An experimental study of the behaviour of double sided welded plate connections in precast concrete frames

Halil Görgün 국제구조공학회 2018 Steel and Composite Structures, An International J Vol.29 No.1

Multi-storey precast concrete skeletal structures are assembled from individual prefabricated components which are erected on-site using various types of connections. In the current design of these structures, beam-to-column connections are assumed to be pin jointed. Welded plate beam to-column connections have been used in the precast concrete industry for many years. They have many advantages over other jointing methods in component production, quality control, transportation and assembly. However, there is at present limited information concerning their detailed structural behaviour under bending and shear loadings. The experimental work has involved the determination of moment-rotation relationships for semi-rigid precast concrete connections in full scale connection tests. The study reported in this paper was undertaken to clarify the behaviour of such connections under symmetrical vertical loadings. A series of full-scale tests was performed on sample column for which the column geometry and weld arrangements conformed with successful commercial practice. Proprietary hollow core slabs were tied to the beams by tensile reinforcing bars, which also provide the in-plane continuity across the connections. The strength of the connections in the double sided tests was at least 0.84 times the predicted moment of resistance of the composite beam and slab. The secant stiffness of the connections ranged from 0.7 to 3.9 times the flexural stiffness of the attached beam. When the connections were tested without the floor slabs and tie steel, the reduced strength and stiffness were approximately a third and half respectively. This remarkable contribution of the floor strength and stiffness to the flexural capacity of the joint is currently neglected in the design process for precast concrete frames. In general, the double sided connections were found to be more suited to a semi-rigid design approach than the single sided ones. The behaviour of double sided welded plate connection test results are presented in this paper. The behaviour of single sided welded plate connection test results is the subject of another paper.

On the consideration of the masses of helical springs in damped combined systems consisting of two continua

M. Gürgöze,S. Zeren,M. M. A. Bicak 국제구조공학회 2008 Structural Engineering and Mechanics, An Int'l Jou Vol.28 No.2

This study is concerned with the establishment of the characteristic equation of a combined system consisting of a cantilever beam with a tip mass and an in-span visco-elastic helical spring-mass, considering the mass of the helical spring. After obtaining the “exact” characteristic equation of the combined system, by making use of a boundary value problem formulation, the characteristic equation is established via a transfer matrix method, as well. Further, the characteristic equation of a reduced system is obtained as a special case. Then, the characteristic equations are numerically solved for various combinations of the physical parameters. Further, comparison of the results with the massless spring case and the case in which the spring mass is partially considered, reveals the fact that neglecting or considering the mass of the spring partially can cause considerable errors for some combinations of the physical parameters of the system.

Alternative approach for the derivation of an eigenvalue problem for a Bernoulli-Euler beam carrying a single in-span elastic rod with a tip-mounted mass

Metin Gürgöze,Serkan Zeren 국제구조공학회 2015 Structural Engineering and Mechanics, An Int'l Jou Vol.53 No.6

Many vibrating mechanical systems from the real life are modeled as combined dynamicalsystems consisting of beams to which spring-mass secondary systems are attached. In most of thepublications on this topic, masses of the helical springs are neglected. In a paper (Cha et al. 2008) publishedrecently, the eigencharacteristics of an arbitrary supported Bernoulli-Euler beam with multiple in-spanhelical spring-mass systems were determined via the solution of the established eigenvalue problem, wherethe springs were modeled as axially vibrating rods. In the present article, the authors used the assumedmodes method in the usual sense and obtained the equations of motion from Lagrange Equations and arrivedat a generalized eigenvalue problem after applying a Galerkin procedure. The aim of the present paper issimply to show that one can arrive at the corresponding generalized eigenvalue problem by following a quitedifferent way, namely, by using the so-called “characteristic force” method. Further, parametricinvestigations are carried out for two representative types of supporting conditions of the bending beam.

