Papers by SÜLEYMAN ADANUR
International Journal of Concrete Structures and Materials
The past two decades have witnessed rapid advances in the use of fiber-reinforced polymer (FRP) c... more The past two decades have witnessed rapid advances in the use of fiber-reinforced polymer (FRP) composites in different engineering fields. Advantages such as high strength-to-weight ratio, corrosion resistance, and tailority have led to immense interest in the use of FRPs in wide spectrum repair and strengthening of structures. Despite their many advantages, FRPs are highly sensitive to high temperatures, which pose a major concern for fire potential structures such as buildings. Applying proper thermal insulation can enhance the fire performance of FRP and reduce the possible fire damage to the FRP strengthened element. This study set out to experimentally investigate the effectiveness of two insulation systems, “FIRECOAT” and “REALROCK” on fire performance of CFRP and GFRP strengthened concrete specimens. Various configurations and exposure durations were considered to evaluate the effectiveness of insulating materials. To perform the experiments, cylindrical concrete specimens w...
This paper presents the finite element analysis of a suspension bridge subjected to earthquake gr... more This paper presents the finite element analysis of a suspension bridge subjected to earthquake ground motion using simplified models. For this purpose, two simplified models are considered. It is assumed that each element compose of the deck, cable and hangers in the first model. As second model, the elastic foundation analogy method is used. Also, actual bridge model is selected. Finite element earthquake analyses of the simplified and real bridge models are performed. One of the world's longest modern type suspension bridges, Fatih Sultan Mehmet Bridge, is selected as a numerical example. As ground motions, Kocaeli earthquake occurred on August 17, 1999 in Kocaeli, Turkey is chosen since it took place at the vicinity of the bridge. The response values obtained from simplified and actual bridge models are compared with each other.
Experimental Techniques, Nov 29, 2010
This study investigated the water level effects on the dynamic characteristics of a prototype arc... more This study investigated the water level effects on the dynamic characteristics of a prototype arch dam model using ambient vibration testing were investigated. Achievement of this purpose involved construction of a prototype arch damreservoir-foundation model under laboratory. The dam body was constructed with 60 cm height. Ambient vibration tests on the arch dam estimated its natural frequencies, mode shapes and damping ratios for different water levels. In the ambient vibration tests, ambient excitations are provided from small impact effects and the responses of the arch dam are measured. It can be stated from the study that natural frequencies are not overly changed among 0-30 cm water levels; however they are increased for higher water levels. The difference between the first natural frequencies of the arch dam obtained from empty reservoir (H = 0 cm) and full reservoir (H = 60 cm) is about 20-25%.
In this study, deterministic and stochastic dynamic responses of suspension bridges are investiga... more In this study, deterministic and stochastic dynamic responses of suspension bridges are investigated by considering geometrically nonlinear behavior. Bosporus Suspension Bridge is chosen as an example. S16E component of Pacoima Dam record of 1971 San Fernando earthquake and east-west component of 1992 Erzincan earthquake are used as ground motions. Filtered white noise model modified by Clough and Penzien is considered as a ground motion in the stochastic analyses. The ground motion model includes the effects of incoherence, wave passage, and site response. The bridge towers and deck displacement and internal forces are obtained in the end of the analyses. Because of the complex nature of earth crust, it is emphasized that the multiple support seismic excitations should be taken into account in the deterministic and stochastic analyses of long span structures like suspension bridges. ÖZET Bu çalışmada, asma köprülerin deterministik ve stokastik dinamik analizleri; geometrik olarak lineer olmayan davranış dikkate alınarak incelenmektedir. Uygulama olarak Boğaziçi Asma Köprüsü seçilmiştir. Yer hareketi olarak 1971 San Fernando depremi Pacoima Barajı S16E bileşeni ile 1992 Erzincan depremi doğu-batı bileşeni ivme kayıtları kullanılmaktadır. Stokastik analizlerde yer hareketini temsil etmek üzere Clough ve Penzien tarafından düzeltilerek elde edilen filtre edilmiş beyaz gürültü modeli dikkate alınmaktadır. Yer hareketi modeli, mesnetlere etkiyen yer hareketlerinin yansıma ve kırılmalarla değişebilir olmasından kaynaklanan korelasyon etkisini, dalga yayılma etkisini ve zemin özelliklerinin yer