• Title/Summary/Keyword: 정형해석

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Seismic Response of a High-Rise RC Bearing-Wall Structure with Irregularities of Weak Story and Torsion at Bottom Stories (저층부에 약층과 비틀림 비정형성을 가진 고층 비정형 RC벽식 구조물의 지진응답)

  • 이한선;고동우
    • Journal of the Earthquake Engineering Society of Korea
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    • v.7 no.6
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    • pp.81-91
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    • 2003
  • Recently, many high-rise reinforced concrete(RC) bearing-wall structures of multiple uses have been constructed, which have the irregularities of weak(or soft) story and torsion at the lower stories simultaneously. The study stated herein was performed to investigate seismic performance of such a high-rise RC structure through a series of shaking table tests of a 1: 12 model. Based on the observations of the test results, the conclusions are drawn as follows: 1) Accidental torsion due to the uncertainty on the properties of structure can be reasonably predicted by using the dynamic analysis than by using lateral force procedure. 2) The mode coupled by translation and torsion induced the overturning moments not only in the direction of excitations but also in the perpendicular direction: The axial forces in columns due to this transverse overturning moment cannot be adequately predicted using the existing mode analysis technique, and 3) the hysteretic curve and the strength diagram between base shear and torque(BST) clearly reveal the predominant mode of vibrations and the failure mode.

A Study on the Wind-Induced Response Characteristics of Freeform Shaped Tall Building using FSI Analysis (FSI 해석에 의한 비정형 초고층 빌딩의 풍응답 특성에 관한 연구)

  • Park, Sung Chul;Kim, Hyo Jin;Han, Sang Eul
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.27 no.4
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    • pp.223-230
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    • 2014
  • In this paper, the wind-induced response characteristics of freeform shaped tall building is studied by using FSI analysis. The analytical models are twist shaped ones at representing type of atypical tall building, and this study focused on the relationship between twist angle and wind acceleration. Firstly, 1-way FSI analysis is performed, so maximum lateral displacement of the analytical model for 100 years return period wind speed is calculated, then the elastic modulus of a structure that satisfies the constraints condition is evaluated. And 2-way FSI analysis is carried out. so acceleration of the analytical model for the evaluated modulus of elasticity and arbitrary density is predicted through time history analysis. The basic model is a set of a square shape, height is 400m, slenderness ratio is 8, and twist model is rotated at square model from 0 to 90 degrees at intervals of 15 degrees and from 90 to 360 degrees at intervals of 90 degrees. According to the result of predicting wind acceleration by the shape of each model, the wind vibration effect of square shape model is confirmed to be sensitive more than a twist shape ones.

Seismic Performance Evaluation of Special Moment Steel Frames with Torsional Irregularities - I Seismic Design (비틀림 비정형을 갖는 철골특수모멘트골조의 내진성능평가 - I 내진설계)

  • Han, Sang Whan;Kim, Tae O;Ha, Seong Jin
    • Journal of Korean Society of Steel Construction
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    • v.29 no.5
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    • pp.361-368
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    • 2017
  • ASCE 7-10 defines the torsional irregular structure as the one that has large torsional responses caused by the eccentricity. The code requires that these structures should be designed abide by the torsional provisions. This study evaluates the influence of torsional provisions on the performance of the designed multiple steel moment frames with different eccentricity. In this study, 3D response history analyses are performed. The results show that the moment frame design according to the standard with torsional irregularity provisions showed larger performance as the eccentricity increased and the distribution of plastic hinges similarly to orthopedic structures.

Drought evaluation using unstructured data: a case study for Boryeong area (비정형 데이터를 활용한 가뭄평가 - 보령지역을 중심으로 -)

  • Jung, Jinhong;Park, Dong-Hyeok;Ahn, Jaehyun
    • Journal of Korea Water Resources Association
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    • v.53 no.12
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    • pp.1203-1210
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    • 2020
  • Drought is caused by a combination of various hydrological or meteorological factor, so it is difficult to accurately assess drought event, but various drought indices have been developed to interpret them quantitatively. However, the drought indexes currently being used are calculated from the lack of a single variable, which is a problem that does not accurately determine the drought event caused by complex causes. Shortage of a single variable may not be a drought, but it is judged to be a drought. On the other hand, research on developing indices using unstructured data, which is widely used in big data analysis, is being carried out in other fields and proven to be superior. Therefore, in this study, we intend to calculate the drought index by combining unstructured data (news data) with weather and hydrologic information (rainfall and dam inflow) that are being used for the existing drought index, and to evaluate the utilization of drought interpretation through verification of the calculated drought index. The Clayton Copula function was used to calculate the joint drought index, and the parameter estimation was used by the calibration method. The analysis showed that the drought index, which combines unstructured data, properly expresses the drought period compared to the existing drought index (SPI, SDI). In addition, ROC scores were calculated higher than existing drought indices, making them more useful in drought interpretation. The joint drought index calculated in this study is considered highly useful in that it complements the analytical limits of the existing single variable drought index and provides excellent utilization of the drought index using unstructured data.