An experimental study of the behaviour of double sided bolted billet connections in precast concrete frames

Halil Görgün 국제구조공학회 2018 Steel and Composite Structures, An International J Vol.29 No.5

Precast concrete structures are erected from individual prefabricated components, which are assembled on-site using different types of connections. In the present design of these structures, beam-to-column connections are assumed pin jointed. Bolted billet beam to-column connections have been used in the precast concrete industry for many years. They have many advantages over other jointing methods in component production, quality control, transportation and assembly. However, there is currently limited information concerning their detailed structural behaviour under vertical loadings. The experimental work has involved the determination of moment-relative rotation relationships for semi-rigid precast concrete connections in full-scale connection tests. The study reported in this paper was undertaken to clarify the behaviour of such connections under symmetrical vertical loadings. A series of full-scale tests was performed on sample column for which the column geometry and bolt arrangements conformed to successful commercial practice. Proprietary hollow core floor slabs were tied to the beams by 2T25 tensile reinforcing bars, which also provide the in-plane continuity across the connections. The contribution of the floor strength and stiffness to the flexural capacity of the joint is currently neglected in the design process for precast concrete frames. The flexural strength of the connections in the double-sided tests was at least 0.93 times the predicted moment of resistance of the composite beam and slab. The secant stiffness of the connections ranged from 0.94 to 1.94 times the flexural stiffness of the attached beam. In general, the double-sided connections were found to be more suited to a semi-rigid design approach than the single sided ones. The behaviour of double sided bolted billet connection test results are presented in this paper. The behaviour of single sided bolted billet connection test results is the subject of another paper.

Knowledge, Practice, and Risk Profile of Breast Cancer among Women Attending a Primary Care Center

Raja Lexshimi RG,Ho Siew Eng,Hamidah Hassan,Farawahida 한국간호과학회 2007 한국간호과학회 학술대회 Vol.2007 No.11

Review on Sustained Relief of Osteoarthritis Symptoms with a Proprietary Extract from Pine Bark, Pycnogenol

Peter Jo¨rg Rohdewald 한국식품영양과학회 2018 Journal of medicinal food Vol.21 No.1

The review summarizes the effects of the standardized proprietary bark extract of the French maritime pine (Pycnogenol®) in mild osteoarthritis (OA), stage 1 and 2. The extract exerts antioxidative, anti-inflammatory, and chondroprotective effects in vitro and in vivo. Its phenolic acids as well as catechin and taxifolin are quickly absorbed. Active metabolites, produced by gut microbiota in the intestinal tract from oligomeric procyanidins, appear in blood 6 h following ingestion and remain for at least 14 h, providing a long-lasting flow of anti-inflammatory substances for relief of OA symptoms. These constituents of Pycnogenol could be detected in serum, blood cells, and synovial fluid of OA patients. The resulting inhibition of cartilage-destructing proteases and pain-producing cyclo-oxygenases provides the basis for relief from pain, improvement of stiffness, enhanced mobility, and well-being in three clinical studies with the pine bark extract as an adjunct supplement. Sparing the use of nonsteroidal anti-inflammatory drugs, supplementation with the pine bark extract reduced gastric complications and hospital admissions of OA patients. Because of its favorable safety profile and sustained anti-inflammatory action, Pycnogenol represents an option as an add-on supplement for OA patients.

