Relationship between fractal dimensions of fracture surface and impact toughness of polycaprolactone/nano-CaCO3composites

2018 ◽  
Vol 37 (8) ◽  
pp. 3115-3122
Author(s):  
Ji-Zhao Liang
Keyword(s):  
Impact Toughness ◽  
Fracture Surface ◽  
Fractal Dimensions

Photon emission as a probe of chaotic processes accompanying fracture

1989 ◽  
Vol 4 (5) ◽  
pp. 1272-1279 ◽  
Author(s):  
S. C. Langford ◽  
Ma Zhenyi ◽  
J. T. Dickinson
Keyword(s):  
Fracture Surface ◽  
Photon Emission ◽  
Deterministic Chaos ◽  
Fractal Dimensions ◽  
Significant Degree ◽  
Box Dimension ◽  
Dynamic Crack ◽  
Emission Data ◽  
Correlation Integral ◽  
The Fourier Transform

Photon emission accompanying the fracture of an epoxy and single crystal MgO is examined for evidence of deterministic chaos by means of the autocorrelation function, the Fourier transform, the correlation integral of Grassberger and Procaccia, and the fractal box dimension. A positive Lyapunov exponent is also obtained from the epoxy phE data. Each of these measures is consistent with a significant degree of deterministic chaos associated with attractors of relatively low dimension. A typical epoxy fracture surface was analyzed for fractal character by means of the slit island technique, yielding a fractal dimension of 1.32 ± 0.03. The fractal dimensions of the fracture surface and the photon emission data (box dimension) of the epoxy are in good agreement. These observations suggest that fluctuations in photon emission intensity during fracture reflect the production of fractal surface features as they are being produced and thus provide important information on the process of dynamic crack growth.

scholarly journals On the Determining Role of Texture in Causing Delamination During Impact Fracture of Ti and Nb-Ti Microalloyed Steel

2019 ◽  
Author(s):  
Mingyu Sun ◽  
Xuemin Wang ◽  
R.D.K. Misra
Keyword(s):  
Impact Toughness ◽  
Fracture Surface ◽  
Impact Energy ◽  
Cleavage Fracture ◽  
Microalloyed Steel ◽  
Microalloyed Steels ◽  
Brittle Transition ◽  
High Toughness ◽  
The Impact

700 MPa grade Ti and Nb-Ti microalloyed steels produced by thermo-mechanical control rolled processes (TMCP) were studied to elucidate texture that contributes to delamination and consequent impact toughness. The microstructure of Ti and Nb-Ti steels consisted of ferrite and bainite. Compared with Ti steel, Nb-Ti steel was characterized by a microstructure with finer ferrite and more bainite. The results from tensile and impact tests indicated that there is insignificant change in tensile properties, but toughness was greater in Nb-Ti steel compared with Ti steel. More severe delamination in Nb-Ti steel is attributed to stronger α-fiber (RD ||<110>) texture than Ti steel, especially {100}<110>, {113}<110> and {112}<110> texture. Typical cleavage river patterns were not observed on delaminated fracture surface, instead the cleavage fracture surface indicated some dimples. Interestingly, the impact energy of samples with delamination was greater than samples without delamination in the ductile–brittle transition region. The study suggests that delamination in the ductile–brittle transition zone may also be representative of high toughness.

Image Reconstruction and Analysis of Three-Dimensional Fracture Surfaces Based on the Stereo Matching Method

2004 ◽  
Vol 261-263 ◽  
pp. 1593-1598
Author(s):  
M. Tanaka ◽  
Y. Kimura ◽  
A. Kayama ◽  
L. Chouanine ◽  
Reiko Kato ◽  
...  
Keyword(s):  
Fractal Dimension ◽  
Image Reconstruction ◽  
Fracture Surface ◽  
Fractal Analysis ◽  
Stereo Matching ◽  
Three Dimensional ◽  
Fractal Dimensions ◽  
Matching Method ◽  
Fracture Surfaces ◽  
Box Counting Method

A computer program of the fractal analysis by the box-counting method was developed for the estimation of the fractal dimension of the three-dimensional fracture surface reconstructed by the stereo matching method. The image reconstruction and fractal analysis were then made on the fracture surfaces of materials created by different mechanisms. There was a correlation between the fractal dimension of the three-dimensional fracture surface and the fractal dimensions evaluated by other methods on ceramics and metals. The effects of microstructures on the fractal dimension were also experimentally discussed.

Correlation between impact strength and fractal dimensions of fracture surface for PLLA/nano-CaCO3 composites

2014 ◽  
Vol 35 ◽  
pp. 109-115 ◽  
Author(s):  
Ji-Zhao Liang ◽  
De-Rong Duan ◽  
Chak-Yin Tang ◽  
Chi-Pong Tsui
Keyword(s):  
Fracture Surface ◽  
Impact Strength ◽  
Fractal Dimensions

scholarly journals A Fractographical Study on Dissimilar Weld Joints of SAF 2205 and Hastelloy C-276

2018 ◽  
Vol 188 ◽  
pp. 02018
Author(s):  
Emrullah Çelikkol ◽  
Mustafa Tümer ◽  
Ş. Hakan Atapek ◽  
M. Zaim Kerimak
Keyword(s):  
Impact Toughness ◽  
Fracture Surface ◽  
Heat Affected Zone ◽  
Root Zone ◽  
Welding Parameters ◽  
Face Centered Cubic ◽  
Dissimilar Weld ◽  
Gas Tungsten Arc ◽  
Saf 2205 ◽  
The Impact

