Uncertainty quantification for the Modal Phase Collinearity of complex mode shapes

The Modal Phase Collinearity (MPC) is a modal indicator designed to decide whether the mode shape used in its computation real or complex-valued vector. Its estimate inherits statistical properties of corresponding estimate. While framework for uncertainty quantification parameters well-known and developed context subspace-based system identification methods, MPC has not been carried out yet. In this paper, estimates when shapes are vectors. case, theoretical value strictly lower than 1 it shown that distribution can be approximated as Gaussian. variance resulting confidence intervals developed. proposed validated Monte Carlo simulations illustrated on experimental data an offshore structure.