지식 문화, 다원주의 그리고 기본권

Sandku¨hler, Hans Jo¨rg 고려대학교 철학연구소 2003 철학연구 Vol.0 No.26

From terms to schemata

Jö,rg Plassen 한국불교연구원 2012 불교연구 Vol.36 No.-

不然 李箕永 연구의 철학적, 문헌학적 경향은 교리 분류와 개념의 연구가 강조되어 있으므로 유럽 선생님들인 Étienne Lamotte와 Paul Demiéville의 상당한 영향을 보인다. 현대 종교학에서 이기영 교수의 불교에 대한 이성적인 접근은 20세기 서양 종교의 영향으로 다소 구식이라고 여겨진다. 다만 지금의 문화적인 전환이 얼마나 오래 지속될지 모르므로 한국불교학은 여러 다른 시도를 하며 철학적, 문헌학적 유산의 장점을 잘 지키고 보전하는 것이 바람직하다. 이에 대한 하나의 접근 방법은 불교 사상역사에서 텍스트 이미지의 역할에 대한 의식을 깨우는 것이다. 본고는 Kant가 처음 도입하고 후에는 철학, 심리학, 인지과학에서 발달된 스키마의 개념이 어떻게 적용될 수 있는지 힌트를 주는 것이 목적이다. 이 시도에서 두 가지 경우가 간단히 논의되겠다. 하나는 Michael Kimmel의 전 작품을 통하여 ‘이미지 스키마타를 이용함으로써 화엄 수행과 철학에서의 이미지 사용을 좀 더 정확히 이해하는 것이다. 더 중요하는 것은 Gilles Fauconnier과 Mark Turner의‘개념의 결합’을 사용하여 은유 스키마타가 Peter N. Gregory에 의해 제기된 질문을 (왜 기신론이 동아시아 화염에서 중요하게 되었는가?) 해결할 열쇠를 제공할 수 있다고 주장 한다. 두 텍스트는 개념 병렬이 아니라 오히려 (원효의 논소 안에서) 두 은유 스키마타의 병렬로 연관된다. The philosophical and philological bent of Puryŏn Rhi Ki-young’s 不然 李箕永 research, emphasizing very much on the study of doctrinal differentiations and philosophic terms, clearly shows the influence of his European teachers Étienne Lamotte and Paul Demiéville. Within contemporary Religious Studies, Prof. Rhi’s to some extent also theologically informed approach usually is considered somewhat outdated. And yet, we do not know how long the current wave of cultural studies will last, and Korean Buddhology might be well advised to continue to preserve and build upon its precious philosophical and philological heritage. As this essay argues, to this avail one might draw upon a in the given context hitherto somewhat neglected method complementary to the study of philosophic terms and concepts, the analysis of the impact of textual images on the history of religious thought. In particular, this essay is intended to give a perspective on how the concept of schemata, first invented by Kant and then taken up in Philosophy, Psychology and Cognitive Sciences, might be employed to this avail. After a short introduction to the use of imagery in Hwaŏm Buddhism, we draw upon Michael Kimmel’s application of the notion of “image schemas” to the “golden lion”. Kimmels’s analysis does not only give an accurate model of how this dynamic textual image actually functions, but also provides a methodological yardstick enabling us to distinguish between more “soteriologically” and rather “philosophically” oriented usages of imagery, and thus as some potential also for the philological task of (re)grouping East Asian Hwaŏm texts by authors, resp. workshops. Subsequently, it is demonstrated how an analysis of the interaction of metaphor schemata may help to provide an answer to a long standing question initially raised by Peter N. Gregory, i.e. how it came about that the Ch’i-hsin fun was linked to the Hua-yen-ching and achieved its prominent position in the doctrinal classification scheme of later Hua-yen. Applying Gilles Fauconnier’s and Mark Turner’s notions of “Conceptual blending”, it is argued that rather than philosophical concepts, it were two metaphors employed to circumscribe the Buddha’s mind which, due to unification in a conceptual (or, perhaps better, schematic) blend, lead to the association of the texts.

Optimization and Analysis of Leakage Reactance for a Converter Transformer of the Electric Transport System

Dawood Kamran,Kömürgöz Güven,Işik Fatih 대한전기학회 2024 Journal of Electrical Engineering & Technology Vol.19 No.1

Converter transformers are widely used in the electric transport system and it is crucial equipment for the rectifer unit of the transport’s tracking substations. Leakage reactance is a crucial criterion during the development of a converter transformer. Almost all of the analytical methods consider only the axial leakage fux density during the evaluation of the leakage reactance. Radial leakage fux density is neglected in the analytical methods. Neglecting the radial leakage fux density during the computation of the leakage reactance in the two-winding transformers and other power transformers does not signifcantly afect the results. However, in the case of the converter transformers, radial leakage fux density also needs to be fully considered. In some of the converter transformers; windings, core, insulation material, and other parts of the transformer are so complex that analytical methods are impossible or difcult to implement. Hence, any other method is needed to evaluate the diferent parameters of the transformer. The optimal selection of leakage reactance is an important parameter during the design of the converter transformer. Numerical computational methods are one of the most commonly used techniques to solve and analyse the complex models of transformers. To accurately compute the leakage reactance of the electric transport system transformer (traction transformer), a transient method is used, which considers the efect of the radial leakage fux density. A prototype converter transformer of the electric transport system has been developed to obtain the experimental results. A transient method results and prototype transformer results show excellent agreement and verify the correctness of the fnite element model. The results of the traditional analytical and magnetostatics fnite element analysis are also compared with the short-circuit experimental test.

Das Grundgesetz mit 65: Reif für den Ruhestand oder im besten Alter?

Jö,rg Menzel 헌법이론실무학회 2015 헌법연구 Vol.2 No.1