Abstract. The present paper proposes a new index for damage detection based on nonlinear features extracted from prediction errors computed by multiple convolutions using the discrete-time Volterra series. A reference Volterra model is identified with data in the healthy condition and used for monitoring the system operating with linear or nonlinear behavior. When the system has some structural change, possibly associated with damage, the index metrics computed could give an alert to separate the linear and nonlinear contributions, besides provide a diagnostic about the structural state. To show the applicability of the method, an experimental test is performed using nonlinear vibration signals measured in a clamped buckled beam subject to different levels of force applied and with simulated damages through discontinuities inserted in the beam surface.
The aim of this paper is to identify a nonlinear model using time responses obtained from a sine sweep excitation applied to a simplif ied solar array structure. The nonlinearity is mainly caused by impacts, gaps and friction between the clamped interfaces of adjacent panels. A nonparametric model is identif ied using Volterra series, where the kernels are expanded with Kautz functions in order to decrease the problems associated with convergence and number of samples. The multiple convolutions provided by the Volterra kernels are used to propose a decision criterion based on a threshold limit to detect the level of linear or nonlinear behavior. The approach is also able to separate the linear and nonlinear contributions of the measured total response. The application performed in the experimental setup demostrates that the proposed method is successful in identifying the main nonlinear mechanism involved, despite of the complicated nature of the nonlinear system investigated.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.