On the use of pseudo-forces to consider initial conditions in 3D time- and frequency-domain acoustic analysis.

Abstract
This work is mainly concerned with a general strategy, based on well known concepts of classical mechanics, for taking into account initial conditions in frequency-domain (FD) and time-domain (TD) analyses. A general approach, extended here to three-dimensional applications, is presented. Special problems associated with analyses through Discrete-Fourier-Transform (DFT) algorithms, as those occurring in consequence of a non-correct choice of extended period or those connected with aliasing phenomenon, are also discussed. Furthermore, an alternative starting procedure for time-marching schemes (in TD analyses) is proposed. At the end of the paper, to validate the proposed techniques and to demonstrate their generality, two- and three-dimensional problems with non-homogeneous initial conditions are solved through frequency- and time-domain approaches by employing the Finite Element Method (FEM). Numerical results are compared with existing analytical solutions.
Description
Keywords
3D wave equation, Initial conditions, Frequency and time domain analyses, Finite element method
Citation
MARTINS, C. J. et al. On the use of pseudo-forces to consider initial conditions in 3D time- and frequency-domain acoustic analysis. Computer Methods in Applied Mechanics and Engineering, v. 195, n. 33-36, p. 4371-4382, jul. 2006. Disponível em: <https://www.sciencedirect.com/science/article/pii/S0045782505004172>. Acesso em: 11 jan. 2013.