• Title/Summary/Keyword: Static Structural

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A Study on Experiment and Structural Analysis for High-Durability of Orthotropic Steel Deck Bridge (고내구성을 위한 강바닥판교의 실험 및 해석 연구)

  • Kong, Byung-Seung;Kim, Min-Ho
    • Proceedings of the KSR Conference
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    • 2007.11a
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    • pp.462-467
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    • 2007
  • From the research which it sees verification of the whole interpretation and local interpretation of the durability steel deck bridge a static test and it produces the test body which it sells with character and it executes smallness pul lek detailed interpretation it leads and the appropriate characteristic of smallness pul lek detailed interpretation and to sleep a nominal stress price and it compares it judges it does. The stress quality from each structure region which it follows in load stock location it analyzes and from the hazard which evaluates, the objective region the length rib and the bottom grater weld zone, the length rib and width rib connection department and the width rib with the father it divided. It investigated the stress distribution of the test body from these objective location, FEM interpretation it led and the conduct against each structure state tax it analyzed. General conduct the load stock location the floor plate is located in the center with interpretation price together symmetry characteristic to seem, it cannot be like that it cannot there is one actual test price. Like this reason the length rib and width rib connection actually production even production characteristic security it is a day when it is impossible with the curvature junction department which it blows, it follows in examination body deferment condition and form feed with the fact that it is visible a big difference even with error of some it becomes. Consequently for a data and the research which are more accurate it is judged with the fact that the effort which is prudent will be necessary.

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The Effect of Genu Valgum on the Body Mass Index, Moment of Lower Limb Joints, Ground Reaction Force (신체질량지수, 하지관절의 모멘트, 지면반발력이 무릎외반슬에 미치는 영향)

  • Lee, Yong-Seon
    • Korean Journal of Applied Biomechanics
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    • v.25 no.3
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    • pp.257-263
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    • 2015
  • Objective : The purpose of this study was to investigate the effect of genu valgum on the body mass index, movement of lower limb joints, and ground reaction force. Methods : Gait patterns of 30 college students with genu valgum were analyzed and the static Q angle of the femur was measured for selecting genu valgum of the subjects. To analyze the kinetic changes during walking, the six-camera Vicon MX motion analysis system was used. The subjects were asked to walk 12 meters using the more comfortable walking method for walking. After they walked 12 meters more than 10 times, their most natural walking patterns were chosen three times and analyzed. Results : As a result of measuring a relationship between genu valgum and Q-angle, as the Q-angle increases, it showed a genu valgum also increased. Body Mass Index showed a significant difference between the groups was higher in the genu valgum group.(p<.001). The analysis result showed that genu valgum had a significant effect on the internal rotation moment in the hip joint(p<.05). Also, genu valgum had a significant effect on the internal rotation moment of the knee joint(p<.05). The comparative analysis of the Medial-Lateral ground reaction force in the genu valgum group showed a tendency to increase the medial ground reaction force(p<.05). The vertical ground reaction forces of the middle of the stance phase(Fz0) showed a significant increase in genu valgum group(p<.05), in particular the results showed a decrease in the early stance phase(p<.001). Conclusion : In conclusion, the change in body mass is considered to be made by proactive regular exercise for improvement of the genu valgum. In addition, the prevention of the deformation caused by secondary of the genu valgum in this study may be used as an indicator of the position alignment rehabilitation for structural and functional improvements. Applying a therapeutic exercise program for the next lap will require changes in posture alignment.

Structural Behavior of Cement Concrete Pavement at Transverse Joint Using Model Test

  • Ko, Young-Zoo;Kim, Kyung-Soo;Bae, Ju-Seong
    • KCI Concrete Journal
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    • v.12 no.2
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    • pp.23-30
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    • 2000
  • This paper presents behavior of concrete pavement at transverse joint subject to static test load. The test was conducted on 1/10 scale model in the laboratory. Load transfer across the crack is developed either by the interlocking action of the aggregate particles at the faces of the joint or by a combination of aggregate interlock and mechanical devices such as dowel bars. In this study, significant three variables considered to the performance of joints were selected. : (a)diameter of dowel bars(2.5mm, 3.0mm, 4.0mm), (b)presence or absence of dowel bars, (c)aggregate types(crushed stone, round stone). Experimental results were analyzed to find relationships among displacement of discontinuous plane at jointed slab, load transfer efficiency and joint opening, etc. Displacement of discontinuous plane at joint was decreased according to the increase of dowel bar diameter. In addition, it is found that model slabs made using crushed stone had better load transfer characteristics by aggregate interlock than model slabs made using similarly graded round stone. Displacement of discontinuous plane was increased according to the increase of loading. In addition, it was decreased as dowel diameter(2.5mm, 3.0mm, 4.0mm) was increased. In the case of slab without dowel bars, displacement of discontinuous plane was greatly increased and load transfer effciency of slab applied crushed stone was shown 30 percent greater than round stone. In addition, load transfer efficiency of slabs, which were made using crushed and round stone without dowel bars, was decreased to 20 percent and 30 percent, respectively as it was compared with slabs made us-ing dowel bars.