Evaluation and Adjustment of Lateral Displacement of Complex-shaped RC Tall Buildings Considering the Displacement by Tilt Angle of Each Floor (층경사각에 의한 횡변위를 고려한 비정형 고층건물의 횡변위 평가/보정)

  • Kim, Yungon
    • Journal of the Korea Concrete Institute
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    • v.27 no.5
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    • pp.551-558
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    • 2015
  • Lateral displacement in the most complex-shaped tall buildings is caused by eccentric gravity loads which are induced by the difference in location between a center of mass and a center of stiffness. The lateral displacements obtained from analysis, using conventional procedures, are prone to overestimate the actual values because much of realignment efforts made during construction phase are ignored. In construction sequence analysis, the self-leveling of slab and the verticality of columns/walls could be considered at each construction stage. Moreover, the displacement compensation can be achieved by manual process such as re-centering - locating to global coordinates through surveying. Because the lateral displacement increases with the building height, it is necessary to set up adjustment plan through construction stage analysis in advance in order to result in displacements less than the allowable limits. Because analytical solution includes lots of assumptions, the pre-adjusting displacement should be reasonably controlled with considerations for the uncertainty due to these assumptions.

Flood monitoring and prediction using online unstructured data (비정형데이터를 활용한 홍수 모니터링 및 예측)

  • Lee, Jeong Ha;Hwang, Seok Hwan
    • Proceedings of the Korea Water Resources Association Conference
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    • 2019.05a
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    • pp.118-118
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    • 2019
  • 현재 홍수예보는 정형데이터인 유량 및 수위 등을 활용하여 이뤄지고 있다. 하지만 실제 사람들이 체감하는 홍수에 대한 위험도는 홍수예보 발령과는 달라 홍수예보가 이뤄지지 않은 지역에서 인명사고가 발생하기도 한다. 이는 수위 측정이 이뤄지지 않는 소규모 하천이나 사람들의 유동성이 큰 도심지역에서 빈번하게 발생한다. 이를 보완하기 위해서는 사람들의 체감 정도 및 인구의 유동성을 고려한 비정형데이터를 활용해야 한다. 특히 소셜 네트워크 서비스(Social Network Commuinty, SNS)를 사용하는 사람들이 많아지면서 기존에 사용되어 왔던 정형데이터 센서 이외의 데이터를 제공한다. 또한 개개인이 작성하는 글은 실시간으로 활용이 가능하여 인구의 유동성 및 시 공간적 데이터를 얻기에 유용하여 활용성이 매우 높은 비정형데이터이다. 따라서 본 연구에서는 SNS 데이터를 추출하고 이를 분석하여 2018년에 발생했던 강우사상과의 패턴을 비교하여 홍수예보에서의 활용성을 분석하였다. 홍수와 관련한 키워드를 중심으로 시 공간적 정보 및 추출이 가능한 웹 크롤러(Web Crawler) 프로그램을 작성하였으며 이를 토대로 데이터를 수집하였다. 수집한 데이터와 실제 홍수사상을 비교 분석을 한 결과 강우량 및 수위와 해당 지역에 대한 데이터의 양이 유사한 패턴을 보인 것으로 확인되었다. 실시간으로 데이터를 수집하고 이를 분석하여 리드타임을 충분히 확보한다면 홍수예측에 활용 가능할 것이라 생각된다. 본 연구는 한국건설기술연구원 19주요-대4-시드사업인 '커뮤니티 빅데이터 패턴 해석을 통한 수난(水難) 발생 및 규모 예측 기술 개발(20190126-001) '로 수행되었습니다.

