Abstract: An anti-fatigue and safety control method for ultra-long life service structures under extreme environment, comprising: judge the fatigue fracture mode in the long life stage of the service structure; according to the interaction principle of defect-matrix, obtain the internal defect induced fatigue cracking mechanism in ultra-high cycle regime under the service environment; considering the environmental factors, clarify the internal defect-matrix-environment interaction mechanism under service conditions and obtain the environmental weakening coefficient; considering the environmental factors, establish a fatigue life prediction model based on defect-load-life correlation under service conditions in ultra-high cycle regime; the process parameters of material metallurgy and manufacturing, design parameters of structural strength, structural service stress and environmental parameters are regulated based on the concept of integrated design/manufacturing.

Abstract: The present disclosure provides a machine vision-based automatic focusing and automatic centering method and system, which belongs to the technical field of machine vision-based automatic control. An object stage is controlled to move in an imaging distance range of an electron microscope, and images scanned by the electron microscope when the object stage is at different imaging distances are acquired. The image definition of an object stage image is calculated according to a gray-scale value of each pixel in the object stage image, the imaging position when an image definition value is the maximum is determined, and the object stage is controlled to move to the position, so as to realize machine vision-based accurate focusing.

Abstract: The application discloses a time-dependent local stress-strain method for high-temperature structural strength and service life analysis. The method is aimed at a load component under high-temperature conditions, and the load component has a structural discontinuity area. The method includes: a step for obtaining working conditions, a step for obtaining material parameters, an elastoplasticity analysis step, a limit analysis step, an elasticity analysis step, a boundary condition setting step, an iterative operation step, and a result integration step. The application also discloses time-dependent local stress-strain tool software for high-temperature structural strength and service life analysis. The tool software includes: a parameter acquisition assembly, a finite element modeling and operation assembly, an iterative operation assembly, and a result display assembly.

Abstract: A creep strength analysis and assessment method includes comparing whether a maximum value of a local strain and a membrane strain are less than a corresponding allowable strain, and if less, determining that a component is safe; otherwise, performing the following steps: performing stress linearization on a path to obtain a local primary membrane stress PL and a local primary bending stress Pb; averaging shear stress components on the path to obtain an average shear stress ?m; obtaining a strength limit Smt, a time-independent minimum stress strength value Sm and a temperature- and time-dependent stress strength limit St for a given material, a design lifetime and a design temperature; comparing whether PL, PL+Pb and PL+Pb/Kt are less than Smt, KSm and St; and comparing whether ?m is less than 0.6Sm and 0.6St, and if less, the component is safe, otherwise, the component is unsafe.

Abstract: The disclosure relates to a dual-criterion diagram for designing and assessing the life and strength of high-temperature rotating components and its establishment. In addition, the disclosure relates to a method for designing and assessing the life and strength of high-temperature rotating components based on the dual-criterion diagram for designing and assessing the life and strength of high-temperature rotating components. The advantages of the disclosure include a simple design and assessment process, high operability, and reliable assessment results. The invention is expected to be applied finally to assessment and evaluation of high-cycle fatigue life of rotating components at high temperatures.

Abstract: A creep strength analysis and assessment method includes comparing whether a maximum value of a local strain and a membrane strain are less than a corresponding allowable strain, and if less, determining that a component is safe; otherwise, performing the following steps: performing stress linearization on a path to obtain a local primary membrane stress PL and a local primary bending stress Pb; averaging shear stress components on the path to obtain an average shear stress ?m; obtaining a strength limit Smt, a time-independent minimum stress strength value Sm and a temperature- and time-dependent stress strength limit St for a given material, a design lifetime and a design temperature; comparing whether PL, PL+Pb and PL+Pb/Kt are less than Smt, KSm and St; and comparing whether ?m is less than 0.6Sm and 0.6St, and if less, the component is safe, otherwise, the component is unsafe.

