9 results about "Creep fatigue" patented technology

The present application relates to the technical field of high-temperature component creep fatigue test and life assessment, and particularly relates to a high-temperature structure deformation accumulation dynamic creep fatigue load design method under a peak regulation working condition. High-temperature creep performance, cyclic deformation performance, a target test temperature, a typical start-stop number or equivalent cycle number, a main load level range during steady operation, and basic parameters of stress / strain control capability of a testing machine of a target high-temperature structure or a sample thereof are obtained. A stress / strain hybrid control mode is used to generate a dynamic creep fatigue load waveform of the high-temperature structure or the sample thereof. When a dynamic creep fatigue load is executed on a creep fatigue testing machine and a cycle feature meets preset stability and repeatability criteria, the load design is determined to be effective. The present application is easy to implement on existing equipment: the designed load waveform can be realized through software control on a creep fatigue testing machine with stress / strain double closed loop and program loading function, without the need to increase additional hardware, and the engineering operability is strong.

The application provides an aero-engine part creep-fatigue life design method. A part finite element model is established, mission profile stress analysis is carried out to obtain the principal stress cycle peak stress σ max and the principal stress cycle stress ratio R of the dangerous position of the part; a creep-fatigue interaction judgment criterion is established by using the relationship between (1-R)*σ max and twice the material proportional limit 2σ s ; a creep-fatigue damage interaction envelope line of the part is established; the creep-fatigue life of the dangerous position of the part is calculated based on the relationship between (1-R)*σ max and 2σ s . The relationship between (1-R)*σ max and 2σ s is used as the judgment criterion, the constraint relationship of temperature and load on the creep-fatigue interaction effect is comprehensively considered; the creep-fatigue interaction damage limit with reliability indexes is determined through the interaction damage envelope line with specific confidence and survival rate requirements; the creep-fatigue life calculation method considers the influence of stress relaxation on creep damage and fatigue damage in the cycle process, and the applicability of the analysis method under different stress states is ensured.

The application discloses a turbine disc creep-fatigue test load determination method and belongs to the technical field of aero-engines. The method comprises the following steps: performing transient stress and creep analysis on a turbine disc, calculating fatigue damage components and creep damage components in each stage, and accumulating total fatigue damage values and total creep damage values in a complete flight cycle; determining a flight state with the maximum total damage as a standard cycle; taking the standard cycle as the only reference, a complete set of test parameters are determined: the maximum creep damage state temperature is set as a test temperature, the maximum stress is used to determine a test rotating speed, the test cycle number is determined by backstepping, and the peak value holding time is determined by backstepping. The application realizes the cooperative and accurate design of thermal-mechanical loads, ensures that the test highly simulates actual working conditions, and provides a scientific basis for engine life determination.

The invention discloses a test method for creep fatigue performance of a turbine disc mortise. The test method comprises the following steps: manufacturing a first simulation piece and a second simulation piece to simulate the mortise bottom and the mortise bottom angle of a turbine disc; the first simulation piece comprises a first fixed section, a first middle section and a second fixed section which are connected in sequence, the first middle section comprises a first transition section, a second transition section and a first working section, the first working section comprises a first groove and a second groove which are arranged at an interval in the width direction, and the first groove and the second groove are arc-shaped grooves; the second simulation piece comprises a third fixed section, a second middle section and a fourth fixed section which are connected in sequence, the second middle section comprises a third transition section, a fourth transition section and a second working section, the second working section comprises a third groove and a fourth groove which are arranged at an interval in the width direction, and the third groove and the fourth groove are V-shaped grooves; and carrying out creep fatigue performance test on the first simulation piece and the second simulation piece to obtain creep fatigue performance data of the turbine disc mortise.

