydrogen induced cracking simulation method, which comprises the following steps: carrying out a hydrogen filling mechanical property test on a metal material to obtain a true stress-true strain curve of the metal material in a hydrogen environment; carrying out a hydrogen-filled fracture toughness test on the metal material to obtain a stress intensity factor of the metal material in a hydrogen environment; constructing a cohesion constitutive model; a metal material electron back scattering diffraction microscopic characterization test is carried out, microstructure characteristics are obtained, and a polycrystalline model is constructed; constructing a crystal plastic constitutive model; coupling crystal plasticity constitutive and cohesion constitutive, and calibrating crystal plasticity to-be-determined parameters by adopting a trial-and-error method; and carrying out finite element simulation analysis on hydrogen-induced cracking behaviors with different microstructure characteristics in a hydrogen environment to obtain stress-strain data and crack data of the hydrogen-induced cracking behaviors. According to the invention, high-precision simulation of the hydrogen-induced cracking micromechanism of the metal material in the hydrogen environment is realized.

The present invention relates to the technical field of mechanical property testing of metal materials, and in particular to a testing method for obtaining material fracture properties based on 0.5T-CT specimen reconstitution technology. The testing method for obtaining material fracture properties based on 0.5T-CT specimen reconstitution technology comprises: preparing an original 0.5T-CT specimen of a base material, and carrying out a fracture property test to obtain a residual 0.5T-CT specimen after the test; testing and analyzing the base material to obtain a full-range equivalent stress-strain relation curve of the base material; determining the range of materials that can be used for preparing a reconstituted specimen; welding a reusable material and an auxiliary material for specimen reconstitution to obtain a reconstituted 0.5T-CT specimen; testing and analyzing a weld material to obtain a stress-strain relation curve of the weld material; determining fracture parameters of the reconstituted 0.5T-CT specimen; and on the basis of the fracture parameters, carrying out a fracture toughness test of the reconstituted 0.5T-CT specimen to obtain fracture properties of the base material and / or the weld material. The testing method in the present invention is simple, and the testing result is accurate.

The invention discloses a testing device for a sandwich structure of a composite material and an I-type fracture toughness testing method. The testing device comprises a guide slide rail; a test connection structure fixed relative to the guide slide rail; the guide sliding block is in sliding connection with the guide sliding rail; the sample connecting structure is detachably fixed with the sliding block; loading the connecting structure; provided is a crack detection device. The I-type fracture toughness testing method is suitable for any one of the testing devices for the sandwich structure of the composite material, and comprises the following steps: preparing a sample of the sandwich structure of the composite material; the composite material sandwich structure sample is installed on a testing device, and the composite material sandwich structure testing device is installed on a universal testing machine; adjusting a crack detection device; carrying out initial loading; carrying out secondary loading; recording a load value, a displacement value and an effective crack propagation value; after the test is finished, the chuck of the universal testing machine is loosened, the computer calculates the GIC value of the composite sandwich structure sample, a test result is derived, and a load displacement curve and an R curve are made.

The invention relates to a composite material II-type interlayer fracture toughness measuring device for obtaining a complete R curve, which is suitable for a tensile load device to carry out fracture toughness test on a test piece made of a polymer matrix composite material, and comprises a base, a support plate arranged in a special-shaped I-shaped structure, a loading lug plug, a support table and an adjusting plate, the supporting plate is detachably installed on the top face of the base, the adjusting plate is installed on the top face of the supporting plate in a horizontal sliding mode, the supporting table is fixedly installed on the top face of the adjusting plate, the small end of the loading lug plug is connected with the output end of the tension load device, and the large end of the loading lug plug fixes one end of a test piece in a pin hole matching mode. And the other end of the test piece is mounted on the trapezoidal part of the supporting table, so that the test efficiency is improved, and a complete II-type interlayer fracture toughness curve of the composite material is obtained.

The invention discloses a metal material hydrogen compatibility simulation test method based on hydrogen content. The method comprises the following steps: S1, sample preparation; s2, charging hydrogen in a high-pressure hydrogen environment; s3, diffusible hydrogen is measured; s4, preparing an electrochemical hydrogen charging solution; s5, carrying out hydrogen charging by using an electrochemical hydrogen charging solution; s6, storing the sample; s7, drawing a hydrogen concentration change curve; s8, electrogalvanizing process parameters are set; s9, performing hydrogen charging in a simulated high-pressure hydrogen environment; s10, the sample is galvanized; s11, carrying out a slow tensile test and a fracture toughness test on the sample; and S12, evaluating the high-pressure hydrogen embrittlement of the sample based on the results of the slow tensile test and the fracture toughness test. According to the method, the hydrogen embrittlement performance of the material under different hydrogen pressure environments can be obtained, and the influence of the influence factors on the high-pressure hydrogen embrittlement performance of the steel can be analyzed in combination with the process, alloy components and stress states of the steel.

