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Türkiye’nin mevcut yapı stokunun önemli bir kısmı, depreme maruz kalmış ama kullanıma devam edilmekte olan orta katlı betonarme binalardan oluşmaktadır. Hasar görmüş binaların tekrar depreme maruz kaldıklarında gösterecekleri performansın belirlenmesi afet ve risk yönetimi açısından oldukça önemlidir. Bu çalışmada, depremde orta derecede hasar görmüş orta katlı betonarme bir binanın hasar görmeden önceki ve sonraki durumlarının hasar olasılıkları değerlendirilmiştir. Bu kapsamda her iki durum için bina üç boyutlu modellenmiş, doğrusal olmayan statik itme analizine tabi tutulmuş, göreli kat ötelemeleri ile hasargörebilirlik olasılık eğrileri elde edilmiştir. Sonuç olarak her iki durumdaki olası hasar oranları elde edilmiş ve risk yönetimi açısından değerlendirilmiştir.

Summary In precast technology, the effective design and construction are related to the behaviour of the connections between the structural members in order to cater for all service, environmental and earthquake load conditions. Therefore, the design and detailing of the connections should be undertaken consistently and with awareness of the desired structural response. In the research presented herein, an analytical expression is proposed for the prediction of the resistance of precast pinned connections under shear monotonic and cyclic loading. The proposed formula addresses the case where the failure of the connection occurs with simultaneous flexural failure of the dowel and compression failure of the concrete around the dowel, expected to occur either when (i) adequate concrete cover of the dowels is provided (d > 6 D) or (ii) adequate confining reinforcement (as defined in the article) is foreseen around the dowels in the case of small concrete covers (d

Biodiesel is a renewable and decomposable fuel which is derived from edible and non-edible oils. It has different properties compared to conventional diesel but can be used directly in diesel engines. Different fuel properties characterise different combustion-phasing parameters such as cyclic variations of Indicated Mean Effective Pressure (IMEP) and maximum pressure (Pmax). In this study, cyclic variations of combustion parameters such as IMEP and Pmax were investigated using a multi-cylinder diesel engine operating with conventional diesel and palm biodiesel. The experiments were conducted using different engine loads; 20, 40, and 60% at a constant engine speed of 2500 rpm. The coefficient of variation (COV) and standard deviation of parameters were used to evaluate the cyclic variations of the combustion phasing parameters for the test fuels at specific engine test conditions. It was observed that palm biodiesel has lower COV IMEP compared to conventional diesel but is higher in COV Pmax at higher engine loads respectively. In addition, palm biodiesel tends to have a higher recurrence for the frequency distribution for maximum pressure. It can be concluded from the study that the fuel properties of palm biodiesel have influenced most of the combustion parameters.

Blade fault is one of the most causes of failure in turbo machinery. This paper discussed the time frequency analysis for blade rubbing detection from casing vibration signal. Feasibility of Short Time Fourier Transform (STFT), Wigner-Ville distribution (WVD) and Choi-Williams distribution (CWD) were examined for blade rub detection in a multi stage blade system through an experimental data. Analysis results of the experimental data showed that these time frequency analysis methods have some inevitable deficiencies in segregating the blade passing frequency (BPF) components of the three rotor stage signals. However, CWD demonstrated a better time-frequency resolution in analyzing the multi stage rotor system signal.

The modelling approach in the case of connections in precast buildings is specific. The assembly of the constitutive parts of the connection requires the inclusion of contact definitions in the model. In addition, the material non-linearity including the influence of the spatial stress distribution should be taken into account where appropriate. Here a complex model of a beam-to-column dowel connection is presented. Experiments on the analysed connection were performed within the framework of the European project SAFECAST (Performance of Innovative Mechanical Connections in Precast Building Structures under Seismic Conditions). Several material and interaction parameters were investigated and the influence of each of them was evaluated. The set of parameters which gave the best match with the experiments was chosen.

