Open Access
ARTICLE
M. Timmel1, M. Kaliske1, S. Kolling2, R. Mueller3
CMC-Computers, Materials & Continua, Vol.5, No.3, pp. 161-172, 2007, DOI:10.3970/cmc.2007.005.161
Abstract A damage approach based on a material model with microstructural evolution is presented. In contrast to phenomenological constitutive laws, the material response is given by mechanisms at the microscale. At first, a micromechanical substructure is chosen, which represents the overall material behaviour. Then the system is described using a micromechanical model. A geometrical modification of the microstructure is allowed to minimize the total energy. Consequently, the global stiffness is reduced. In this context, thermodynamical considerations are based on configurational forces. With the help of the discussed approach, void growth phenomena of materials, which lead to softening behaviour, can be taken… More >
Open Access
ARTICLE
A. J. C. Crespo1, M. Gómez-Gesteira1, R. A. Dalrymple2
CMC-Computers, Materials & Continua, Vol.5, No.3, pp. 173-184, 2007, DOI:10.3970/cmc.2007.005.173
Abstract Smoothed Particle Hydrodynamics is a purely Lagrangian method that can be applied to a wide variety of fields. The foundation and properties of the so called dynamic boundary particles (DBPs) are described in this paper. These boundary particles share the same equations of continuity and state as the moving particles placed inside the domain, although their positions and velocities remain unaltered in time or are externally prescribed. Theoretical and numerical calculations were carried out to study the collision between a moving particle and a boundary particle. The boundaries were observed to behave in an elastic manner in absence of viscosity.… More >
Open Access
ARTICLE
V. Vavourakis, D. Polyzos1
CMC-Computers, Materials & Continua, Vol.5, No.3, pp. 185-196, 2007, DOI:10.3970/cmc.2007.005.185
Abstract Very recently, Vavourakis, Sellountos and Polyzos (2006) ({CMES: Computer Modeling in Engineering {\&} Sciences, vol. 13, pp. 171--184}) presented a comparison study on the accuracy provided by five different elastostatic Meshless Local Petrov-Galerkin (MLPG) type formulations, which are based on Local Boundary Integral Equation (LBIE) considerations. One of the main conclusions addressed in this paper is that the use of derivatives of the Moving Least Squares (MLS) shape functions decreases the solution accuracy of any MLPG(LBIE) formulation. In the present work a new, free of MLS-derivatives and non-singular MLPG(LBIE) method for solving elastic problems is demonstrated. This is accomplished by… More >
Open Access
ARTICLE
Cheng-Hung Huang1, Hsin-Hsien Wu2
CMC-Computers, Materials & Continua, Vol.5, No.3, pp. 197-212, 2007, DOI:10.3970/cmc.2007.005.197
Abstract The conjugate gradient method (CGM) is applied in an inverse fin design problem in estimating the optimum shapes for the non-Fourier spine and longitudinal fins based on the desired fin efficiency and fin volume at the specified time. One of the advantages in using CGM in the inverse design problem lies in that it can handle problems having a huge number of design parameters easily and converges very fast.
The validity of using CGM in solving the present inverse design problem is justified by performing the numerical experiments. Several test cases involving different design fin efficiency, design fin volume, specified… More >
Open Access
ARTICLE
Le-Chung Shiau1, Shih-Yao Kuo2
CMC-Computers, Materials & Continua, Vol.5, No.3, pp. 213-222, 2007, DOI:10.3970/cmc.2007.005.213
Abstract A high precision high order triangular plate element is developed for the linear flutter analysis of thermally buckled composite sandwich plates. Due to uneven thermal expansion in the two local material directions, the buckling mode of the plate may be shifted from one pattern to another for certain fiber orientation or plate aspect ratio as the aerodynamic pressure is present. This buckle pattern change alters the frequencies and modes of the plate and that in turn changes the flutter coalescent modes. Numerical results show that temperature has a destabilizing effect on the flutter boundary but the aerodynamic pressure has a… More >