The utility model relates to an anti-buckling device and a testing system for a fracture toughness test thin plate MT sample, the anti-buckling device comprises two anti-buckling assemblies, the two anti-buckling assemblies respectively comprise a pressing plate contacted with the MT sample and ear plates arranged at the two sides of the pressing plate, and the thin plate-shaped MT sample to be tested is clamped between the two pressing plates; a crack observation groove penetrating through the thickness direction of the pressing plate is formed in the middle of the pressing plate and is used for observing a prefabricated crack on an MT sample; the fastening assembly penetrates through the buckling-restrained assemblies in the thickness direction of the MT sample and is used for fastening and clamping the MT sample between the buckling-restrained assemblies; and the antifriction assembly is arranged between the anti-buckling assembly and the MT sample. Compared with the prior art, the device can effectively prevent the MT sample piece from buckling in the fracture toughness test process, and has the advantages of simplicity in installation, independent support, convenience in crack observation and the like.

The invention discloses a fracture toughness testing method and system, electronic equipment and a storage medium, and relates to the technical field of fracture toughness tests.The method comprises the steps that in the process of carrying out a fracture toughness test on a sample, a DIC system is used for measuring and obtaining a curve of crack opening displacement at multiple preset positions of a preset notch of the sample along with time; and obtaining a critical point in the curve of the crack opening displacement of each preset position along with the time change, performing linear fitting, and then determining the crack opening displacement at the tip of the preset gap. Based on the digital image technology, the fracture deformation process of the sample can be truly and effectively reflected, the crack opening displacement at the tip of the preset notch of the sample is accurately determined, the testing efficiency is high, the testing result is accurate and reliable, and the fracture toughness of the sample at multiple temperatures can be rapidly and accurately measured.

The invention relates to an RPV material small-size sample fracture toughness conversion evaluation method, which comprises the related steps of material fracture toughness testing based on energy method parameters, obtaining of crack initiation driving force energy parameters in a nuclear power structure integrity service state, and nuclear power structure service safety evaluation. The method provided by the invention overcomes the problems that the evaluation of the surface shallow crack is too conservative (the constraint effect of the crack front edge is not considered) and the SIF, J integral and other numerical simulation methods cannot be applied to the unloading process in the existing specification, and can be suitable for the load unloading characteristics of the primary loop of the reactor; and the deep technical support is provided for the long-life safe operation of the RPV of the nuclear power plant.

The invention discloses a hydrogen compatibility simulation test method in a high-pressure environment based on hydrogen diffusion. The method comprises the following steps: S1, preparing a sample; s2, performing a hydrogen permeation test in a high-pressure hydrogen environment; s3, preparing a hydrogen permeation cathode hydrogen filling solution; s4, performing a hydrogen permeation test in a simulated high-pressure hydrogen environment; s5, applying and adjusting cathode hydrogen charging current under simulated high-pressure hydrogen permeation; s6, determining a dynamic hydrogen charging current; s7, performing a smooth slow tensile simulation test in a high-pressure hydrogen environment; s8, carrying out a notch slow tensile simulation test in a high-pressure hydrogen environment; s9, carrying out a fracture toughness test; and S10, performing high-pressure hydrogen embrittlement evaluation based on the results of the smooth slow tensile simulation test and the fracture toughness test. According to the method, the hydrogen embrittlement performance of the material under different hydrogen pressure environments can be obtained, and the influence of the influence factors on the high-pressure hydrogen embrittlement performance of the steel can be analyzed in combination with the process, alloy components and stress states of the steel.

