Authors
Engineering College, University of Babylon/Babylon
Abstract
The mathematical procedure in this study covers the calculation of sectorial
properties of the equivalent cross-sectional storey for high-rise building frames. The
formulation is efficiently used to obtain the free vibration analysis of high-rise
buildings which are constructed from several columns, beams, shear walls and
bracing etc. the analysis is based on transformation the complex system to a simple
tall column to represent a cantilevered tall building structure. This is partitioned to
nodes one of which indicates a storey with equivalent cross-sectional properties for
all storeys' elements after calculation of these properties with respect to the shear
center of high-rise building. A thin walled bar finite element with seven degrees of
freedom at each node is assumed. A new formulation of the stiffness and consistent
mass matrices of the thin- walled element is presented in this study. The effect of
cross sectional warping and its properties on the flexural, torsional and axial
properties was investigated, using discrete element approach in idealizing the
structure in high rise building. For the purpose of the present study, it is assumed
that the cross-sectional types under condition are only of thin-walled sections.
Algorithm method was developed which covers the calculation of sectorial
properties of the cross section for floor plan in high-rise building, to study the share
of columns for lateral shear force resistance, and investigate the behavior of different
types of high-rise building with inclusion of warping restraint. The effect of natural
frequency with height of tall buildings, and the mode shape for different crosssectional
plans of high-rise building was studied. To check the efficiency and
accuracy, the mathematical procedure is demonstrated for static and dynamic
examples by comparing the results with those obtained by using software ANSYS
program. A difference of 15% is shown. An eigen value problem is analyzed and
numerical examples are discussed.
Keywords
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