Author/Authors :
Torkzadeh Peyman نويسنده is Assistant Professor of Department of Civil Engineering, Faculty of Engineering, Shahid Bahonar University of Kerman. , Alavi Arsalan نويسنده Department of Civil Engineering, Faculty of Engineering , Rahgozar Reza نويسنده Department of Civil Engineering, Faculty of Engineering , Hajabasi Mohamad Ali نويسنده Department of Mechanical Engineering, Faculty of Engineering
Abstract :
In modern tall and slender structures, dynamic
responses are usually the dominant design requirements,
instead of strength criteria. Resonance is often a threatening
phenomenon for such structures. To avoid this problem,
the fundamental eigenfrequency, an eigenfrequency of
higher order, should be maximized. An optimization
problem with this objective is constructed in this paper and
is applied to a high-rise building. Using variational method,
the objective function is maximized, contributing to a
particular profile for the first mode shape. Based on this
preselected profile, a parametric formulation for flexural
stiffness is calculated. Due to some near-zero values for
stiffness, the obtained formulation will be modified by
adding a lower bound constraint. To handle this constraint
some new parameters are introduced; thereby allowing for
construction of a model relating the unknown parameters.
Based on this mathematical model, a design algorithmic
procedure is presented. For the sake of convenience, a
single-input design graph is presented as well. The main
merit of the proposed method, compared to previous
researches, is its hand calculation aspect, suitable for
parametric studies and sensitivity analysis. As the presented
formulations are dimensionless, they are applicable
in any dimensional system. Accuracy and practicality of
the proposed method is illustrated at the end by applying it
to a real-life structure.
