• Title/Summary/Keyword: Structure of Elements

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Experimental Study On shear Capacity of P.C Vertical Joints (P.C 수직접합부의 전단내력에 대한 실험연구)

  • 김원종;김상식;지호청
    • Proceedings of the Korea Concrete Institute Conference
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    • 1994.10a
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    • pp.362-367
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    • 1994
  • In Precast Concrete Structure, safety of structure depends on strength of joint. Asa result, there exists a necessity to review the effects of elements consisting joints, since these elements are important factors for evalaution of joint strength. However, there elements are different for construction methods and may be changed even during construction. Obviously, the change of elements can cause the change of joint strength; yet, the effects of the variables are not clearly defined. The behavior of the joints are complicated and evaluated only through experiments. Consequently, the main objective of this paper is to review effects of components consisting Precast Joints, I order to keep higher joint strength than specified in the design code.

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Experimental study on laterally restrained steel columns with variable I cross sections

  • Cristutiu, Ionel-Mircea;Nunes, Daniel Luis;Dogariu, Adrian Ioan
    • Steel and Composite Structures
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    • v.13 no.3
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    • pp.225-238
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    • 2012
  • Steel structural elements with web-tapered I cross section, are usually made of welded thin plates. Due to the nonrectangular shape of the element, thin web section may be obtained at the maximum cross section height. The buckling strength is directly influenced by lateral restraining, end support and initial imperfections. If no lateral restraints, or when they are not effective enough, the global behaviour of the members is characterized by the lateral torsional mode and interaction with sectional buckling modes may occur. Actual design codes do not provide a practical design approach for this kind of elements. The paper summarizes an experimental study performed by the authors on a relevant number of elements of this type. The purpose of the work was to evaluate the actual behaviour of the web tapered beam-columns when applying different types of lateral restraints and different web thickness.

A Study on the Sainte-Chapelle in Terms of Semper's Theory of Four Elements (젬퍼의 4요소 이론의 관점에서 본 생트 샤펠에 관한 연구)

  • Kim, Ran-Soo
    • Korean Institute of Interior Design Journal
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    • v.17 no.2
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    • pp.47-55
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    • 2008
  • This paper attempted to analyze the Sainte-Chapelle(1242-48) in Paris in terms of Gottfried Semper's theory of four elements. For this aim, this study was divided into two parts: the first part regarding Semper's theory, which included not only the theories of four elements and four technical arts but also the concepts of the two types of primitive dwellings; the second part regarding the Sainte-Chapelle, composed of the overall study and the characteristics of the building and finally the analysis of it in terms of Semper's theory. The Sainte-Chapelle was regarded as a real example of Semper's four elements, in that the building was composed of a sacred altar containing Christ's earthly relics, stereotomic bases made of stone, a tectonic structure featuring linearity, and textile stained glass as an elaborate enclosure. While the bases and the structure were employed as serving elements, the altar and the stained glass played critical roles to make a whole space immaterial and monumental. These two elements served to reveal not only biblical typology but also the religious and political vision of Saint Louis to establish Paris is as a new Holy Land.

A Micro-Flow Sensor With Multiple Temperature Sensing Elements for Wide Range Flow Velocity Measurement (다단계 온도 감지막을 가진 고영역 흐름측정용 마이크로 흐름센서)

  • Chung Wan-Young;Kim Tae-Yong;Seo Yong-Su
    • Journal of Institute of Control, Robotics and Systems
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    • v.12 no.1
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    • pp.85-92
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    • 2006
  • A new silicon micro flow sensor with multiple temperature sensing elements was proposed and fabricated in considering wide range flow velocity measuring device. Thermal mass flow sensor measures the asymmetry of temperature profile around the heater which is modulated by the fluid flow. A micro mass flow sensor was normally composed of a central heater and a pair of temperature sensing elements around it. A new 2-D wide range micro flow sensor structure with three pairs of temperature sensing elements and a central heater was proposed and numerically simulated by Finite Difference Formulation to confirm the feasibility of the wide flow range sensor structure. To confirm the simulation result, the new flow sensor was fabricated on silicon substrate and the basic flow sensing properties of the sensor were measured.

Seismic retrofit of a soft first story structure considering soil effect

  • Michael Adane;Jinkoo Kim
    • Earthquakes and Structures
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    • v.24 no.5
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    • pp.345-352
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    • 2023
  • This paper studied the effect of soil-structure interaction (SSI) on the seismic response and retrofit of a reinforced concrete structure with a soft-first story for different soil types. A 5-story structure built on a 30m deep homogeneous soil mass was considered as a case study structure, and steel column jacketing and steel bracing were chosen as seismic retrofit methods. Seismic responses of a fixed-base and a flexible base structure subjected to seven scaled earthquake records were obtained using the software OpenSees to investigate the effect of soil on seismic response and retrofit. The nonlinearBeamColumn elements with the fiber sections were used to simulate the nonlinear behavior of the beams and columns. Soil properties were defined based on shear wave velocity according to categorized site classes defined in ASCE-7. The finite element model of the soil was made using isoparametric four-noded quadrilateral elements and the nonlinear dynamic responses of the combined system of soil and structure were calculated in the OpenSees. The analysis results indicate that the soil-structure interaction plays an important role in the seismic performance and retrofit of a structure with a soft-first story. It was observed that column steel jacketing was effective in the retrofit of the model structure on a fixed base, whereas stronger retrofit measures such as steel bracing were needed when soil-structure interaction was considered.