hareketine etkisini içermektedir. Analizler sonucunda köprü kuleleri ve tabliyesine ait yerdeğiştirme ve kesit tesirleri elde edilmiştir. Yer tabakasının karmaşık yapısından dolayı, yer hareketlerinin farklı noktalardaki değişiminden doğan etkilerin asma köprüler gibi uzun açıklıklı sistemlerin deterministik ve stokastik analizlerinde dikkate alınması gerektiği vurgulanmaktadır. GİRİŞ Asma köprüler kule, kablo, askı ve tabliye gibi değişik davranış gösteren elemanlardan oluşmaktadır. Dış kuvvetler altında özellikle kablo ve askılar büyük çekme kuvvetine maruz kaldıklarından bu kuvvetlerin eleman rijitlik matrislerine etkisi büyük olmaktadır. Yapı elemanlarının geometrik olarak lineer olmayan davranışı olarak adlandırılan bu özellik asma köprülerin analizinde dikkate alınması gerekmektedir. Literatürde geometrik olarak lineer olmama durumun dikkate alınarak yapılmış çalışmalar mevcuttur [1-9].
Experimental Mechanics, Aug 5, 2010
This study determines the dynamic characteristics of a prototype arch dam-reservoir-foundation sy... more This study determines the dynamic characteristics of a prototype arch dam-reservoir-foundation system using Operational Modal Analysis method. Achievement of this purpose involved construction of a prototype arch dam-reservoir-foundation system under laboratory conditions. Ambient vibration tests on the arch dam model identified its natural frequencies, mode shapes, and damping ratios. Natural excitations such as small impact loads vibrated to arch dam. Sensitivity accelerometers which were placed on the dam's crest collected signals in measurements. Measurements were recorded for empty and full reservoirs. Operational Modal Analysis software processed signals which were collected from the ambient vibration tests. Enhanced Frequency Domain Decomposition technique estimated dynamic characteristics of the dam. Results showed that there was an approximate 20-25% difference between natural frequencies related to empty and full reservoirs.
Natural Hazards and Earth System Sciences, Dec 9, 2010
This paper evaluates the performance of masonry buildings during the 20 and 27 December 2007 Bala... more This paper evaluates the performance of masonry buildings during the 20 and 27 December 2007 Bala (Ankara) earthquakes. Bala is a township located 50 km southeast from Ankara city in Turkey. The majority of the buildings in the affected region are built in masonry. Most of masonry buildings were formed with random or coursed stone and mud brick walls without any reinforcement. Many of these buildings were damaged or had collapsed. The cracking and failure patterns of the buildings are examined and interpreted according to current provisions for earthquake resistance of masonry structures. The damages are due to several reasons such as poor construction quality and poor workmanship of the buildings. In addition to these reasons, the two earthquakes hit the buildings within seven days, causing progressive damage.
International Journal of Steel Structures, Jun 1, 2017
In this study, a comprehensive investigation of the stochastic analysis of a suspension bridge su... more In this study, a comprehensive investigation of the stochastic analysis of a suspension bridge subjected to spatially varying ground motions is carried out for variable local soil cases and wave velocities. Bosphorus Suspension Bridge built in Turkey and connects Europe to Asia in Istanbul is selected as a numerical example. The spatial variability of the ground motion is considered with the incoherence, wave-passage and site-response effects. The incoherence effect is examined by taking into account Harichandran and Vanmarcke model, the site-response effect is outlined by using firm, medium and soft soil types, and the wave-passage effect is investigated by using 1000-2000, 500-1000, and 300-500 m/s wave velocities for the firm, medium and soft soils, respectively. Mean of maximum response values obtained from the spatially varying ground motions are compared with those of the specialized cases of the ground motion model. At the end of the study, it is seen that total displacements are dominated by dynamic component. The response values obtained for SMFF soil condition are generally the largest. When the varying local soil condition is considered, the variation of relative contributions of response components to the total response values for varying wave velocity cases is insignificant. Also, the variation of the wave velocity has important effect on the deck and towers total response values as compared with those of the constantly travelling wave velocity case. It is concluded that the site-response effect of ground motion on the response of suspension bridges is more important than that of the wave-passage, and the variation of the wave velocities depending on the local soil conditions, has important effects on the dynamic behavior of suspension bridge.
