In this study, a method that estimates stiffness and mass matrices of shear building from modal test data is presented. This method applied of building depends on the number of measurement points that are less in number than the total structural degrees of freedom, and on the first two orders of structural mode measured. By means of this method it is possible to use modal data of unmeasurable points to estimate total stiffness and mass matrices of structure. Some examples are studied in this paper, and its result shows that this method is reliable.

Tributary area based-lumped mass model is a simplified modeling technique and it is popularly adopted in earthquake engineering for the evaluation of seismic performance of structures. However, the technique provides somewhat less accuracy due to its different frequencies and mode shapes, compared to the detailed FE model. For the basic understanding this study investigates the sensitivity of the lumped mass locations on the mode shapes and modal participation factors, considering a cantilever typed column structure.

This paper presents a new method for conveniently estimating static displacements of a structure based on its vibration data. In the proposed method, structural static displacements can be obtained using a normalized modal flexibility matrix assisted by a known mass perturbation method in order to overcome several shortcomings of existing displacement sensors such as the limitation on installation due to surrounding environments and the inconvenience to the public during static loading tests. For validating the feasibility of the proposed method, experimental validation was carried out on a simply-supported beam model. It was found that the proposed method can be an effective alternative to conventional static displacement estimation.