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Method for modeling high-temperature multi-axis stress and strain relationship under tension and torsion loads

A technique of stress-strain, modeling method, applied in the field of fatigue strength

Active Publication Date: 2017-05-31
BEIJING UNIV OF TECH
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Problems solved by technology

[0003] At present, the stress-strain model at high temperature is mainly solved by using the Ramberg-Osgood formula, but this model can only describe the constant-amplitude stress-strain relationship in the stable stage, and each set of parameters can only correspond to one loading rate

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  • Method for modeling high-temperature multi-axis stress and strain relationship under tension and torsion loads
  • Method for modeling high-temperature multi-axis stress and strain relationship under tension and torsion loads
  • Method for modeling high-temperature multi-axis stress and strain relationship under tension and torsion loads

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Embodiment Construction

[0032] The specific embodiment of the present invention will be described with reference to the accompanying drawings.

[0033] The present invention is further illustrated by uniaxial and tension-torsion tests at high temperatures. The test material is GH4169, the material of the turbine disk of an aero-engine, and the test temperature is 650°C. The test adopts strain loading, and the loading waveform is a triangular wave.

[0034] A high-temperature multiaxial stress-strain relationship modeling method under tension-torsion loading, the specific implementation method is as follows:

[0035] Step 1): Use the uniaxial test data to fit the model parameters. The fitted parameter values ​​are shown in Table 1, and the uniaxial stress-strain hysteresis loop is used for verification. The verification effect is shown in figure 2 ;

[0036] Table 1 Fitting parameters using uniaxial high temperature test data

[0037] E k Z n Q b a1 a2 C1 C2 178000 400 2425 ...

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Abstract

The invention discloses a method for modeling high-temperature multi-axis stress and strain relationship under tension and torsion loads. The method comprises the following steps of utilizing single-axis test data to fitting model parameters, and utilizing a single-axis stress and strain hysteresis loop to verify; analyzing the stress and strain states of each multi-axis component under the tension and tension loads; refining the loading process into enough load steps, and utilizing a yield criterion to judge whether each load step is elastic loading or non-elastic loading; for elastic loading step, utilizing an elastic matrix and a Hooke's law multi-axis type to solve the multi-axis stress states; for plastic loading step, utilizing a stress return algorithm to calculate the multi-axis strain increment, and utilizing a radial backflow method to solve the multi-axis stress state; according to the model predicting result and the stress and strain hysteresis loop drawn by the high-temperature tension and torsion test results, finding that the plastic strain and stress peak and valley values are close to the loop shape. After proofing by predicting results, the method can well calculate the high-temperature multi-axis stress and strain relationship under tension and torsion loads.

Description

technical field [0001] The invention relates to the field of fatigue strength, in particular to a multiaxial stress-strain relationship modeling method at high temperature. Background technique [0002] The multiaxial fatigue strength design at high temperature is an important content in the strength design of high temperature components such as aero-engines and gas turbines. For example, the turbine disk of an engine in actual service has to bear huge centrifugal force and axial force at high temperature, so its dangerous parts are in a state of multiaxial stress and strain at high temperature. Studying the multiaxial stress-strain constitutive relationship of engine turbine disk materials at high temperature is of great significance for engine safety performance monitoring and fatigue life prediction. [0003] At present, the stress-strain model at high temperature is mainly solved by using the Ramberg-Osgood formula, but this model can only describe the constant-amplitud...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G01N3/32
CPCG01N3/32G01N2203/0005G01N2203/0026G01N2203/0073G01N2203/0075G01N2203/0266G01N2203/0676G01N2203/0682
Inventor 尚德广王巨华李道航任艳平李芳代
Owner BEIJING UNIV OF TECH
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