EM - Escola de Minas
URI permanente desta comunidadehttp://www.hml.repositorio.ufop.br/handle/123456789/6
Notícias
A Escola de Minas de Ouro Preto foi fundada pelo cientista Claude Henri Gorceix e inaugurada em 12 de outubro de 1876.
Navegar
3 resultados
Resultados da Pesquisa
Item Time-domain analysis of framed structures based on “exact” structural-property matrices for nonprismatic Timoshenko’s elements.(2022) Pillon, Fenando R.; Ribeiro, Iara Souza; Araújo, Francisco Célio de; Degenhardt, RichardThis paper applies a unified process to calculate ”exact” (consistent) finite-element (FE) matrices for framed structures having nonprismatic elements and including shear- deformation and rotational-inertia effects. In this process, the exact expressions for the element stiffness and nodal-load coefficients result from applying the principle of virtual forces (PVF) at the element level. Rigidity values, determined at a certain number of cross sections in the frame element, are employed to describe how the corresponding rigidities vary along its length. For that, interpolation polynomials of different orders are consid- ered. Exact Timoshenko’s shape functions, built under the most general cases of rigidity variation, are used for evaluating the mass matrix coefficients. In the applications, com- plex 2D frames with nonprismatic elements are considered to simulate bridge structures under seismic excitation and a generic harmonic load. Comparisons with highly accurate response time-histories obtained by employing ANSYS (3D) solid-FE models are effected to verify the robustness of the proposed formulation.Item Nonlinear analysis of semirigid steel frames having nonprismatic shear-deformable members.(2022) Araújo, Francisco Célio de; Ribeiro, Iara Souza; Machado, Roberta MariaStarting from the principle of virtual forces (PVF), one devises a flexibility-type method to obtain, based on the Timoshenko beam theory (TBT), exact expressions for the structural properties of nonprismatic frame elements. One adopts polynomials of different orders to interpolate the sectional rigidity values over the elements and employs exact Timoshenko’s shape functions for evaluating deformation-dependent structural properties, such as geometric stiffness. In this respect, we present a mathematically formal process to obtain the changes in the preexisting element forces needed to calculate geometric stiffnesses. The procedure adopted in this paper easily allows one to include higher-order nonlinear terms in the analysis. Robustness of the proposed formulation is observed by conducting geometrically nonlinear analyses of 2D semirigid steel frames possessing nonprismatic members. General nonlinear curves describing the semirigid connections may be easily incorporated into the analysis.Item A novel strategy to construct exact structural-property matrices for nonprismatic Timoshenko’s frame elements.(2020) Araújo, Francisco Célio de; Ribeiro, Iara SouzaAssuming Timoshenko’s beam hypothesis, this paper proposes a unified strategy to derive exact finiteelement (FE) matrices for framed structures having elements with variable rigidity. Its basic idea is to apply the principle of virtual forces (PVF), at the element level, to obtain a flexibility-based set of equations from which structural-property and nodal-load coefficients can be directly evaluated. The variable physical-geometric characteristics along the frame elements are approximated by polynomials of different orders. For evaluating structural-property coefficients that depend on the deformation of the structure, as e.g. the geometric stiffness coefficients, one employs Timoshenko’s consistent shape functions. A novel process for building them under the most general cases of rigidity variation is presented in this paper. In this study, we particularly apply the technique to effect second-order analyses of 2D frames with nonprismatic elements.