Damping Identification with Acceleration Measurements Based on Sensitivity Enhancement Method

Abstract

The damping is important for forward and inverse structural dynamic analysis, and damping identification has become a hot issue in structural health monitoring recently. The dynamic responses of the structure can be measured in practice, and the structural parameter usually can be identified by inverse response sensitivity analysis. To reduce the measurement noise effect and enhance the effectiveness of the response sensitivity method, an enhanced sensitivity analysis method was proposed to identify the structural damping based on the Principal Component Analysis (PCA) method. The measured acceleration responses were analyzed by PCA method, and the updated analytical responses and the response sensitivities were projected into the subspace determined by the first-order principal component. The projection equations were adopted to identify the parameters of damping model. The proposed damping identification method was numerically validated with a planar truss structure at first, and then the experimental study was conducted with a steel planar frame structure. It shows that the proposed method is effective in identifying the parameters of damping model with better accuracy compared with the conventional acceleration response sensitivity method, and it is also robust to the sensor placement and measurement noise.

An Updating Method for Finite Element Models of Flexible‐Link Mechanisms Based on an Equivalent Rigid‐Link System

“…Model. A Rayleigh damping model (modal damping model) has been assumed since it is a popular and effective approach to represent damping [27,28,35,36]. Hence, damping matrix C e is a linear combination of mass and stiffness matrices through the Rayleigh coefficients α and β: C e � αM e + βK e .…”

Application of modelling and simulation to evaluate the theta method used in diagnostics of automotive shock absorbers

“…It changes during the time of system exploitation and intensity of use. There were many attempts to determine (to measure) mechanical system damping [9,19,24], including vehicle suspension damping (see works [2][3][4] or [5,6,8] as well as [11][12][13] or [14,18,20], and also [21][22][23]). It affects the comfort of passengers and traffic safety.…”

“…This method is not recommended because of its very high sensitivity to the dry friction in the suspension system [25]. In the other group, the vehicle wheel is forced to vibrate vertically with a frequency of (16)(17)(18)(19)(20)(21)(22)(23)(24)(25) Hz and then this frequency is gradually reduced until the vibration fades out to 'sweep' the frequency range that covers the natural frequencies of the 'sprung mass' and 'unsprung mass' supported by spring elements of the suspension system and pneumatic tires. In this case, the known fact of high sensitivity of system vibration to damping in the resonance zone is made use of.…”

Improved Time Domain Substructural Damage Identification Method on Large‐Span Spatial Structure

“…e small local damage may lead to disastrous damage under strong earthquake, so the small local damage detection becomes a key issue for the structural health monitoring of the largespan spatial structure. e damage detection method based on vibration information [2][3][4][5] has been proposed and developed in the past three decades, and it has been applied in various structures (e.g., bridges [6], frame structures, and plane trusses [7,8]).…”