Abstract: The disclosure relates to a dual-criterion diagram for designing and assessing the life and strength of high-temperature rotating components and its establishment. In addition, the disclosure relates to a method for designing and assessing the life and strength of high-temperature rotating components based on the dual-criterion diagram for designing and assessing the life and strength of high-temperature rotating components. The advantages of the disclosure include a simple design and assessment process, high operability, and reliable assessment results. The invention is expected to be applied finally to assessment and evaluation of high-cycle fatigue life of rotating components at high temperatures.

Abstract: The invention relates to a design method of high-temperature nickel-based bolts based on damage tolerance theory, comprising the following steps: S1: acquiring operating parameters for the design; S2: selecting a material for bolts; S3: acquiring mechanical properties of the materials; S4: determining a pretension stress ?p of a single bolt; S5: determining the service stress ?s under the steady state; S6: determining the number n, the effective cross-section area A and the distribution of bolts; S7: determining a maximum allowable crack dimension; S8: calculating the maximum allowable service stress ?th using the crack propagation threshold Kth at the design temperature; S9: comparing the service stress ?s and the maximum allowable service stress ?th, if ?s is smaller than ?th, then the bolts are safe in the design life; otherwise, return to step S4 and reduce the pretension stress ?p.

Abstract: Disclosed is a method of measurement and determination on fracture toughness of structural materials at high temperature, comprising: preliminary assessing the ductility of a material based on a high-temperature uniaxial tensile test and the fracture characteristic; designing and manufacturing a CT specimen; conducting a monotonic loading fracture test on the CT specimen at high temperature; modifying a load-displacement curve output by a testing machine; determining a passivation coefficient M for the crack of the structural material; reversely recursing instant load-displacement data pairs corresponding to the instant crack length; calculating a J_R crack extension resistance curve of the tensile test; examining the validity of the J_R crack extension resistance curve and the fracture toughness JIC; calculating the fracture toughness per equivalent of the structural material KIC. The present invention overcomes the difficulty of placing an extensometer inside a high-temperature furnace.

Abstract: A calibration method for brittle fracture assessment parameters for pressure vessel materials based on the Beremin model includes selecting at least two types of specimens of different constraints, and calculating the fracture toughness values K0 corresponding to 63.2% failure probability for each type of specimens at a same calibration temperature by using the respective fracture toughness data. The method proceeds by obtaining the stress-strain curve of the material at the calibration temperature, generating finite element models for each type of specimens, and calculating the maximum principal stress and element volume of every element at K=K0 in each model. A series of values of m are assumed to compute a group of ?u values for each type of specimens, and then m˜?u curves are plotted for each type of specimens. Brittle fracture assessment parameters are then determined for the material according to the coordinates of the intersection of the m˜?u curves.

Abstract: The invention relates to a design method of high-temperature nickel-based bolts based on damage tolerance theory, comprising the following steps: S1: acquiring operating parameters for the design; S2: selecting a material for bolts; S3: acquiring mechanical properties of the materials; S4: determining a pretension stress ?p of a single bolt; S5: determining the service stress ?s under the steady state; S6: determining the number n, the effective cross-section area A and the distribution of bolts; S7: determining a maximum allowable crack dimension; S8: calculating the maximum allowable service stress ?th using the crack propagation threshold Kth at the design temperature; S9: comparing the service stress ?s and the maximum allowable service stress ?th, if ?s is smaller than ?th, then the bolts are safe in the design life; otherwise, return to step S4 and reduce the pretension stress ?p.

Abstract: A manufacturing method for a high-temperature-resistant metal-packaged fiber Bragg grating sensor includes using a regenerated fiber Bragg grating obtained via high-temperature annealing as a sensitive element so that the grating will not be erased when used at high temperature. The method also includes using a magnetron sputtering method which makes an optical fiber and metal combine better to form on the surface of the optical fiber an adhesive layer and a conductive layer, thereby causing little damage to optical fiber because of the absence of the processes of coarsening, sensitization, etc. of electroless plating and the fact that the method is performed in an anhydrous environment. After magnetron sputtering, the method includes using an electroplating method to thicken and deposit a protective layer, and embedding the optical fiber in a flexible-structure metallic substrate through the electroplating method to achieve the all-metal package.

