Statistical Treatment of Crack Propagation Data

2001 ◽  
Author(s):  
R. A. Heller
AIAA Journal ◽  
1984 ◽  
Vol 22 (10) ◽  
pp. 1485-1490 ◽  
Author(s):  
F. Hikami ◽  
T. W. Chou

Author(s):  
Ilya I. Kudish

A unified model of fatigue that is applicable to a variety of mechanical in nature fatigue phenomena including contact and structural fatigue is introduced. The model considers two- and three-dimensional stress states. The model is based on crack mechanics, kinetics of crack propagation, and statistical treatment of material defects. The foundation of the model follows from the analysis [1, 2], a model of contact fatigue [3], and the asymptotic formulas for the stress intensity coefficients (see [4]) developed earlier. The model takes into account the local stress distribution, initial statistical distribution of defects versus their size, defect location and crack propagation directions related to the specific stress state of the material, material fatigue resistance parameters, etc. The main assumptions used for the model derivation and their validity are discussed.


2020 ◽  
Vol 21 (6) ◽  
pp. 610
Author(s):  
Xiaoliang Cheng ◽  
Chunyang Zhao ◽  
Hailong Wang ◽  
Yang Wang ◽  
Zhenlong Wang

Microwave cutting glass and ceramics based on thermal controlled fracture method has gained much attention recently for its advantages in lower energy-consumption and higher efficiency than conventional processing method. However, the irregular crack-propagation is problematic in this procedure, which hinders the industrial application of this advanced technology. In this study, the irregular crack-propagation is summarized as the unstable propagation in the initial stage, the deviated propagation in the middle stage, and the non-penetrating propagation in the end segment based on experimental work. Method for predicting the unstable propagation in the initial stage has been developed by combining analytical models with thermal-fracture simulation. Experimental results show good agreement with the prediction results, and the relative deviation between them can be <5% in cutting of some ceramics. The mechanism of deviated propagation and the non-penetrating propagation have been revealed by simulation and theoretical analysis. Since this study provides effective methods to predict unstable crack-propagation in the initial stage and understand the irregular propagation mechanism in the whole crack-propagation stage in microwave cutting ceramics, it is of great significance to the industrial application of thermal controlled fracture method for cutting ceramic materials using microwave.


Metrologiya ◽  
2020 ◽  
pp. 16-24
Author(s):  
Alexandr D. Chikmarev

A single program has been developed to ensure that the final result of the data processing of the measurement calibration protocol is obtained under normal conditions. The calibration result contains a calibration function or a correction function in the form of a continuous sedate series and a calibration chart based on typical additive error probabilities. Solved the problem of the statistical treatment of the calibration protocol measuring in normal conditions within a single program “MMI–calibration 3.0” that includes identification of the calibration function in a continuous power series of indications of a measuring instrument and chart calibration. An example of solving the problem of calibration of the thermometer by the working standard of the 3rd grade with the help of the “MMI-calibration 3.0” program.


2014 ◽  
Vol 52 (4) ◽  
pp. 283-291 ◽  
Author(s):  
Gwan Yeong Kim ◽  
Kyu Sik Kim ◽  
Joong Cheol Park ◽  
Shae Kwang Kim ◽  
Young Ok Yoon ◽  
...  

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