Vol.11, No.3, 2009-Table of Contents
  • Interfaces Between two Dissimilar Elastic Materials
  • Abstract In this paper the near tip solutions for interface corners written in terms of the stress intensity factors are presented in a unified expression. This single expression is applicable for any kinds of interface corners including corners and cracks in homogeneous materials as well as interface corners and interface cracks lying between two dissimilar materials, in which the materials can be any kinds of linear elastic anisotropic materials or piezoelectric materials. Through this unified expression of near tip solutions, the singular orders of stresses and their associated stress/electric intensity factors for different kinds of interface problems can be determined through… More
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  • The Method of Fundamental Solutions for One-Dimensional Wave Equations
  • Abstract A meshless numerical algorithm is developed for the solutions of one-dimensional wave equations in this paper. The proposed numerical scheme is constructed by the Eulerian-Lagrangian method of fundamental solutions (ELMFS) together with the D'Alembert formulation. The D'Alembert formulation is used to avoid the difficulty to constitute the linear algebraic system by using the ELMFS in dealing with the initial conditions and time-evolution. Moreover the ELMFS based on the Eulerian-Lagrangian method (ELM) and the method of fundamental solutions (MFS) is a truly meshless and quadrature-free numerical method. In this proposed wave model, the one-dimensional wave equation is reduced to an implicit… More
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  • A Direct Forcing Immersed Boundary Method Based Lattice Boltzmann Method to Simulate Flows with Complex Geometry
  • Abstract In the present study, a lattice Boltzmann method based new immersed boundary technique is proposed for simulating two-dimensional viscous incompressible flows interacting with stationary and moving solid boundaries. The lattice Boltzmann method with known force field is used to simulate the flow where the complex geometry is immersed inside the computational domain. This is achieved via direct-momentum forcing on a Cartesian grid by combining "solid-body forcing" at solid nodes and interpolation on neighboring fluid nodes. The proposed method is examined by simulating decaying vortex, 2D flow over an asymmetrically placed cylinder, and in-line oscillating cylinder in a fluid at rest.… More
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  • Design of Non-linear Beam-type Spring for Designated Loading and Displacement for Use in Lower-limb Orthosis
  • Abstract In this study, a method for designing an in-plane, free-form, beam-type spring for use in a lower-limb orthosis was developed. A spring designed by this method follows a predefined relationship between loading and displacement. To facilitate the analysis of the spring, it was divided into several beam segments. The stiffness equations related to loading (including moment and force) and displacements (linear and rotation) of each beam segment were found to follow a modified (non-linear) Castigliano's second theorem (NCST) and were assembled by using the continuity of nodal points of neighbouring curve segments. Using the proposed method, a spring designer can… More
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