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- MakaleYalnız künye2018Scopus SJRQ1Application of Artificial Neural Networks to the prediction of out-of-plane response of infill walls subjected to shake table
Onat, Onur; Gul, Muhammet
The main purpose of this paper is to predict missing absolute out-of-plane displacements and failure limits of infill walls by artificial neural network (ANN) models. For this purpose, two shake table experiments are performed. These experiments are conducted on a 1:1 scale one-bay one-story reinforced concrete frame (RCF) with an infill wall. One of the experimental models is composed of unreinforced brick model (URB) enclosures with an RCF and other is composed of an infill wall with bed joint reinforcement (BJR) enclosures with an RCF. An artificial earthquake load is applied with four acceleration levels to the URB model and with five acceleration levels to the BJR model. After a certain acceleration level, the accelerometers are detached from the wall to prevent damage to them. The removal of these instruments results in missing data. The missing absolute maximum out-of-plane displacements are predicted with ANN models. Failure of the infill wall in the out-of-plane direction is also predicted at the 0.79g acceleration level. An accuracy of 99% is obtained for the available data. In addition, a benchmark analysis with multiple regressionis performed. This study validates that the ANN-based procedure estimates missing experimental data more accurately than multiple regression models.
AtıfScopus33WoS29OpenAlex14
İncele - MakaleYalnız künye2018Scopus SJRQ1Assessment of the combined in-plane and out-of-plane behavior of brick infill walls within reinforced concrete frames under seismic loading
Onat, Onur; Correia, António A.; Lourenço, Paulo B.; Koçak, Ali
Understanding the out-of-plane response of masonry infill walls and preventing their progressive collapse mechanisms is very important for earthquake-prone countries to prevent loss of life and economic loss. In fact, having a realistic collapse mechanism assessment allows suitable prevention measures to be adopted. With this purpose in mind, two full-scale one-bay one-story substructures of reinforced concrete frames (RCF) with infill walls were tested on a shake table. These 2 specimens were designed to represent the response of a typical RC Frame at the fifth floor of an 8-story building, namely the out-of-plane failure of its infill wall under combined bidirectional seismic load. Both specimens were composed of a single-leaf clay brick infill wall surrounded by the RC Frame. However, while the first specimen corresponds to an unreinforced masonry configuration, the second specimen includes horizontal bed joint reinforcement as a strengthening/retrofitting technique. The main novelty of this study is the application of a bidirectional and simultaneous dynamic loading to the specimen, such that in-plane and out-of-plane effects are evaluated together. This work presents several interesting experimental results, with particular emphasis on the bearing capacity of the specimens against out-of-plane failure. As expected, the in-plane capacity of the reinforced infill specimen is larger than that of the unreinforced infill specimen. Nevertheless, the out-of-plane bearing capacities of the two specimens are very similar, in contrast to their ductility capacity, which is significantly increased in the reinforced masonry specimen. The capacities of the two specimens for both in-plane and out-of-plane directions, as predicted by formulations in the literature, are given. The differences found between these calculations and the results of the tests are discussed, and may possibly be explained by the parameters considered in the different formulations.
AtıfScopus49OpenAlex44İncele - MakaleYalnız künye2018Scopus SJRQ2Curing effect on mortar properties produced with styrene-butadiene rubber
Cemalgil, Selim; Etli, Serkan; Onat, Onur
This paper presents an experimentally investigation pertinent to the mechanical properties of rubberized mortar (RM) with styrene-butadiene rubber (SBR). The SBR were used with constant water-to-cement ratio of 0.485 and two different volume proportion of SBR particles were utilized as aggregates. One types of SBR particles with fineness modulus of 4.951 were utilized 0%, 10%, and 20% of aggregate volume. Effectiveness of SBR replacement ratio, curing and aging effect on the compressive strength, flexural strengths as well as load-displacement. Compressive and flexural strength of concrete were investigated at the end of 28-days and 56-days age. Obtained results demonstrated that utilization of SBR reduced the flexural strength of SBR mortar at the earlier curing age while SBR increased. Moreover, mechanical properties of mortar mentioned above were significantly affected by the water cure timing with an increasing proportion of the replacement level of SBR.
AtıfScopus11WoS11OpenAlex13İncele - MakaleYalnız künye2017Scopus SJRQ1An integral based fuzzy approach to evaluate waste materials for concrete
Onat, Onur; Celik, Erkan
Waste materials in concrete have been considered as one of the most important issues by the authorities, policy makers and researchers to maintain engineering serviceability in terms of economy, durability and sustainability. Therefore, evaluation and selection of waste materials with respect to multi criteria decision making (MCDM) for the construction industry has been gained importance for recovery and reuse. In this paper, Choquet integral based fuzzy approach is proposed for evaluating the most suitable waste materials with respect to compressive strength, tensile strength, flexural strength, compactness, toughness (resistivity for dynamic loads), water absorption and accessibility. On conclusion, waste tyre and silica fume were determined as the most suitable waste materials for concrete production. The obtained results are recommended to assist the authorities on configuring well designed strategies for construction industry with disposal materials.
AtıfScopus12WoS12OpenAlex9İncele - MakaleAçık Erişim2017Scopus SJRQ3Structural model calibration of RC structure with twoleaf cavity brick infill wall by deterministic approach
Onat, Onur; Lourenço, Paulo B.; Koçak, Ali
An adaptive solution for updating structural model of a RC structure with two-leaf cavity brick infill wall under flexible boundary problem is presented in this paper. The structure was simulated with Diana 9.4.4 finite element software. Next, an elastic foundation with interface elements was used to overcome this stiffness problem of the foundation. The validation of the structure was made with the optimization based modal updating using MATLAB. Five calibration types were performed and compared with experimental data.
AtıfScopus8WoS8OpenAlex6İncele - MakaleAçık Erişim2016Scopus SJRQ2Nonlinear analysis of RC structure with massive infill wall exposed to shake table
Onat, Onur; Lourenço, Paulo B.; Koçak, Ali
AtıfOpenAlex10İncele - MakaleYalnız künye2015Scopus SJRQ2Experimental and numerical analysis of RC structure with two leaf cavity wall subjected to shake table
Onat, Onur; Lourenço, Paulo B.; Koçak, Ali
This paper presents finite element (FE) based pushover analysis of a reinforced concrete structure with a two-leaf cavity wall (TLCW) to estimate the performance level of this structure. In addition to this, an unreinforced masonry (URM) model was selected for comparison. Simulations and analyses of these structures were performed using the DIANA FE program. The mentioned structures were selected as two storeys and two bays. The dimensions of the structures were scaled 1: 1.5 according to the Cauchy Froude similitude law. A shake table experiment was implemented on the reinforced concrete structure with the two-leaf cavity wall (TLCW) at the National Civil Engineering Laboratory (LNEC) in Lisbon, Portugal. The model that simulates URM was not experimentally studied. This structure was modelled in the same manner as the TLCW. The purpose of this virtual model is to compare the respective performances. Two nonlinear analyses were performed and compared with the experimental test results. These analyses were carried out in two phases. The research addresses first the analysis of a structure with only reinforced concrete elements, and secondly the analysis of the same structure with reinforced concrete elements and infill walls. Both researches consider static loading and pushover analysis. The experimental pushover curve was plotted by the envelope of the experimental curve obtained on the basis of the shake table records. Crack patterns, failure modes and performance curves were plotted for both models. Finally, results were evaluated on the basis of the current regulation ASCE/SEI 41-06.
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