Identification of weakly non-linear systems using equivalent linearization

Many vibrating systems when experimentally tested show weak non-linearity. In these cases linear response features such as natural frequencies and damping ratios though clearly identifiable, nevertheless show amplitude dependency. This paper describes an approach where the underlying non-linear differential equation governing the system may be identified. As input the equivalent linear response parameters measured over a range of amplitudes are used. A commercial aircraft trim panel mounting is considered as an example to demonstrate the technique.