Theoretical and experimental dynamic characteristics of a RC building model for construction stages

Temel Turker,Alemdar Bayraktar 사단법인 한국계산역학회 2016 Computers and Concrete, An International Journal Vol.17 No.4

Dynamic characteristics, named as natural frequencies, damping ratios and mode shapes, affect the dynamic behavior of buildings and they vary depending on the construction stages. It is aimed to present the effects of construction stages on the dynamic characteristics of reinforced concrete (RC) buildings considering theoretical and experimental investigations. For this purpose, a three-storey RC building model with a 1/2 scale was constructed in the laboratory of Civil Engineering Department at Karadeniz Technical University. The modal testing measurements were performed by using Operational Modal Analysis (OMA) method for the bare frame, brick walled and coated cases of the building model. Randomly generated loads by impact hammer were used to vibrate the building model; the responses were measured by uni-axial seismic accelerometers as acceleration. The building’s modal parameters at these construction stages were extracted from the processed signals using the Enhanced Frequency Domain Decomposition (EFDD) technique. Also, the finite element models of each case were developed and modal analyses were performed. It was observed from the experimental and theoretical investigations that the natural frequencies of the building model varied depending on the construction stages considerably.

CROSSED SEMIMODULES AND CAT¹-MONOIDS

Temel, Sedat The Kangwon-Kyungki Mathematical Society 2019 한국수학논문집 Vol.27 No.2

The main idea of this paper is to introduce the notion of $cat^1$-monoids and to prove that the category of crossed semimodules ${\mathcal{C}}=(A,B,{\partial})$ where A is a group is equivalent to the category of $cat^1$-monoids. This is a generalization of the well known equivalence between category of $cat^1$-groups and that of crossed modules over groups.

Vibration based damage detection in a scaled reinforced concrete building by FE model updating

Temel Türker,Alemdar Bayraktar 사단법인 한국계산역학회 2014 Computers and Concrete, An International Journal Vol.14 No.1

The traditional destructive tests in damage detection require high cost, long consuming time, repairing of damaged members, etc. In addition to these, powerful equipments with advanced technology have motivated development of global vibration based damage detection methods. These methods base on observation of the changes in the structural dynamic properties and updating finite element models. The existence, location, severity and effect on the structural behavior of the damages can be identified by using these methods. The main idea in these methods is to minimize the differences between analytical and experimental natural frequencies. In this study, an application of damage detection using model updating method was presented on a one storey reinforced concrete (RC) building model. The model was designed to be 1/2 scale of a real building. The measurements on the model were performed by using ten uni-axial seismic accelerometers which were placed to the floor level. The presented damage identification procedure mainly consists of five steps: initial finite element modeling, testing of the undamaged model, finite element model calibration, testing of the damaged model, and damage detection with model updating. The elasticity modulus was selected as variable parameter for model calibration, while the inertia moment of section was selected for model updating. The first three modes were taken into consideration. The possible damaged members were estimated by considering the change ratio in the inertia moment. It was concluded that the finite element model calibration was required for structures to later evaluations such as damage, fatigue, etc. The presented model updating based procedure was very effective and useful for RC structures in the damage identification.

Vibration based damage identification of concrete arch dams by finite element model updating

Temel Türker,Alemdar Bayraktar,Barış Sevim 사단법인 한국계산역학회 2014 Computers and Concrete, An International Journal Vol.13 No.2

Vibration based damage detection is very popular in the civil engineering area. Especially, special structures like dams, long-span bridges and high-rise buildings, need continues monitoring in terms of mechanical properties of material, static and dynamic behavior. It has been stated in the International Commission on Large Dams that more than half of the large concrete dams were constructed more than 50 years ago and the old dams have subjected to repeating loads such as earthquake, overflow, blast, etc.,. So, some unexpected failures may occur and catastrophic damages may be taken place because of theloss of strength, stiffness and other physical properties of concrete. Therefore, these dams need repairs provided with global damage evaluation in order to preserve structural integrity. The paper aims to show the effectiveness of the model updating method for global damage detection on a laboratory arch dam model. Ambient vibration test is used in order to determine the experimental dynamic characteristics. The initial finite element model is updated according to the experimentally determined natural frequencies and mode shapes. The web thickness is selected as updating parameter in the damage evaluation. It is observed from the study that the damage case is revealed with high accuracy and a good match is attained between the estimated and the real damage cases by model updating method.

Structural evaluation of Aspendos (Belkıs) Masonry Bridge

Temel Türker 국제구조공학회 2014 Structural Engineering and Mechanics, An Int'l Jou Vol.50 No.4

In this study, the structural performance of a seven span masonry arch bridge was evaluated. Investigations were performed on Aspendos (Belkıs) Masonry Arch Bridge which was located on road of Aspendos Acropolis City in Antalya, Turkey. The old bridge was constructed in the early of fourth century AD, but it was exposed to the earthquakes in this region and the overloading by the river water. The old bridge was severely damaged and collapsed by probably an earthquake many years ago and a new bridge was then reconstructed on the remains of this old bridge by Seljuk in the 13th century. The bridge has also been affected from overflowing especially in the spring of each year, so some protective measures should be taken for this monumental bridge. Therefore, the structural performance under these loading has to be known. For this purpose, an initial finite element model was developed for the bridge and it was calibrated according to ambient vibration test results. After that, it was analyzed for different load cases such as dead, live, earthquake and overflow. Three load combinations were taken into account by deriving from these load cases. The displacements and the stresses for these combination cases were attained and compared with each other. The structural performance of Aspendos Masonry Arch Bridge was determined by considering the demand-capacity ratio for the tensile stress of the mortar used in Aspendos Masonry Arch Bridge. After these investigations, some concluding remarks and offers were presented at the end of this study.

