Two basic approaches in a search of the crack propagation angle

2017 ◽  
Vol 40 (8) ◽  
pp. 1191-1200 ◽  
Author(s):  
Y. G. Matvienko ◽  
E. M. Morozov
Keyword(s):  
Crack Propagation ◽  
Propagation Angle ◽  
Basic Approaches ◽  
Crack Propagation Angle

Application of Multi-Parameter Fracture Mechanics to Study of Crack Propagation Angle in Selected Mixed-Mode Geometry

2013 ◽  
Vol 592-593 ◽  
pp. 209-212 ◽  
Author(s):  
Lucie Šestáková Malíková ◽  
Václav Veselý
Keyword(s):  
Fracture Mechanics ◽  
Crack Propagation ◽  
Mixed Mode ◽  
Initial Crack ◽  
Propagation Angle ◽  
Linear Elastic ◽  
Higher Order Terms ◽  
Elastic Fracture ◽  
Cracked Specimens ◽  
Crack Propagation Angle

The multi-parameter fracture mechanics becomes more and more significant, because it is shown that it can help to describe fracture processes occurring in cracked specimens more precisely than conventional linear elastic fracture mechanics. In this paper, the concept based on the Williams expansion derived for approximation of stress/displacement crack-tip fields is presented and applied on a mixed-mode configuration. Two fracture criteria for estimation of the initial crack propagation angle are introduced. A parametric study is performed in order to investigate the dependence of the crack propagation angle on the stress intensity factors ratio. Influence and importance of taking into account the so-called higher-order terms of the Williams expansion are discussed and some recommendations are stated.

scholarly journals Anti-plane crack in human bone. I. Mathematical modelling

2018 ◽  
Vol 26 (1) ◽  
pp. 81-90
Author(s):  
Eduard Marius Crăciun ◽  
Marin Marin ◽  
Adrian Răbâea
Keyword(s):  
Composite Material ◽  
Crack Propagation ◽  
Mathematical Modelling ◽  
Hilbert Problem ◽  
Plane Crack ◽  
Propagation Angle ◽  
Linear Elastic ◽  
Elastic Composite ◽  
Crack Propagation Angle ◽  
Riemann Hilbert Problem

Abstract We consider an anti-plane crack in a bone, considered as an initially deformed orthotropic, linear elastic composite material. Elastic incremental fields in the composite material are obtained following theories of Guz’s representation and of Riemann-Hilbert problem. Critical values of crack propagation angle are determined using Sih’s generalized criterion.

scholarly journals Influence of Stress Intensity Factor on Rail Fatigue Crack Propagation by Finite Element Method

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5720
Author(s):  
Ruipeng Gao ◽  
Mengmeng Liu ◽  
Bing Wang ◽  
Yiran Wang ◽  
Wei Shao
Keyword(s):  
Stress Intensity Factor ◽  
Fatigue Crack ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Crack Propagation ◽  
Crack Length ◽  
Rolling Contact ◽  
Mode I ◽  
Propagation Angle ◽  
Crack Propagation Angle

Wheel rail rolling contact fatigue is a very common form of damage, which can lead to uneven rail treads, railhead nuclear damage, etc. Therefore, ANSYS software was used to establish a three-dimensional wheel–rail contact model and analyze the effects of several main characteristics, such as the rail crack length and crack propagation angle, on the fatigue crack intensity factor during crack propagation. The main findings were as follows: (1) With the rail crack length increasing, the position where the crack propagated by mode I moved from the inner edge of the wheel–rail contact spot to the outer edge. When the crack propagated to 0.3–0.5 mm, it propagated to the rail surface, causing the rail material to peel or fall off and other damage. (2) When the crack propagation angle was less than 30°, the cracks were mainly mode II cracks. When the angle was between 30 and 70°, the cracks were mode I–II cracks. When the angle was more than 70°, the cracks were mainly mode I cracks. When the crack propagation angle was 60°, the equivalent stress intensity factor reached the maximum, and the rail cracks propagated the fastest.

Fatigue Characterization of Long Dynamic Risers in Deep Waters

2007 ◽  
Author(s):  
Mohammad Iranpour ◽  
Farid Taheri ◽  
J. Kim Vandiver
Keyword(s):  
Fatigue Crack ◽  
Crack Propagation ◽  
Fatigue Damage ◽  
Fatigue Crack Propagation ◽  
Current Profile ◽  
Variable Amplitude ◽  
Deep Waters ◽  
Continuous Current ◽  
Mode Vibration ◽  
Basic Approaches

Continuous current action on risers develops vortices. These vortices cause risers to respond in a dynamic manner, leading to relatively large oscillations in the flexural and circumferential stresses. Vortex-induced vibration (VIV) and the resulting changes in the level of stresses in a riser could therefore cause detrimental fatigue induced problems, ranging from leakage to catastrophic failure of the riser. As a result, the VIV induced fatigue has always been a critical parameter in the design of risers, particularly when considering risers in deep waters. An experimental investigation into the fatigue crack propagation was conducted using a series of field data obtained on the high mode vibration of a relatively long flexible model riser. The field test data clearly illustrated the variable amplitude nature of the loading imposed on the riser by the current profile. There are currently several methods available for consideration of the crack growth rate due to overload and/or underloads; however, none has been developed based on data obtained for an actual riser. Indeed, fatigue experimental data on risers subject to VIV are relatively scarce in the literature. In this study the influence of the different harmonics resulting from VIV on the overall fatigue damage of the material is investigated. It is shown that the available basic approaches for assessing the fatigue crack propagation of components under variable amplitude loadings may significantly underestimate the VIV-induced fatigue damage of risers.

scholarly journals Numerical Investigation on Crack Propagation for a Central Cracked Brazilian Disk Concerning Friction

2021 ◽  
Vol 11 (6) ◽  
pp. 2839
Author(s):  
Jiuzhou Huang ◽  
Xin Pan ◽  
Jianxiong Li ◽  
Shiming Dong ◽  
Wen Hua
Keyword(s):  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Crack Propagation ◽  
Relative Length ◽  
Mode I ◽  
Brazilian Disk ◽  
Crack Type ◽  
T Stress ◽  
Crack Propagation Angle

This paper concerns the effect of friction on crack propagation for the centrally cracked Brazilian disk under diametric forces by using a modified finite element method. It shows that the mode II stress intensity factor decreases obviously with the increase of friction after the crack is closed, while friction has no influence on the stress intensity factor of mode I and T-stress. Meanwhile, there are some significant influences on the crack propagation due to the change of the friction after the crack is closed with the appropriate loading angle and relative length of the crack. When T-stress is positive, the effect of friction becomes obvious and the crack propagation angle increases with a lager friction coefficient. With increasing the friction, the deviation for the crack propagation trajectory increases and the curvature of path decreases, which may lead to the change of crack type. Additionally, the larger relative crack length can amplify the effect of friction, which is similar to the loading angle.

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