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Elastic Beam (elastic + beam)
Selected AbstractsA unified formulation for continuum mechanics applied to fluid,structure interaction in flexible tubesINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 12 2005C. J. Greenshields Abstract This paper outlines the development of a new procedure for analysing continuum mechanics problems with a particular focus on fluid,structure interaction in flexible tubes. A review of current methods of fluid,structure coupling highlights common limitations of high computational cost and solution instability. It is proposed that these limitations can be overcome by an alternative approach in which both fluid and solid components are solved within a single discretized continuum domain. A single system of momentum and continuity equations is therefore derived that governs both fluids and solids and which are solved with a single mesh using finite volume discretization schemes. The method is validated first by simulating dynamic oscillation of a clamped elastic beam. It is then applied to study the case of interest,wave propagation in highly flexible tubes,in which a predicted wave speed of 8.58 m/s falls within 2% of an approximate analytical solution. The method shows further good agreement with analytical solutions for tubes of increasing rigidity, covering a range of wave speeds from those found in arteries to that in the undisturbed fluid. Copyright © 2005 John Wiley & Sons, Ltd. [source] Nonlinear actuation model for lateral electrostatically-actuated DC-contact RF MEMS series switchesMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 6 2007A. Lázaro Abstract In this work, a nonlinear model to predict actuation characteristics in lateral electrostatically-actuated DC-contact MEMS switches is proposed. In this case a parallel-plate approximation cannot be applied. The model is based on the equilibrium equation for an elastic beam. It is demonstrated that the contribution of fringing fields is essential. The model relies on finite-difference discretization of the structures, applying boundary conditions and is solved with a Gauss-Seidel relaxation iteration scheme. Its usefulness is demonstrated in a series MEMS switch with lateral interdigital electrostatic actuation. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1238,1241, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22450 [source] Model of inelastic impact of unit loadsPACKAGING TECHNOLOGY AND SCIENCE, Issue 1 2009Tomasz Piatkowski Abstract In this study, the authors present a model of the inelastic impact of bodies that takes place during handling of unit loads (cubiform parcels). A modified non-linear Kelvin model is proposed, in which the relationships between object strains and elastic and damping forces of the impact are represented by power functions. The results of analytical investigations on the proposed model were confirmed by experiments consisting in tests of free fall of the load on rigid ground and on elastic beam. The developed model allows the assessment of the influence of mechanical properties of loads and conveyor-line deflection mechanisms as well as impact velocity, on the dynamic forces exerted on the manipulated objects during the impact. Copyright © 2008 John Wiley & Sons, Ltd. [source] A simplified analysis method for piled raft foundations in non-homogeneous soilsINTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS, Issue 2 2003Pastsakorn Kitiyodom Abstract A simplified method of numerical analysis based on elasticity theory has been developed for the analysis of axially and laterally loaded piled raft foundations embedded in non-homogeneous soils and incorporated into a computer program "PRAB". In this method, a hybrid model is employed in which the flexible raft is modelled as thin plates and the piles as elastic beams and the soil is treated as springs. The interactions between structural members, pile,soil,pile, pile,soil,raft and raft,soil,raft interactions, are approximated based on Mindlin's solutions for both vertical and lateral forces with consideration of non-homogeneous soils. The validity of the proposed method is verified through comparisons with some published solutions for single piles, pile groups and capped pile groups in non-homogeneous soils. Thereafter, the solutions from this approach for the analysis of axially and laterally loaded 4-pile pile groups and 4-pile piled rafts embedded in finite homogeneous and non-homogeneous soil layers are compared with those from three-dimensional finite element analysis. Good agreement between the present approach and the more rigorous finite element approach is demonstrated. Copyright © 2002 John Wiley & Sons, Ltd. [source] | ||||||||||