To improve versatility and simplicity of fracture toughness value perdition.SOLUTION: A fracture toughness value prediction method is provided, involving acquiring a fracture toughness parameter at the time when a locally generated stress on a test piece evaluation part in a fracture toughness test as obtained through a first numerical analysis reaches a local breaking stress at a fracture initiation point obtained based on a brittle fracture test as a fracture toughness value of a target material.SELECTED DRAWING: Figure 2

The invention relates to a fatigue life prediction method based on a physical failure mechanism in a liquid lead bismuth environment, and the method comprises the following steps: building a representative volume element model, and defining elements belonging to a slip band; defining a crystal plasticity constitutive equation; determining parameters in the crystal plasticity constitutive equation; calculating the average shear strain range of the slip band; carrying out a fracture toughness test to obtain specific fracture energy; establishing a fatigue life prediction model based on a physical failure mechanism; carrying out a symmetrically cyclic low-cycle fatigue test on the metal material in a predicted-temperature high-oxygen liquid lead bismuth environment to determine the thickness of an oxide film; and establishing a fatigue life prediction model in the high-oxygen-concentration liquid lead bismuth environment, and predicting the fatigue life of the metal material in the high-oxygen-concentration liquid lead bismuth environment. According to the method, the fatigue life in the liquid lead-bismuth environment can be predicted by carrying out a low-cycle fatigue test for calibrating crystal plasticity constitutive equation parameters in the air at the predicted temperature and a fracture toughness test in the air and liquid lead-bismuth environment.

The deep rock fracture toughness test system and method provided by the embodiment of the present application, wherein the system comprises a test sample, a vacuum pressure chamber and a host computer; the vacuum pressure chamber is provided with a confining pressure loading device, an axial pressure loading device, an electric resistance testing device and a camera device; the host computer is used to control the confining pressure loading device and the axial pressure loading device to load pressure on the test sample, so that the initial crack on the test sample is expanded; the host computer is also used to acquire the electric resistance change of the test sample and the expansion image of the initial crack when the initial crack on the test sample is expanded, and determine the fracture toughness of the test sample according to the electric resistance change of the test sample and the expansion image of the initial crack. The small change of the crack of the test sample is detected by monitoring the electric resistance change of the test sample, and the accurate crack change data is obtained by combining the image in the crack expansion process, so that the detection accuracy of the crack is improved, and the calculation accuracy of the rock fracture toughness is ensured.

This invention discloses a test method for evaluating the hydrogen embrittlement susceptibility index of welded joints using principal component analysis, belonging to the field of material performance evaluation technology. The method includes the following steps: S1, processing the pipe welded joint into a notched round bar slow strain rate tensile specimen and conducting a slow strain rate tensile test; S2, processing the pipe welded joint into a stepped-notch CT specimen for fracture toughness and conducting a fracture toughness test; S3, calculating the specific performance loss rate under hydrogen-doped conditions and performing standardization; S4, calculating the hydrogen embrittlement susceptibility evaluation index I. PC S5. Perform scanning electron microscopy analysis on the slow strain rate tensile fracture surface to determine the risk level of hydrogen-induced cracking in the sample; S6. Determine the I-value that distinguishes different risk levels of hydrogen-induced cracking. PC Scope. This invention employs the aforementioned test method for evaluating the hydrogen embrittlement sensitivity index of welded joints using principal component analysis, which improves the statistical significance of small sample data and yields a more objective and comprehensive evaluation system for hydrogen embrittlement sensitivity.

The embodiment of the invention provides a stress relieving device for a fracture toughness test. The stress relieving device comprises a plurality of guide columns, a base assembly, a top seat assembly, a first pressing block and a second pressing block, the multiple guide columns are arranged on the edge area of the base assembly at intervals, and a first pressing block is arranged in the center area of the base assembly. The top seat assembly can slide in the direction from the second ends to the first ends of the guide columns along the guide columns, and the top seat assembly is provided with second pressing blocks corresponding to the first pressing blocks; the side, facing the top seat assembly, of the base assembly is used for bearing a sample weldment and hammering the sample weldment under the cooperative action of the first pressing block and the second pressing block so as to eliminate residual stress of the sample weldment and enable the sample weldment to generate indentations. By means of the guide column, the base assembly, the top base assembly, the first pressing block and the second pressing block, a weld joint and an adjacent area of a sample weldment can be effectively hammered, residual stress of the sample weldment is eliminated, and the indentation depth is accurately controlled through cooperation of the first pressing block and the second pressing block.

This invention discloses a testing device and method for fracture toughness testing of welded joints in pipeline steel under corrosive environments, belonging to the technical field of fracture toughness testing equipment. It includes a test vessel unit and a testing unit. The test vessel unit comprises a test vessel body and a test vessel lid, the lid of which can close onto the opening of the test vessel body. The test vessel lid has an air inlet and an air outlet; the air inlet is used to connect to an air inlet pipe, and the air outlet is used to connect to an air outlet pipe. The testing unit includes a bending clamp assembly and a loading linear displacement measuring assembly. The bending clamp assembly is connected to the shaft of the testing machine and can be used to clamp the test specimen. Driven by the shaft of the testing machine, the bending clamp assembly can press down on the test specimen. The loading linear displacement measuring assembly is connected to a measuring point on the test specimen and is used to measure the linear displacement of the measuring point. This invention enables fracture toughness testing of welded joints under corrosive environments, ensuring the accuracy and safety of the test.

