The exact prediction of the dynamic response of multistory building structures is an important subject in the structural engineering. Three dimensional analyses of multistory building structures with shear cores by a finite element model require tedious input data preparation, longer computation time, and larger computer memory. In this study, an efficient three dimensional model for analyses of multistory building structures with shear cores is proposed. The proposed model is developed idealizing the structures as an assemblage of frame and shear core system and is considered to overcome the shortcomings of a three dimensional finite element model without deteriorating the accuracy of analysis results.
Each of the element stiffness are assembled into the story stiffness at each floor level based on the rigid diaphragm effect of the floor slab. The matrix condensation technique is employed to obtain the condensed global stiffness matrix with two lateral degrees of freedom (DOF) and one torsional DOF per each floor.
Performance of the proposed analysis model is compared to the three dimensional finite element model in terms of frequencies, mode shapes and displacements. The results from those two models are very close and it was decided that the analysis model proposed in this study can predict the behavior of the building structures with acceptable accuracy. Taking the advantage of the efficiency of the proposed analysis model, dynamic analyses of multistory building structures can be performed on a personal computer with reduced computing time.