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Detection of damage in truss structures using Simplified Dolphin Echolocation algorithm based on modal data

  • Kaveh, Ali;Vaez, Seyed Rohollah Hoseini;Hosseini, Pedram;Fallah, Narges
    • Smart Structures and Systems
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    • v.18 no.5
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    • pp.983-1004
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    • 2016
  • Nowadays, there are two classes of methods for damage detection in structures consisting of static and dynamic. The dynamic methods are based on studying the changes in structure's dynamic characteristics. The theoretical basis of this method is that damage causes changes in dynamic characteristics of structures. The dynamic methods are divided into two categories: signal based and modal based. The modal based methods utilize the modal properties consisting of natural frequencies, modal damping and mode shapes. As the modal properties are sensitive to changes in the structure, these can be used for detecting the damages. In this study, using dynamic method and modal based approach (natural frequencies and mode shapes), the objective function is formulated. Then, detection of damages of truss structures is addressed by using Simplified Dolphin Echolocation algorithm and solving inverse optimization problem. Many scenarios are used to simulate the damages. To demonstrate the ability of the algorithm, different truss structures with several multiple elements scenarios are tested using a few runs. The influence of the two different levels of noise in the modal data for these scenarios is also considered. The last example of this article is investigated using a different mutation. This mutation obtains the exact answer with fewer loops and population by limited computational effort.

Studies on two bay and three storey infilled frame with different interface materials: Experimental and finite element studies

  • Muthukumar, S.;Satyanarayanan, K.S.;Senthil, K.
    • Structural Engineering and Mechanics
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    • v.64 no.5
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    • pp.543-555
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    • 2017
  • The non-linear behaviour of integral infilled frames (in which the infill and the frame are bonded together with help of various interface materials) is studied both experimentally and numerically. The experiments were carried out on one-sixth scale two-bay and three-storey reinforced concrete frames with and without infill against static cyclic loading. Three interface materials - cement mortar, cork and foam have been used in between the infill and the frame. The infill, interface and the frame are bonded together is called integral frame. The linear and non-linear behaviors of two dimensional bare frame and integral infilled frame have been studied numerically using the commercial finite element software SAP 2000. Linear finite element analysis has been carried out to quantify the effect of various interface materials on the infilled frames with various combinations of 21 cases and the results compared. The modified configuration that used all three interface materials offered better resistance above others. Therefore, the experiments were limited to this modified infilled frame case configuration, in addition to conventional (A1-integral infilled frame with cement mortar as interface) and bare frame (A0-No infill). The results have been compared with the numerical results done initially. It is found that stiffness of bare frame increased by infilling and the strength of modified frame increased by 20% compare to bare frame. The ductility ratio of modified infilled frame was 42% more than that of the conventional infilled frame. In general, the numerical result was found to be in good agreement with experimental results for initial crack load, ultimate load and deformed pattern of infill.

Experimental study on hysteretic behavior of steel moment frame equipped with elliptical brace

  • Jouneghani, Habib Ghasemi;Haghollahi, Abbas
    • Steel and Composite Structures
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    • v.34 no.6
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    • pp.891-907
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    • 2020
  • Many studies reveal that during destructive earthquakes, most of the structures enter the inelastic phase. The amount of hysteretic energy in a structure is considered as an important criterion in structure design and an important indicator for the degree of its damage or vulnerability. The hysteretic energy value wasted after the structure yields is the most important component of the energy equation that affects the structures system damage thereof. Controlling this value of energy leads to controlling the structure behavior. Here, for the first time, the hysteretic behavior and energy dissipation capacity are assessed at presence of elliptical braced resisting frames (ELBRFs), through an experimental study and numerical analysis of FEM. The ELBRFs are of lateral load systems, when located in the middle bay of the frame and connected properly to the beams and columns, in addition to improving the structural behavior, do not have the problem of architectural space in the bracing systems. The energy dissipation capacity is assessed in four frames of small single-story single-bay ELBRFs at ½ scale with different accessories, and compared with SMRF and X-bracing systems. The frames are analyzed through a nonlinear FEM and a quasi-static cyclic loading. The performance features here consist of hysteresis behavior, plasticity factor, energy dissipation, resistance and stiffness variation, shear strength and Von-Mises stress distribution. The test results indicate that the good behavior of the elliptical bracing resisting frame improves strength, stiffness, ductility and dissipated energy capacity in a significant manner.

