Open Access
ARTICLE
Masanori Kikuchi 1
CMES-Computer Modeling in Engineering & Sciences, Vol.11, No.2, pp. 49-60, 2006, DOI:10.3970/cmes.2006.011.049
Abstract Three kinds of fracture specimens are tested
under different constraint conditions. By the SEM(Scanning
Electron Microscope) observation, it is shown that
the roughness of fracture surface is different from each
other largely. This is the effect of constraint condition.
The dimple fracture process is simulated by the finite
element method using Gurson’s constitutive equation,
and the crack tip stress fields are obtained. The distributions
of stress triaxiality qualitatively agree with the
experimental results. The J-R curves obtained also qualitatively
agree with those of experiments, and the fracture
surface roughness is well simulated. More >
Open Access
ARTICLE
Jong Youn Park1, Young-Sam Cho2, Sung Youb Kim1, Sukky Jun3, Seyoung Im1
CMES-Computer Modeling in Engineering & Sciences, Vol.11, No.2, pp. 61-72, 2006, DOI:10.3970/cmes.2006.011.061
Abstract We present a coarse-graining computation for deformations of CNTs (carbon nanotubes) via QC (quasicontinuum), particularly targeting analysis of multi-walled carbon nanotubes. Higher order triangular elements are utilized for proper interpolation of atom positions of the CNT on the basis of QC approach. The computing scheme enables one to differentiate between the fully atomistic zone and the coarse-grained zone in the framework of the multiscale computing. Several numerical examples demonstrate the effectiveness and accuracy of the present methodology. More >
Open Access
ARTICLE
K. Yashiro1, Y. Nakashima1, Y. Tomita1
CMES-Computer Modeling in Engineering & Sciences, Vol.11, No.2, pp. 73-80, 2006, DOI:10.3970/cmes.2006.011.073
Abstract A simple back force model is proposed for
a dislocation cutting into γ' precipitate, taking the work
formaking and recovering an anti-phase boundary (APB)
into account. The first dislocation, or a leading partial of
a superdislocation, is acted upon by a back force whose
magnitude is equal to the APB energy. The second dislocation,
or a trailing partial of a superdislocation, is attracted
by the APB with a force of the same magnitude.
The model is encoded in the 3D discrete dislocation dynamics
(DDD) code and applied to the cutting behavior
of dislocations at a γ/γ' interface covered by an… More >
Open Access
ARTICLE
G.P. Nikishkov1
CMES-Computer Modeling in Engineering & Sciences, Vol.11, No.2, pp. 81-90, 2006, DOI:10.3970/cmes.2006.011.081
Abstract This paper presents the object oriented approach to programming the finite element method using the Java language. The developed finite element code consists of ten Java packages. Three main methods are related to generation of finite element models, solution of elastic and elastic-plastic boundary value problems, and visualization of models and solution results. Object-oriented model of the code is described. It is demonstrated that Java 1.5 new features are useful in development of the finite element code. Java 3D is used for visualization of models and results. More >
Open Access
ARTICLE
T. Fujimoto1 and T. Nishioka1
CMES-Computer Modeling in Engineering & Sciences, Vol.11, No.2, pp. 91-102, 2006, DOI:10.3970/cmes.2006.011.091
Abstract In the dynamic fracture of metallic material, some cracks propagate with the incidence of plastic deformation, and distinct plastic strain remains near the post-propagation area. In order to elucidate these dynamic nonlinear fracture processes, the moving finite element method is developed for nonlinear crack propagation. The T* integral is used as the parameter to estimate crack tip condition. First, the effect of material viscosity and crack propagation velocity have been discussed based on the numerical results for fracture under pure mode I high speed loading. Under mixed mode loading, numerical simulations for fracture path prediction are demonstrated for various crack… More >