A continuous–discrete approach for evaluation of natural frequencies and mode shapes of high-rise buildings
Journal Title: International journal of advanced structural engineering - Year 2016, Vol 8, Issue 3
Abstract
In this paper, a continuous–discrete approach based on the concept of lumped mass and equivalent continuous approach is proposed for free vibration analysis of combined system of framed tube, shear core and outrigger-belt truss in high-rise buildings. This system is treated as a continuous system (i.e., discrete beams and columns are replaced with equivalent continuous membranes) and a discrete system (or lumped mass system) at different stages of dynamic analysis. The structure is discretized at each floor of the building as a series of lumped masses placed at the center of shear core. Each mass has two transitional degrees of freedom (lateral and axial( and one rotational. The effect of shear core and outrigger-belt truss on framed tube system is modeled as a rotational spring placed at the location of outrigger-belt truss system along structure’s height. By solving the resulting eigen problem, natural frequencies and mode-shapes are obtained. Numerical examples are presented to show acceptable accuracy of the procedure in estimating the fundamental frequencies and corresponding mode shapes of the combined system as compared to finite element analysis of the complete structure. The simplified proposed method is much faster and should be more suitable for rapid interactive design.
Authors and Affiliations
Mohsen Malekinejad, Reza Rahgozar, Ali Malekinejad, Peyman Rahgozar
Modified creep and shrinkage prediction model B3 for serviceability limit state analysis of composite slabs
Relatively little research has been reported on the time-dependent in-service behavior of composite concrete slabs with profiled steel decking as permanent formwork and little guidance is available for calculating long-t...
Prediction of residual shear strength of corroded reinforced concrete beams
With the aim of providing experimental data on the shear capacity and behavior of corroded reinforced concrete beams that may help in the development of strength prediction models, the test results of 13 corroded and fou...
Vibration control of bridge subjected to multi-axle vehicle using multiple tuned mass friction dampers
The effectiveness of tuned mass friction damper (TMFD) in reducing undesirable resonant response of the bridge subjected to multi-axle vehicular load is investigated. A Taiwan high-speed railway (THSR) bridge subjected t...
A contact element for dynamic analysis of beams to a moving oscillator on tensionless elastic foundation
This paper presents the contact elements for dynamic analysis of Euler–Bernoulli beams to a moving oscillator on tensionless elastic foundation considering discontinuous contact. The elastic foundation is modeled by line...
Wind-induced vibrations of structures using design spectra
This paper discusses the estimation of wind dynamic response of two types of structures by following classical and novel approaches. A new method for structural analysis based on wind design spectra is introduced and tes...