The Analysis of Nonlinear Circuits Using a Hybrid Haar Wavelet MRTD/FDTD Technique (Haar 웨이블릿 MRTD 와 FDTD를 이용한 비선형 회로 해석)

  • 배덕호;박범석;주세훈;김형동
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.11 no.4
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    • pp.667-673
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    • 2000
  • This paper presents the modeling method of nonlinear circuits with lumped elements by using a hybrid Haar -wavelet MRTD/FDTD techniques. To analyze nonlinear circuits with lumped elements, the Haar-wavelet MRTD scheme is applied to the entire structure of interest and the conventional FDTD scheme is locally used to describe the characteristics of the lumped elements. To validate the scheme, microstrip structure with lumped elements and a single diode mixer are simulated.

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Interaction analysis of three storeyed building frame supported on pile foundation

  • Rasal, S.A.;Chore, H.S.;Sawant, V.A.
    • Coupled systems mechanics
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    • v.7 no.4
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    • pp.455-483
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    • 2018
  • The study deals with physical modeling of a typical three storeyed building frame supported by a pile group of four piles ($2{\times}2$) embedded in cohesive soil mass using three dimensional finite element analysis. For the purpose of modeling, the elements such as beams, slabs and columns, of the superstructure frame; and that of the pile foundation such as pile and pile cap are descretized using twenty noded isoparametric continuum elements. The interface between the pile and the soil is idealized using sixteen node isoparametric surface element. The soil elements are modeled using eight nodes, nine nodes and twelve node continuum elements. The present study considers the linear elastic behaviour of the elements of superstructure and substructure (i.e., foundation). The soil is assumed to behave non-linear. The parametric study is carried out for studying the effect of soil- structure interaction on response of the frame on the premise of sub-structure approach. The frame is analyzed initially without considering the effect of the foundation (non-interaction analysis) and then, the pile foundation is evaluated independently to obtain the equivalent stiffness; and these values are used in the interaction analysis. The spacing between the piles in a group is varied to evaluate its effect on the interactive behaviour of frame in the context of two embedment depth ratios. The response of the frame included the horizontal displacement at the level of each storey, shear force in beams, axial force in columns along with the bending moments in beams and columns. The effect of the soil- structure interaction is observed to be significant for the configuration of the pile groups and in the context of non-linear behaviour of soil.

On the kinematic coupling of 1D and 3D finite elements: a structural model

  • Yue, Jianguang;Fafitis, Apostolos;Qian, Jiang
    • Interaction and multiscale mechanics
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    • v.3 no.2
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    • pp.192-211
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    • 2010
  • In most framed structures the nonlinearities and the damages are localized, extending over a limited length of the structural member. In order to capture the details of the local damage, the segments of a member that have entered the nonlinear range may need to be analyzed using the three-dimensional element (3D) model whereas the rest of the member can be analyzed using the simpler one-dimensional (1D) element model with fewer degrees of freedom. An Element-Coupling model was proposed to couple the small scale solid 3D elements with the large scale 1D beam elements. The mixed dimensional coupling is performed imposing the kinematic coupling hypothesis of the 1D model on the interfaces of the 3D model. The analysis results are compared with test results of a reinforced concrete pipe column and a structure consisting of reinforced concrete columns and a steel space truss subjected to static and dynamic loading. This structure is a reduced scale model of a direct air-cooled condenser support platform built in a thermal power plant. The reduction scale for the column as well as for the structure was 1:8. The same structures are also analyzed using 3D solid elements for the entire structure to demonstrate the validity of the Element-Coupling model. A comparison of the accuracy and the computational effort indicates that by the proposed Element-Coupling method the accuracy is almost the same but the computational effort is significantly reduced.

A Hydroelastic Response Analysis of Ships with Forward Speed in Regular Waves (규칙파중을 항행하는 선박의 유탄성응답해석)

  • Lee, S.C.;Bae, S.Y.
    • Journal of Power System Engineering
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    • v.14 no.5
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    • pp.48-55
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    • 2010
  • When a large ship is advancing in waves, ship undergoes the hydroelastic response, which has influences on structural stability and the fatigue destruction etc. of the ship. Therefore, to predict accurate hydroelastic response, it is necessary to analyze hydroelastic response including fluid-structure interaction. In this research, a ship is divided into many hull elements to calculate the fluid forces and wave exciting forces on each elements using three-dimensional source distribution method. The calculated fluid forces and wave exciting forces are assigned to nodes of hull elements. The neighbor nodes are connected with elastic beam elements. We analyzed hydroelastic responses, and those are formulated by using finite element method. Particularly, to estimate the influence of forward speed on the hydroelastic responses, we use two different methods : Full Hull Rotation Method(FHRM) and Sectional Hull Rotation Method(SHRM).

Structure and Challenges of a Security Policy on Small and Medium Enterprises

  • Almeida, Fernando;Carvalho, Ines;Cruz, Fabio
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.12 no.2
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    • pp.747-763
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    • 2018
  • Information Technology (IT) plays an increasingly important role for small and medium-sized enterprises. It has become fundamental for these companies to protect information and IT assets in relation to risks and threats that have grown in recent years. This study aims to understand the importance and structure of an information security policy, using a quantitative study that intends to identify the most important and least relevant elements of an information security policy document. The findings of this study reveal that the top three most important elements in the structure of a security policy are the asset management, security risk management and define the scope of the policy. On the other side, the three least relevant elements include the executive summary, contacts and manual inspection. Additionally, the study reveals that the importance given to each element of the security policy is slightly changed according to the sectors of activity. The elements that show the greatest variability are the review process, executive summary and penalties. On the other side, the purpose of the policy and the asset management present a stable importance for all sectors of activity.