Numerical Analysis of Crack Propagation in Silicon Nitride

2011 ◽  
Vol 490 ◽  
pp. 216-225 ◽  
Author(s):  
Waldemar Karaszewski
Keyword(s):  
Numerical Analysis ◽  
Crack Propagation ◽  
Coefficient Of Thermal Expansion ◽  
Experimental Studies ◽  
Three Dimensional ◽  
Contact Fatigue ◽  
High Hardness ◽  
Rolling Contact ◽  
Three Dimensional Model ◽  
Ring Crack

The properties of ceramics, specifically low density, high hardness, high temperature capability and low coefficient of thermal expansion are of most interest to rolling element manufacturers. The influence of ring crack size on rolling contact fatigue failure has been studied using numerical fracture analysis. Such cracks are very often found on ceramic bearing balls and decrease fatigue life rapidly. The numerical calculation are based on a three dimensional model for the ring crack propagation. The stress intensity factors along crack front are analyzed using a three-dimensional boundary element model. The numerical analysis is verified by experimental studies.

Hertzian Crack Propagation in Ceramic Rolling Elements

2014 ◽  
Vol 598 ◽  
pp. 92-98 ◽  
Author(s):  
Waldemar Karaszewski
Keyword(s):  
Crack Propagation ◽  
Coefficient Of Thermal Expansion ◽  
Rolling Contact Fatigue ◽  
Experimental Studies ◽  
Three Dimensional ◽  
Contact Fatigue ◽  
High Hardness ◽  
Rolling Contact ◽  
Three Dimensional Model ◽  
Ring Crack

The properties of ceramics, specifically low density, high hardness, high temperature capability and low coefficient of thermal expansion are of most interest to rolling element manufacturers. The influence of ring crack size on rolling contact fatigue failure has been studied using numerical fracture analysis. Such cracks are very often found on ceramic bearing balls and decrease fatigue life rapidly. The numerical calculation are based on a three dimensional model for the ring crack propagation. The stress intensity factors along crack front are analyzed using a three-dimensional boundary element model. The numerical analysis is verified by experimental studies.

Analysis of Ceramic Elements with Ring-Crack Defects in Lubricated Rolling Contact

2016 ◽  
Vol 250 ◽  
pp. 43-49 ◽  
Author(s):  
Waldemar Karaszewski
Keyword(s):  
Coefficient Of Thermal Expansion ◽  
Rolling Contact Fatigue ◽  
Experimental Studies ◽  
Three Dimensional ◽  
Contact Fatigue ◽  
High Hardness ◽  
Rolling Contact ◽  
Three Dimensional Model ◽  
Element Analysis ◽  
Ring Crack

The properties of ceramics, specifically low density, high hardness, high temperature capability and low coefficient of thermal expansion are of most interest to rolling element manufacturers. Surface ring cracks on lubricating rolling contact fatigue failure has been studied using numerical fracture analysis. Such cracks are very often found on ceramic bearing balls and decrease fatigue life rapidly. The numerical calculations are based on a three-dimensional model of the ring crack. The stress intensity factors along crack front are analyzed using a finite element analysis. The numerical analysis is verified by experimental studies.

scholarly journals A Numerical Model for Solving Three-Dimensional Rolling Contact Problems with Elastic Coating Layers

2021 ◽  
Vol 69 (4) ◽  
Author(s):  
Yinhu Xi ◽  
Marcus Björling ◽  
Andreas Almqvist
Keyword(s):  
Numerical Model ◽  
Rolling Contact Fatigue ◽  
Three Dimensional ◽  
Contact Fatigue ◽  
Contact Problems ◽  
Rolling Contact ◽  
Three Dimensional Model ◽  
Stick Slip ◽  
Influence Coefficients ◽  
Traction Distribution

AbstractIn this work, a numerical model is proposed for three-dimensional rolling contact problems with one or two elastic layers, and the tangential contact solution is emphasized. Previous works on this topic have mostly been two-dimensional, in which only longitudinal creepage has been considered. With the three-dimensional model presented in this work, all possible creepages, such as the longitudinal, lateral and spin creepages are taken into account. In order to improve the calculation efficiency, the conjugate gradient method and the FFT technique are employed. The influence coefficients for displacement and stress are obtained from the corresponding frequency response functions. The numerical results are validated against existing results and good agreement can be found. The effects of the different layers’ thicknesses and elastic moduli under different creepage combinations on the traction distribution and stick/slip results are investigated. It can be seen that by adjusting the layer parameters the traction and stick/slip results can be modified significantly, and it may, therefore, be very useful information for improving the rolling contact fatigue and mitigating wear problems in various mechanical systems. Graphical Abstract

