Method for obtaining J resistance curve of ductile material by I type crack elastoplasticity theoretical equation

A technology of resistance curve and ductile material, which is applied in the direction of analyzing materials, testing material strength by applying stable bending force, testing material strength by applying stable tension/compression, etc. The process is cumbersome and other problems, to achieve the effect of easy popularization and application, solid theoretical foundation, and clear physical meaning

A technology of resistance curve and ductile material, which is applied in the direction of analyzing materials, testing material strength by applying stable bending force, testing material strength by applying stable tension/compression, etc. The process is cumbersome and other problems, to achieve the effect of easy popularization and application, solid theoretical foundation, and clear physical meaning

CN108548720AInactive Publication Date: 2018-09-18SOUTHWEST JIAOTONG UNIV
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  • Method for obtaining J resistance curve of ductile material by I type crack elastoplasticity theoretical equation
  • Method for obtaining J resistance curve of ductile material by I type crack elastoplasticity theoretical equation
  • Method for obtaining J resistance curve of ductile material by I type crack elastoplasticity theoretical equation

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Embodiment Construction

[0031] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0032] The invention includes two parts: round bar uniaxial tension test and I-type crack sample test, J integral calculation principle-finite element model.

[0033] 1. Round bar uniaxial tensile test and type I crack test

[0034] Carry out round bar uniaxial tensile test on ductile materials to obtain their true stress-strain curves, and then use the fracture toughness test method recommended by the national standard GB / T21143-2014 to carry out the fracture toughness test of CT specimens. The specimen width W=50mm, thickness B =25mm, the crack length a / W is between 0.5 and 0.8, and the P-h test curve of the sample is obtained by stretching.

[0035] 2. Calculation principle of J integral - finite element model

[0036] figure 2 The three-dimensional finite element simulation model of the CT sample is given. Through theoretical ...

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Abstract

The invention discloses a method for obtaining the J resistance curve of a ductile material by an I type crack elastoplasticity theoretical equation. The method comprises the following steps: performing tensile or bending test on an I type through crack sample to obtain the P-h curve of the sample, substituting the P-h curve into the elastoplasticity theoretical equation to obtain the real-time crack length and J integral of the sample corresponding to any loading point, and performing crack propagation correction on the J integral result by an incremental technology to obtain the J resistancecurve of the material. The method avoids an error caused by the approximate solution of the plastic factor eta p during the calculation of the J integral by using traditional test methods, and is convenient to carry out the fracture toughness test of the ductile material at a high temperature, under irradiation or in other special environments.

Description

technical field [0001] The invention relates to the theory and method of fracture toughness testing of ductile materials, and is especially convenient for testing the fracture toughness of materials in special environments such as high temperature, and specifically relates to a method for obtaining the J resistance curve of ductile materials with the elastic-plastic theoretical formula of type I cracks. Background technique [0002] In nuclear power, petrochemical, aerospace and other fields, there are a large number of components that serve under high temperature, high pressure, radiation and other conditions. As time goes by, the materials will inevitably undergo corrosion, oxidation and other phenomena, resulting in material degradation and damage. Carrying out the fracture toughness test of service materials is of great significance to the reliability and safety assessment of structures. [0003] After years of development, there are many classic fracture toughness testi...

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Application Information

Patent Timeline
18 Sep 2018
Publication
CN108548720A
IPC
G01N3/08; G01N3/18; G01N3/20
CPC
G01N3/08; G01N3/18; G01N3/20; G01N2203/0017; G01N2203/0023; G01N2203/0062
Inventors
蔡力勋; 彭云强