This invention discloses a method and system for life health management of HR3C materials, relating to the field of data processing technology. The method includes: collecting operational condition data of HR3C materials under service conditions; conducting creep, fatigue, and creep-fatigue interaction performance tests on welds and heat-affected zones to obtain real-time service condition data; constructing a microstructure-performance coupling model based on the results of high-temperature accelerated aging tests; and performing micro-damage calculations and remaining life prediction based on the microstructure-performance coupling model and real-time service condition data, generating a health assessment index to perform health management. This invention solves the technical problems of existing technologies being unable to accurately and in real-time assess the damage evolution of HR3C materials under complex high-temperature conditions, and the insufficient accuracy of life prediction and health management. It achieves the technical effect of accurately assessing micro-damage and dynamically predicting remaining life through performance coupling analysis under multiple operating conditions and feedback from the aging process, thereby improving the accuracy of health management.

This invention relates to a method for simulating waveforms and predicting the remaining service life of high-temperature components under overload damage, belonging to the field of material life prediction technology under complex high-temperature loads. The steps are as follows: under the same temperature and load-holding stress conditions, the creep fatigue cycle life of the material is determined through two sets of repeated stress-strain mixed-controlled creep fatigue interactive tests; a creep fatigue damage evolution equation considering the overload effect is constructed based on the proportion of the creep fatigue cycle life; a viscoplastic constitutive model coupled with continuous damage mechanics is established; the viscoplastic constitutive model coupled with continuous damage mechanics is solved in the UMAT subroutine of the ABAQUS platform; and the remaining creep fatigue life of the component is calculated using the viscoplastic constitutive model in the ABAQUS platform. This invention, through the designed HCFIO overload damage simulation waveform, accurately reproduces the entire overload-holding-recovery service process of high-temperature components under single-failure conditions, solving the problem that existing tests cannot simulate real overload scenarios.

This invention relates to a steam generator joint strength design method and system based on a linear matching method. The method includes: obtaining design parameters of the tube sheet joint; obtaining mechanical property parameters of different material types of the tube sheet joint under different temperature loads; obtaining the expanded joint model; obtaining the temperature field distribution of the tube sheet joint in each operating condition; importing information such as load conditions and material properties to establish a cyclic finite element model; conducting finite element analysis under service conditions based on the linear matching method to obtain the stress-time curve and strain-time curve of the tube sheet joint in steady-state cycles; determining the most dangerous location of the tube sheet joint; determining the creep damage at the most dangerous location in steady-state cycles; determining the fatigue damage at the most dangerous location in steady-state cycles; determining the allowable creep-fatigue cycles at the most dangerous location; and determining whether the tube sheet joint meets the creep-fatigue strength design requirements.

This invention relates to the technical field of materials mechanics testing, and provides a creep-fatigue testing device and method for determining test parameters for thin-walled tube structures. The device includes: a clamping assembly, a rigid inner plug, a split outer clamp, and a positioning pin; the rigid inner plug is connected to an external loading system via a connecting structure; a temperature control assembly, including a heating mechanism and a cooling mechanism; the heating and cooling mechanisms are arranged along the axial direction of the thin-walled tube structure to form a gauge-length heating zone and a clamping cooling zone; and a measurement assembly for acquiring the axial deformation parameters and temperature parameters of the thin-walled tube structure during the test. This invention balances clamping stability and specimen integrity, allowing direct creep-fatigue testing of thin-walled tube structures while fully preserving the inherent shape, size, and stress distribution characteristics of the thin-walled tube structure; it achieves precise zonal control of damage modes, constructing a differentiated damage system on a single thin-walled tube structure, and accurately controlling the damage evolution rate in each region.

This invention relates to the field of life assessment and load spectrum compilation technology for high-temperature components of aero-engines, and provides a time-domain cyclic counting method for creep-fatigue loads on turbine disks. The method includes: preprocessing the measured load-time history; simplifying the preprocessed load history using trapezoidal wave equivalence; dividing the load history based on the rainflow counting method; extracting the load-holding parameters for each cycle based on the division results; and outputting all parameters of the time-domain load sequence of creep-fatigue interaction effects. This invention enables the output cyclic sequence to accurately reflect the creep-fatigue interaction effects experienced by the turbine disk in actual service; it has clear logical definitions and repeatable operation procedures, significantly improving the processing efficiency and engineering applicability of complex load spectra for high-temperature components such as turbine disks.