In precast technology, mostly (but not exclusively), frame structures with pinned beam-to-column connections are preferred, especially in low-rise buildings due to the flexibility, lower cost and more favourable behaviour they provide, especially in the case of large spans and pretensioned interconnected members. However the available literature on the behaviour of pinned connections, especially under seismic loading, can be characterized as poor, even though their use in Europe and elsewhere is rather extended. In the terms of the present research a nonlinear 3D numerical model was developed and calibrated against available experimental data to be used as an effective tool for the analytical prediction of the behaviour of pinned connections, under monotonic and cyclic shear loading. The experimental data were derived from the European FP7 project SAFECAST, Grant Agreement Number 218417. The tests were performed at the Laboratory for Earthquake Engineering of the National Technical University of Athens, Greece. From the numerical results useful information was obtained on component level about: (a) the type of the observed failure mechanism; (b) the amount of dissipated energy; (c) the location of the developed plastic hinges along the steel dowel, and (d) the evolution of stresses and strains along the dowel(s) and in the mass of the surrounding grout. However the numerical model can be further utilized to investigate and quantify the effect of several parameters (that were not experimentally investigated in depth, or were not investigated at all) on the response of pinned connections.

The dowel type of the connection is the most common in Europe. However, the knowledge about its seismic behaviour was incomplete and poorly understood. To analyse the failure of dowel mechanism the numerical model in the FEA software ABAQUS was defined and calibrated using the results of the experimental investigations. Cyclic as well as monotonic response was analyzed. The most important observations are: (1) standard theory assuming that the failure mechanism is initiated by flexural yielding of the dowel and crushing of the surrounding concrete has been confirmed, (2) the strength of the connection considerably depends on the depth of the plastic hinge in the dowel, (3) in the case of the cyclic loading the strength is reduced due to the smaller depth of the plastic hinge, (4) neoprene bearing pad can considerably increase the strength of the connection, particularly when large relative displacements between the beam and the column are developed, and (5) in the case of large rotations between the beam and the column, cyclic resistance is reduced by 15–20%, because the dowel is loaded not only in flexure but also in tension.

The development of the new hypersonic impulse facility at the University of Michigan capable of generating aerothermal flow conditions representative of flight Mach numbers ranging between 4 and 11 is discussed. Three conditions were designed and run extensively for the purposes of validating and characterizing the generated flows. The conditions were chosen to span a range of accessible flow properties while maintaining relevance to the studies of supersonic combustion. The performance of the facility was assessed based on its ability to repeatedly and accurately generate flow conditions of interest. The temporal and spatial uniformity of the flow were determined using simultaneous pitotstatic pressure measurements, pressure measurements with a pitot rack, and schlieren imaging. Flow uniformity, useful test time, and core-flow sizes are established. A shot-to-shot statistical analysis of the resulting shock speeds reveal their variability to amount to a fraction of a percent, attributing to the ability of the facility to consistently generate the desired flow conditions.

The dual reciprocity method is applied to determine the hydrodynamic pressure distribution in a three-dimensional dam–reservoir system subjected to earthquake excitation. The reservoir domain is idealized as a finite region of irregular geometry adjacent to the dam followed by an infinite domain of uniform cross-section in the upstream direction. The reservoir hydrodynamic pressure response is governed by the Helmholtz equation subject to free surface, dam–reservoir interface, absorbing bottom/banks and radiation boundary conditions. A three-dimensional (3D) dual reciprocity model is developed to determine the hydrodynamic pressure in the finite reservoir domain. A radiation matrix is developed and introduced to relate the hydrodynamic pressure and its normal derivative on the interface between the finite and infinite domains. The three-dimensional radiation model used is developed by applying a two-dimensional dual reciprocity formulation along the interface of the finite and infinite reservoirs together with a continuum solution in the upstream direction of the infinite domain. The model is compared for the hydrodynamic response of a three-dimensional rectangular reservoir and found to be in excellent agreement with results obtained from a model based on the analytical formulation existing in the literature. Copyright © 2003 John Wiley & Sons, Ltd.

