• Title/Summary/Keyword: Structure load

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Nonlinear analysis of the RC structure by higher-order element with the refined plastic hinge

  • IU, C.K.
    • Computers and Concrete
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    • v.17 no.5
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    • pp.579-596
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    • 2016
  • This paper describes a method of the refined plastic hinge approach in the framework of the higher-order element formulation that can efficaciously evaluate the limit state capacity of a whole reinforced concrete structural system using least number of element(s), whereas the traditional design of a reinforced concrete structure (i.e. AS3600; Eurocode 2) is member-based approach. Hence, in regard to the material nonlinearities, the efficient and economical cross-section analysis is provided to evaluate the element section capacity of non-uniform and arbitrary concrete section subjected to the interaction effects, which is helpful to formulate the refined plastic hinge method. In regard to the geometric nonlinearities, this paper relies on the higher-order element formulation with element load effect. Eventually, the load redistribution can be considered and make full use of the strength reserved owing to the redundancy of an indeterminate structure. And it is particularly true for the performance-based design of a structure under the extreme loads, while the uncertainty of the extreme load is great that the true behaviour of a whole structural system is important for the economical design approach, which is great superiority over the conservative optimal strength of an individual and isolated member based on traditional design (i.e. AS3600; Eurocode 2).

An Experimental Study for the Fatigue Strength Assessment of Longi-web Connections (Longi-web 연결부의 피로강도 평가에 관한 실험적 연구)

  • Kang, Sung-Won;Kim, Jeong-Hwan;Kim, Kwang-Seok;Kang, Joong-Kyoo;Heo, Joo-Ho;Kim, Myung-Hyun
    • Journal of the Society of Naval Architects of Korea
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    • v.45 no.1
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    • pp.87-92
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    • 2008
  • In the load-carrying fillet weldments, which are common in ship structures, fatigue cracks can occur at the weld root, in addition to the weld toe. In particular, fatigue cracks originating from the weld root are difficult to detect and cause a significant reduction in the fatigue strength of a weldment. Therefore, it is important to note the fatigue failure mode of load-carrying fillet weldment. In this study, a series of fatigue test was carried out for the fatigue strength evaluation of longi-web connections that are typical kinds of the load-carrying fillet weldment.

Comparison of Maximum Section Forces of Greenhouse Structures with respect to Roof Types (원예시설의 지붕형식에 따른 단면력의 비교분석)

  • 이석건;이현우;손정억;이종원
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.36 no.3
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    • pp.84-89
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    • 1994
  • Section forces of greenhouse structures were studied to suggest basic information for the structural design of greenhouses with respect to roof types and support conditions. Structural analyses were performed for pitched and arched roof, and fixed and hinged support under snow loads and wind loads. Followings are the results obtained and are expected to be useful in determining the span length and roof type in greenhouse design. 1. Special considerations might he required for roof design at the heavy snow region, and for the support design at the strong wind region, respectively. 2. Single-span structure was found to be stronger than multi-span structure under the snow load, but the former was found to be weaker than the latter under the wind load. 3. Arched roof structure was expected to be safer than pitched roof structure if the dimensions and loads were equal. 4. Greenhouse orientation and roof slope should be considered in optimum structural design of grrenhouses, because these two factors are closely related with the influence of wind load and snow load.

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Inverse active wind load inputs estimation of the multilayer shearing stress structure

  • Chen, Tsung-Chien;Lee, Ming-Hui
    • Wind and Structures
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    • v.11 no.1
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    • pp.19-33
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    • 2008
  • This research investigates the adaptive input estimation method applied to the multilayer shearing stress structure. This method is to estimate the values of wind load inputs by analyzing the active reaction of the system. The Kalman filter without the input term and the adaptive weighted recursive least square estimator are two main portions of this method. The innovation vector can be produced by the Kalman filter, and be applied to the adaptive weighted recursive least square estimator to estimate the wind load input over time. This combined method can effectively estimate the wind loads to the structure system to enhance the reliability of the system active performance analysis. The forms of the simulated inputs (loads) in this paper include the periodic sinusoidal wave, the decaying exponent, the random combination of the sinusoidal wave and the decaying exponent, etc. The active reaction computed plus the simulation error is regard as the simulated measurement and is applied to the input estimation algorithm to implement the numerical simulation of the inverse input estimation process. The availability and the precision of the input estimation method proposed in this research can be verified by comparing the actual value and the one obtained by numerical simulation.

LDO regulator with improved regulation characteristics using gate current sensing structure (게이트 전류 감지 구조를 이용한 향상된 레귤레이션 특성의 LDO regulator)

  • Jun-Mo Jung
    • Journal of IKEEE
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    • v.27 no.3
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    • pp.308-312
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    • 2023
  • The gate current sensing structure was proposed to more effectively control the regulation of the output voltage when the LDO regulator occurs in an overshoot or undershoot situation. In a typical existing LDO regulator, the regulation voltage changes when the load current changes. However, the operation speed of the pass transistor can be further improved by supplying/discharging the gate terminal current in the pass transistor using a gate current sensing structure. The input voltage of the LDO regulator using the gate current sensing structure is 3.3 V to 4.5 V, the output voltage is 3 V, and the load current has a maximum value of 250 mA. As a result of the simulation, a voltage change value of about 12 mV was confirmed when the load current changed up to 250 mA.

