Abstract
Traditionally, vibration analysis in operating conditions (on the road or on a bench) had to be combined with experimental modal analysis in controlled laboratory conditions in order to understand the modal behavior of the structure. This requires additional measurement costs and time. However, in many applications, the real operating conditions may differ significantly from those applied during the classic (experimental) modal test and hence the vibration modes from the classic modal test might not be representative for the active modes in operation conditions due to the real life loadings. The need for a capability of doing a modal analysis on data from operating conditions is obvious.
Over the last years, several modal parameter estimation techniques have been proposed and studied for modal parameter extraction from output-only data; previously only a deflection shape analysis could be done on this data to understand the behavior of an object in operating conditions. Each method needs to make a number of assumptions and has some limitations.
In this paper, the capabilities and limitations of the different identification techniques will be studied on response data on a car in driving conditions. The industrial applicability of using this kind of data for a modal analysis will be investigated by doing some analysis on data measured in different kinds of conditions.