Sürdürülebilir Kalkınma Amaçları
Yayınlar
- MakaleAçık Erişim2021The stress analysis of a shear wall with matrix displacement method using rectangular finite element
Ates, Sevket; Ergün, Mustafa
The aim in this study is to numerically present some characteristic features of the rectangular finite elementusing the matrix displacement method and to show the utility of this element in plane stress problemscompared to the finite element method. The paper consisted of three parts. In the first part, all of the finiteelement formulation steps from choosing the convenient coordinate system to creating element stiffnessmatrix are presented respectively. In the second part of the study, a static finite element analysis of the shearwall is also made by ANSYS Mechanical APDL. In the final part, the results (displacements, strains andstresses) obtained from the previous parts are compared with each other by the help of tables and graphics.The results show that this method is effective and preferable for the stress analysis of shell structures. Furtherstudies should be conducted in order to indicate the efficiency of the matrix displacement method for thesolution of different types of plane stress problems using different finite elements.
- MakaleYalnız künye2018THE MOST APPROPRIATE EARTHQUAKE RECORD GROUPS FOR DYNAMIC ANALYSIS OF A BUILDING
Atmaca, Barbaros; Ergun, Mustafa; Ates, Sevket
In this paper, seven real earthquake records are scaled according to Eurocode 8 design acceleration spectrum by using SESCAP (Selection and Scaling Program). SESCAP is a scaling program based on time domain scaling method and developed by using MATLAB, GUI software. Real and scaled earthquake records are used for linear time history analyses of a six-storied reinforced concrete building modeled as spatial by SAP2000. Eurocode 8 allows the use of real earthquake records for linear and nonlinear time history analyses of structures. In the case of using three earthquake records in linear and nonlinear time history analyses, maximum results of structural responses are used for design of structures. If at least seven time history analyses are performed, the mean responses of the structures are taken into account rather than the maximum results. For the selection of maximum results of structural response from thirty five groups are created by calculating combination of threes of seven real and scaled earthquake records, and another group including all of the seven real and scaled earthquake records are created for selection of mean. Relative floor displacements along X axis of the building are preferred as structural response of the building in this study. It is seen that differences between mean value and maximum value of the relative floor displacements along X axis of the building induced by seven and three scaled earthquake records respectively are less than ones obtained from real earthquake records.
- MakaleYalnız künye2018Scopus SJRQ1Stochastic responses of isolated bridge with triple concave friction pendulum bearing under spatially varying ground motion
Yurdakul, Muhammet; Ates, Sevket
This study aims to investigate the stochastic response of isolated and non-isolated highway bridges subjected to spatially varying earthquake ground motion model. This model includes wave passage, incoherence and site response effects. The wave passage effect is examined by using various wave velocities. The incoherency effect is investigated by considering the Harichandran and Vanmarcke coherency model. The site response effect is considered by selecting homogeneous firm, medium and soft soil types where the bridge supports are constructed. The ground motion is described by power spectral density function and applied to each support point. Triple concave friction pendulum (TCFP) bearing which is more effective than other seismic isolation systems is used for seismic isolation. To implement seismic isolation procedure, TCFP bearing devices are placed at each of the support points of the deck. In the analysis, the bridge selected is a five-span featuring cast-in-place concrete box girder superstructure supported on reinforced concrete columns. Foundation supported highway bridge is regarded as three regions and compared its different situation in the stochastic analysis. The stochastic analyses results show that spatially varying ground motion has important effects on the stochastic response of the isolated and non-isolated bridges as long span structures.
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İncele - MakaleYalnız künye2014Scopus SJRQ2Comparison of the dynamic responses of gülburnu highway bridge using single and triple concave friction pendulums
Yurdakul, Muhammet; Ates, Sevket; Altunisik, Ahmet Can
The main object of this study is to determine and compare the structural behavior of base isolated long span highway bridge, Gülburnu Highway Bridge, using single concave friction pendulum (SCFP) and triple concave friction pendulum (TCFP). The bridge is seismically isolated in the design phase to increase the main period and reduce the horizontal forces with moments using SCFP bearings. In the content of the paper, firstly three dimensional finite element model (FEM) of the bridge is constituted using project drawings by SAP2000 software. The dynamic characteristics such as natural frequencies and periods, and the structural response such as displacements, axial forces, shear forces and torsional moments are attained from the modal and dynamic analyses. After, FEM of the bridge is updated using TCFP and the analyses are performed. At the end of the study, the dynamic characteristics and internal forces are compared with each other to extract the TCFP effect. To emphasize the base isolation effect, the non-isolated structural analysis results are added to graphics. The predominant frequencies of bridge non-isolated, isolated with SCFP and isolated with TCFP conditions decreased from 0.849Hz to 0.497Hz and 0.338Hz, respectively. The maximum vertical displacements are obtained as 57cm, 54cm and 44cm for non-isolated, isolated with SCFP and isolated with TCFP conditions, respectively. The maximum vertical displacement reduction between isolated with TCFP bearing and isolated with SCFP bearing bridge is %23. Maximum axial forces are obtained as 60619kN, 18728kN and 7382kN, maximum shear forces are obtained as 23408kN, 17913kN and 16249kN and maximum torsional moments are obtained as 24020kNm, 7619kNm and 3840kNm for non-isolated, isolated with SCFP and isolated with TCFP conditions, respectively.
