Papers by Keyword: Boundary Element Analysis

Abstract: The stress distribution of structure in plan coil spring usually is three dimensional. The singularities of Cauchy principal integral and logarithmic integral during calculating the elements of the coefficient matrix are studied respectively so that the singularity of Cauchy integral is eliminated in this paper, which is based on boundary integral equation in axisymmetric potential problem. Moreover, the order of singularity in logarithmic integral is reduced. Comparison between the results deduced here and the analytical solutions shows that the present derivation is correct and the algorithm is efficient as well.

Abstract: In this work, a boundary element formulation for 2D linear viscoelastic solid polymers subjected to body force of gravity has been presented. Structural analysis of solid polymers is one of the most important subjects in advanced engineering structures. From basic assumptions of the viscoelastic constitutive equations and the weighted residual techniques, a simple but effective boundary element formulation is implemented for standard linear solid (SLS) model. The SLS model provides an approximate representation of observed behavior of a real advanced polymer in its viscoelastic range. This approach avoids the use of relaxation functions and mathematical transformations, and it is able to solve quasistatic viscoelastic problems with any load time-dependence and boundary conditions. Problem of pressurization of thick-walled viscoelastic tanks made of PMMA polymer, which subjected to a body force, is completely analyzed.

Abstract: In this paper, a 2D boundary element approach able to model viscoelastic functionally graded materials (FGM) is presented. A numerical implementation of the Somigliana identity for displacements is developed to solve 2D problems of exponentially graded elasticity. An FGM is an advanced material in which its composition changes gradually resulting in a corresponding change in properties of the material. The FGM concept can be applied to various materials for structural and functional uses. Our model needs only the Green’s function of nonhomogeneous elastostatic problems with material properties that vary continuously along a given dimension. We consider the material properties to be an exponential function of Cartesian coordinates x. As application, a numerical example is provided to validate the proposed boundary integral equation approach.

Abstract: This paper establishes a near-field acoustic radiation pressure solving model applying with acoustics theory and derives an initial acoustic levitation calculating formula of rotundity objects. Combining with finite element and boundary element analysis, levitate conditions of levitated objects are calculated. This paper takes rectangular ultrasonic oscillator for example, testing and analyzing conditions of near-field acoustic levitation by using self-designed test equipments, the results are proved to be better.

Abstract: Boundary element (BE) analysis is well known as a tool for assessing the stiffness and strength of engineering components, but, along with finite element (FE) techniques, it is also finding new applications as a means of simulating the behaviour of deformable objects within virtual reality simulations since it exploits precisely the same kind of surface-only definition used for visual rendering of three-dimensional solid objects. This paper briefly reviews existing applications of BE and FE within virtual reality, and describes recent work on the BE-based simulation of aspects of surgical operations on the brain, making use of commercial hand-held force-feedback interfaces (haptic devices) to measure the positions of the virtual surgical tools and provide tactile feedback to the user. The paper presents an overview of the project then concentrates on recent developments, including the incorporation of simulated tumours in the virtual brain.

Abstract: In this paper, the boundary element analysis of viscoelastic strain energy release rate ) (t G for the cracked linear viscoelastic solids has been attempted. The ) (t G has been defined as the derivative of the viscoelastic potential energy ) (t P with respect to crack length a . Numerical results show the applicability of the proposed method to the analysis of the cracked linear viscoelastic structures.