Affiliations: Department of Mechanical Engineering and Industrial
Production, New University of Lisbon, 2829-516 Monte de Caparica,
Portugal | Department of Mechanical Engineering, Instituto
Superior Técnico, Technical University of Lisbon, Av. Rovisco Pais,
1049-001 Lisboa, Portugal
Abstract: The identification of the rigid body properties of a structure is an
important matter in various structural dynamic applications, namely in
structural modification (coupling/uncoupling), optimization and vibration
control. In most situations, the experimental route is the only via to obtain
the desired dynamic properties. This goal is achieved by an inverse process
which starts from the measurement of Frequency Response Functions (FRFs) and
ends on matrices describing the mass distribution of a rigid body. The objective of the present article is the evaluation and comparison of the
performance of three different kinds of identification methods that share a
common characteristic – they all use FRFs as inputs to the inverse process.
One of them, the Inertia Restraint Method (IRM) makes use of the accelerance
FRF (information condensed at zero frequency), while the other two methods make
use of receptance FRFs as inputs, although in different manners; in one of them
the properties are evaluated directly from the measurement data – Direct
Physical Parameter Identification Method (DPPIM) – whereas the other type
requires a modal identification procedure as an intermediate step – Modal
Method (MM). An actual experimental structure forms the case study to
illustrate the performance of the three different techniques.