Journal of Hydraulic Research, Nov 1, 2005
The effects of the sediment on the earthquake response of concrete gravity dams subjected to hori... more The effects of the sediment on the earthquake response of concrete gravity dams subjected to horizontal and vertical asynchronous ground motion are investigated including dam-reservoir-sediment-foundation interaction in this paper. Dam-reservoir-sediment-foundation interaction is modeled by the finite element method. The equations of motion of the dam-reservoir-sediment-foundation system are determined using the Lagrangian approach. Solutions are obtained for dam-reservoir-foundation and dam-reservoir-sediment-foundation systems
Journal of Testing and Evaluation, Sep 26, 2016
An improved finite element model was used to obtain more accurate modeling of engineering structu... more An improved finite element model was used to obtain more accurate modeling of engineering structures. The main goal of this paper was to determine how this improved modeling procedure affects the dynamic response of buildings based on experimental modal parameters such as natural frequencies, mode shapes and damping ratios. For experimental assessment, three small, one-story, two-bay, reinforced concrete buildings with raft foundation were constructed under laboratory conditions. The initial three -dimensional finite element models, built with the ANSYS software, were used to analytically identify modal parameters, including natural frequencies and mode shapes. Following the analytical study, the ambient vibration tests were performed to obtain modal parameters, experimentally. The enhanced frequency domain decomposition method and the stochastic subspace identification method were used to identify the modal parameter. The analytical and experimental modal parameters were compared and then initial finite element models were updated to minimize the differences by changing of some uncertain parameters such as materials properties. With model updating, the maximum difference between the measured and initially obtained frequency was reduced from 28.47 to 4.88 %. To show the model updating effect on dynamic response of building models, dynamic analysis with the experimental computed damping ratios and 5 % damping ratio were carried out using 1992 Erzincan earthquake ground motion record. For the experimental damping ratios, the maximum differences in the displacements and stresses between the initial and updated models were obtained as 23 and 32 %, respectively. These differences were calculated as 43 and 15 % for the 5 % damping ratio. Comparisons of dynamic analyses results for the initial and updated model show that the finite element model updating affects the dynamic response of the buildings considerably.
Journal of Testing and Evaluation, 2010
In this study, dynamic characteristics of a prototype arch dam-reservoir-foundation model are det... more In this study, dynamic characteristics of a prototype arch dam-reservoir-foundation model are determined by operational modal analysis method using frequency and time domain techniques. For this purpose, a prototype arch am-reservoir-foundation model is constructed in laboratory conditions. Ambient vibration tests were conducted to the arch dam to identify its natural frequencies, mode shapes, and damping ratios. Natural excitations such as small impact effects were used to vibrate the arch dam. Sensitivity accelerometers were used to collect signals from the measurements. Measurements were recorded for empty and full reservoirs. The signals collected from the tests were processed by operational modal analysis software, and the dynamic characteristics of the dam were estimated using enhanced frequency domain decomposition and stochastic subspace identification techniques. The dynamic characteristics obtained from both techniques are close to each other. It can be stated that the both enhanced frequency domain decomposition and stochastic subspace identification techniques are very useful to identify the modal parameter of the prototype arch dam. In addition, it is observed that there is 20–25 % difference between natural frequencies for empty and full reservoirs.
