TIME-DOMAIN ANALYSIS OF UNBOUNDED MEDIA USING RATIONAL APPROXIMATION

摘要

In the field of sail-structure interaction formulation of the farce-displacement, relationship in a way that enables the combination of the dynamic models for the soil and the structure is of major importance. Today, the dynamic stiffness ofl the soil can be calculated by means of the boundary element method, but for discrete frequencies only. In this paper, am algorithm for the interpolation of discrete stiffness matrices by a continuous matrix-valued rational function is proposed. Here, the coupling between different degrees of freedom is fully preserved. The rational approximation in the spectral domain can be split into a series of linear functions in (iΩ), following a successive procedure. Interpretation of these linear functions as differential operators in time results in a system of first order differential equations which can be coupled to a finite element model in a time-domain analysis.