Load spectrum simplification method for aircraft construction crack extension test

A technology for crack propagation test and aircraft structure, applied in the field of load spectrum simplification for crack propagation test of aircraft structure, can solve problems such as increasing development cost, restricting aircraft development time, long fatigue test cycle, etc., achieving large engineering application value and shortening the test. The effect of cycle and method is simple and easy to implement

Active Publication Date: 2014-09-10
CHINA AIRPLANT STRENGTH RES INST
View PDF3 Cites 25 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, in the prior art aviation fatigue/crack growth test, due to the complexity of the crack growth of aviation metal materials, the fati

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
  • Load spectrum simplification method for aircraft construction crack extension test
  • Load spectrum simplification method for aircraft construction crack extension test
  • Load spectrum simplification method for aircraft construction crack extension test

Examples

Experimental program
Comparison scheme
Effect test

Example Embodiment

[0031] The present invention will be described in further detail below by means of specific embodiments:

[0032] see figure 1 , which is the simplification method of the load spectrum for the crack growth test of the aircraft structure of the present invention-the segmental processing relationship diagram of the typical crack growth curve. The main characteristic parameters of the load spectrum simplification method for the aircraft structure crack growth test of the present invention include the crack growth threshold ΔK th , crack tip stress intensity factor K, half-crack length a, load spectrum.

[0033] During the whole process of crack growth, based on the idea of ​​low load interception combined with DK th , K and a cut off the load spectrum in sections, by figure 1 It can be seen that the load spectrum loaded at each stage is different.

[0034] see figure 2 , which is a flow chart of the load spectrum simplification method for the aircraft structure crack growth...

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 load spectrum simplification method for an aircraft construction crack extension test. The load spectrum simplification method comprises the following steps: (1) determining the structural type of a crack extension test piece and a material containing a crack part, and determining the fatigue crack extension threshold value deltaKth of the material; (2) determining a stress intensity factor of a crack tip of the material; (3) estimating the crack length in the crack extension test and processing in a segmenting manner; (4) deleting the stress cycle lower than the fatigue crack extension threshold value in a load spectrum according to the segmentation condition to form a load spectrum corresponding to the lengths of the segments of the crack, and finally applying the load spectrum in the crack extension test. The load spectrum simplification method disclosed by the invention is used for determining the cark tip stress intensity factor value of a crack-containing structure and simplifying the load spectrum for the crack extension test in the segmenting manner in combination with the fatigue crack extension threshold value deltaKth of the material, so that the load spectrum can be directly applied in the aircraft construction crack extension test, and the method is simple and feasible and is capable of effectively shortening the test period.

Description

technical field [0001] The invention belongs to the aircraft load spectrum loading technology, and relates to a load spectrum simplification method for the crack growth test of an aircraft structure. Background technique [0002] With the vigorous development of the domestic aviation industry, more and more civilian / military aircraft need to undergo fatigue / crack growth tests, and the test cycle is generally relatively long, which seriously restricts the development time of the aircraft, and is also a waste of manpower and financial resources. [0003] For a long time, the idea of ​​shortening the test period by simplifying the load spectrum has been continued. On this basis, low-load interception, high-load interception technology, and simplified constant-amplitude spectrum have been formed. Among them, the idea of ​​low-load cut-off technology is to cut off the load levels in the load spectrum that do not contribute to crack growth, thereby reducing the number of load leve...

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): G01N3/00G06F19/00
Inventor 张侃庞宝才闫文伟臧伟锋许飞
Owner CHINA AIRPLANT STRENGTH RES INST
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
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap