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Yumin Cheng - One of the best experts on this subject based on the ideXlab platform.

  • the interpolating Complex Variable element free galerkin method for temperature field problems
    International Journal of Applied Mechanics, 2015
    Co-Authors: Yajie Deng, Chao Liu, M J Peng, Yumin Cheng
    Abstract:

    In this paper, an interpolating Complex Variable moving least-squares (ICVMLS) method is presented. In the ICVMLS method, the trial function of a two-dimensional problem is formed with a one-dimensional basis function, and the shape function of the ICVMLS method satisfies the property of Kronecker δ function. The ICVMLS method has greater computational efficiency than the moving least-squares (MLS) approximation. Then combining the ICVMLS method with the Galerkin weak form of temperature field problems, an interpolating Complex Variable element-free Galerkin (ICVEFG) method is proposed. In the ICVEFG method, we can obtain the equation system by applying the essential boundary conditions directly. Compared with the element-free Galerkin (EFG) method and the Complex Variable element-free Galerkin (CVEFG) method, the ICVEFG method in this paper has higher accuracy and efficiency.

  • an improved Complex Variable element free galerkin method for two dimensional large deformation elastoplasticity problems
    Computer Methods in Applied Mechanics and Engineering, 2014
    Co-Authors: K M Liew, Yumin Cheng
    Abstract:

    Abstract This paper presents the formulation and numerical implementation of the improved Complex Variable element-free Galerkin (ICVEFG) method for two-dimensional large deformation problems of elastoplasticity in total Lagrangian description. The ICVEFG method is a novel element free Galerkin (EFG) method based on the improved Complex Variable moving least-squares (ICVMLS) approximation. The ICVMLS approximation has all the advantages inherited from the Complex Variable moving least-squares (CVMLS) approximation. The function J in the ICVMLS approximation has an explicit physical meaning, compared with the former. The Galerkin weak form is employed to obtain the equations system and the penalty method is used to apply essential boundary conditions. Several numerical examples presented show that the ICVEFG method has greater precision and efficiency compared to the EFG and CVEFG methods.

  • the Complex Variable element free galerkin cvefg method for two dimensional elastodynamics problems
    International Journal of Applied Mechanics, 2012
    Co-Authors: Yumin Cheng, J F Wang
    Abstract:

    The Complex Variable moving least-squares (CVMLS) approximation is discussed in this paper, and the mathematical and physical meaning of the Complex functional in the CVMLS approximation is presented. With the CVMLS approximation, the trial function of a two-dimensional problem is formed with a one-dimensional basis function. Then combining the CVMLS approximation and the Galerkin weak form, we investigate the Complex Variable element-free Galerkin (CVEFG) method for two-dimensional elastodynamics problems. The penalty method is used to apply the essential boundary conditions, and the implicit time integration method, which is the Newmark method, is used for time history analysis. Then the corresponding formulae of the CVEFG method for two-dimensional elastodynamics problems are obtained. For the purposes of demonstration, some selected numerical examples are solved using the CVEFG method. Compared with the EFG method, the CVEFG method has greater precision.

  • Complex Variable element free galerkin method for viscoelasticity problems
    Chinese Physics B, 2012
    Co-Authors: Yumin Cheng, Miaojuan Peng
    Abstract:

    Based on the Complex Variable moving least-square (CVMLS) approximation, the Complex Variable element-free Galerkin (CVEFG) method for two-dimensional viscoelasticity problems under the creep condition is presented in this paper. The Galerkin weak form is employed to obtain the equation system, and the penalty method is used to apply the essential boundary conditions, then the corresponding formulae of the CVEFG method for two-dimensional viscoelasticity problems under the creep condition are obtained. Compared with the element-free Galerkin (EFG) method, with the same node distribution, the CVEFG method has higher precision, and to obtain the similar precision, the CVEFG method has greater computational efficiency. Some numerical examples are given to demonstrate the validity and the efficiency of the method.