The non-linear analysis of single-degree-of-freedom (SDOF) systems provides the essential background information for both strength-based design and displacement-based evaluation/design methodologies through the development of the inelastic response spectra. The recursive solution procedure called the piecewise exact method, which is efficiently used for the response analysis of linear SDOF systems, is re-formulated in this paper in a unified format to analyse the non-linear SDOF systems with multi-linear hysteresis models. The unified formulation is also capable of handling the P-delta effect, which generally involves the negative post-yield stiffness of the hysteresis loops. The attractiveness of the method lies in the fact that it provides the exact solution when the loading time history is composed of piecewise linear segments, a condition that is perfectly satisfied for the earthquake excitation. Based on simple recursive relationships given for positive, negative and zero effective stiffnesses, the unified form of the piecewise exact method proves to be an extremely powerful and probably the best tool for the SDOF inelastic time-history and response spectrum analysis including the P-delta effect. A number of examples are presented to demonstrate the implementation of the method. Copyright © 2003 John Wiley & Sons, Ltd.

International audience; In this paper, a fluid-structure interaction (FSI) algorithm of the finite element method (FEM), which can take into account the effects of geometric and material nonlinearities of the tank, buckling of the tank shell, and nonlinear sloshing behavior of the contained liquid, is utilized to evaluate the actual behavior of broad cylindrical steel tanks when subjected to strong earthquake motions. In order to clarify a key question--whether anchoring would prevent earthquake damage to tanks--numerical analyses are carried out on the same tank model having two different support conditions: anchored and unanchored. In addition to two horizontal components of ground motion, the vertical component is also taken into account in order to determine the relative importance of vertical ground motion in the behavior of tanks. The consistency of provisions presented in current design codes and numerical analysis results is evaluated.

Seismic response of liquid storage tanks is quite different from conventional structures not only due to hydrodynamic effects acting on the tank shell but also owing to many Sources of nonlinear behavior mechanisms of tanks Such as buckling of the tank shell, large amplitude nonlinear sloshing, nonlinear tank-soil interaction, material yielding, plastic rotation of base plate and successive contact and separation between tank base and soil. For the assessment of earthquake response of such structures, numerical methods are indispensable tools since they offer a concise way of accurately considering all these nonlinearities in the same model. Yet, before using numerical techniques for design purposes for the evaluation of different configurations of the fluid-tank systems when subjected to several earthquake ground motions, they should be validated by experimental results. For this purpose, in this study, a fully nonlinear fluid-structure interaction algorithm of finite element method is employed for the seismic analysis of anchored and unanchored steel liquid storage tanks. An existing experimental study carried Out on anchored and unanchored tanks is utilized for the verification of the numerical procedure. In the numerical models, Arbitrary Lagrangian Eulerian (ALE) description of the liquid-structure interface which is described by the mesh nodes at the boundary is employed. Fluid motion is governed by compressible Navier-Stokes equations. Both material and geometric nonlinearities are considered in order to accurately determine stress, strain and strain rate distributions throughout the tank. Successive contact and separation between base plate and foundation along with friction effects are taken into account by contact modeling algorithm. Response parameters of tanks, such as free Surface sloshing wave height, pressure time histories, base plate uplifting and shell stresses obtained by numerical simulations are correlated with those of experimentally observed. By means of experimental and numerical results, the principal effects of base uplifting on the seismic response of unanchored cylindrical steel tank are highlighted with comparing that of rigidly restrained tank. Moreover, the provisions given in the current tank seismic design codes for metal cylindrical tanks are discussed and the response parameters of tanks are computed per minimum requirements of these codes. The results are compared with findings of numerical and experimental studies and the comments on the consistency of these results are explained in detail. Strong correlation between the experimental and numerical results is obtained for investigated response parameters although code requirements present deviations from the reference experimental study especially for uplift displacement and free surface wave height. (C) 2009 Elsevier Ltd. All rights reserved.

