Tubular system is one of the most efficient structural system for high-rise buildings. For its structural characteristics, such as the cantilevered tube action and the shear lag effect, it is necessary to predict its structural behavior under lateral loading.
Structural Analysis using three dimensional finite element model can offer the exact analysis results. But three dimensional analysis of framed-tube structure is neither easy nor efficient because of longer computational effort, large memory requirement, tedious input preparation and bulky output. An efficient model for analysis of framed-tube system is proposed in this study. This proposed model can save the computational time and effort by using the assumption of the rigid floor diaphragm and the matrix condensation technique. Moreover the proposed model can represent the interaction between plane frames consisting the tubular system by using the link degrees of freedom which are temporary used to satisfy the vertical dispacement compatibility at the corners of a framed-tube.
The accuracy and the efficiency of the proposed model is confirmed by the example analysis results, such as displacements, member forces, natural periods and time histories, with those obtained using a three dimensional finite element model on the computer code SAP-IV.
