3903 Measurements of Crack Opening Displacement Distribution using Digital Image Correlation Method and Evaluation of Fatigue Crack Propagation Rate

2006 ◽  
Vol 2006.1 (0) ◽  
pp. 837-838
Author(s):  
Kensaku SHINOHARA ◽  
Tashiyuki TORII ◽  
Kouichi NAMBA ◽  
Kenichi SHIMIZU
Keyword(s):  
Fatigue Crack ◽  
Digital Image Correlation ◽  
Digital Image ◽  
Crack Opening ◽  
Correlation Method ◽  
Crack Propagation Rate ◽  
Propagation Rate ◽  
Image Correlation ◽  
Fatigue Crack Propagation Rate ◽  
Opening Displacement

scholarly journals Material Test on Strain Fracture and Crack Opening Displacement Based on Digital Image Correlation Method

2016 ◽  
Vol 62 (3) ◽  
pp. 3-22
Author(s):  
J. Bian ◽  
Zx. Ge
Keyword(s):  
Residual Stress ◽  
Digital Image Correlation ◽  
Digital Image ◽  
Fracture Property ◽  
Stress Measurement ◽  
Crack Opening ◽  
Welding Residual Stress ◽  
Image Correlation ◽  
Correlation Technique ◽  
Opening Displacement

Abstract As a machining technology, welding can cause serious accidents by overloading or operation mistakes. Through analyzing the causes of various welding accidents, we found that the major cause for damage imposed after welding parts are loaded is the fracture of materials. Therefore, studying the influence of welding residual stress on the fracture property of materials is of great significance. This paper applied the digital image correlation technique to study the fracture property of welding parts under the influence of welding residual stress. In addition, standard parts and welding parts were selected to carry out a contrast experiment. Room temperature tensile tests were performed on both standard parts and test pieces after residual stress measurement. Using displacement field and strain field data obtained through VIC-2D software, the stress intensity factor around the crack tip of each specimen under the conditions of small load was calculated and corresponding analysis was carried out.

scholarly journals Digital Image Correlation (DIC) Technique for Fatigue Crack Growth Analysis Using ∆CTOD Criteria

2018 ◽  
Vol 7 (4.38) ◽  
pp. 1362
Author(s):  
Akshay B. Patil ◽  
Suraj P. Toppo ◽  
Dr. RKP Singh
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Digital Image Correlation ◽  
Crack Growth ◽  
Digital Image ◽  
Crack Tip ◽  
Image Correlation ◽  
Crack Tip Opening Displacement ◽  
Opening Displacement ◽  
Crack Tip Opening

The present paper deals with an experimental determination of fatigue crack growth rate (FCGR) of microalloyed steel (38MnVS6) to study the crack propagation in forged automobile crankshafts. The criterion based on crack tip opening displacement range (∆CTOD) is used to investigate the fatigue crack growth rate. In the current work use of 2D-digital image correlation (DIC) technique for the measurement of crack tip opening displacement (CTOD) and crack length (a) is proposed. Digital Image Correlation (DIC) is a full field displacement and strain measurement technique. It is easier to measure the crack tip opening displacement (CTOD) and crack length (a) with this technique than other. Fatigue crack growth curve based on crack tip opening displacement (CTOD) criteria is presented using DIC.  

Effects of Grain Size on Fatigue Crack Propagation in Copper Film

2010 ◽  
Vol 452-453 ◽  
pp. 289-292
Author(s):  
Kenichi Shimizu ◽  
Tashiyuki Torii
Keyword(s):  
Grain Size ◽  
Fatigue Crack ◽  
Crack Propagation ◽  
Crack Opening Displacement ◽  
Fatigue Crack Propagation ◽  
Fatigue Cracks ◽  
Crack Opening ◽  
Crack Propagation Rate ◽  
Propagation Rate ◽  
Opening Displacement

Using a fatigue testing method by which fatigue cracks can be initiated and propagated in a film adhered to cover a circular through-hole in a base plate subjected to cyclic loads, annealed copper films of 100m thickness with different crystal grain sizes were fatigued. The fatigue crack propagation in the film with large grains was often decelerated, so the crack propagation rate of the film with the large grain was lower than that of the film with the small grain. When the crack propagation was decelerated, the crack opening displacement obtained from the film with large grain size was smaller than that obtained from the film with small grain size. The relationship between the fatigue crack propagation rate and the stress intensity factor estimated from the crack opening displacement was identical for the cracks in the film with the large grain and the small grain.

Influence of microstructural evolution and localized delta ferrite number on high-cycle fatigue crack opening and propagation rate

2020 ◽  
pp. 146442072097670 ◽  
Author(s):  
Mudaser Ullah ◽  
Faisal Qayyum ◽  
Hassan Elahi ◽  
Fariha Mukhtar ◽  
Qasim Ali ◽  
...  
Keyword(s):  
Fatigue Crack ◽  
Crack Propagation ◽  
Heat Affected Zone ◽  
Crack Opening ◽  
Crack Propagation Rate ◽  
Propagation Rate ◽  
Fatigue Crack Propagation Rate ◽  
Filler Alloy ◽  
Delta Ferrite ◽  
Ferrite Number

In this research, percentages of nickel as austenizer and chromium as ferritizer, in the molten metal pool of SS304L weldments are varied to analyze the effect on the produced delta ferrites morphology and volume. The resulting localized precipitation of delta ferrite and its effect on the fatigue crack propagation rate of the material are examined in this work. The estimation of localized delta ferrite number for a particular weld zone is assessed through the development of a MATLAB code for image processing. It is observed that a reduction in the percentage of nickel in filler alloy yields randomly scattered granular ferrites in the fusion zone and equiaxed grain growing in the heat-affected zone with the development of blocky ferrites on the grain boundaries, whereas increased percentage of chromium in the filler causes the precipitation of dendritic clusters and vermicular ferrites in fusion zone and heat-affected zone of weldments, respectively. The effect of ferrite numbers and their morphology on the crack opening displacements and the corresponding fatigue crack propagation rate in different weld zones are analyzed. It is observed that the ferrite number ranging between 15 and 19 provides optimum fatigue strength for SS 304L. Paris curves are plotted from the test data, which shows that the weldment attained with filler alloy having Cr 26.60% and Ni 10.92% depicts the highest fatigue life compared to other studied weldments.

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