A conventional lumped-mass stick model is based on the tributary area method to determine the masses lumped at each node and used in earthquake engineering due to its simplicity in the modeling of structures. However the natural frequencies of the conventional model are normally not identical to those of the actual structure. To solve this problem, recently an updated lumped-mass stick model is developed to provide the natural frequencies identical to actual structure. The present study is to investigate the seismic response accuracy of the updated lumped-mass stick model, comparing with the response results of the shaking table test. For the test, a small size four-story steel frame structure is prepared and tested on shaking table applying five earthquake ground motions. From the comparison with shaking table test results, the updated model shows an average error of 3.65% in the peak displacement response and 9.68% in the peak acceleration response. On the other hand, the conventional model shows an average error of 5.15% and 27.41% for each response.

An advanced lumped-mass stick (LMS) model is developed to improve the dynamic response accuracy of the conventional LMS model. In order to display the performance of the advanced LMS model, a four-story frame structure is prepared and performed a shaking table test using several earthquake ground motions. The frame structure consists of stainless steel and mass plates. The horizontal natural frequencies of first to fourth mode are 1.86Hz to 48.83Hz. In this paper, the seismic responses resulted from the advanced LMS model of the structure are compared with the results of the shaking table test.

There are several techniques to build the lumped-mass stick model, which are tributary-area based conventional model, frequency adaptive model, and advanced model combining the conventional and frequency adaptive models. The present study is to compare the seismic response accuracy of the models including FE model. The target structure is a nuclear containment structure and 45 earthquake ground motions are considered for the seismic analysis. The results show that the advanced lumped-mass model provides similar and more consistent responses to the FE model, compared to other models.

An advanced lumped-mass stick (LMS) model introduced in this paper is to overcome the disadvantages of the conventional lumped mass stick model, such as frequency error and low accuracy of dynamic responses. In order to show the performance of the advanced lumped-mass stick model, the experimental test using shaking table is conducted, considering a scaled four-story frame structure. The material of the frame model is stainless and the total mass of the model is about 39kg. The displacement and acceleration responses resulted from the advanced LMS model are compared with those of experimental results, including the response results of the conventional LMS model of the frame model.

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.