Open Access
ARTICLE
Xiangkui Zhang1, Changsheng Wang1,2, Ping Hu1
CMES-Computer Modeling in Engineering & Sciences, Vol.111, No.6, pp. 473-492, 2016, DOI:10.3970/cmes.2016.111.473
Abstract The basic idea of quasi-conforming method is that the strain-dis- placement equations are weakened as well as the equilibrium equations. In this paper, an 18-DOF triangular element for couple stress theory is proposed within the framework of quasi-conforming technique. The formulation starts from truncated Taylor expansion of strains and appropriate interpolation functions are chosen to calculate strain integration. This element satisfies C0 continuity with second order accuracy and weak C1 continuity simultaneously. Numerical examples demonstrate that the proposed model can pass the C0 More >
Open Access
ARTICLE
Nives Brajčić Kurbaša1, Blaž Gotovac1, Vedrana Kozulić1
CMES-Computer Modeling in Engineering & Sciences, Vol.111, No.6, pp. 493-530, 2016, DOI:10.3970/cmes.2016.111.493
Abstract This paper presents exponential Atomic Basis Functions (ABF), which are called Eup(x,ω). These functions are infinitely differentiable finite functions that unlike algebraic up(x) basis functions, have an unspecified parameter - frequency w. Numerical experiments show that this class of atomic functions has good approximation properties, especially in the case of large gradients (Gibbs phenomenon). In this work, for the first time, the properties of exponential ABF are thoroughly investigated and the expression for calculating the value of the basis function at an arbitrary point of the domain is given in a form suitable for implementation in numerical analysis. Application of… More >
Open Access
ARTICLE
Liu Duo-Neng1,2, Hou Zhong-Xi1, Guo Zheng1, Yang Xi-Xiang1, Gao Xian-Zhong1
CMES-Computer Modeling in Engineering & Sciences, Vol.111, No.6, pp. 531-565, 2016, DOI:10.3970/cmes.2016.111.531
Abstract Dynamic soaring is a flight maneuver to exploit gradient wind field to extend endurance and traveling distance. Optimal trajectories for permissible wind conditions are generated for loitering dynamic soaring as well as for traveling patterns with a small unmanned aerial vehicle. The efficient direct collection approach based on the Runge-Kutta integrator is used to solve the optimization problem. The fast convergence of the optimization process leads to the potential for real-time applications. Based on the results of trajectory optimizations, the general permissible wind conditions which involve the allowable power law exponents and feasible reference wind strengths supporting dynamic soaring are… More >
Open Access
ARTICLE
Xuechuan Wang1, Satya N. Atluri2
CMES-Computer Modeling in Engineering & Sciences, Vol.111, No.6, pp. 567-585, 2016, DOI:10.3970/cmes.2016.111.567
Abstract This paper compares the variational iteration method (VIM), the Adomian decomposition method (ADM) and the Picard iteration method (PIM) for solving a system of first order nonlinear ordinary differential equations (ODEs). A unification of the concepts underlying these three methods is attempted by considering a very general iterative algorithm for VIM. It is found that all the three methods can be regarded as special cases of using a very general matrix of Lagrange multipliers in the iterative algorithm of VIM. The global variational iteration method is briefly reviewed, and further recast into a Local VIM, which is much more convenient… More >