The embodiment of the invention provides a material fracture toughness testing device and method, and relates to the technical field of material fracture toughness testing. The device comprises a supporting assembly which comprises a workpiece platform and two supporting rollers; two mark points P1 and P2 are arranged on the plane A of the workpiece platform along the parallel line of the axes of the two supporting rollers; the loading assembly comprises a liftable loading roller; two sides of the bottom of the loading roller are provided with two first light emitters, and projection points of the first light emitters on a plane A are O1 and O2; the image recognition system is used for acquiring images of P1, P2, O1 and O2; the control system is used for controlling the workpiece platform to translate and rotate, so that the line segment P1P2 and the line segment O1O2 are collinear; and the auxiliary positioning structure comprises a limiting element and a second illuminator, and can ensure that the prefabricated notch of the test workpiece is accurately positioned right below the axis of the loading roller. The method can ensure that the test workpiece meets the spatial geometric constraint condition of the fracture toughness test, and improves the accuracy and reliability of the test.

The application relates to the technical field of material performance testing, and particularly relates to a heterogeneous material fracture toughness testing method, a double cantilever beam sample and a manufacturing method. The heterogeneous material fracture toughness testing method comprises the following steps: a double cantilever beam sample is provided, the double cantilever beam sample comprises a base layer, a first substrate and a separation layer, the first substrate is provided with the base layer on both sides in a first direction, the separation layer is arranged between the first substrate and any base layer, a separation area and a to-be-tested area are formed between the first substrate and the base layer adjacent to the separation layer in a second direction, and the separation area has a prefabricated crack; a sample testing step is performed, the double cantilever beam sample is installed on a testing device, the double cantilever beam sample is loaded by the testing device to make the to-be-tested area delaminate, and target data is acquired; and a result calculation step is performed, and a type I interlaminar fracture toughness value is acquired according to the target data. The heterogeneous material fracture toughness testing method provided by the application can improve testing accuracy.

The invention discloses a part interlayer fracture toughness test method, device and equipment and a storage medium, and the method comprises the steps: applying different loading forces to a standard test part based on a mechanical test system, and obtaining test data of each test point at different test moments through a digital image correlation technology DIC; performing top-hat transformation processing on the test image of each test point to obtain a processed test image, and obtaining the size of the precrack according to the processed test image; and calculating according to the precrack size and the loading force of each test point at different test moments to obtain the interlayer fracture toughness of the standard test part. The method comprises the following steps: on the basis of acquiring crack opening displacement and angle of a fiber reinforced composite material I-type interlayer fracture toughness test piece through DIC, synchronizing the dynamic change process of the length of a prefabricated crack extending along with loading of a load at different moments with a real-time load, and meanwhile, optimizing an acquired test image by combining a Top-hat technology, so as to obtain a test result of the I-type interlayer fracture toughness of the fiber reinforced composite material I-type interlayer fracture toughness of the fiber reinforced composite material I-type interlayer fracture toughness test piece. And the measurement precision of the interlayer fracture toughness is improved.

The application discloses a kind of based on ENDB sample dynamic fracture toughness testing device, including test auxiliary device and Hopkinson bar experimental device, Hopkinson bar experimental device includes incident bar and transmission rod, test auxiliary device includes load transmission structure, dial, support seat component, sample fixing assembly and auxiliary fixing assembly, dial, sample fixing assembly and support seat are fixed by distance adjusting component of three through three connections.This application can accurately adjust the included angle α between loading rod and prefabricated crack, so that the dynamic fracture toughness test of a variety of different angles III and I, III mixed type can be realized, the dynamic fracture toughness test experiment of a variety of diameter sizes ENDB sample can be satisfied, and a certain fracture failure play space is reserved between dial and sample, to improve sample damage effect and the accuracy of experimental results.The whole device has no direct or indirect contact with the outside world, reduces the loss of energy, improves the accuracy of experimental results.

