Uncoupling techniques for the dynamic characterization of sub-structures

Abstract

The characterization of the dynamic behavior of sub-structures may be of great importance in certain complex structures. A possible approach is through the use of uncoupling techniques. This is the subject of the present paper, where various issues are raised and different possibilities to circumvent the encountered problems are discussed. These problems are mostly due to numerical instabilities associated to the calculation procedures, namely to the ill-conditioning that often appears and causes complications in the inversion of the involved matrices. The location of the possible points of measurement may also influence the results. Several variations to the main algorithms are tried in order to reduce the numerical problems. This study will be based on numerical simulations to compare the various approaches and to draw some final conclusions.