International audience; The long-period components in earthquake ground motions, which attenuate gradually with distance, can induce sloshing waves in the liquid containment tanks although they are located far away from the seismic source. The resulting sloshing waves generate additional forces impacting the wall and roof of the tanks and may cause extensive damage on the tank structure. Numerous examples of tank damages due to sloshing of fluid have been observed during many earthquakes. Nevertheless, the effect of sloshing is usually primitively considered in most of the seismic design codes of tanks. On the other hand, the derivation of an analytical solution for the sloshing response of a liquid storage tank subjected to harmonic excitation includes many assumptions and simplifications. Most of the analytical solutions in the recent literature assumed the containing liquid to be invicid, incompressible and irrotational, and the tank structure to be an isotropic elastic plate with uniform stiffness, mass and thickness. Even though, experimental works are necessary to study the actual behavior of the system, they are time consuming, very costly and performed only for specific boundary and excitation conditions. However, appropriate numerical simulation using fluid structure interaction techniques can be used to predict the hydrodynamic forces due to the high-speed impacts of sloshing liquid on a tank wall and roof. These simulations can reduce the number of experimental tests. The nonlinear finite element techniques with either Lagrangian and/or Eulerian formulations may be employed as a numerical method to model sloshing problems. But, most of the Lagrangian formulations used to solve such problems have failed due to high mesh distortion of the fluid. The arbitrary Lagrangian Eulerian techniques are capable of keeping mesh integrity during the motion of the tank. In this study, an explicit nonlinear finite element analysis method with ALE algorithm is developed and sloshing phenomenon is analyzed. The analysis capabilities of the method are explained on a technical level. Although, the developed numerical procedure is applicable to deformable structures, the accuracy of the method is validated with the existing analytical formulation derived from potential flow theory as well as the experimental data carried out on rigid tanks when subjected to harmonic and earthquake ground motions. High consistency between numerical and experimental results in terms of peak level timing, shape and amplitude of sloshing waves is obtained not only for non-resonant excitation but also for resonant frequency motion.

Theoretical analysis is carried out to evaluate the performance of a Wavelength Division Multiplexing (WDM) network transmission system in the presence of crosstalk due to Waveguide Grating Router (AWG) router. It is found that linear crosstalk induced by the AWG induces higher penalty when the number of add/drop channels is increased and therefore imposes severe limitation on the maximum number of add/drop channels and the number of users accessing the WDM network.

