Yazar "Hilmi, Zahraa Husham Ibrahim" seçeneğine göre listele

Listeleniyor 1 - 2 / 2
  • [ X ]
    Öğe
    Effective expressions for the estimation of the first and third natural periods of minarets based on extensive and comprehensive parametric modal analyses
    (Elsevier Ltd, 2025) Erkal, Aykut; Hilmi, Zahraa Husham Ibrahim
    This paper investigates the modal behaviour of minarets by conducting parametric modal analyses with a comprehensive set of geometric and material properties and critically proposes effective expressions to estimate the first and third natural periods of minarets. To make this unprecedented attempt, firstly, previously studied 52 minarets were examined to systematically select the geometric and material properties of 189 representative minarets. Subsequently, numerical models of these 189 minarets were created and assigned with the selected values for height, cross-sectional area, moment of inertia, modulus of elasticity, and mass density. Then, modal analysis was applied to each representative minaret to obtain modal characteristics to see the effect of each variable. Next, an iterative optimization algorithm was used to establish four effective expressions for the first and third natural periods, considering the effect of five and three variables. Finally, the performance of the proposed expressions was checked with 35 of the previously studied minarets whose dynamic characteristics are available. The results demonstrated a satisfactory level of accuracy. For example, the expression for the fundamental period with 5 variables presented discrepancies mostly far less than 19 % for 28 minarets of a total of 35 minarets. © 2025 Institution of Structural Engineers
  • [ X ]
    Öğe
    Efficient formulations for the prediction of natural periods of minarets through extensive parametric modal analyses
    (Altınbaş Üniversitesi / Lisansüstü Eğitim Enstitüsü, 2024) Hilmi, Zahraa Husham Ibrahim; Erkal, Aykut
    This study explores the dynamic behaviour of minarets through parametric modal analyses of an unprecedentedly large number of numerical models to establish efficient formulations for predicting the natural periods of minarets. Firstly, a comprehensive database of the geometrical and material properties of minarets, from previous studies, was compiled and thoroughly examined to systematically select a broad spectrum of those properties. Subsequently, the selected properties were implemented in the creation of a set of 189 representative minarets. Following the numerical modelling of these minarets using SAP2000, modal analyses were conducted to determine their modal characteristics. To understand the impact of each parameter, both multiple nonlinear regression analyses and iterative optimization analyses were performed. Then, considering the effects of five and three parameters at a time, four equations were derived for the 1st and 3rd natural periods. Lastly, the accuracy of the established equations was validated by comparing their performance on 35 previously studied other minarets with a variety of different properties. The proposed equations exhibited a considerably satisfactory level of precision.