Generalized receptance-based method for accurate and efficient modal synthesis

Modal synthesis plays an important role in efficient dynamic analyses of la rge structural assemblies. However, the numerical accuracy and the computat ional efficiency which existing modal synthesis methods have achieved to da te are not quite satisfactory. This paper presents a new generalized recept ance-based modal synthesis method which is numerically very accurate and co mputationally very efficient. The method employs receptance data computed a t just few frequency values to formulate a derived equivalent eigensystem f rom which required eigenvalues and eigenvectors of interest can be solved. It provides mathematical generalization for existing mode-based modal synth esis methods since modal data are essentially those receptance data at reso nant frequencies. A normalization procedure is also presented which can be used to mass normalize computed mode shapes which are often required in pra ctice. Compensation for the contribution of higher uncomputed modes to rece ptance data at lower frequency of interest is made to improve analysis accu racy by using lower calculated modes and known system matrices. Numerical r esults are presented to demonstrate the effectiveness of the proposed metho d. Copyright (C) 1999 John Wiley & Sons, Ltd.