Nonlinear phase separation testing of an experimental wing-engine structure

Modal testing of nonlinear engineering structures is currently a research area that attracts substantial attention. Recently, a nonlinear generalisation of phase separation testing has been proposed for identifying nonlinear normal modes (NNMs) based on input and output measurements. The nonlinear phase separation (NPS) method integrates identification and continuation tools to calculate multiple NNMs from broadband data. The present contribution reports the first experimental application of the NPS method. The structure of interest is a model inspired by a wing with two engines connected by means of nonlinear pylons with softening-hardening stiffness characteristics. The frequency-energy dependences of four NNMs in the 0-100 Hz range are estimated, including modal interactions. NNMs identified using the NPS method are also compared to free-decay testing results.