Analysis of Non-Linear Vibration Behaviour of Large Aerospace Structures

In this publication the principles for modal analysis of real aerospace structures with weak non-linearities are described. A separation of damping and stiffness non-linearities as well as a restriction on coupling of only a few modes has proved to be beneficial. By this means, nearly all practical phenomena can be sufficiently described. An appropriate and new concept for the identification of non-linearities in the framework of vibration testing is described in detail. The fundamentals of the used methods are initially elucidated on a analytical three degree of freedom system. Afterwards, an example from practice is used in order to demonstrate the usability of the approach. In the example the non-linear analysis during vibration testing of a large transport aircraft is shown