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CONTENTS
Volume 6, Number 4, April 2014
 

Abstract
Historical masonry mosques are the most important structures of Islamic societies. To estimate the static and dynamic behavior of these historical structures, an examination of their restoration studies is very important. In this study, Kara Mustafa Pasha Mosque, which was built as a domed mosque by Kara Mustafa Pasha between 1666-1667 in Amasya, Turkey, has been analyzed. This study investigates the structural behavior and architectural features of the mosque. In order to determine specific mechanical properties, compression and three-point bending tests were conducted on materials, which have similar age and show similar properties as the examined mosque. Additionally, a three-dimensional finite element model of the mosque was developed and the structural responses were investigated through static and dynamic analyses. The results of the analyses were focused on the stresses and displacements. The experimental test results indicate that the construction materials have greatly retained their mechanical properties over the centuries. The obtained maximum compression and tensile stresses from the analyses have been determined as smaller than the materials\' strengths. However, the stresses calculated from dynamic analysis might cause structural problems in terms of tensile stresses.

Key Words
masonry mosque; finite element model; experimental tests; static analysis; time history analysis

Address
Burcin S. Seker : Merzifon Vocational School, Amasya University, Merzifon, Amasya, Turkey
Ferit Cakir : Department of Architectural, Amasya University, Amasya, Turkey
Adem Dogangun : Department of Civil Engineering, Uludag University, Bursa, Turkey
Habib Uysal : Department of Civil Engineering, Ataturk University, Erzurum, Turkey

Abstract
This paper investigates the seismic response of lightweight acceleration-sensitive non-structural components (NSCs) mounted on irregular reinforced concrete (RC) primary structures (P-structures) using non-linear dynamic finite element (FE) analysis. The aim of this paper is to study the influence of NSC to P-structure vibration period ratio, peak ground acceleration, NSC to P-structure height ratio, and P-structure torsional behaviour on the seismic response of the NSCs. Representative constitutive models were used to simulate the behaviour of the RC P-structures. The NSCs were modelled as vertical cantilevers fixed at their bases with masses on the free ends and varying lengths so as to match the frequencies of the P-structures. Full dynamic interaction is considered between the NSCs and P-structures. A set of 21 natural and artificial earthquake records were used to evaluate the seismic response of the NSCs. The numerical results indicate that the behaviour of the NSCs is significantly influenced by the investigated parameters. Comparison between the FE results and Eurocode (EC8) predictions suggests that EC8 underestimates the response of NSCs mounted on the flexible sides of irregular RC P-structures when the fundamental periods and heights of the NSCs match those of the P-structures. The perceived cause of this discrepancy is that EC8 does not take into account the amplification in the dynamic response of NSCs induced by the torsional behaviour of RC P-structures.

Key Words
dynamic analysis; Eurocode 8; finite element; irregular RC buildings; non-structural components; torsion

Address
Ayad B. Aldeka and Samir Dirar : School of Civil Engineering, University of Birmingham, Edgbaston, Birmingham, B15 2TT, United Kingdom
Andrew H.C. Chan : School of Science, Information Technology and Engineering, Federation University Australia, Victoria, Australia 3350 (formerly School of Civil Engineering, University of Birmingham)

Abstract
Time history analyses have been preferred commonly in earthquake engineering area to determine earthquake performances of structures in recent years. Advances in computer technology and structural analysis have led to common usage of time history analyses. Eurocode 8 allows the use of real earthquake records as an input for linear and nonlinear time history analyses of structures. However, real earthquake records with the desired characteristics sometimes may not be found, for example depending on soil classes, in this case artificial and synthetic earthquake records can be used for seismic analyses rather than real records. Selected earthquake records should be scaled to a code design spectrum to reduce record to record variability in structural responses of considered structures. So, scaling of earthquake records is one of the most important procedures of time history analyses. In this paper, four real earthquake records are scaled to Eurocode 8 design spectrums by using SESCAP (Selection and Scaling Program) based on time domain scaling method and developed by using MATLAB, GUI software, and then scaled and real earthquake records are used for linear time history analyses of a six-storied building. This building is modeled as spatial by SAP2000 software. The objectives of this study are to put basic procedures and criteria of selecting and scaling earthquake records in a nutshell, and to compare the effects of scaled earthquake records on structural response with the effects of real earthquake records on structural response in terms of record to record variability of structural response. Seismic analysis results of building show that record to record variability of structural response caused by scaled earthquake records are fewer than ones caused by real earthquake records.