Steel and Composite Structures, Apr 25, 2008
ABSTRACT This paper demonstrates an application of the perturbation based stochastic finite eleme... more ABSTRACT This paper demonstrates an application of the perturbation based stochastic finite element method (SFEM) for predicting the performance of structural systems made of composite sections with random material properties. The composite member consists of materials in contact each of which can surround a finite number of inclusions. The perturbation based stochastic finite element analysis can provide probabilistic behavior of a structure, only the first two moments of random variables need to be known, and should therefore be suitable as an alternative to Monte Carlo simulation (MCS) for realizing structural analysis. A summary of stiffness matrix formulation of composite systems and perturbation based stochastic finite element dynamic analysis formulation of structural systems made of composite sections is given. Two numerical examples are presented to illustrate the method. During stochastic analysis, displacements and sectional forces of composite systems are obtained from perturbation and Monte Carlo methods by changing elastic modulus as random variable. The results imply that perturbation based SFEM method gives close results to MCS method and it can be used instead of MCS method, especially, if computational cost is taken into consideration.
DergiPark (Istanbul University), Jun 1, 2000
Structural Engineering and Mechanics, May 25, 2012
Experimental Mechanics, Nov 11, 2016
Determining the structural behavior of masonry structures is a challenge due to their lack of hom... more Determining the structural behavior of masonry structures is a challenge due to their lack of homogeneity. The seismic behavior of masonry structures is especially complex. The aim of this study was to examine the structural behavior of Zağanos Bastion using both experimental and numerical methods. The Operational Modal Analysis technique, including the Enhanced Frequency Domain Decomposition Method, and the Stochastic Subspace Identification Method were used to illustrate experimentally the dynamic characteristic of the bastion. A finite element model was developed using ANSYS software in order that the dynamic characteristics of the bastion, including natural frequencies and mode shapes, could be calculated numerically. Seismic analysis was carried out using the 1999 Kocaeli earthquake ground motion record to determine the linear and nonlinear seismic behavior of the bastion. The Turkish Earthquake Code and its general technical specifications were used to evaluate the seismic results. The results show that the maximum and minimum principal stresses exerted on the masonry components exceeded the code requirements at some points, but in general the requirements for the stresses were satisfied.
Fiber reinforced polymer (FRP) composites have found increasingly wide applications in civil engi... more Fiber reinforced polymer (FRP) composites have found increasingly wide applications in civil engineering due to their high strength-to-weight ratio and high corrosion resistance for last two decades. This paper presents a numerical study on the stochastic seismic analysis of a cablestayed bridge subjected to earthquake ground motion using carbon fiber reinforced polymer (CFRP) cables. Jindo Bridge is chosen and schemed using CFRP cables. The cross-sectional areas of CFRP cables are determined by the principle of either equivalent cable stiffness or equivalent cable strength. The analysis of the selected bridge is conducted and the results obtained for CFRP cables are compared with steel counterpart. The results indicate that response values obtained for CFRP cables correspond well with those of the steel cables.
Springer eBooks, 2006
In this study, dynamic response of rock-fill dams to asynchronous ground motion is investigated. ... more In this study, dynamic response of rock-fill dams to asynchronous ground motion is investigated. The Keban Dam, constructed in Elaziğ, Turkey, is chosen as a numerical example. In the asynchronous dynamic analysis, wave velocities of 500 m/s, 1000 m/s, 2000 m/s and infinite are used for the travelling ground motion. Stresses are obtained for the wave velocities, and compared with
Springer eBooks, Jan 19, 2007
ABSTRACT In this paper, the stochastic dynamic responses of a suspension bridge subjected to asyn... more ABSTRACT In this paper, the stochastic dynamic responses of a suspension bridge subjected to asynchronous and antisynchronous ground motions are performed. Asynchronous and antisynchronous dynamic analyses are carried out for various wave velocities of the traveling earthquake ground motion. As an example Bosporus Suspension Bridge, built in Istanbul, is chosen. Filtered white noise (FWN) ground motion model modified by Clough and Penzien is used as ground motion model. The intensity parameter for the FWN model is obtained by equating the variance of this model to the variance of the two thirds of the S16E component of Pacoima Dam record of 1971 San Fernando earthquake, applied in the vertical direction. Mean of maximum displacements and internal forces obtained from the considered analyses are compared with each other.
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Papers by SÜLEYMAN ADANUR