Crack Branching Characteristics at Different Propagation Speeds: From Quasi-Static to Supersonic Regime

2014 ◽  
Vol 81 (12) ◽  
Author(s):  
Y. J. Jia ◽  
B. Liu
Keyword(s):  
Dynamic Fracture ◽  
Circumferential Stress ◽  
Propagation Speed ◽  
Crack Branching ◽  
Classical Dynamic ◽  
Fracture Behaviors ◽  
Supersonic Regime ◽  
Crack Propagation Speed ◽  
Mass Spring ◽  
Discrete Mass

Classical dynamic fracture mechanics predicts that the crack branching occurs when crack propagation speed exceeds a subsonic critical velocity. In this paper, we performed simulations on the dynamic fracture behaviors of idealized discrete mass–spring systems. It is interesting to note that a crack does not branch when traveling at supersonic speed, which is consistent with others' experimental observations. The mechanism for the characteristics of crack branching at different propagation speeds is studied by numerical and theoretical analysis. It is found that for all different speed regimes, the maximum circumferential stress near the crack tip determines the crack branching behaviors.

scholarly journals Comparison of peridynamic and phase-field models for dynamic brittle fracture in glassy materials

2020 ◽  
Author(s):  
Javad Mehrmashhadi ◽  
Mohammadreza Bahadori ◽  
Florin Bobaru
Keyword(s):  
Brittle Fracture ◽  
Phase Field ◽  
Phase Field Model ◽  
Propagation Speed ◽  
Experimental Tests ◽  
Crack Branching ◽  
Fracture Crack ◽  
Crack Propagation Speed ◽  
Dynamic Brittle Fracture ◽  
Crack Paths

We report computational results obtained with three different models for dynamic brittle fracture. The results are compared against recent experimental tests on dynamic fracture/crack branching in glass induced by impact. Two peridynamic models (one using the meshfree discretization, the other being the LS-DYNA’s discontinuous-Galerkin implementation) and a phase-field model lead to interesting and important differences in terms of reproducing the experimentally observed fracture behavior and crack paths. We monitor the crack branching location, the angle of crack branching, the crack propagation speed, and some particular features seen in the experimental crack paths: small twists/kinks near the far edge of the sample. We discuss the models’ performance and provide possible reasons behind the failure of some of the models to correctly predict the observed behavior.

Atomic Simulation of Effect of Stacking Fault and Dislocation on Fracture Behavior in Fe Crystal

2008 ◽  
Vol 385-387 ◽  
pp. 457-460 ◽  
Author(s):  
Cheng Lu ◽  
Yuan Gao ◽  
Hong Tao Zhu ◽  
A. Kiet Tieu
Keyword(s):  
Crack Propagation ◽  
Edge Dislocation ◽  
Propagation Speed ◽  
Stacking Fault ◽  
Embedded Atom Method ◽  
Crystalline Materials ◽  
Atomic Simulation ◽  
Embedded Atom ◽  
Fracture Behaviors ◽  
Crack Propagation Speed

The defects in crystalline materials significantly affect the fracture behaviors. In this paper molecular dynamics (MD) model using a potential of embedded atom method (EAM) has been developed to investigate the effect of the major crystalline defects, stacking fault and edge dislocation, on the crack propagation in Fe crystal. Six cases with different locations of stacking fault and edge dislocation have been studied. The strain distribution in lattice aggregate was heterogeneous. The dislocations were observed slipping along directions [100] and [-100] on the plane (100). Simulation results showed that the location of the stacking fault and edge dislocation significantly influenced the crack propagation speed.