The application belongs to the technical field of fracture toughness evaluation, and specifically discloses a small-size fracture toughness testing method for metal materials based on fracture cross-section characteristics, which utilizes the fracture cross-section shape of a test sample, considers the elastic energy distribution of a normal fracture zone dominated by I-type fracture and a shear fracture zone dominated by II-type fracture, establishes a linear relationship between G and J, carries out a fracture test by using a multi-sample method with different thicknesses, determines different groups of data, obtains and estimates values by combining a least square method, forms a new method for evaluating the small-size fracture toughness of metal materials based on fracture cross-section characteristics, and avoids the difficulty of directly using standard pieces for evaluation for materials such as high-strength steel, and has significant engineering application value.

The present invention discloses a preparation method of a recombined compact tension specimen, comprising the following steps: 1) preparing a specimen for a target material and spraying speckles on the surface of the specimen; 2) conducting a fracture toughness test on the specimen, and during the fracture toughness test, measuring the specimen by using a full-field strain measurement system; 3) determining a plastic strain region on the surface of the specimen according to the measurement result of the full-field strain measurement system and excising the plastic strain region, and retaining the non-plastic strain regions on both sides of the specimen to obtain a recombined block; 4) welding the recombined block with auxiliary materials to obtain the recombined compact tension specimen. The preparation method of the recombined compact tension specimen of the present invention, through reasonable recombination means and verification means, enables the performance of the recombined specimen to be similar to that of the original specimen; and the non-plastic deformation regions (recombined blocks) after the fracture toughness test can be recombined into two or more specimens, increasing the material utilization rate by three times or more.

This application belongs to the field of fracture toughness testing under corrosive environments, and specifically discloses a method for calibrating the stress intensity factor loading rate in fracture toughness testing under corrosive environments. The method includes: preparing a specimen and creating a pre-crack; using a corrosive solution to create a pre-corrosive environment at the crack tip; establishing a corrosive environment on a testing machine and performing a three-point bending test on the specimen in the corrosive environment at a preset testing machine loading rate to obtain the specimen's yield strength; loading the specimen in the corrosive environment using multiple different testing machine loading rates to 60%-90% of the yield strength, and recording the force-time curves for each loading; calculating the corresponding stress intensity factor loading rate based on the force-time curves and performing linear fitting to obtain the corresponding functional relationship. This application solves the problem that when conducting fracture toughness testing under corrosive environments, it is impossible to directly set the stress intensity factor loading rate, and existing calibration methods cannot accurately reflect the coupling effect of the corrosive environment.

The present invention belongs to the technical field of molding dies for polymer material sample products, and specifically discloses a molding die for polymer material fracture toughness samples, including a lower hollow mold, both sides of the lower hollow mold are fixedly connected with a sliding shell, the top of the lower hollow mold is provided with an upper hollow mold, both sides of the upper hollow mold are fixedly connected with a sliding bar, the sliding bar is slidably connected inside the sliding shell, the bottom of the lower hollow mold is provided with a cooling mechanism, the cooling mechanism is used to quickly cool the mold, the interior of the lower hollow mold is provided with an anti-burr mechanism, the anti-burr mechanism is used to reduce burrs after the pattern is formed. Through the cooling mechanism, the mold is provided with air cooling and water cooling, and the mold can be quickly cooled under the condition of double heat dissipation, thereby improving the efficiency of heat dissipation, shortening the cooling time of the polymer material in the mold, and then improving the efficiency of the polymer material fracture toughness test.

The utility model relates to the field of metal material fracture mechanical tests, and particularly discloses a fracture toughness test clamp suitable for various thicknesses, which comprises a clamp seat and two opposite loading arms, the loading arms are slidably connected onto the clamp seat, the two loading arms are simultaneously in threaded connection onto a two-way screw, the two-way screw is mounted on the clamp seat, and the two-way screw is in threaded connection with the clamp seat. The two loading arms are used for getting close to or getting away from each other along the two-way screw, and the two-way screw is in threaded connection to the center line of the loading arms. The scheme is used for solving the problem that a traditional integrated tool cannot adapt to samples with different thicknesses.

The utility model provides a sample preparation tool for an I-type fracture toughness test. The sample preparation tool comprises a platform, the upper surface of the platform is horizontal and is used for placing a lower-layer base material; a base material limiting mechanism; the limiting device is arranged on the upper surface of the platform and is used for limiting the end parts of the laminated lower-layer base material and the upper-layer base material and limiting the displacement of the lower-layer base material and the upper-layer base material in the horizontal direction; the film fixing mechanism comprises a first gasket, a second gasket and a gasket pressing part; the first gasket is arranged on the upper surface of the platform, and the thickness of the first gasket is the same as that of the lower-layer base material located at the bottom; the second gasket is arranged on the first gasket, and the thickness of the second gasket is the same as that of an adhesive layer between the lower-layer base material and the thin film; the gasket pressing part is used for pressing the second gasket and the first gasket to the upper surface of the platform. When the sample preparation tool for the I-type fracture toughness test is used for sample preparation, the accurate position of a film in a sample and the accurate and uniform thickness of an adhesive layer can be ensured, and the tool is simple to operate and high in sample preparation efficiency.