  • a novel Complex Variable element free galerkin method for two dimensional large deformation problems
    Computer Methods in Applied Mechanics and Engineering, 2012
    Co-Authors: Funong Bai, Yumin Cheng, K M Liew
    Abstract:

    Abstract Based on Complex Variable theory and moving least-squares (MLS) approximation, the improved Complex Variable moving least-squares (ICVMLS) approximation is discussed in this paper. Compared with Complex Variable moving least-squares (CVMLS) approximation, the function in the ICVMLS approximation has an explicit physics meaning. By using a new basis function, the ICVMLS approximation can obtain greater precision and computational efficiency. Based on the ICVMLS approximation, an improved Complex Variable element-free Galerkin (ICVEFG) method, which belongs to a novel element free Galerkin (EFG) method, is presented for two-dimensional large deformation problems. The Galerkin weak form is employed to obtain the equations, while the penalty method is used to apply the essential boundary conditions. Then the corresponding formulae of the ICVEFG method for two-dimensional large deformation problems are obtained. Compared with the EFG method, the ICVEFG method has greater precision and efficiency.

K M Liew - One of the best experts on this subject based on the ideXlab platform.

  • a numerical framework for two dimensional large deformation of inhomogeneous swelling of gels using the improved Complex Variable element free galerkin method
    Computer Methods in Applied Mechanics and Engineering, 2014
    Co-Authors: Zan Zhang, K M Liew
    Abstract:

    Abstract A numerical framework based on the improved Complex Variable element-free Galerkin (ICVEFG) method is developed for large deformation analysis of inhomogeneous swelling of gels. In this work, a decomposed free-energy function is derived that avoids the difficulty of treating the chemical potential as a temperature-like Variable by changing the chemical potential load into a mechanical load. The Galerkin weak form equation system is derived for inhomogeneous swelling of gels. The essential boundary conditions are imposed through the penalty method. This leads to the corresponding formulae of the improved Complex Variable moving least-squares (ICVMLS) approximation for 2-D large deformation inhomogeneous swelling of gels. Some example problems of inhomogeneous swelling induced behaviors such as wrinkling, crease and bifurcation are investigated using the developed ICVEFG framework.

  • an improved Complex Variable element free galerkin method for two dimensional large deformation elastoplasticity problems
    Computer Methods in Applied Mechanics and Engineering, 2014
    Co-Authors: K M Liew, Yumin Cheng
    Abstract:

    Abstract This paper presents the formulation and numerical implementation of the improved Complex Variable element-free Galerkin (ICVEFG) method for two-dimensional large deformation problems of elastoplasticity in total Lagrangian description. The ICVEFG method is a novel element free Galerkin (EFG) method based on the improved Complex Variable moving least-squares (ICVMLS) approximation. The ICVMLS approximation has all the advantages inherited from the Complex Variable moving least-squares (CVMLS) approximation. The function J in the ICVMLS approximation has an explicit physical meaning, compared with the former. The Galerkin weak form is employed to obtain the equations system and the penalty method is used to apply essential boundary conditions. Several numerical examples presented show that the ICVEFG method has greater precision and efficiency compared to the EFG and CVEFG methods.

  • a novel Complex Variable element free galerkin method for two dimensional large deformation problems
    Computer Methods in Applied Mechanics and Engineering, 2012
    Co-Authors: Funong Bai, Yumin Cheng, K M Liew
    Abstract:

    Abstract Based on Complex Variable theory and moving least-squares (MLS) approximation, the improved Complex Variable moving least-squares (ICVMLS) approximation is discussed in this paper. Compared with Complex Variable moving least-squares (CVMLS) approximation, the function in the ICVMLS approximation has an explicit physics meaning. By using a new basis function, the ICVMLS approximation can obtain greater precision and computational efficiency. Based on the ICVMLS approximation, an improved Complex Variable element-free Galerkin (ICVEFG) method, which belongs to a novel element free Galerkin (EFG) method, is presented for two-dimensional large deformation problems. The Galerkin weak form is employed to obtain the equations, while the penalty method is used to apply the essential boundary conditions. Then the corresponding formulae of the ICVEFG method for two-dimensional large deformation problems are obtained. Compared with the EFG method, the ICVEFG method has greater precision and efficiency.

