Estimation of bias error by modal testing of mechanical vibrating structures

This paper presents metrological aspects of bias error and linearity by modal testing mobility measurements. Verification of an analytical mathematical model by the use of experimental results was performed. A single Frequency Response Function (FRF) for each natural mode was obtained to reveal weak structural condition in terms of "inertance". Variety of excitation type is discussed in attempt to study the dynamic error generation by mechanical mobility measurements. Results from analytical mathematical model and experiments are presented.