scholarly journals Correlation between Fractal Dimension and Areal Surface Parameters for Fracture Analysis after Bending-Torsion Fatigue

Metals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1790
Author(s):  
Wojciech Macek
Keyword(s):  
Fractal Dimension ◽  
Fracture Surface ◽  
Surface Topography ◽  
Fatigue Loading ◽  
Loading Conditions ◽  
Surface Method ◽  
Loading Ratio ◽  
Topography Data ◽  
Areal Surface ◽  
Total Fracture

This paper investigates the fracture surface topography of two steel and aluminum alloys subject to bending-torsion fatigue loadings, as well as their susceptibility to fatigue performance and failure mechanisms. Using fracture surface topography data analysis, elements with different geometries were elaborated. A correlation between the fractal dimension, other selected parameters of surface topography such as areal Sx, and fatigue loading conditions was found. Distinctions in particular regions of cracks were also recognized through proving the correctness and universality of the total fracture surface method. The influence of fatigue loading parameters on the surface topography of fatigue fractures was demonstrated. For the analyzed cases, results show that the fractal dimension and standard surface topography parameters represent a correlation between them and loading conditions. As a single parameter, the appropriate loading ratio cannot be outright calculated with fractal dimension, but can be estimated with some approximation, taking into account additional assumptions.

Fractal Dimension for Ceramic Fracture Surface

2005 ◽  
Vol 904 ◽  
Author(s):  
Jerzy Bielecki ◽  
Piotr Kotowski
Keyword(s):  
Fractal Dimension ◽  
Fracture Surface ◽  
Cross Section ◽  
Static Loading ◽  
Fractal Dimensions ◽  
Loading Conditions ◽  
Ceramic Fracture ◽  
Section Method ◽  
Fractal Characteristics ◽  
Cross Section Method

AbstractAn investigation of an influence of loading parameters on fractal dimension of electrotechnical ceramics fracture has been presented. Investigation objects were samples made of C110 and C130 ceramics. Specimens were breaking under cyclic and static loading conditions. To estimate fractal characteristics a method used for metals fracture had been adapted. Fractal dimensions were estimated for profiles obtained by the vertical cross section method. Obtained results show that fractal dimension does not characterises the material. That dimension does not characterises loading conditions, as well.

DEMONSTRATION OF WATERSHED SEGMENTATION ON SIMULATED SURFACE TOPOGRAPHY DATA

2015 ◽  
Vol 76 (10) ◽  
Author(s):  
Mohd Fauzi Ismail ◽  
Nor Hidayawati Mohd Zaini ◽  
Talib Ria Jaafar ◽  
Nuraini Che Pin
Keyword(s):  
Surface Topography ◽  
Surface Texture ◽  
Simulated Data ◽  
Functional Requirements ◽  
Watershed Segmentation ◽  
Simulated Surface ◽  
The Hill ◽  
The Relationship ◽  
Topography Data ◽  
Areal Surface

Surface texture comprises of many features of interest, which may or may not be essential for surface functional requirements. Features on the surface topography data refers to the peak, pit and the relationship between them; instead of the point on the valleys only. Hence, the objective of this paper is to demonstrate the watershed segmentation on the simulated surface topography data. Watershed segmentation is applied on the selected areal surface texture to determine the regions of the features of the hill and dales. The segmentation of the features is developed by using MATLAB. The developed application is then validated with the simulated topography data. The application’s result on the simulated data shows that, the watershed segmentation method works as intended.  

scholarly journals Fracture Surface Behavior of 34CrNiMo6 High-Strength Steel Bars with Blind Holes under Bending-Torsion Fatigue

Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 80
Author(s):  
Wojciech Macek ◽  
Ricardo Branco ◽  
José Domingos Costa ◽  
Jarosław Trembacz
Keyword(s):  
Fractal Dimension ◽  
Fracture Surface ◽  
Surface Topography ◽  
Normal Stress ◽  
Stress Amplitude ◽  
Fatigue Crack Initiation ◽  
High Strength ◽  
Fold Increase ◽  
Lower Shear ◽  
Steel Bars

The present study evaluates the fracture surface response of fatigued 34CrNiMo6 steel bars with transverse blind holes subjected to bending with torsion loading. The analysis of the geometric product specification was performed by means of height parameters Sx, functional volume parameters Vx, and fractal dimension Df. Surface topography measurements were carried out using an optical profilometer with focus variation technology. The experimental results show that the doubling the bending to torsion moment ratio B/T from B/T = 1 to B/T = 2, maintaining the same normal stress amplitude, greatly reduces both Sa, Vv as well as the fractal dimension Df of the analyzed specimen fractures by 32.1%, 29.8%, and 16.0%, respectively. However, as expected, a two-fold increase in the B/T ratio, maintaining the same normal stress amplitude, resulted in a larger number of cycles to fatigue crack initiation, Ni, which can be explained by the lower shear stress level. These experiments prove that parameters Sx, Vx, Df are smaller for larger Ni values, which is an important finding. In addition, it was found a high consistency of surface topography measurements for the two sides of the broken specimens. The proposed methodology is both reliable and applicable for other engineering applications involving different geometries and loading conditions.

Fractal dimension of the fracture surface of porous ZrO2 – MgO composite

2020 ◽  
pp. 74-82
Author(s):  
A. S. Buyakov ◽  
◽  
Yu. A. Zenkina ◽  
S. P. Buyakova ◽  
S. N. Kulkov ◽  
...  
Keyword(s):  
Fractal Dimension ◽  
Fracture Surface

Fractal Dimension of the Fracture Surface of Porous ZrO2–MgO Composite

2020 ◽  
Vol 11 (5) ◽  
pp. 1253-1259
Author(s):  
A. S. Buyakov ◽  
Yu. A. Zenkina ◽  
S. P. Buyakova ◽  
S. N. Kulkov
Keyword(s):  
Fractal Dimension ◽  
Fracture Surface
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