Numerical study of the seismic behavior of steel frame-tube structures with bolted web-connected replaceable shear links

  • Lian, Ming;Cheng, Qianqian;Zhang, Hao;Su, Mingzhou
    • Steel and Composite Structures
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    • v.35 no.3
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    • pp.305-325
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    • 2020
  • Beams of steel frame-tube structures (SFTSs) typically have span-to-depth ratios of less than five. This makes a flexural beam unsuitable for such an application because the plastic hinges at the beam-ends cannot be adequately developed. This leads to lower ductility and energy dissipation capacities of SFTSs. To address this, SFTSs with bolted web-connected replaceable shear links (SFTS-BWSLs) are proposed. In this structural system, a web-connected replaceable shear link with a back-to-back double channel section is placed at the mid-length of the deep beam to act as a ductile fuse. This allows energy from earthquakes to be dissipated through link shear deformation. SFTS and SFTS-BWSL buildings were examined in this study. Several sub-structures were selected from each designed building and finite element models were established to study their respective hysteretic performance. The seismic behavior of each designed building was observed through static and dynamic analyses. The results indicate that the SFTS-BWSL and SFTS have similar initial lateral stiffness and shear leg properties. The SFTS-BWSL had lower strength, but higher ductility and energy dissipation capacities. Compared to the SFTS, the SFTS-BWSL had lower interstory drift, base shear force, and story shear force during earthquakes. This design approach could concentrate plasticity on the shear link while maintaining the residual interstory drift at less than 0.5%. The SFTS-BWSL is a reliable resistant system that can be repaired by replacing shear links damaged due to earthquakes.

A STUDY ON A MULTI-LEVEL SUBSTRUCTURING METHOD FOR COMPUTATIONS OF FLUID FLOW (유동계산을 위한 다단계 부분 구조법에 대한 연구)

  • Kim J.W.
    • Journal of computational fluids engineering
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    • v.10 no.2
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    • pp.38-47
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    • 2005
  • Substructuring methods are often used in finite element structural analyses. In this study a multi-level substructuring(MLSS) algorithm is developed and proposed as a possible candidate for finite element fluid solvers. The present algorithm consists of four stages such as a gathering, a condensing, a solving and a scattering stage. At each level, a predetermined number of elements are gathered and condensed to form an element of higher level. At the highest level, each sub-domain consists of only one super-element. Thus, the inversion process of a stiffness matrix associated with internal degrees of freedom of each sub-domain has been replaced by a sequential static condensation of gathered element matrices. The global algebraic system arising from the assembly of each sub-domain matrices is solved using a well-known iterative solver such as the conjugare gradient(CG) or the conjugate gradient squared(CGS) method. A time comparison with CG has been performed on a 2-D Poisson problem. With one domain the computing time by MLSS is comparable with that by CG up to about 260,000 d.o.f. For 263,169 d.o.f using 8 x 8 sub-domains, the time by MLSS is reduced to a value less than $30\%$ of that by CG. The lid-driven cavity problem has been solved for Re = 3200 using the element interpolation degree(Deg.) up to cubic. in this case, preconditioning techniques usually accompanied by iterative solvers are not needed. Finite element formulation for the incompressible flow has been stabilized by a modified residual procedure proposed by Ilinca et al.[9].

A Two-Phase Component Identification Method using Static and Dynamic Relationship between Classes (클래스들 간의 정적ㆍ동적 관계에 의한 2단계 컴포넌트 식별방법)

  • Choi Mi-Sook;Cho Eun-Sook;Park Jai-Nyun;Ha Jong-Sung
    • Journal of KIISE:Computing Practices and Letters
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    • v.11 no.1
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    • pp.1-14
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    • 2005
  • It is difficult to identify reusable and independent components in component-based development(CBD) process. Therefore existing methodologies have dealt the problem of component identification based on only developer's intuition and heuristics. As a result, it is difficult to identify the business components by common developers. Therefore, in this paper, we propose a new baseline and technique to identify the business components based on domain model such as use case diagrams, class diagrams, and sequence diagrams. proposed method identifies components through two phases; system component identification and business component identification. Especially, we consider structural characteristics as well as dependency characteristics according to methods call types and directions in identifying components. We also present a case study and comparative analysis and assessment to prove the practical use of our technique.

Intolerance of Uncertainty Scale: Construct validity of Prospective and Inhibitory factor structure (불확실성에 대한 인내력 부족 척도: 전향적·억제적 요인의 구인 타당도 검증)

  • Choi, Hyo Sun;Kim, Eun-Kyung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.9
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    • pp.338-344
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    • 2020
  • Intolerance of Uncertainty is associated with numerous psychopathologies, including generalized anxiety disorders. However, several studies differ in the factor structures applicable for the Intolerance of Uncertainty Scale (IUS), and there exists a debate regarding the factorial and construct validity. Thus, in the current study, the IUS was newly translated to explore and verify the structures and factors relative to the cultural background of Korea. The study involved an exploratory factor analysis of randomly extracted data from 260 of 533 adults selected. Results determined that a prospective factor of 3 items and inhibitory factor of 5 items was appropriate. In addition, a confirmatory factor analysis and correlation analysis of the remaining 273 data revealed that a structural model comprising of the 8-items two factors model was well suited (x2=37.699, TLI=0.951, CFI=0.969, RMSEA=0.063, SRMR=0.039), and showed significant static correlation with worry, depression, and state-trait anxiety.