  • Complex Variable boundary element free method for two dimensional elastodynamic problems
    Computer Methods in Applied Mechanics and Engineering, 2009
    Co-Authors: K M Liew, Yumin Cheng
    Abstract:

    Abstract We proposed a new direct meshless boundary integral equation technique – the Complex Variable boundary element-free method (CVBEFM) based on the Complex Variable moving least-squares (CVMLS) approximation and the boundary element-free method (BEFM), to study the two-dimensional elastodynamic problems. With the CVMLS approximation, the trial function of a two-dimensional problem is formed with a one-dimensional basis function. The number of unknown coefficients in the trial function of the CVMLS approximation is less than that in the trial function of the moving least-squares (MLS) approximation. Therefore it requires fewer nodes in the meshless method which formed from the CVMLS approximation than that formed from the MLS approximation with no lose of precision. The Laplace transform is used to formulate the boundary integral equations of the two-dimensional elastodynamics and then the formulae of the CVBEFM for two-dimensional elastodynamic problems are derived. The CVBEFM is a direct numerical method in which the basic unknown quantities are the real solutions of the nodal Variables. Moreover in the CVBEFM, the boundary conditions can be applied directly and easily that leads to a greater computational precision. In this paper, we selected a few numerical examples to illustrate the applicability of the CVBEFM.

  • Complex Variable moving least squares method a meshless approximation technique
    International Journal for Numerical Methods in Engineering, 2007
    Co-Authors: K M Liew, Yumin Cheng, Cong Feng, S Kitipornchai
    Abstract:

    Based on the moving least-squares (MLS) approximation, we propose a new approximation method-the Complex Variable moving least-squares (CVMLS) approximation. With the CVMLS approximation, the trial function of a two-dimensional problem is formed with a one-dimensional basis function. The number of unknown coefficients in the trial function of the CVMLS approximation is less than in the trial function of the MLS approximation, and we can thus select fewer nodes in the meshless method that is formed from the CVMLS approximation than are required in the meshless method of the MLS approximation with no loss of precision. The meshless method that is derived from the CVMLS approximation also has a greater computational efficiency. From the CVMLS approximation, we propose a new meshless method for two-dimensional elasticity problems-the Complex Variable meshless method (CVMM)-and the formulae of the CVMM for two-dimensional elasticity problems are obtained. Compared with the conventional meshless method, the CVMM has a greater precision and computational efficiency. For the purposes of demonstration, some selected numerical examples are solved using the CVMM.

Yanfeng Wang - One of the best experts on this subject based on the ideXlab platform.

Danfeng Liu - One of the best experts on this subject based on the ideXlab platform.

  • pinning impulsive synchronization of Complex Variable dynamical network
    Communications in Nonlinear Science and Numerical Simulation, 2015
    Co-Authors: Danfeng Liu
    Abstract:

    Abstract In this paper, pinning combining with impulsive control scheme is adopted to investigate the synchronization of Complex-Variable dynamical network. Based on the Lyapunov function method and mathematical analysis technique, sufficient conditions for achieving synchronization is first analytically derived. This result extends the condition derived for real-Variable dynamical network to Complex-Variable network. Further, adaptive strategy is adopted to relax the restrictions on the impulsive intervals and reduce the control cost. Noticeably, the proposed adaptive pinning impulsive control scheme is universal for different dynamical networks to some extent. The impulsive instants are chosen by solving a series of maximum problems subject to the derived conditions. Several numerical simulations are performed to illustrate the effectiveness and correctness of the derived theoretical results.

  • adaptive impulsive synchronization of uncertain drive response Complex Variable chaotic systems
    Nonlinear Dynamics, 2014
    Co-Authors: Danfeng Liu
    Abstract:

    In this paper, impulsive synchronization of drive-response Complex-Variable chaotic systems is investigated. The drive-response systems with known parameters is considered via impulsive control and adaptive scheme as well as systems with unknown parameters. Noticeably, adaptive strategy is adopted to relax the restriction on the impulsive interval, and the system parameters need not to be known beforehand. According to the Lyapunov stability theory, some synchronization criteria are derived and verified by several numerical simulations.

Junwei Sun - One of the best experts on this subject based on the ideXlab platform.