FAMILY SIZE, HUMAN CAPITAL AND GROWTH: STRUCTURAL PATH ANALYSIS OF RWANDA

Tugrul Temel 중앙대학교 경제연구소 2013 Journal of Economic Development Vol.38 No.4

This paper analyzes the macroeconomic role that different household groups play in human capital formation, sectoral growth and income distribution in Rwanda. Using a disaggregated SAM for Rwanda and, with the assistance of structural path analysis, the paper explores the macroeconomic implications of family size for human capital, sectoral growth and income distribution. The findings support the so-called quantity-quality trade-off hypothesis: the smaller the family size, the higher the investment in human capital. In particular, the human capital investment of households with 1-3 children tends to be more pronounced than that of households with more than 3 children. Moreover, households with 1-3 children act as an important intermediate pole transmitting the influence of human capital investment on agricultural production. As a result, promoting family planning programs seems to be a viable strategy for economic growth and poverty reduction.

Structural evaluation of Aspendos (Belkis) Masonry Bridge

Turker, Temel Techno-Press 2014 Structural Engineering and Mechanics, An Int'l Jou Vol.50 No.4

In this study, the structural performance of a seven span masonry arch bridge was evaluated. Investigations were performed on Aspendos (Belkis) Masonry Arch Bridge which was located on road of Aspendos Acropolis City in Antalya, Turkey. The old bridge was constructed in the early of fourth century AD, but it was exposed to the earthquakes in this region and the overloading by the river water. The old bridge was severely damaged and collapsed by probably an earthquake many years ago and a new bridge was then reconstructed on the remains of this old bridge by Seljuk in the 13th century. The bridge has also been affected from overflowing especially in the spring of each year, so some protective measures should be taken for this monumental bridge. Therefore, the structural performance under these loading has to be known. For this purpose, an initial finite element model was developed for the bridge and it was calibrated according to ambient vibration test results. After that, it was analyzed for different load cases such as dead, live, earthquake and overflow. Three load combinations were taken into account by deriving from these load cases. The displacements and the stresses for these combination cases were attained and compared with each other. The structural performance of Aspendos Masonry Arch Bridge was determined by considering the demand-capacity ratio for the tensile stress of the mortar used in Aspendos Masonry Arch Bridge. After these investigations, some concluding remarks and offers were presented at the end of this study.

Chemical compositions and larvicidal effectiveness of Rhododendron ponticum essential oil on Neodiprion sertifer larvae

Gokturk Temel,Anasashvili Nunu Chachkhiani,Dumbadze Guguli 한국응용곤충학회 2023 Journal of Asia-Pacific Entomology Vol.26 No.4

In many countries throughout the world, the European pine sawfly, Neodiprion sertifer (Geoffroy, 1785) (Hy menoptera: Diprionidae) is known as a significant forest pest that damages pine needles. As a result of the insect damage, young pine trees, especially, might dry up totally. Mechanical, biotechnical, biological, and chemical approaches are applied in research to keep it under control. Due to the increasing danger of chemical contam ination associated with the use of synthetic pesticides to control insects, alternative control strategies have been sought, and studies on essential oils have been prioritized. In this research, in addition to determining the chemical analysis of Rhododendron ponticum L. (Ericales; Ericaceae) essential oil by GC–MS, the larvicidal effects of R. ponticum on N. setifer in the six larval stages were also investigated. The research was conducted in the Artvin Çoruh University Central Laboratory under laboratory settings (25 ± 1 ◦ C, 65 ± 5% RH, and 14L:10D h photoperiods) during 2020–21. 1-Methyl-2-pyrrolidone (38.41%), Phenylethy alcohol (10.07%), Linalool (8.01%), Myrtenol 5.68%), β-Pinene (4.26%), Citronellol (4.05%), α-Pinene (3.02%) were found to be the major components of R. ponticum oil. The administration of R. ponticum essential oil at 10, 15, and 20 μL/Petri doses, as well as controls at the 24th, 48th, 72nd, and 96th hours, produced various rates of death (19.6–100%) on six larval stages of N. sertifer. According to LD 50 and LD 90 values, the highest toxicity was determined as L 1 (0.58 μL/ larva) and the lowest toxicity was as L 6 (10.44 μL/larva). In conclusion, R. ponticum essential oil showed high toxicity against L 1 and L 2 larval stages of N. sertifer.

Normality and quotient in crossed modules over groupoids and 2-groupoids

Sedat Temel 강원경기수학회 2019 한국수학논문집 Vol.27 No.1

The aim of this paper is to consider the categorical equivalence between crossed modules within groupoids and 2-groupoids; and then relate normality and quotient in these two categories.

The experimental and numerical investigation on thermal responses of passive thermal protected batteries in different packs from low to high discharge rates

Umit Nazli Temel,Ferhat Kilinc 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.7

This study contains experimental and numerical investigation of the shape effect of the pack on the performances of PCM (or GNP/PCM) based passive thermally protected battery packs. Also, the performances of the PCM and thermally enhanced GNP/PCM composite for battery thermal protection are compared from low to high discharge rates. The thermal response results show that the cylindrical pack performs worse than the rectangular pack in terms of the maximum temperature and maximum temperature difference performance criteria. For the maximum temperature restriction criteria, 7 % GNP/RT44 composite, that has enhanced thermal conductivity, performs better at first, but then its performance deteriorates compared to RT44 depending on the increase of its viscosity. It was determined that 7 % GNP/RT-44 extend the effective protection times by 95.8 %, 73.3 % and 28.0 % at the discharge rates of 4.4 W, 6.6 W and 8.8 W, respectively.