Sm. Pandit et Zq. Hu, DETERMINATION OF RIGID-BODY CHARACTERISTICS FROM TIME-DOMAIN MODAL TEST DATA, Journal of sound and vibration, 177(1), 1994, pp. 31-41
A new method is presented to identify the characteristics of a rigid b
ody and its supports, such as the center of gravity, the moment of ine
rtia, and the stiffness and damping matrices, based on the measured ti
me domain vibration data. Transformation matrices are formed using onl
y the geometric co-ordinates relative to an arbitrarily selected origi
n to relate the pure translational measurement to both translation and
rotation of the rigid body system. The rigid body modes and mode shap
es, carefully selected from the accurately determined modes and mode s
hapes (rigid body and structural), are used, together with the special
matrix structure, such as symmetry. The test result shows that the ce
nter of gravity and the moment of inertia are determined with good acc
uracy. The simple test procedure makes it an easily implementable meth
od in practice.