Characterization of non-linear bearings using the Hilbert–Huang transform

Abstract

Changes in the performance of bearings can significantly vary the distribution of internal forces and moments in a structure as a result of environmental or operational loads. The response of a bearing has been traditionally idealized using a linear model but a non-linear representation produces a more accurate picture at the expense of modelling complexity and computational time. In this article, a lead rubber bearing is idealized using the hysteretic Bouc-Wen model. The Hilbert-Huang transform is then employed to characterize the features of the non-linear system from the instantaneous frequencies of the bearing response to a time-varying force. Instantaneous frequencies are also shown to be a useful tool in detecting sudden damage to the bearings simulated by a reduction in the effective stiffness of the force-deformation loop.

Characterization of the road profile and the rotational stiffness of supports in a bridge based on axle accelerations of a crossing vehicle

“…The boundary conditions of the bridge are modeled using rotational springs at the left ( K 1 ) and right ( K 2 ) supports. Other researchers use the hysteretic Bouc–Wen model to represent the translational stiffness of the bearing and to predict the response of an existing bridge (Gutierrez Soto & Adeli, 2019) or the parameters of the bearing model in real time from the forces directly applied to the bearing using the Hilbert–Huang transform (González & Aied, 2015) or a Bayesian framework (Yuen et al., 2019). This paper assumes that a linear approximation of the rotational response will suffice to assess a change in support conditions in the presence of small traffic loads.…”

Modelling the Nonlinear Behavior of the Pot Bearings of Railway Bridge KW51

“…In most bridge modelling applications, linear models are employed to capture the structural behaviour of the bridge. In these models, the bridge supports are idealized and assumed to behave as perfect roller or pin supports while, in reality, bearing friction often causes the supports to behave in a non-linear fashion (Ülker Kaustell 2017; González and Aied 2015). At low excitation amplitudes, bearings designed as roller supports can act as fixed bearings (see e.g.…”

Damage detection using angular velocity

“…They suggested that, because of the inappropriate function of the expansion joints (due to accumulation of debris and the temperature differential), the boundary conditions of the structure were altered, causing alteration in the resonant frequencies of the bridge. González and Aied[52] employed the Hilbert-Huang transform to characterize the features and identify the changes in the response of a lead rubber bearing. However, the accuracy of the proposed method was limited by the noise level.…”