Determination method for high-temperature multi-axis constitutive relation considering non-proportional additional hardening

A constitutive relation and determination method technology, applied in the field of high-temperature multiaxial fatigue strength theory, can solve problems such as not being able to determine the high-temperature multi-axial constitutive relation well, so as to improve the reliability of life prediction, simple parameter determination, and physical significance clear effect

Active Publication Date: 2018-03-02
BEIJING UNIV OF TECH
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Problems solved by technology

However, there is no constitutive equation to consider the influence of non-proportional additional s

Method used

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  • Determination method for high-temperature multi-axis constitutive relation considering non-proportional additional hardening
  • Determination method for high-temperature multi-axis constitutive relation considering non-proportional additional hardening
  • Determination method for high-temperature multi-axis constitutive relation considering non-proportional additional hardening

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Embodiment Construction

[0037] The present invention will be explained with reference to the drawings.

[0038] The present invention is further illustrated through the high-temperature tensile and torsion multiaxial fatigue test. The test material is Ni-based superalloy GH4169, the loading waveform for strain control is triangular wave, and other loading parameters are shown in Table 1.

[0039] Table 1 Test conditions for high temperature tensile and torsion multiaxial fatigue test

[0040]

[0041] Among them, Δε eq / 2 is the equivalent strain amplitude, Δε x / 2 is the axial strain amplitude, Δγ xy / 2 is the shear strain amplitude, Is the phase angle, f is the frequency, and T is the temperature.

[0042] A method for determining high-temperature multiaxial constitutive relations considering non-proportional additional strengthening, such as figure 1 As shown, the specific calculation method is as follows:

[0043] Step 1): Determine the basic parameters, the determined material parameters are shown in ...

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Abstract

The invention discloses a determination method for a high-temperature multi-axis constitutive relation considering non-proportional additional hardening. The method comprises the steps that (1) basicparameters are determined, a high-temperature multi-axis strain history is read, and back stress deviators and isotropic hardening parameters are assigned to be 0; (2) stress tensors are calculated byuse of the Hooke's law; (3) whether the stress tensors calculated in the step (2) enter an inelastic stage is judged by use of the yield criterion, if the stress tensors are still at an elastic stage, next calculation is performed according to the step (5), and if the stress tensors enter the inelastic stage, next calculation is performed according to the step (4); (4) a value, calculated in thestep (3), of the yield criterion is utilized to calculate accumulated inelastic strain, inelastic strain tensors, elastic strain tensors, back stress deviators and isotropic hardening parameters; and(5) whether loading is completed is judged, if not, the steps (2), (3), (4) and (5) are repeated, and otherwise the high-temperature multi-axis constitutive relation considering non-proportional additional hardening is obtained.

Description

Technical field [0001] The invention belongs to the field of high temperature multiaxial fatigue strength theory, and particularly relates to a method for determining high temperature multiaxial constitutive relations considering non-proportional additional strengthening. Background technique [0002] The hot-end parts of aerospace vehicles, pressure vessels, nuclear power plants, power plants, and vehicles in service are often subjected to high-temperature multi-axis cyclic loads, and due to the complexity of their structure, the weak parts of these hot-end parts are often located Multi-axis non-proportional cyclic loading status. The non-proportional additional strengthening caused by multi-axial non-proportional cyclic loading will affect the validity of the calculations of fatigue damage, creep damage and oxidation damage at high temperatures. Therefore, in order to improve the reliability of life prediction under high-temperature multi-axial loading, it is particularly impo...

Claims

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Application Information

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IPC IPC(8): G06F17/50
CPCG06F30/17G06F2119/06
Inventor 尚德广李道航刘小冬李志高惠杰王金杰
Owner BEIJING UNIV OF TECH
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