A method for evaluating the toughness reliability of a tank, comprising the steps of: acquiring a required fracture toughness value on the basis of the change over time of a stress amplification factor and the design life of the tank; a step of acquiring a transition temperature of the material from a Charpy transition curve based on a Charpy impact test of the tank; acquiring a fracture toughness value according to a fracture toughness test of the material of the tank; a step for acquiring design tolerance conditions on the basis of the relationship between a temperature index, which is the reciprocal of the difference between each test temperature and the transition temperature, and the fracture toughness value at each test temperature; acquiring a required temperature index according to the design allowable condition and the required fracture toughness value; a step of acquiring an allowable Charpy transition curve having a required transition temperature based on the required temperature index; and a step for evaluating the toughness reliability of the material of the can on the basis of the allowable Charpy transition curve.

This invention belongs to the field of material and structural performance testing technology, specifically relating to a method for estimating the plane strain fracture toughness of materials based on small specimens and energy principles. The method includes the following steps: S1, designing small specimens for fracture toughness testing; S2, conducting fracture toughness testing; S3, analyzing the fracture morphology of the small specimens; S4, calculating the energy consumed per unit area in each region; and S5, calculating the plane strain fracture toughness of the material. The method described in this invention for estimating the plane strain fracture toughness of materials based on small specimens and energy principles can significantly improve the efficiency of obtaining plane strain fracture toughness and save on related experimental costs. Furthermore, the entire process is simple, convenient, and fast, with strong engineering practicality and applicability.

The application discloses a pipeline girth weld fracture toughness testing method, which comprises the following steps: processing a notch and a fatigue pre-crack on a test piece with a predetermined size, wherein the length direction of the test piece is consistent with the axial direction of the pipeline; expanding the fatigue pre-crack at the front end of the notch of the test piece and performing fatigue pre-cracking; after the fatigue pre-cracking reaches a target value, processing a side groove on the test piece; continuously loading the test piece at a constant rate, while monitoring the load and displacement during the loading process; stopping after the test piece reaches a preset degree of crack expansion; during the continuous loading, measuring the crack expansion by using a regularization method; measuring the initial crack length and the final crack length; and inversing the crack length in the crack expansion process according to the measured initial crack length and the final crack length. The application can accurately obtain the fracture toughness of the pipeline girth weld, make the safety evaluation of the pipeline girth weld more accurate, and thus guarantee the safe operation of the pipeline.

A fracture toughness testing machine evaluates fracture toughness of a specimen in pure mode. The testing machine includes: a testing-load applying device for applying a predetermined testing load to the specimen, in which the stresses are present; and a cancelling-load applying device for applying a cancelling load to the specimen to cancel the stresses therein. The cancelling-load applying device includes: a pressing-force applying portion that applies a pressing force to the specimen as the canceling load; and a pressing-force determining portion that determines magnitude of the force. The pressing-force determining portion calculates the magnitude of the force using pre-stored equations so that an energy release rate related to in-plane shear mode crack deformation becomes zero.

The invention belongs to the field of performance prediction of titanium alloy, and particularly relates to a TC11 titanium alloy fracture toughness prediction method considering heat treatment temperature. Comprising the following steps: (1) carrying out double annealing heat treatment on the TC11 titanium alloy at different temperatures, carrying out quasi-static stretching and fracture toughness tests on the TC11 titanium alloy subjected to heat treatment, and recording test data; (2) establishing a TC11 titanium alloy fracture toughness prediction model considering the heat treatment temperature by introducing a correction term of the heat treatment temperature; (3) fitting the prediction model in the step (2) according to test data in the step (1) to obtain values of a basic toughness coefficient m and a temperature sensitivity coefficient n; and (4) verifying the TC11 titanium alloy fracture toughness prediction model. By introducing the heat treatment temperature correction term, the quantitative relation between the heat treatment temperature and the fracture toughness is established, the fracture toughness is predicted, the test cost is reduced, and the material design is optimized.