S. Gao¹, K. Nakasa², K. Nogi³, L. Huang⁴

CMC-Computers, Materials & Continua, Vol.22, No.1, pp. 39-54, 2011, DOI:10.3970/cmc.2011.022.039

Abstract An incremental press-forming method was newly developed for the fabrication of spiral plates of a continuous screw conveyer, boring screw, screw pump and so on. In this method, a pair of V-shaped punches and dies with two opposite inclined edges are used instead of punch and die with spiral surfaces. The experiments on incremental forming were carried out on aluminum alloy and steel disks with a hole and a slit, and the deformation process of the plate during and after the press-forming was simulated by a finite element method (FEM). The press-forming shows that the spiral plate has a correct… More >

Veturia Chiroiu¹, Ligia Munteanu¹, Pier Paolo Delsanto²

CMC-Computers, Materials & Continua, Vol.16, No.1, pp. 75-100, 2010, DOI:10.3970/cmc.2010.016.075

Abstract Conventional continuum theories are unable to capture the observed indentation size effects, due to the lack of intrinsic length scales that represent the measures of nanostructure in the constitutive relations. In order to overcome this deficiency, the Toupin-Mindlin strain gradient theory of nanoindentation is formulated in this paper and the size dependence of the hardness with respect to the depth and the radius of the indenter for multiple walled carbon nanotubes is investigated. Results show a peculiar size influence on the hardness, which is explained via the shear resistance between the neighboring walls during the buckling of the multiwalled nanotubes. More >

Hrvoje Gotovac¹, Vedrana Kozulić², Blaž Gotovac¹

CMC-Computers, Materials & Continua, Vol.15, No.3, pp. 173-198, 2010, DOI:10.3970/cmc.2010.015.173

Abstract The space-time Adaptive Fup Collocation Method (AFCM) for solving boundary-initial value problems is presented. To solve the one-dimensional initial boundary value problem, we convert the problem into a two-dimensional boundary value problem. This quasi-boundary value problem is then solved simultaneously in the space-time domain with a collocation technique and by using atomic Fup basis functions. The proposed method is a generally meshless methodology because it requires only the addition of collocation points and basis functions over the domain, instead of the classical domain discretization and numerical integration. The grid is adapted progressively by setting the threshold as a direct measure… More >

Chein-Shan Liu¹

CMC-Computers, Materials & Continua, Vol.11, No.1, pp. 15-32, 2009, DOI:10.3970/cmc.2009.011.015

Abstract Motivated by the evolutionary and dissipative properties of parabolic type partial differential equation (PDE), Liu (2008a) has proposed a natural and mathematically equivalent approach by transforming the quasilinear elliptic PDE into a parabolic one. However, the above paper only considered a rectangular domain in the plane, and did not treat the difficulty arisen from the quasilinear PDE defined in an arbitrary plane domain. In this paper we propose a new technique of internal and boundary residuals in a fictitious rectangular domain, which are driving forces for the ordinary differential equations based on the Fictitious Time Integration Method (FTIM). Several numerical… More >

Ramana M. Pidaparti¹, Anuj Puri², Mathew J. Palakal², Ajay Kashyap³

CMC-Computers, Materials & Continua, Vol.2, No.1, pp. 65-76, 2005, DOI:10.3970/cmc.2005.002.065

Abstract A two-dimensional corrosion initiation and growth model for aircraft aluminum materials is developed. The model takes into account the electro-chemical parameters as well as specific rules governing corrosion mechanisms. The simulation program is implemented in a cellular automata framework. The corrosion initiation and growth patterns obtained from simulations are compared qualitatively and quantitatively to the experimental data obtained from the Center for Materials Diagnostics at the University of Dayton Research Institute, Dayton. The results indicate that the present model effectively captures the corrosion damage process including initiation and growth. The effects of various electro-chemical parameters on the damage growth obtained… More >