Artigo Produção Nacional Revisado por pares

From frequency-dependent mass and stiffness matrices to the dynamic response of elastic systems

2001; Elsevier BV; Volume: 38; Issue: 10-13 Linguagem: Inglês

10.1016/s0020-7683(00)00137-2

ISSN

1879-2146

Autores

Ney Augusto Dumont, Rodrigo Cardoso de Oliveira,

Tópico(s)

Vibration and Dynamic Analysis

Resumo

More than three decades ago, Przemieniecki introduced a formulation for the free vibration analysis of bar and beam elements based on a power series of frequencies. In the present paper, the authors generalize this formulation for the analysis of the dynamic response of elastic systems submitted to arbitrary nodal loads as well as initial displacements. Based on the mode-superposition method, a set of coupled, higher-order differential equations of motion is transformed into a set of uncoupled second-order differential equations, which may be integrated by means of standard procedures. Motivation for this theoretical achievement is the hybrid boundary element method, which has been developed by the authors for time-dependent as well as frequency-dependent problems. This formulation, as a generalization of Pian's previous achievements for finite elements, yields a stiffness matrix for which only boundary integrals are required, for arbitrary domain shapes and any number of degrees of freedom. The use of higher-order frequency terms drastically improves numerical accuracy. The introduced modal assessment of the dynamic problem is applicable to any kind of finite element for which a generalized stiffness matrix is available. Some academic examples illustrate the theory.

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