Toplumsal yaşamın sürdürülebilirliğini sağlamak, can ve mal kaybınaneden olan afetlere karşı direnci artırmak, toplulukları afete hazırlık konusundabilinçlendirmek ve tüm bileşenleri hazırlıklı bulundurmakla mümkün olabilir. Afetplanlaması olası bir afet sonrasında toplumun olumsuz yönde etkilenmesiniazaltmak ve kaynakların doğru kullanım hedeflerini gözeten bir yaklaşımdır.Ülkemizdeki kayıplarda da önemli bir yere sahip depremin riskdeğerlendirmelerinde deterministik ve olasılıksal yöntemler olmak üzere ikitemel yaklaşım bulunmaktadır. Bu çalışmada deprem risk değerlendirmesine, yerhareketi, yapı envanteri ve yöntem bileşenlerinde mevcut olan belirsizliklerinetkisi araştırılmıştır. Çalışmada, Marmara bölgesinin önemli fay hatlarınayakın ve Kocaeli Depremi (1999) şiddetinin en fazla hissedildiği yerleşimlerdenbiri olan Gebze (Kocaeli) ilçesi seçilmiş, deprem senaryolarıyla risk yapısıdeğerlendirilmiştir. Senaryo depremleri uygulanırken depremin kaynağı, depreminbüyüklüğü ve zemin parametrelerinin riske etkisi incelenmiştir. Riskdeğerlendirmeleri sonuçlarına göre bina hasarı, can kaybı ve barınak ihtiyacıoranları hesaplanmıştır. Ayrıca mahalle bazında beklenen şiddet, hasarseviyeleri zemin etkisinin dikkate alındığı ve alınmadığı durumlar için haritaüzerinde ayrı ayrı gösterilmiştir. Bu değerlendirmeler ülkemiz için hazırlanmışsismik tehlike bilgisi, yerel zemin bilgisi ve bina envanterindeki unsurlarıiçeren veriler ile CBS verilerini birleştirebilen ön hasar tespit yazılımı, AFAD-REDkullanılarak gerçekleştirilmiştir. Sonuç olarak, deprem risk planlamasında yerhareketi tahmin belirsizliklerinin kayıp tahmini sonuçları üzerindeki önemi gösterilmiştir., To obtain the sustainability of social life andto increase resistance to disaster that cause loss of life and properties; itis possible to raise awareness in the community about disaster preparedness andengross to take all the components. Disaster planning is an approach thattargets the correct use of resources to decrease negative impacts in thecommunity after the disaster. In Turkey, earthquake losses have an important rolein disaster planning. There are two basic approaches for earthquake lossestimation used in disaster planning namely deterministic and probabilistic. Uncertaintiesof the seismic risk assessment parameters can be generated from ground motioncomputations, structural inventories and risk methodologies. In this study, uncertaintiesin the ground motion estimations are investigated. Gebze district that locatedclose to major fault lines at Marmara region, and had significant damage duringKocaeli earthquake (1990), is selected as a study case for the risk assessmentscenarios. The uncertainties parameters in ground motion computation that havemajor effect on the risk assessment are considered as earthquake source,earthquake magnitude and soil parameters. As a result, building damage ratios,loss of life and the need for shelter are computed. The soil amplificationeffects on the seismic intensity level and damage ratios are emphasized. Theearthquake hazard estimation and risk assessment computation were performedutilizing geographic information system based software AFAD-RED. The software combinesthe scenario based seismic hazard procedure with the existing buildinginventories and soil data for the risk estimations. As a result, it isconcluded that, uncertainties in ground motion computations have importanteffect on the seismic risk assessment and should be considered in disasterplanning process.

Corrigendum to ‘‘Cyclic failure analysis of the beam-to-column dowel connections in precast industrial buildings’’ [Eng. Struct. 52 (2013) 179–191] Blaž Zoubek , Tatjana Isakovic , Yasin Fahjan , Matej Fischinger a University of Ljubljana, Faculty of Civil and Geodetic Engineering, Jamova 2, 1000 Ljubljana, Slovenia Gebze Institute of Technology, Department of Earthquake and Structural Engineering, Istanbul Caddesi 141, 41400 Gebze, Turkey

Acknowledgements. The authors would like to deeply thank Professor Sami A. Kilic and Bachelor of Science student Ceki Erginbas for the design of the experimental setup. The sloshing experiment was funded by Grant No. 07HT102 of the Bogazici University’s Research Fund (B.U. Arfon), for which Professor Kilic is the main investigator. The authors would like also to express their deepest gratitude to Professor Erdal Safak of Kandilli Observatory of Bogazici University for careful review of the manuscript and his valuable recommendations. This work is supported by the Scientific and Technological Research Council of Turkey (TUBITAK-MAG) through contract number 108M607 and by Research Fund of Gebze Institute of Technology under project number 2009-A-25. The first author is granted by Eiffel excellence scholarship of the French Ministry of Foreign and European Affairs.

The strong ground motion network operated by Bogazici University in and around Istanbul has been described, including the rapid response and early warning system, structural instrumentation, instrument calibration and, processing, availability and utilization of the data.