Behavior of High-Rise Steel Building With The Inclusion of Warping


The mathematical procedure in this study covers the calculation of sectorialproperties of the equivalent cross-sectional storey for high-rise building frames. Theformulation is efficiently used to obtain the free vibration analysis of high-risebuildings which are constructed from several columns, beams, shear walls andbracing etc. the analysis is based on transformation the complex system to a simpletall column to represent a cantilevered tall building structure. This is partitioned tonodes one of which indicates a storey with equivalent cross-sectional properties forall storeys' elements after calculation of these properties with respect to the shearcenter of high-rise building. A thin walled bar finite element with seven degrees offreedom at each node is assumed. A new formulation of the stiffness and consistentmass matrices of the thin- walled element is presented in this study. The effect ofcross sectional warping and its properties on the flexural, torsional and axialproperties was investigated, using discrete element approach in idealizing thestructure in high rise building. For the purpose of the present study, it is assumedthat the cross-sectional types under condition are only of thin-walled sections.Algorithm method was developed which covers the calculation of sectorialproperties of the cross section for floor plan in high-rise building, to study the shareof columns for lateral shear force resistance, and investigate the behavior of differenttypes of high-rise building with inclusion of warping restraint. The effect of naturalfrequency with height of tall buildings, and the mode shape for different crosssectionalplans of high-rise building was studied. To check the efficiency andaccuracy, the mathematical procedure is demonstrated for static and dynamicexamples by comparing the results with those obtained by using software ANSYSprogram. A difference of 15% is shown. An eigen value problem is analyzed andnumerical examples are discussed.