Abstract: Disclosed is a method of measurement and determination on fracture toughness of structural materials at high temperature, comprising: preliminary assessing the ductility of a material based on a high-temperature uniaxial tensile test and the fracture characteristic; designing and manufacturing a CT specimen; conducting a monotonic loading fracture test on the CT specimen at high temperature; modifying a load-displacement curve output by a testing machine; determining a passivation coefficient M for the crack of the structural material; reversely recursing instant load-displacement data pairs corresponding to the instant crack length; calculating a J_R crack extension resistance curve of the tensile test; examining the validity of the J_R crack extension resistance curve and the fracture toughness JIC; calculating the fracture toughness per equivalent of the structural material KIC. The present invention overcomes the difficulty of placing an extensometer inside a high-temperature furnace.

Abstract: A manufacturing method for a high-temperature-resistant metal-packaged fiber Bragg grating sensor includes using a regenerated fiber Bragg grating obtained via high-temperature annealing as a sensitive element so that the grating will not be erased when used at high temperature. The method also includes using a magnetron sputtering method which makes an optical fiber and metal combine better to form on the surface of the optical fiber an adhesive layer and a conductive layer, thereby causing little damage to optical fiber because of the absence of the processes of coarsening, sensitization, etc. of electroless plating and the fact that the method is performed in an anhydrous environment. After magnetron sputtering, the method includes using an electroplating method to thicken and deposit a protective layer, and embedding the optical fiber in a flexible-structure metallic substrate through the electroplating method to achieve the all-metal package.

Abstract: The present invention relates to an extensometer for measuring high-temperature structural deformations by magnification, the structure of the extensometer is that: two mounting block assemblies are mounted at the planar ends of two extension bars respectively, the top ends of the extension bars are connected tightly with the surface of a test piece, two connecting pieces are mounted at the inner sides of the two mounting block assemblies respectively, a deformation magnifying mechanism and a sensor bracket are mounted on the connecting pieces, a sensor is mounted on the sensor bracket, two connecting pieces are mounted on a same straight line, and the straight line is parallel to a straight line at which the top ends of the two extension bars are located, so as to ensure that the deformation of the test piece is delivered equally to the deformation magnifying mechanism on the connecting pieces.

Abstract: A calibration method for brittle fracture assessment parameters for pressure vessel materials based on the Beremin model includes selecting at least two types of specimens of different constraints, and calculating the fracture toughness values K0 corresponding to 63.2% failure probability for each type of specimens at a same calibration temperature by using the respective fracture toughness data. The method proceeds by obtaining the stress-strain curve of the material at the calibration temperature, generating finite element models for each type of specimens, and calculating the maximum principal stress and element volume of every element at K=K0 in each model. A series of values of m are assumed to compute a group of ?u values for each type of specimens, and then m˜?u curves are plotted for each type of specimens. Brittle fracture assessment parameters are then determined for the material according to the coordinates of the intersection of the m˜?u curves.

Abstract: The present invention relates to an extensometer for measuring high-temperature structural deformations by magnification, the structure of the extensometer is that: two mounting block assemblies are mounted at the planar ends of two extension bars respectively, the top ends of the extension bars are connected tightly with the surface of a test piece, two connecting pieces are mounted at the inner sides of the two mounting block assemblies respectively, a deformation magnifying mechanism and a sensor bracket are mounted on the connecting pieces, a sensor is mounted on the sensor bracket, two connecting pieces are mounted on a same straight line, and the straight line is parallel to a straight line at which the top ends of the two extension bars are located, so as to ensure that the deformation of the test piece is delivered equally to the deformation magnifying mechanism on the connecting pieces.