A meshless method with enriched weight functions for three-dimensional crack propagation

2006 ◽  
Vol 65 (12) ◽  
pp. 1970-2006 ◽  
Author(s):  
Marc Duflot
Keyword(s):  
Crack Propagation ◽  
Meshless Method ◽  
Three Dimensional ◽  
Weight Functions

Numerical study of multi-dimensional hyperbolic telegraph equations arising in nuclear material science via an efficient local meshless method

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Imtiaz Ahmad ◽  
Aly R. Seadawy ◽  
Hijaz Ahmad ◽  
Phatiphat Thounthong ◽  
Fuzhang Wang
Keyword(s):  
Meshless Method ◽  
Material Science ◽  
Numerical Study ◽  
Research Work ◽  
Time Integration ◽  
Three Dimensional ◽  
Nuclear Material ◽  
Telegraph Equations ◽  
Model Equations ◽  
Derivatives Of

Abstract This research work is to study the numerical solution of three-dimensional second-order hyperbolic telegraph equations using an efficient local meshless method based on radial basis function (RBF). The model equations are used in nuclear material science and in the modeling of vibrations of structures. The explicit time integration technique is utilized to semi-discretize the model in the time direction whereas the space derivatives of the model are discretized by the proposed local meshless procedure based on multiquadric RBF. Numerical experiments are performed with the proposed numerical scheme for rectangular and non-rectangular computational domains. The proposed method solutions are converging quickly in comparison with the different existing numerical methods in the recent literature.

Cleavage Planes of Icosahedral Quasicrystals: A Molecular Dynamics Study

2003 ◽  
Vol 805 ◽  
Author(s):  
Frohmut Rösch ◽  
Christoph Rudhart ◽  
Peter Gumbsch ◽  
Hans-Rainer Trebin
Keyword(s):  
Molecular Dynamics ◽  
Brittle Fracture ◽  
Crack Propagation ◽  
Three Dimensional ◽  
Propagation Direction ◽  
Mode I ◽  
Dynamic Crack ◽  
Fracture Surfaces ◽  
Icosahedral Quasicrystals ◽  
Crack Tip Plasticity

ABSTRACTThe propagation of mode I cracks in a three-dimensional icosahedral model quasicrystal has been studied by molecular dynamics techniques. In particular, the dependence on the plane structure and the influence of clusters have been investigated. Crack propagation was simulated in planes perpendicular to five-, two- and pseudo-twofold axes of the binary icosahedral model.Brittle fracture without any crack tip plasticity is observed. The fracture surfaces turn out to be rough on the scale of the clusters. These are not strictly circumvented, but to some extent cut by the dynamic crack. However, compared to the flat seed cracks the clusters are intersected less frequently. Thus the roughness of the crack surfaces can be attributed to the clusters, whereas the constant average heights of the fracture surfaces reflect the plane structure of the quasicrystal. Furthermore a distinct anisotropy with respect to the in-plane propagation direction is found.

Shape and energies of a dynamically propagating crack under bending

2003 ◽  
Vol 18 (10) ◽  
pp. 2379-2386 ◽  
Author(s):  
Dov Sherman ◽  
Ilan Be'ery
Keyword(s):  
Crack Propagation ◽  
Energy Release Rate ◽  
Energy Release ◽  
Release Rate ◽  
Crack Front ◽  
Three Dimensional ◽  
Strain Energy Release ◽  
Governing Parameter ◽  
Propagating Crack ◽  
Front Shape

We report on the exact shape of a propagating crack in a plate with a high width/thickness ratio and subjected to bending deformation. Fracture tests were carried out with brittle solids—single crystal, polycrystalline, and amorphous. The shape of the propagating crack was determined from direct temporal crack length measurements and from the surface perturbations generated during rapid crack propagation. The shape of the crack profile was shown to be quarter-elliptical with a straight, long tail; the governing parameter of the ellipse axes is the specimen's thickness at most length of crack propagation. Universality of the crack front shape is demonstrated. The continuum mechanics approach applicable to two-dimensional problems was used in this three-dimensional problem to calculate the quasistatic strain energy release rate of the propagating crack using the formulations of the dynamic energy release rate along the crack loci. Knowledge of the crack front shape in the current geometry and loading configuration is important for practical and scientific aspects.