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Analysis of Rainfall-Runoff Modelling using GRM based on formal and informal likelihood measure (정형·비정형우도를 이용한 GRM 강우-유출 모형 분석)

  • Seong, Yeonjeong;Hwang, Ingyu;Jung, Younghun
    • Proceedings of the Korea Water Resources Association Conference
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    • 2021.06a
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    • pp.300-300
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    • 2021
  • 최근 기후변화와 기상이변으로 예측하지 못한 게릴라성의 국지성호우로 인해서 과거 장마와 같은 피해가 아닌 변화된 강우패턴으로 막대한 피해가 나타나고 있다. 또한, 이러한 게릴라성 호우는 예측 또한 어려운 경향을 나타낸다. 이러한 피해를 방지하기 위해 단기유출 예측을 위해 사용되는 다양한 모형들 가운데 GRM(Grid based Rainfall-runoff Model)을 사용하였으며, GRM모델은 단기유출해석에 사용되며 국내에서 개발된 물리적 기반 모형이다. 본 연구에서는 한강의 하류인 청미천 유역을 대상으로 강우-유출 분석을 진행하였으며, 환경부의 11개 기상관측소의 자료를 이용한 티센망도 기반의 면적강우량으로 산정하였고 이를 GRM에 적용하였다. 강우자료의 Event 선정기간은 2011년 6월 29일부터 2011년 7월 1일까지 86.83mm 강수가 내린 Event이다. 공간자료는 국토지리정보원의 90M DEM(Digital Elevation Model), 농촌진흥청의 정밀토양도와 토심, 환경부 환경공간서비스의 대분류 토지이용도를 이용하였다. 또한, 검정을 위해서 정형우도인 NSE, 비정형우도인 Log-normal 우도를 이용하여 분석하였으며, 각각의 결과값은 NSE 0.966, Log-normal은 -1214.97의 값을 나타냈다. 추후, 다양한 적합지표를 이용하여 GRM의 강우패턴별, 유역별대표매개수가 산정된다면 홍수방어를 위한 강우-유출 모형으로 매우 유용하게 활용될 것으로 판단된다.

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Form-finding of Free-form Membrane Structure based on Geometrically Non-linear Analysis and Interface method (기하학적 비선형해석을 이용한 비정형 막 구조물의 형상탐색과 인터페이스 기법)

  • Kim, Jee-In;Na, Yoo-Mi;Kang, Joo-Won;Lee, Jae-Hong
    • Journal of Korean Association for Spatial Structures
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    • v.12 no.1
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    • pp.77-85
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    • 2012
  • The membrane structure maintains stable form by giving initial tension to ductile membrane and increasing the stiffness of exterior that is much adopted in the large span spatial structure by making its thickness thin. This kind of membrane structure has characteristic that can express free-form curve, so the selection of structural form is very important. So, this paper proposes the expression of free-form surface based on NURBS basis function and the finite element method considering geometrical nonlinearity for the deduction of large deformation result. Also, for minimizing the approximation of the surface that is derived from the form-finding result, the interface method that change finite element mesh to NURBS is proposed. So, the optimum surface of free-form membrane is derived.

A Development of NURBS-Based Pre and Post Processor for Structural Analysis of Free-Shaped Beam (자유형상 보요소 해석을 위한 NURBS기반의 전·후처리 모듈 개발)

  • Jung, Sung-Jin;Park, Se-Hee
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.10
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    • pp.6673-6678
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    • 2015
  • Recently, the free form buildings are constructed frequently. Exterior and interior components of these buildings have the free cross-section and a curved shape. So, There are many usages of classical finite element having tapered section and free-style shape. Some general commercial applications like ETABS, SAP2000, MIDAS are usually used for the safety evaluation of the free form structures. However, there are some limits in the accuracy of structural analysis and the length of analysis time because a very complicated finite element mesh have to be used. Therefore, In this study, a pre and post program module was developed to take advantage of general 3-D curved beam element which has a free-style curved shape and mathematical backgrounds. Pre-post processing module has been developed in this study was developed to control the curvature of the curved members by the NURBS control points. As a result, fast geometric modeling than was possible commercial applications. In addition, realistic depiction of the shape and behavior patterns were possible because of the free-form building allows visual check of the free form.

A Study on Free-form Design Shape Creation through Geometric Transformation of Digital Design Tool (디지털디자인도구의 Geometry 변형을 통한 비정형 디자인 형태 생성 방법에 관한 연구)

  • Park, Sang-Jun
    • The Journal of the Korea Contents Association
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    • v.16 no.5
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    • pp.306-317
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    • 2016
  • Both the formal type of architecture and free-form architecture have basic factors and methods for basic expression. Because the use of digital design tools for creation of free-form design mostly depends on the character and ability of designer, this study aims to propose establishment of free-form design creation method as a prototype, including the method to create free-form design, through setting up rules that can be used in common. This study is carried out on the basis of the application of digital design tools used for creation of conceptual free-form styles at the phase of conceptualization and development, which is different from the general theory of free-from design. The free-from style in the modern architecture has begun with the changes in digital design tools and design concepts. In the case study based on the free-form designs in precedent studies, the morphological characteristics have been analyzed and interpreted by using the language of digital design tools, so that this study will suggest the techniques to realize the free-form style on the basis of geometric transformation by using the digital design tools, as well.