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Showing 1 to 18 of 18 for “"initial imperfections"”.
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Effects of residual stresses and initial imperfections on earthquake response of steel moment frames
… contain seismic loading, includes the effects of initial geometric imperfections and inelastic behavior compounded by residual stresses, it is critical to explore the impact of these parameters on the seismic behavior of typical steel buildings before the DM is required for seismic design. To …
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On the Effect of Initial Imperfections On the Behavior of Thin-Walled Axially Compressed Circular Cylinders
Made available in DSpace on 2014-12-10T17:25:55Z (GMT). No. of bitstreams: 1 7020986.pdf: 2155306 bytes, checksum: f7d7b9fe32c30256adbaaa86390ad113 (MD5) Previous issue date: 1970
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Creep buckling of shells of revolution loaded under uniform external pressure
… by the parameter a/h ratio, magnitude of initial imperfections and material selection. The spherical shell has a lifetime longer than the cylindrical shell having the same a/h ratio, initial imperfections and material constants, while the critical mode numbers are the same.
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Asymptotic post-buckling analysis by Koiter's method with a general purpose finite element code
Many structures are sensitive to initial imperfections, sometimes leading to a great decrease in buckling load. Koiter showed that the effect of initial imperfections is largely determined by the initial post-buckling behavior of the perfect structure. The present work seeks to implement Koiter’s …
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Bifurcação secundária instável em placas retangulares
… in thin flat plates under the effects of initial imperfections and coupled modes is analysed in the presented work. Through this analysis it is detected, along the imperfect fundamental equilibrium path, secondary points of bifurcation which may be stable or unstable. The obtained results …
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Global bifurcations and chaos in nonlinear mechanical systems
… for externally excited nonlinear systems with initial imperfections and a semisimple linear operator. Explicit restrictions are obtained on parameters where such systems can exhibit chaotic dynamics. The results are demonstrated on a shallow arch system, which is subjected to a spatio-temporal …
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Investigation of the Stability of Metallic/Composited-Cased Solid Propellant Rocket Motors under External Pressure
… buckling loads and mode shapes. The effect of initial imperfections on the structural responses are also incorporated in the formulations. A variety of numerical examples are investigated to demonstrate the validity and efficiency of the purposed theory under various boundary condiitions and …
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Sensitivity analysis of ship longitudinal strength
… viz., yield. stress, Young's modulus, thickness, initial imperfections, breadth, depth, etc. The results obtained with this approach are in good agreement with those obtained by use of a more complex nonlinear finite element program USAS, developed by American Bureau of Shipping.
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Nonlinear flutter of composite shear-deformable panels in a high-supersonic flow
… faces of the panel. The possibility of small initial imperfections and in-plane edge restraints are also considered. Aerodynamic loads based on the third-order piston theory are used and the panel flutter equations are derived via Galerkin’s method. Periodic solutions and their bifurcations …
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Vibration, buckling and postbuckling of laminated composites with delaminations
… and the imperfection in the plate in the form of initial global deflection and initial delamination openings are included. A simple contact algorithm which precludes the physically inadmissible overlapping between delaminated surfaces is proposed and incorporated in the analysis. A sublaminate …
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Nonlinear Stability Analysis of Frame-Type Structures with Random Geometric Imperfections Using a Total-Lagrangian Finite Element Formulation
… the probability that a structure having random initial geometric imperfections will become unstable at a load less than a specified fraction of the perfect critical load. The overall objective of this dissertation is to present such a method for frame-type structures that become unstable at …
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Elastic and inelastic analysis of panel collapse by stiffener buckling
… by considering the plate effective width), initial imperfections and plasticity are included. The method uses the Rayleigh-Ritz approach. Based on an assumed strain distribution, a displacement field is obtained for the tripping model, and the total potential energy functional is then …
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Layerwise theory for discretely stiffened laminated cylindrical shells
… skin. The layerwise theory is also used to model initial imperfections of the unstressed configuration. A finite element scheme of the layerwise model is developed and applied here to investigate the effect of imperfections on the response of laminated cylindrical shells. Using a finite element …
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Consideración de las imperfecciones en el análisis de placas de acero, de secciones armadas de puentes de acero y mixtos, mediante el método de los elementos finitos
… Thesis provides recommendations to consider the initial imperfections, geometric imperfections and residual stresses, to obtain realistic results in the assessment of bridges’ plated sections with FEM.
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Stochastic Methods for Robust Design of Launch Vehicle Structures
The important role of initial imperfections on decreasing the buckling load of imperfection sensitive thin-shelled structures, commonly used on launch vehicles such as the Ariane family, has been widely studied since the 1930s. Research in this area has resulted in a variety of analytical and …
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Interphase properties and their effects on the compression mechanics of polymeric composites
… strength, as is made further evident by the initial postbuckling description of the fiber-binder system. Completion of the nonlinear (kinematic and constitutive) buckling problem by asymptotic approximation will lead to a fundamental description of the failure mode and strength as related to …
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Hull girder ultimate strength and fracture toughness of damaged marine structures
… the ultimate strength of stiffened plates with imperfections in the form of imperfections, where a non-linear finite element method is employed on a wide range of typical ship panel geometries. The new simplified analytical method must be generalized to deal with such combined load cases. The …
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The effect of stiffener dimensions on the buckling of webplates subjected to bending
… gave information on the behaviour of girders initially plane and girders which were subject to sane initial imperfections. These results threw some interesting light on the comparative behaviour of the girders in these two states.<br/><br/>