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Cellular beams with circular, oval and sinusoidal openings are used in construction practice now. The problems of determination of deformations of such beams and critical loads under local buckling of web are considered. Calculation of cellular I-beams deformations was performed using the finite element method. Critical loads were also determined with the numerical calculation by FEM. [ABSTRACT FROM AUTHOR]

Long and thin cantilever plates loaded by bending moment often lose the stability. The solutions as the bending moment is used are investigated, but as the loading is the bending moment and torsion moment, such problems are not analysed. In this study the buckling equation was obtained and it can be solved by the method of Lagrange constants varying. But mathematical difficulties arise as the buckling conditions are obtained. The engineering energy method has more acceptability. Therefore the new solution of buckling equation was obtained in this study as the loading is the bending moment and torsion moment. [ABSTRACT FROM AUTHOR]

It is consider the buckling problem of a simply supported one row perforated beam-wall with hexagonal holes subjected to action of uniformly distributed load. The solution for estimation of critical load is performed in analytical form and compared with the results received by FEM. Together with perforated beams it was also solved the buckling problem for continuous beam-wall. [ABSTRACT FROM AUTHOR]

The problem of analytical determination of critical load of simply supported I-beams with flexible web, subjected to action of uniformly distributed load in span is solved. It is considered possibility of losing two forms buckling of wall: from shear near ended section or from normal compressed stresses in central part of beam. Comparison of results obtained analytically with calculation of buckling by the FEM indicates on their good correspondence. It was also obtained expression for critical thickness of wall, under which take place changing of forms of buckling under same dimensions of beam. It was suggested design of structures for increase of critical load for every form of buckling. [ABSTRACT FROM AUTHOR]

Analysis of Russian SN&R and European EN 1993-1-5-2006 requirements to local stability of flexible web plate girders is performed. Comparison of results of calculation of critical loads of simply supported plate girders under action of uniformly distributed load with the finite element method and with the approximate formulas was fulfilled. It was determined degree of divergence in values of critical shear stresses calculated on different Norms. Correction of calculated relation is offered. Results are represented in table and in graphical forms. [ABSTRACT FROM AUTHOR]

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The Counterintuitive behavior, i.e. the permanent deflection of the elastic-plastic beam which rests in opposite direction of the impulsive loading, normally appears and disappears abruptly in certain small ranges of the loading and structural parameters. One of the most important issues in the study of this phenomenon is the determination of the region within which the counter-intuitive response occurs. In the present study, the counterintuitive dynamic behavior of the elastic-plastic fully-clamped beams, formerly used by researchers during an experiment, is numerically simulated. Finite element code ANSYS/LS-DYNA and Galerkin's method are applied to study this phenomenon. Displacement-time history curves of mid-span of the beams are investigated in detail and the region of the occurrence of the counterintuitive behavior is determined as well. Furthermore, using finite element code, the energy diagrams of the beams are also studied. The computations, which were carried out by the two applied numerical methods showed that as long as the initial deflection of the fully-clamped beam lies within a proper range, there is a continuous region for the occurrence of the counterintuitive behavior. The simulation results also indicated that the Galerkin's method demands less computation time than the finite element analysis, and the predicted counterintuitive region by the former has slightly wider band in comparison to the latter. Moreover, the investigations showed that this anomalous behavior will occur for all motions with proper ratio of internal energy to kinetic energy. [ABSTRACT FROM AUTHOR]

This paper deals with progressive approach concerning improving of seismic resistance of structures. One of the possible solutions consists in base isolation of the structures. However, these structures require different computational approach. This brings us to the primary objective of this paper. An experiment was performed in order to compare experimentally investigated seismic response with a classical approach which lies in using of ground acceleration as an input. The secondary objective was to use the digital image processing and analysis methods as a measuring technique in practice. The results of numerical analysis and the experiment are compared and discussed. [ABSTRACT FROM AUTHOR]

Copyright of Mechanika is the property of Mechanika and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)