Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Article Citation - WoS: 8Citation - Scopus: 8Free Vibration Analysis of Damaged Composite Beams(Techno Press, 2015) Cünedioğlu, Yusuf; Beylergil, BertanIn this study, free vibration analyses of symmetric laminated cantilever and simply supported damaged composite beams are investigated by using finite element method (FEM). Free vibration responses of damaged beams are examined using Euler Bernoulli beam and classical lamination theories. A computer code is developed by using MATLAB software to determine the natural frequencies of a damaged beam. The local damage zone is assumed to be on the surface lamina of the beam by broken fibers after impact. The damaged zone is modeled as a unidirectional discontinuous lamina with 0 degrees orientations in this study. Fiber volume fraction (v(f)), fiber aspect ratio (L-f/d(f)), damage length (L-D) and its location (lambda/L), fiber orientation and stacking sequence parameters effects on natural frequencies are investigated. These parameters are affected the natural frequency values significantly.Conference Object Citation - Scopus: 2Design of Reconfigurable Doubly-Curved Canopy Structure(CRC Press, 2013) Maden, Feray; Korkmaz, Koray; Akgün, YenalIn this paper, a new reconfigurable doubly-curved structure has been developed for a canopy roof. The proposed structure can transform itself to various configurations according to the activity and user requirements. It not only changes its shape from a planar geometry to doubly-curved geometries by means of actuators, but also becomes stable and carries loads. The main differences between proposed structure and similar deployable bar structures are that the proposed structure is more flexible with 2DoF and it requires less number of bars and joints. To obtain the doubly-curved geometry, a novel method has been introduced. After discussing the kinematic behavior of the system, a set of structural analyses are performed in three different geometric configurations of the proposed structure.Article Citation - WoS: 75Citation - Scopus: 95A Review of Planar Scissor Structural Mechanisms: Geometric Principles and Design Methods(Taylor and Francis Ltd., 2011) Maden, Feray; Korkmaz, Koray; Akgün, YenalThis study deals with a review of planar scissor structural mechanisms (SSMs) and reports on how they can be easily transformed from a stowed to a deployed configuration. These mechanisms have an important transformation capacity of their extension and rotation properties, and many examples have been proposed that vary in size, type and geometry. Although there are many studies dealing with designing new planar or spatial SSMs and their calculation methods, there is no systematic study demonstrating the basic typologies, geometric principles, design rules and constraints of such SSMs. Further, current calculation methods are based on the inductive approach in which the dimension of one scissor unit (SU) is given, but the span of the whole structure is found later according to the number of SUs that are used to assemble the structure. However, this approach is not convenient for architectural applications, because it requires a deductive approach in which the dimensions and required number of SUs are calculated according to defined span length. On the basis of this concept, this article, first, analyses the geometric design of SSMs systematically in terms of their possible configurations and then develops trigonometric calculation methods for different types of SSMs, using a deductive approach.Article Citation - WoS: 87Citation - Scopus: 100Determining Attribute Weights in a Cbr Model for Early Cost Prediction of Structural Systems(American Society of Civil Engineers (ASCE), 2006) Doğan, Sevgi Zeynep; Arditi, David; Günaydın, Hüsnü MuratThis paper compares the performance of three optimization techniques, namely feature counting, gradient descent, and genetic algorithms (GA) in generating attribute weights that were used in a spreadsheet-based case based reasoning (CBR) prediction model. The generation of the attribute weights by using the three optimization techniques and the development of the procedure used in the CBR model are described in this paper in detail. The model was tested by using data pertaining to the early design parameters and unit cost of the structural system of 29 residential building projects. The results indicated that GA-augmented CBR performed better than CBR used in association with the other two optimization techniques. The study is of benefit primarily to researchers as it compares the impact attribute weights generated by three different optimization techniques on the performance of a CBR prediction tool.Article Citation - WoS: 9Citation - Scopus: 12The Effect of Tube End Constraining on the Axial Crushing Behavior of an Aluminum Tube(Elsevier Ltd., 2008) Taşdemirci, AlperThe effect of various types of end constraining on the deformation and load-displacement behavior of a 3003-H14 Al tube were experimentally and numerically studied. No effect of single-end constraining of tubes was found. Few conditions of double-end constraining tended to revert the deformation mode to mixed and/or diamond mode of deformation. Double-end constraining of tube ends further resulted in an increase in initial drop-load values, widening the initial overshot region in average load-displacement curves. The agreement between numerical and experimental results showed the capabilities of the used numerical model in order to predict end-condition effects in tubular structures.