Structure Analysis of Body Structure for Electrical Multiple Unit (전동차 구조체의 구조해석 연구)

  • 윤성철;백광선;권성태;김명룡
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2004.10a
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    • pp.1335-1338
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    • 2004
  • This paper describes the result of structure analysis of body structure. The purpose of the analysis is to evaluate an safety which body structure shall be considered fully sufficient rigidity so as to satisfy proper system function under maximum load and operating condition. Material of body structure applied an aluminum alloy. Body structure consist of side frame, under frame, roof frame, end frame. FEM analysis is based on 'Performance Test Standard for Electrical Multiple Unit, noticed by Ministry of Construction & Transportation, in 2000 ' and reference code is JIS E 7105. The analysis results have been very safety and stable for design load conditions.

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Fire Loading Analysis of Underground Box Structure with Considering of Concrete Spalling II : Load Carrying Capacity (박리를 고려한 지하박스구조물의 화재하중해석 II : 내하력)

  • Lee, Gye-Hee;Kim, Sun-Hoon
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.20 no.4
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    • pp.485-492
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    • 2007
  • In this study, based on the temperature distribution and the spalling histories those obtained in the companion paper, the thermal stress and moments of underground box structure were estimated. Additionally, the ultimate sectional moment considering with the thermal nonlinearities of material were estimated and the load carrying capacity of underground box structure was also obtained. As results, the load carrying capacity of negative moment part was dominated by thermal moment that come from thermal gradient of the section. However, the load carrying capacity of the positive moment part was rules by the yield stress of rebar that exposed to the high temperature induced spalling phenomena.

Actuator and load test system development for continuous variable thruster (연속가변 추력기용 구동장치 및 부하시험장비 개발)

  • Kim, Namjin;Kim, Hyoungkwon;Park, Hyunho;Lim, Jinwan;Suh, Suhkhoon;Park, Iksoo
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2017.05a
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    • pp.401-405
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    • 2017
  • Continuous variable thrusters require precise thrust control to change the position or attitude of the aircraft and to control the pressure inside the combustion chamber. For this purpose, the thrust is adjusted by moving the pintle structure near the nozzle neck inside the combustion chamber by moving the pintle structure forward and backward, and the actuator is used to move the pintle structure. In this paper, we developed a actuator system for continuous variable thruster and load test system to simulate the load under operating conditions. Also, the performance test of the actuator was performed using the developed load test system

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Comparative assessment of ASCE 7-16 and KBC 2016 for determination of design wind loads for tall buildings

  • Alinejad, Hamidreza;Jeong, Seung Yong;Kang, Thomas H.K.
    • Wind and Structures
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    • v.31 no.6
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    • pp.575-591
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    • 2020
  • Wind load is typically considered as one of the governing design loads acting on a structure. Understanding its nature is essential in evaluation of its action on the structure. Many codes and standards are founded on state of the art knowledge and include step by step procedures to calculate wind loads for various types of structures. One of the most accepted means for calculating wind load is using Gust Load Factor or base bending Moment Gust Load Factor (MGLF), where codes are adjusted based on local data available. Although local data may differ, the general procedure is the same. In this paper, ASCE 7-16 (2017), which is used as the main reference in the U.S., and Korean Building Code (KBC 2016) are compared in evaluation of wind loads. The primary purpose of this paper is to provide insight on each code from a structural engineering perspective. Herein, discussion focuses on where the two codes are compatible and differ. In evaluating the action of wind loads on a building, knowledge of the dynamic properties of the structure is critical. For this study, the design of four figurative high-rise buildings with dual systems was analyzed.

A Study on the Eaves Structure of Korean Jusimpo-type Architecture (한국 주심포식건축의 처마구조에 관한 연구)

  • Yang, Jae-Young
    • Journal of architectural history
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    • v.25 no.3
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    • pp.23-35
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    • 2016
  • The purpose of this study is to classify types of the eaves structure of buildings with the Jusimpo-type structure and to analyze the characteristics of each eaves structure. For this objective, forty buildings were selected and investigated. The results of analysis are summarized as follows. First, the main members of framework which handle a load burden on the long-rafter(長椽) are classified as the Jusim-dori(柱心道里) and the Oemok-dori(外目道里). Based on the method of handling a load, the eaves structure is classified into three types; the Jusim-processing-type(柱心中心形), the Oemok-processing-type(外目中 心形), and the Oemok-processing-variant-type(外目中心變異形). The Jusim-processing-type is the set where the internal length of a long-rafter is longer than the length of the eaves on the basis of the center of a column. The Oemok-processing-type is the set where the external length of a long-rafter is longer than the internal length of it. And the Oemok-processing-variant-type is the set where the internal length of a long-rafter is longer than the external length of it, but it is shorter than the length of the eaves which includes the extruded length of a Buyeon(浮椽). Second, the Jusim-processing-type had been generally adopted in the Jusimpo-type structure of the Goryeo Dynasty. But since the 17th century, the Oemok-processing-type had the highest application rate. Third, the change from the Jusimdori-processing-structure to the Oemokdori-processing-structure means that the long-rafter is moved to the direction of outside of the building, and thus the Jung-dori(中道里) is gradually moved to the column center. And, the change of the eaves with the Jusimpo-type structure was not a process for increasing the length of the eaves but a process for adopting the advantages of the Dapo-type structure by changing the arrangement of purlin. Fourth, the change from the Jusimpo-type structure to the Dapo-type structure could be understood as a process for moving the main point for handling a load from the Jusim-dori to the Oemok-dori.