In this paper, the results of an extensive numerical analysis program devoted to the evaluation of the inelastic response of I-shaped aluminium alloy beams in non-uniform bending are presented. By using a numerical mo...
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In this paper, the results of an extensive numerical analysis program devoted to the evaluation of the inelastic response of I-shaped aluminium alloy beams in non-uniform bending are presented. By using a numerical model implemented in the implicit FE code ABAQUS/Standard and largely calibrated with experimental tests, the main geometrical and mechanical parameters influencing the plastic behaviour of such beams are investigated. the results obtained in this study confirm the important role of the material hardening which, in addition to the local slenderness of compressed elements, has a strong influence on both ultimate moment and rotational capacity of the member. Moreover, it is shown that the influence of the other parameters, namely flange-to-web slenderness ratio, moment gradient, web slenderness and sectional area ratio, on the plastic capacity of the considered beams in terms of strength and deformability is of a secondary importance even if it is not negligible. On the whole, the results, which are obtained for two different tempers, emphasize the need to improve the present guidelines provided by the european code for aluminium structures relating to cross-sectional classification. More accurate class limits for outstand elements, which are able to account for the most important influential parameters on the plastic behaviour, are therefore proposed. (C) 2004 Civil-Comp Ltd. and Elsevier Ltd. All rights re served.
Residual stresses can occur in many engineering components such as aircraft and aerospace. they can be caused by the forces and thermal gradient imposed during the forming process. Compressive stresses are sometimes p...
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ISBN:
(纸本)0878499008
Residual stresses can occur in many engineering components such as aircraft and aerospace. they can be caused by the forces and thermal gradient imposed during the forming process. Compressive stresses are sometimes purposely induced in near surface of materials by shot peening to help resist crack growth and fracture of components and to increase the working life under fatigue load. the knowledge of the magnitude and the distribution of the residual stresses, allows the engineer to optimize the forming operation and the materials choice. theoretical elastic analyses to characterize the calibration coefficients developed under both plane stress conditions are proposed. these coefficients are used to link measured surface and/or subsurface strain to the residual stress. three dimensional finite element analysis were developed and used to predict the magnitude and the direction of principal residual stresses in the depth of the material. the effect of sample geometry is studied of spherical samples on the calibration coefficient.
In this paper, we propose new design methods for linear phase FIR filters with signed power-of-two (SP2) coefficients based on a semi-definite programming (SDP) relaxation method. the proposed methods include a linear...
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Safety of persons, protection of equipment and continuity of power supply are the main objectives of the grounding system of a large electrical installation. For its accurate design, it is essential to determine the p...
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ISBN:
(纸本)0948749733
Safety of persons, protection of equipment and continuity of power supply are the main objectives of the grounding system of a large electrical installation. For its accurate design, it is essential to determine the potential distribution on the earth surface and the equivalent resistance of the system. In this paper, we present a numerical approach based on the boundary element method for grounding analysis in layered soils. the feasibility of this formulation is discussed by means of its application to a real grounding system with different kinds of layered soil models. (C) 2002 Civil-Comp Ltd and Elsevier Science Ltd. All rights reserved.
Iterative Feedback Tuning (IFT) is a direct tuning method using closed loop experimental data. the method is based on numerical optimization and in each iteration an unbiased gradient estimate is used. In this contrib...
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this paper deals withthe Boyd-Barratt paradigm for feedback controller design. this approach combines the Youla parameterization with convex optimization. In this paper, this paradigm is accepted in its entirety, but...
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A dynamic domain decomposition strategy is proposed for the effective parallel implementation of combined finite/discrete element approaches for problems involving multi-fracture and multi-contact phenomena. Attention...
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the many advancements in the area of numerical optimization in conjunction withthe ever-increasing power of computers have made optimization-based filter design an increasingly important field of research. In this pa...
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the many advancements in the area of numerical optimization in conjunction withthe ever-increasing power of computers have made optimization-based filter design an increasingly important field of research. In this pa...
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the many advancements in the area of numerical optimization in conjunction withthe ever-increasing power of computers have made optimization-based filter design an increasingly important field of research. In this paper, several recent optimization methods for the design of FIR and IIR digital filters and filter banks are reviewed.
the optimal control problems associated with bioprocesses are usually very difficult to solve due to their highly nonlinear and multimodal nature. Here, recently developed stochastic algorithms are used to succesfully...
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ISBN:
(纸本)9783952426906
the optimal control problems associated with bioprocesses are usually very difficult to solve due to their highly nonlinear and multimodal nature. Here, recently developed stochastic algorithms are used to succesfully solve two complex case studies: the optimal fed-batch control of induced foreign protein production by recombinant bacteria and the optimal drug scheduling of cancer chemotherapy. these stochastic algorithms are shown to have several advantages over other strategies proposed in the recent literature, including global and rapid convergence properties and very easy implementation.
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