Prediction Method of Three‐Dimensional Crack Propagation Path Based on Deep Learning Application

2020 ◽  
pp. 2001043
Author(s):  
Junxia Wang ◽  
Yuanjie Zheng ◽  
Rong Luo ◽  
Jun Ma ◽  
Yingjie Peng ◽  
...  
Keyword(s):  
Deep Learning ◽  
Crack Propagation ◽  
Three Dimensional ◽  
Prediction Method ◽  
Propagation Path ◽  
Crack Propagation Path

scholarly journals Three Dimensional Simulation of Polycrystalline Cleavage Crack Propagation in Steel

2009 ◽  
Vol 95 (6) ◽  
pp. 498-505 ◽  
Author(s):  
Kei Sugimoto ◽  
Shuji Aihara ◽  
Yoichi Tanaka
Keyword(s):  
Crack Propagation ◽  
Three Dimensional ◽  
Cleavage Crack ◽  
Dimensional Simulation

Numerical Investigations of Corner Singularities in Cracked Bodies

2007 ◽  
Vol 348-349 ◽  
pp. 377-380 ◽  
Author(s):  
Pavel Hutař ◽  
Luboš Náhlík ◽  
Zdeněk Knésl
Keyword(s):  
Fatigue Crack ◽  
Free Surface ◽  
Crack Propagation ◽  
Fatigue Crack Propagation ◽  
Three Dimensional ◽  
Stress Singularity ◽  
Crack Propagation Rate ◽  
Propagation Rate ◽  
Dimensional Structure ◽  
Fatigue Crack Propagation Rate

The influence of corner singularity on the distribution of the stresses around the crack front for a three-dimensional structure is described in this paper. The distribution of stress singularity through the thickness of the middle tension specimen provides us an indication of crack behaviour close to a free surface. An estimation of the region where the change of singularity exponent plays an important role in fatigue crack propagation rate was carried out. A decrease in fatigue crack propagation rate close to the free surface was found. The lower fatigue crack propagation rate in the boundary layer in comparison with the interior of the specimen leads to a change of intersecting angle between crack and free surface and depends on Poisson’s ratio.

Three-Dimensional LEFM Prediction of Fatigue Crack Propagation in a Gas Turbine Disk Material at Component Near Conditions

2015 ◽  
Vol 138 (4) ◽  
Author(s):  
Christian Busse ◽  
David Gustafsson ◽  
Patrik Rasmusson ◽  
Björn Sjödin ◽  
Johan J. Moverare ◽  
...  
Keyword(s):  
Fatigue Crack ◽  
Crack Propagation ◽  
Gas Turbine ◽  
Plastic Flow ◽  
Fatigue Crack Propagation ◽  
Three Dimensional ◽  
Turbine Disk ◽  
Material Behavior ◽  
Linear Elastic ◽  
Disk Material

In this paper, the possibility to use linear elastic fracture mechanics (LEFM), with and without a superimposed residual stress field, to predict fatigue crack propagation in the gas turbine disk material Inconel 718 has been studied. A temperature of 400 °C and applied strain ranges corresponding to component near conditions have been considered. A three-dimensional crack propagation software was used for determining the stress intensity factors (SIFs) along the crack path. In the first approach, a linear elastic material behavior was used when analyzing the material response. The second approach extracts the residual stresses from an uncracked model with perfectly plastic material behavior after one loading cycle. As a benchmark, the investigated methods are compared to experimental tests, where the cyclic lifetimes were calculated by an integration of Paris' law. When comparing the results, it can be concluded that the investigated approaches give good results, at least for longer cracks, even though plastic flow was taking place in the specimen. The pure linear elastic simulation overestimates the crack growth for all crack lengths and gives conservative results over all considered crack lengths. Noteworthy with this work is that the 3D-crack propagation could be predicted with the two considered methods in an LEFM context, although plastic flow was present in the specimens during the experiments.

Sign in / Sign up

Export Citation Format

Share Document