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.

Experimental study on loading rate and notch-to-depth ratio effects on flexural performance of self-compacting concrete with acoustic emission and digital image correlation technologies

2020 ◽  
pp. 030932472094900
Author(s):  
Xudong Chen ◽  
Dandan Shi ◽  
Jinhua Zhang ◽  
Xiyuan Cheng
Keyword(s):  
Acoustic Emission ◽  
Digital Image Correlation ◽  
Digital Image ◽  
Image Correlation ◽  
Correlation Technique ◽  
Self Compacting Concrete ◽  
Opening Displacement ◽  
Emission Analysis ◽  
Cluster Group ◽  
Depth Ratio

As no extra vibration is needed in the casting procedure of self-compacting concrete for its excellent workability under its own dead weight, the material can be applied to construction projects where vibrations are hard to perform. To better utilize self-compacting concrete in practical engineering, it is essential to conduct an in-depth study on its fracture performance. In this study, three-point bending tests on notched self-compacting concrete beams were performed considering different loading rates and notch-to-depth ratios as variables. Acoustic emission technique and digital image correlation method were utilized to collect acoustic emission signals generated in the loading procedure and monitor crack propagation in the fracture process zone, respectively. Results show that the b-value from acoustic emission analysis can be divided into three stages and the variation range increases as the notch-to-depth ratio increases. Based on clustering analysis, three cluster groups can be obtained, and it is found that the ratio of the first cluster group decreases while that of the third cluster group increases when notch-to-depth ratio increases. With the aid of digital image correlation technique, effective crack length and horizontal crack opening displacement can be recorded and it is observed that crack tip opening displacement decreases as the notch-to-depth ratio increases.

Sign in / Sign up

Export Citation Format

Share Document