Local Crack Branching as a Mechanism for Instability in Dynamic Fracture

1995 ◽  
Vol 74 (25) ◽  
pp. 5096-5099 ◽  
Author(s):  
Eran Sharon ◽  
Steven P. Gross ◽  
Jay Fineberg
Keyword(s):  
Dynamic Fracture ◽  
Crack Branching

scholarly journals Dynamic Fracture Behaviors of Selected Aluminum Alloys Under Three-point Bending

2013 ◽  
Vol 9 (4) ◽  
pp. 193-200 ◽  
Author(s):  
Ming-zhi Xing ◽  
Yong-gang Wang ◽  
Zhao-xiu Jiang
Keyword(s):  
Aluminum Alloys ◽  
Dynamic Fracture ◽  
Three Point Bending ◽  
Fracture Behaviors

scholarly journals Crack propagation speed in ceramic during quenching

2018 ◽  
Vol 38 (7) ◽  
pp. 2879-2885 ◽  
Author(s):  
Yingfeng Shao ◽  
Boyang Liu ◽  
Xiaohuan Wang ◽  
Long Li ◽  
Jiachen Wei ◽  
...  
Keyword(s):  
Crack Propagation ◽  
Propagation Speed ◽  
Crack Propagation Speed

Effect of Contact between the Crack Faces on Crack Propagation

2013 ◽  
Vol 577-578 ◽  
pp. 61-64 ◽  
Author(s):  
Guido Dhondt
Keyword(s):  
Crack Propagation ◽  
Propagation Speed ◽  
Crack Propagation Rate ◽  
Propagation Rate ◽  
Contact Conditions ◽  
Contact Formulation ◽  
Positive Mode ◽  
Crack Propagation Speed ◽  
Crack Faces ◽  
Realistic Prediction

In mixed-mode crack propagation the crack faces frequently touch each other. The ensuing friction is expected to decrease the crack propagation speed. This effect is usually not taken into account, however, a realistic prediction of this effect may increase the calculated life and consequently increase the length of the inspection intervals. In this paper, penalty contact conditions are introduced in between the crack faces of the automatically generated mesh in a cyclic crack propagation. Special attention is given to the contact formulation and the area in which contact is defined. It is shown that the resulting crack propagation rate is significantly reduced by the introduction of friction provided that positive Mode-I is not significantly involved.

Mesoscopic fabric models using a discrete mass-spring approach: Yarn-yarn interactions analysis

2005 ◽  
Vol 40 (22) ◽  
pp. 5925-5932 ◽  
Author(s):  
Bilel Ben Boubaker ◽  
Bernard Haussy ◽  
Jean-Francois Ganghoffer
Keyword(s):  
Mass Spring ◽  
Discrete Mass

The analysis of dynamic fracture using lumped mass-spring models

1987 ◽  
Vol 33 (1) ◽  
pp. 47-59 ◽  
Author(s):  
J. G. Williams
Keyword(s):  
Dynamic Fracture ◽  
Lumped Mass ◽  
Mass Spring

ESTIMATION OF DYNAMIC SYSTEM'S EXCITATION FORCES BY THE INDEPENDENT COMPONENT ANALYSIS

2012 ◽  
Vol 04 (03) ◽  
pp. 1250032 ◽  
Author(s):  
ALI AKROUT ◽  
DHOUHA TOUNSI ◽  
MOHAMED TAKTAK ◽  
MOHAMED SLIM ABBÈS ◽  
MOHAMED HADDAR
Keyword(s):  
Independent Component Analysis ◽  
Numerical Procedure ◽  
Component Analysis ◽  
Independent Component ◽  
Dynamic Responses ◽  
Statistical Criterion ◽  
Mass Spring ◽  
Discrete Mass ◽  
Signal Sources ◽  
Good Agreement

This paper deals with a numerical investigation for the estimation of dynamic system's excitation sources using the independent component analysis (ICA). In fact, the ICA concept is an important technique of the blind source separation (BSS) method. In this case, only the dynamic responses of a given mechanical system are supposed to be known. Thus, the main difficulty of such problem resides in the existence of any information about the excitation forces. For this purpose, the ICA concept, which consists on optimizing a fourth-order statistical criterion, can be highlighted. Hence, a numerical procedure based on the signal sources independency in the ICA concept is developed. In this work, the analytical or the finite element (FE) dynamic responses are calculated and exploited in order to identify the excitation forces applied on discrete (mass-spring) and continuous (beam) systems. Then, estimated results obtained by the ICA concept are presented and compared to those achieved analytically or by the FE and the modal recombination methods. Since a good agreement is obtained, this approach can be used when the vibratory responses of a dynamic system are obtained through sensor's measurements.

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