Eureka AIR delivers breakthrough ideas for toughest innovation challenges, trusted by R&D personnel around the world.

Low cycle fatigue life prediction method based on asymmetrical cyclic stress control load

A technology of cyclic stress and low cycle fatigue, which is applied in the direction of applying repetitive force/pulsation force to test the strength of materials, and can solve problems such as inability to accurately predict low cycle fatigue life estimation

Inactive Publication Date: 2013-03-13
CENT SOUTH UNIV
View PDF4 Cites 28 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] The purpose of the present invention is to provide a method for predicting the low-cycle fatigue life of materials under non-symmetrical cyclic stress control loading, which solves the current problem of inability to accurately predict the low-cycle fatigue life of materials under the action of asymmetric cyclic stress

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Low cycle fatigue life prediction method based on asymmetrical cyclic stress control load
  • Low cycle fatigue life prediction method based on asymmetrical cyclic stress control load
  • Low cycle fatigue life prediction method based on asymmetrical cyclic stress control load

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0026] The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0027] The present invention is a method for predicting the low-cycle fatigue life of metal materials under the condition of asymmetric cyclic stress control. Taking the low-cycle fatigue life prediction of AZ91 magnesium alloy material as an example, the implementation details of the life prediction method involved in the present invention will be introduced in detail , whose methods include:

[0028] Step 1: A low cycle fatigue experiment based on asymmetric cyclic stress control is carried out on AZ91 magnesium alloy material (rolling direction sampling), and the step of obtaining its low cycle fatigue life;

[0029] The parameters of cyclic loading conditions include peak stress and stress ratio. The peak stress ranges from 124.0MPa to 262.6MPa, and the stress ratio ranges from -0.4 to 0.4. The peak stresses are 140MPa, 160MPa, 180MPa, 20...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention discloses a low cycle fatigue life prediction method for metal material and based on asymmetrical cyclic stress control load. The method comprises the following steps: (1) acquiring a low cycle fatigue life of a metal material through fatigue experiments of asymmetrical cyclic stress control; (2) according to working conditions of the fatigue experiments and fatigue properties of the material, determining a function relationship of fatigue strength coefficient sigma' f, fatigue strength exponent b, and the peak stress and tensile limit of the material; and (3) establishing a prediction model of low cycle fatigue life of the metal material under asymmetric cyclic stress control conditions, and predicting fatigue life of the material. The method provided by the invention can quickly predict the fatigue life of the metal material under asymmetric cyclic stress load conditions, and provides a theoretical reference for the reliable design and evaluation of parts.

Description

technical field [0001] The invention relates to a method for predicting low-cycle fatigue life of metal materials under the service condition of asymmetric stress cycle stress. Background technique [0002] Fatigue failure is one of the main failure modes of various materials / components. According to statistics, the damage of more than 80% of components is caused by fatigue fracture. The mechanical properties of metal materials, especially the fatigue properties, have attracted much attention. In recent years, research on the fatigue properties of metal materials has become a hot topic. The phenomenon of plastic strain accumulation in materials / components under cyclic stress-controlled loading is known as the ratcheting effect. Although the amount of plastic deformation produced by the material / component in each cycle loading may be small, the accumulated plastic deformation amount cannot be ignored as the cycle progresses, which may directly lead to a large internal deform...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
IPC IPC(8): G01N3/32
Inventor 蔺永诚陈小敏刘正华陈明松
Owner CENT SOUTH UNIV
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Eureka Blog
Learn More
PatSnap group products