Key Words
selection of earthquake records; scaling of earthquake records; time domain scaling method; SESCAP

Address
Mustafa Ergun and Sevket Ates : Department of Civil Engineering, Karadeniz Technical University, 61080, Trabzon, Turkey

Abstract
In this paper, a direct identification of modal parameters using the continuous wavelet transform is proposed. The purpose of this method is to transform the differential equations of motion into a system of algebraic linear equations whose unknown coefficients are modal parameters. The efficiency of the present method is confirmed by numerical data, without and with noise contamination, simulated from a discrete forced system with four degrees-of-freedom (4DOF) proportionally damped.

Key Words
modal identification; dynamics of structures; forced vibration; continuous wavelet transform

Address
Safia Bedaoui, Pierre Argoul : Laboratoire Navier (ENPC/IFSTTAR/CNRS), Ecole des ponts Paris Tech, Universite Paris Est, 6 & 8 Avenue Blaise Pascal, Champs-sur-Marne, 77455 Marne-la-Vallee Cedex 2, France
Safia Bedaoui : Faculty of Civil Engineering, Houari Boumedienne Science & Technology University (USTHB), EL Alia, Bab Ezzouar, Alger, Algeria / Department of Civil Engineering, Faculty of Engineer Sciences, M

Abstract
Although it is widely accepted that the interaction -between masonry infill and structural members significantly affects the seismic response of reinforced concrete (RC) frames, this interaction is generally neglected in current design-oriented seismic analyses of structures. Moreover, the role of masonry infill is expected to be even more relevant in the case of existing frames designed only for gravitational loads, as infill walls can significantly modify both lateral strength and stiffness. However, the additional contribution to both strength and stiffness is often coupled to a modification of the global collapse mechanisms possibly resulting in brittle failure modes, generally related to irregular distributions of masonry walls throughout the frame. As a matter of principle, accurate modelling of masonry infill should be at least carried out by adopting nonlinear 2D elements. However, several practice-oriented proposals are currently available for modelling masonry infill through equivalent (nonlinear) strut elements. The present paper firstly outlines some of the well-established models currently available in the scientific literature for modelling infill panels in seismic analyses of RC frames. Then, a parametric analysis is carried out in order to demonstrate the consequences of considering such models in nonlinear static and dynamic analyses of existing RC structures. Two bay-frames with two-, three- and four-storeys are considered for performing nonlinear analyses aimed at investigating some critical aspects of modelling masonry infill and their effects on the structural response. Particularly, sensitivity analyses about specific parameters involved in the definition of the equivalent strut models, such as the constitutive force-displacement law of the panel, are proposed.

Key Words
masonry infill; nonlinear analysis; existing structures; reinforced concrete; strut models

Address
Carmine Lima, Gaetano De Stefano and Enzo Martinelli : Department of Civil Engineering, University of Salerno, 84084 Fisciano (SA), Italy

Abstract
Some conventional lateral load patterns for pushover analysis, and proposing a new accurate pattern was investigated in present research. The new proposed load pattern has load distribution according weight and stiffness variation in height and mode shape of structure. The assessment of pushover application with mentioned pattern in X type braced steel frames and steel moment resisting frames, with stiffness and mass variation in height, was studied completely and the obtained results were compared with nonlinear dynamic analysis method (including time history analysis). The methods were compared from standpoints of some basic parameters such as displacement, drift and shape of lateral load pattern. It is concluded that proposed load pattern results are closer to nonlinear dynamic analysis (NDA) compared to other pushover load patterns especially in tall and medium-rise buildings having different stiffness and mass during the height.

Key Words
pushover load pattern; nonlinear dynamic analysis; steel frames; tall and medium-rise buildings; load distribution

Address
H. Gholi Pour : Department of Civil and Environmental Engineering, Amirkabir University of Technology, Tehran, Iran
M. Ansari : Department of Civil and Environmental Engineering, Tarbiat Modares University, Tehran, Iran
M. Bayat : Department of Civil Engineering, College of Engineering, Mashhad Branch, Islamic Azad University, Mashhad, Iran


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