A comprehensive study of the delay vector variance method for quantification of nonlinearity in dynamical systems
Mandic, D. P.
The Royal Society
Although vibration monitoring is a popular method to monitor and assess dynamic structures, quantification of linearity or nonlinearity of the dynamic responses remains a challenging problem. We investigate the delay vector variance (DVV) method in this regard in a comprehensive manner to establish the degree to which a change in signal nonlinearity can be related to system nonlinearity and how a change in system parameters affects the nonlinearity in the dynamic response of the system. A wide range of theoretical situations are considered in this regard using a single degree of freedom (SDOF) system to obtain numerical benchmarks. A number of experiments are then carried out using a physical SDOF model in the laboratory. Finally, a composite wind turbine blade is tested for different excitations and the dynamic responses are measured at a number of points to extend the investigation to continuum structures. The dynamic responses were measured using accelerometers, strain gauges and a Laser Doppler vibrometer. This comprehensive study creates a numerical and experimental benchmark for structurally dynamical systems where output-only information is typically available, especially in the context of DVV. The study also allows for comparative analysis between different systems driven by the similar input.
Delay vector variance , Signal nonlinearity , Structural dynamics , Benchmarking , Wind turbine blade
Jaksic, V., Mandic, D. P., Ryan, K., Basu, B. and Pakrashi, V. (2016) 'A comprehensive study of the delay vector variance method for quantification of nonlinearity in dynamical systems', Royal Society Open Science, 3,150493 . doi:10.1098/rsos.150493