Influence of Hole Size on Crack Propagation Mechanism of Nano-Single Crystal Copper

2013 ◽  
Vol 328 ◽  
pp. 679-683
Author(s):  
Ge Li ◽  
Xian Qin Hou ◽  
Zhi Min Liu

By molecular dynamics method, the tensile processes of nanosingle crystal copper with the crack front existence hole were simulated, and the effect of different hole size on crack propagation mechanism was analyzed. The results indicate that as the hole position remain unchanged, the hole diameter was more bigger, the atomic staggered and the crack tip deactivation were more obvious under tensile loads caused more dislocation glide appeared, meanwhile the number of slide-line was more and the trend of crack branch extend to hole position was more obvious.

2013 ◽  
Vol 668 ◽  
pp. 343-346
Author(s):  
Ge Li ◽  
Ming Chen ◽  
Zhi Min Liu

By molecular dynamics method, the tensile processes of nano-single crystal copper with the crack front existence hole were simulated, and the effect of different hole position to crack propagation mechanism was analyzed. The results indicate that as the hole position and crack tip came more closer, dislocation glide would be more obvious in the model interior under the load, the crack tip opening increased lead to occur the typical crack tip deactivation. The more obvious crack branch approached to the hole position, the easier to occurred crack expansion.


2012 ◽  
Vol 581-582 ◽  
pp. 341-344
Author(s):  
Ge Li ◽  
Qing Long Zhang ◽  
Ming Chen ◽  
Lin Yong Zhou

By molecular dynamics method, the tensile processes of nano-single crystal copper with the type I crack under different temperature were simulated, and the effect of different temperature to crack propagation mechanism was analyzed. The results indicate that the temperature has significant effect on crack propagation mechanism of nano-single crystal copper. While the crack is the intrinsic brittle cleavage extension under low temperature and room temperature, the twin crystal is not easily to generate; whereas, dislocation climb caused twin crystal belt appears near the crack tip under high temperature. With load increasing, the length and the width of twin crystals belt increase gradually, and the existence of the twin crystal belt causes the crack branch change to the extending direction.


2012 ◽  
Vol 581-582 ◽  
pp. 827-830 ◽  
Author(s):  
Ge Li ◽  
Qing Long Zhang ◽  
Ming Chen ◽  
Lin Yong Zhou

By FEAt method, the tensile processes of single crystal copper with the type I crack at temperature of 293K were simulated, and the effect of different initial crack lengths to crack propagation mechanism was analyzed. The results indicate that the different initial crack lengths have significant effect on crack propagation mechanism. With the increase of crack length, the critical stress of crack propagation was significantly reduced, the dislocation walls were easy to appear, and mesh staggered of the crack branch along the cleavage plane was more pronounced.


2000 ◽  
Vol 2000.2 (0) ◽  
pp. 33-34
Author(s):  
Ryosuke MATSUMOTO ◽  
Hiroshi KITAGAWA ◽  
Keiko NAKATANI ◽  
Akihiro NAKATANI

Metals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1656
Author(s):  
Mansur Ahmed ◽  
Md. Saiful Islam ◽  
Shuo Yin ◽  
Richard Coull ◽  
Dariusz Rozumek

This paper investigated the fatigue crack propagation mechanism of CP Ti at various stress amplitudes (175, 200, 227 MPa). One single crack at 175 MPa and three main cracks via sub-crack coalescence at 227 MPa were found to be responsible for fatigue failure. Crack deflection and crack branching that cause roughness-induced crack closure (RICC) appeared at all studied stress amplitudes; hence, RICC at various stages of crack propagation (100, 300 and 500 µm) could be quantitatively calculated. Noticeably, a lower RICC at higher stress amplitudes (227 MPa) for fatigue cracks longer than 100 µm was found than for those at 175 MPa. This caused the variation in crack growth rates in the studied conditions.


2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Xiaoqing Xu ◽  
Bohan Liu ◽  
Yibing Li

Polyvinyl butyral (PVB) laminated glass has been widely used as an important component of mechanical and construction materials. Cracks on PVB laminated glass are rich in impact information, which contribute to its impact resistance design. In this paper, a three-dimensional (3D) numerical simulation model describing PVB laminated glass under impact loading is firstly established and validated qualitatively and quantitatively compared with the corresponding experimental results recorded by the high-speed photography system. In the meantime, the extended finite element method (XFEM) is introduced to analyze the crack propagation mechanism of laminated glass based on dynamic stress intensity factors (DSIFs) and propagations of stress waves. Parametric studies are then carried out to investigate the influence of five critical parameters, that is, plate dimension, crack length, impact energy, glass properties, and PVB properties, on crack propagation characteristics of laminated glass. Results show that the interaction between crack tip and stress waves as well as the propagations of stress waves corresponds to the fluctuations of DSIFs at crack tip. Both the structure and material variables are proven to play a very important role in glass cracking DSIFs and thus govern the crack propagation behavior. Results may provide fundamental explanation to the basic crack propagation mechanism on radial cracks in PVB laminated glass under impact loading conditions, thus to instruct its impact design improvement.


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