AtıfScopus5WoS4OpenAlex3İncele - MakaleAçık Erişim2013Scopus SJRQ1Damages on reinforced concrete buildings due to consecutive earthquakes in Van
Ates, Sevket; Kahya, Volkan; Yurdakul, Muhammet; Adanur, Suleyman
Consecutive earthquakes occurred on October 23rd, 2011 in Ercis and on November 9th, 2011 in Edremit that are townships located 90. km and 18. km far from Van city in Turkey, respectively. A total of 28,000 buildings were damaged or collapsed in the city center and the surrounding villages after the Ercis earthquake. This number reached 35,000 after the Edremit earthquake. In the area where the earthquakes occurred, almost all the reinforced concrete buildings were affected.This study presents field observations of damages on reinforced concrete buildings due to the consecutive earthquakes that occurred in Van, Turkey. Damages appearing in the buildings may occur due to several reasons such as site effect, poor construction quality, poor concrete strength, poor detailing in beam-column joints, detailing of stronger beam than column, soft stories, weak stories, inadequate reinforcement, short lap splices, incorrect end hook angle, and short columns. Aftershocks also caused progressive damages on the buildings within 17 days after the earthquakes. According to the results of this study, most of the damaged buildings were not designed and constructed according to the Turkish earthquake code, the so-called Specification for Buildings to be built in Seismic Zones.
AtıfScopus84WoS74OpenAlex92İncele - MakaleYalnız künye2011Scopus SJRQ1Modeling of triple concave friction pendulum bearings for seismic isolation of buildings
Yurdakul, Muhammet; Ates, Sevket
Seismic isolated building structures are examined in this study. The triple concave friction pendulum (TCFP) is used as a seismic isolation system which is easy to be manufactured and enduring more than traditional seismic isolation systems. In the TCFP, take advantage of weight which pendulum carrying and it's geometry in order to obtain desirable result of seismic isolation systems. These systems offer advantage to buildings which subject to severe earthquake. This is result of damping force of earthquake by means of their internal constructions, which consists of multiple surfaces. As the combinations of surfaces upon which sliding is occurring change, the stiffness and effective friction change accordingly. Additionally, the mentioned the TCFP is modeled as of a series arrangement of the three single concave friction pendulum (SCFP) bearings. A two dimensional- and eight- story of a building with and without isolation system are used in the time history analysis in order to investigate of the effectiveness of the seismic isolation systems on the buildings. Results are compared with each other to emphasize efficiency of the TCFP as a seismic isolation device against the other friction type isolation system like single and double concave surfaces. The values of the acceleration, floor displacement and isolator displacement obtained from the results by using different types of the isolation bearings are compared each other. As a result, the findings show that the TCFP bearings are more effective devices for isolation of the buildings against severe earthquakes.
AtıfScopus14OpenAlex12İncele - BildiriAçık Erişim2011Scopus SJRQ2Site-response effects on RC buildings isolated by triple concave friction pendulum bearings
Ates, Sevket; Yurdakul, Muhammet
The main object of this study is to evaluate the seismic response effects on a reinforced concrete building isolated by triple concave friction pendulum (TCFP) bearings. The site-response effects arise from the difference in the local soil conditions at the support points of the buildings. The local soil conditions are, therefore, considered as soft, medium and firm; separately. The results on the responses of the isolated building are compared with those of the non-isolated. The building model used in the time history analysis, which is a two-dimensional and eight-storey reinforced concrete building with and without the seismic isolation bearings and/or the local soil conditions, is composed of two-dimensional moment resisting frames for superstructure and of plane elements featuring plane-stress for substructure. The TCFP bearings for isolating the building are modelled as of a series arrangement of the three single concave friction pendulum (SCFP) bearings. In order to investigate the efficiency of both the seismic isolation bearings and the site-response effects on the buildings, the time history analyses are elaborately conducted. It is noted that the site-response effects are important for the isolated building constructed on soft, medium or firm type local foundation soil. The results of the analysis demonstrate that the siteresponse has significant effects on the response values of the structure-seismic isolation-foundation soil system.
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