S. Frikha et al., Boundary condition identification using condensation and inversion - Application to operating piping network, J SOUND VIB, 233(3), 2000, pp. 495-514
This paper deals with the experimental analysis of piping systems under ope
rating conditions in the held of vibration and acoustic analysis. A new app
roach to identify the boundary conditions of a part of a curvilinear struct
ure is presented. The basic concept consists of solving an inverse problem
where the measured response of the system tested is combined with an incomp
lete analytical model in order to identify the boundary dynamical state in
the frequency domain. As in finite element methods, the tested network is d
escribed using elements and nodes. An original technique using a transfer m
atrix of continuous elements provides a small-size analytical model. In add
ition, condensation procedure is used to eliminate all degrees of freedom (
d.o.f.) having a modelled boundary condition and to reduce the size of the
solved inverse problem. Since identification of boundary conditions is perf
ormed, the analysis of dynamic response of the tested network may be perfor
med without further matrix computation. The validity and the feasibility of
the approach are shown using actual test results. Examples concerning real
applications are also presented. (C) 2000 Academic Press.