This study investigates the sensitivity of design variables such as ultimate strength of concrete, yield stress of reinforcing steel and damping ratio to the seismic response of staggered wall structures. Two different methods for sensitivity analysis, the tornado diagram method and the first-order second-moment method, are applied to two types of model structures. Non-linear dynamic analyses a...

OBJECTIVES The aim of this study was to evaluate the effects of damping on stress concentration in an impacted incisor. METHODS Damping ratios of maxillary incisors were tested using an in vivo modal testing method. A finite element model of the upper central incisor was established for dental trauma analysis. To assess the effect of damping properties on induced stresses in the traumatized i...

In this paper dynamic damping properties of a nominated flexible structural adhesive have been identified using an extended-direct modal based joint identification method. It has been revealed that damping characteristics of adhesive are correlated to both frequency and mode shape. Young’s and shear moduli increase with frequency but damping on the other hand, decrease. The results showed that ...

In case of non-diagonal modal damping, normal modes of vibration do not decouple modal equations. The usual way to handle such a non-diagonal modal damping matrix is to neglect its off-diagonal elements. In this paper, we propose an approximate method based on an asymptotic expansion of the transfer function. It is intermediate between inversion. Indeed, on the one hand, it allows to partially ...

A modal decomposition strategy based on state-variable ensembles is formulated. A nonsymmetric, generalized eigenvalue problem is constructed. The data-based eigenvalue problem is related to the generalized eigenvalue problem associated with free-vibration solutions of the state-variable formulation of linear multi-degree-of-freedom systems. For linear free-response data, the inverse-transpose ...

Abstract The identification of the modal parameters from frequency response functions is a subject that is not new. However, the starting point often comes from the equations that govern the dynamic motion. In this paper, a novel approach is shown, resulting from an analysis that starts on the dissipated energy per cycle of vibration. Numerical and experimental examples were used in order to as...

A time-frequency identification technique based on wavelet transform is formulated and applied to free-decay responses of linear systems with non-proportional viscous damping. The Cauchy mother wavelet is used. Frequencies, modal damping ratios and complex mode shapes are identified from output-only free vibration signals. This identification technique has also shown to be effective when the (n...

For FRF based model updating procedures, the selection of updating frequencies and the choice of a damping approach are important factors to obtain reliable updating resuns. This paper discusses the selection of the updating frequencies and shows that damping approaches like proportional, structural or modal damping are not satisfactory for model updating purposes.