In this study, a dissimilar weld joint between SAF 2205 and Hastelloy C-276 was manufactured by using gas tungsten arc welding and its notched impact fracture behaviour was investigated. Initially, V-type welding mouth was opened and the welding was performed by multi-pass. In welding procedure, ERNiCrMo-3 material used as a filler metal and the heat input was varied between 0.48-1.10 kJ/mm depending on welding parameters. Both welding pool and root zone were protected by an argon atmosphere. Multi notched impact tests were performed at room temperature. Weld metal had an impact toughness value as 92 J and its fracture surface exhibited several oriented cracking paths due to its solidified structure. The impact toughness value was measured as 82 J for heat affected zone of SAF 2205 and its fractograph reflected the coarser and deeper dimples. Heat affected zone of nickel based alloy had the highest impact toughness value as 116 J among the studied joints due to the more plastic deformation capability of nickel having face centered cubic structure, however, its fracture surface under impact loading exhibited several cracks propagating throughout the fusion line having equiaxed dendrites.

scholarly journals Fractal Dimension of Fracture Surface in Rock Material after High Temperature

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Z. Z. Zhang
Keyword(s):  
Fractal Dimension ◽  
Electron Microscope ◽  
High Temperature ◽  
Fracture Surface ◽  
Scanning Electron Microscope ◽  
Fractal Dimensions ◽  
Threshold Value ◽  
Fracture Surfaces ◽  
Increasing Temperature ◽  
Scanning Electron

Experiments on granite specimens after different high temperature under uniaxial compression were conducted and the fracture surfaces were observed by scanning electron microscope (SEM). The fractal dimensions of the fracture surfaces with increasing temperature were calculated, respectively. The fractal dimension of fracture surface is between 1.44 and 1.63. Its value approximately goes up exponentially with the increase of temperature. There is a quadratic polynomial relationship between the rockburst tendency and fractal dimension of fracture surface; namely, a fractal dimension threshold can be obtained. Below the threshold value, a positive correlativity shows between rockburst tendency and fractal dimension; when the fractal dimension is greater than the threshold value, it shows an inverse correlativity.

scholarly journals Investigation on the Creep Failure Mechanism of Sandy Mudstone Based on Micromesoscopic Mechanics

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Xinshuai Shi ◽  
Hongwen Jing ◽  
Weiqiang Chen ◽  
Yuan Gao ◽  
Zhenlong Zhao
Keyword(s):  
Fracture Surface ◽  
Failure Mechanism ◽  
Slope Angle ◽  
Fractal Dimensions ◽  
Creep Damage ◽  
3D Scanning ◽  
Creep Process ◽  
Creep Failure ◽  
Reconstruction Methods ◽  
Sandy Mudstone

In this paper, scanning electron microscope (SEM) tests and 3D scanning technologies were adopted to investigate the creep failure mechanism of sandy mudstone from a micromesoscopic view. The SEM test results showed that the fracture surface micromorphology of the specimens that suffered creep loading was more fractured and rougher. It was also found by the fractal analysis of the SEM microscopic images that the fractal dimensions of the creep failure specimens were larger than those of the uniaxial compression failure, indicating that the creep damage increased the irregularity and a larger degree of roughness fluctuation. The 3D scanning technologies combining with the 3D reconstruction methods proved that the crack expansion path of crept specimens was more complicated, showing a more prominent asperity height and slope angle. Finally, a mesostrain dilating microelement model of the sandy mudstone specimen’s fracture surface was proposed to prove that the dilatancy effect would be more pronounced in the creep process.

Effect of Temperature on Impact Properties of ZA27 Alloy

2012 ◽  
Vol 476-478 ◽  
pp. 75-80 ◽  
Author(s):  
Li Ping Zhong ◽  
Jia Yong Si ◽  
Zi Qiao Zheng
Keyword(s):  
Impact Toughness ◽  
Fracture Surface ◽  
Impact Energy ◽  
Impact Testing ◽  
Impact Fracture ◽  
Impact Behavior ◽  
Effect Of Temperature ◽  
Za27 Alloy ◽  
Different Temperatures ◽  
The Impact

The impact toughness of ZA27 alloy at different temperatures is investigated by pendulum impact testing. In addition, the morphology of impact fracture surface observed by SEM. The results indicate that impact energy of ZA27 alloy is reduced with the temperature rising when the temperature is lower than 100°C. At 100°C to 200°C, impact energy increase as the temperature rising. And when the temperature reaches to 250°C, impact energy suddenly descend. Impact energy is the highest and reaches to 72.768J at 20°C. At impact fracture surface, it is mostly tear ridges and dimples. The higher the impact energy is, the more obvious the characteristic of tear ridges is. Furthermore, dimples are small and distribute more uniformly. Lower the impact energy, the less distinct of tear ridges. Dimples are larger and deeper, their distribution are not uniform. Impact behavior of material could be evaluated by the width of impact curve. The wider the peak of impact curve, the higher the impact toughness. But impact toughness is worse while peak is narrow.

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