1,720,982 research outputs found
A Multiple-Input Multiple-Output Smoothing Technique: Theory and Application to Aircraft Data
No full textInfluence of Some Thin Shell Theories on the Evaluation of the Noise Level in Stiffened Cylinders
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A Comparison of Some Thin Shell Theories used for the Dynamic Analysis of Stiffened Cylinders
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On-line health monitoring of aeronautical structures using a vibration-based method
No full textThe aim of this paper is to apply to a typical aeronautical structure a Vibration Based Method which detects damage in structures when a 'description of normality' is provided. A model of the primary structure of a wing is developed such that damage of different extent and type can be introduced. Despite the only slight modification of the dynamic behaviour of the wing due to the presence of the fault, numerical simulations demonstrate that damage of moderate extent in spar-flanges can be detected using this technique even if the dynamic characteristics vary due to changes in the mass of the fue
Laminated shell model with second-order expansion of the reciprocals of Lamé coefficients Hα, Hβ and interlayer continuities fulfilment
No full textA multilayered, technical shell model accounting for the layerwise kinematics is developed, aimed to conjugate overall and local scale factors. It is based on a third-order zig-zag approximation of in-plane displacements, to satisfy a priori the interlayer stress continuity conditions, a constant transverse displacement and a second-order expansion of Lamé's coefficients across the thickness. The traction-free boundary conditions on transverse shear stresses at the upper and lower bounding surfaces are also enforced. As in any zig-zag model, the unknowns (the three displacements and the two shear rotations on the reference shell surface, as in conventional equivalent single-layer shell models) do not depend on the number of constituent layers, so that the present shell model is cost-effective. Furthermore, linear and third-order single-layer shell models and a linear zig-zag shell model can be obtained as particular cases. Numerical applications concern laminated cylindrical shell and shell panel samples wherein solutions from different two-dimensional models and the three-dimensional elasticity solution are available for comparisons
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