Effect of defect length on rolling contact fatigue crack propagation in high strength steel

2015 ◽  
Author(s):  
T. Makino ◽  
Y. Neishi ◽  
D. Shiozawa ◽  
Y. Neishi ◽  
D. Shiozawa ◽  
...  
Keyword(s):  
Crack Propagation ◽  
High Strength Steel ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
High Strength ◽  
Rolling Contact ◽  
Micro Ct ◽  
Middle Line ◽  
Micro Computed Tomography ◽  
Depth Direction

 The objective of the present paper is to clarify the effect of defect length in depth direction on rolling contact fatigue (RCF) crack propagation in high strength steel. RCF test and synchrotron radiation micro computed tomography (SR micro CT) imaging were conducted. In the case of the defect with the 15 ?m diameter, flaking life decreased with increasing defect length. In a comparison of the CT image and the SEM view, the shapes of defects and the locations of the horizontal cracks were almost the same respectively. The mechanism of RCF crack propagation was discussed by finite element (FE) analysis. Defects led to higher tensile residual stress than that without defects in the region where the defect exists. The shear stress range at 0.1 mm in depth on the middle line of the defect and the range of mode II stress intensity factor at the bottom of a vertical crack increased with increasing defect length.

A Predictive Rolling Contact Fatigue Crack Growth Model: Onset of Branching, Direction, and Growth—Role of Dry and Lubricated Conditions on Crack Patterns

2002 ◽  
Vol 124 (4) ◽  
pp. 680-688 ◽  
Author(s):  
M. C. Dubourg ◽  
V. Lamacq
Keyword(s):  
Fatigue Crack ◽  
Crack Propagation ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Interfacial Crack ◽  
Rolling Contact ◽  
Propagation Behavior ◽  
Branch Formation ◽  
Complex Crack ◽  
Crack Growth Model

Complex crack networks are initiated in rails under Rolling Contact Fatigue. This paper attempts to model the RCF crack propagation with a particular emphasis on the branching conditions and the parameters that play a role on them. The numerical tool proposed rests on the combination of the author’s RCF model, Hourlier and Pineau’s criterion for the branch prediction and experimental data and the corresponding models for fatigue crack extension that are derived from a Joint European project. Parametric studies on the influence of (i) residual stresses, (ii) both interfacial crack and wheel/rail contact frictional effects, (iii) neighboring crack are conducted to reach a better understanding of the RC crack propagation behavior and more particularly the branch conditions, i.e., the length of the primary crack prior to branch formation and the branch direction.

scholarly journals Overall buckling analysis on different formed circular steel tubular columns under axial compression

2019 ◽  
Vol 277 ◽  
pp. 03017
Author(s):  
Xi Feng Yan
Keyword(s):  
Numerical Analysis ◽  
Axial Compression ◽  
Experimental Studies ◽  
Three Dimensional ◽  
Element Model ◽  
Welded Steel ◽  
Eurocode 3 ◽  
Column Design ◽  
Hot Rolled ◽  
Overall Buckling

This paper presents a numerical finite element model (FEM) investigation on the overall buckling behaviour of hot-rolled (HR), submerged arc welded (SAW) and high-frequency welded (HFW) steel circular columns under axial compression. Three dimensional FEM of circular hollow sections were developed using shell elements considering material nonlinearities, geometric imperfections and residual stress. The established FEM was used to simulate experimental studies conducted by past researchers. Good agreement has been found between numerical analysis and past researchers results, which has validated the reasonability of the FEM to carry out further investigation. Based on the validated FEM, numerical analysis incorporating 180 numerical generated HR, SAW and HFW steel circular columns with various section sizes and slenderness were carried out. The numerical analysis results were compared with the existing column design curves in Chinese, European and American codes. The numerical results showed that the design resistances for hot-rolled and welded steel circular columns calculated based on design curve a in both GB 50017-2003 and Eurocode 3 and the design formula in ANSI/AISC 360-2016 should be accepted. In addition, to further improve the design efficiency, new column design curves for hot-rolled and welded steel circular columns were recommended based on the expressions in GB 50017-2003 and Eurocode 3.

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