• 한국강구조학회 논문집
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• 제22권1호
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• pp.99-108
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• 2010

본 연구는 구조상세설계와 모델링 단계에서 활용 가능한 철골 접합부 모델링 자동화 모듈의 개발을 목적으로 한다. 이를 위해 접합부의 구조해석 결과를 3D 모델링의 입력 변수와 표준접합상세지침을 고려하여 라이브러리 D/B로 구축하였다. 구축된 라이브러리 D/B를 접합부 3D 모델링 단계에서 활용하기 위하여 상용 S/W에서 제공하는 OpenAPI 함수를 이용하여 접합부 자동 생성 모듈을 개발하였다. 개발된 모듈을 검증하기 위해 6층 규모의 철골 오피스 구조물을 대상으로 접합부 모델링을 수행하였으며, 접합부 모델링 과정에 대해 기존 프로세스와 연구 프로세스의 비교를 통해 적용성과 효율성을 검증하였다.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제5B권3호
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• pp.243-247
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• 2005

The Different-volume- V-connection transformer is known as an electric power source that can supply 3-phase electric power and single-phase electric power at the same time. Usually, we use two single-phase transformers that have different volumes. In this paper, we propose the use of a 3-phase 5-leg transformer with the different-volume- V-connection. And, we examine the magnetic properties of the 5-leg core model with the different-volume- V-connection. The magnetic properties of cores with the different-volume- V-connection are compared with those with the delta-connection. In order to express the magnetic anisotropy of the core materials and to calculate the iron loss directly, the two-dimensional vector magnetic property is considered with the E&SS modeling in the simulation.

• 한국CDE학회논문집
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• 제21권3호
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• pp.341-352
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• 2016

Manual 3D pipeline modeling from LiDAR scanned point cloud data is laborious and time-consuming process. This paper presents a method to extract the pipe, elbow and branch information which is essential to the automatic modeling of the pipeline connection. The pipe geometry is estimated from the point cloud data through the Hough transform and the elbow position is calculated by the medial axis intersection for assembling the nearest pair of pipes. The branch is also created for a pair of pipe segments by estimating the virtual points on one pipe segment and checking for any feasible intersection with the other pipe's endpoint within the pre-defined range of distance. As a result of the automatic modeling, a complete 3D pipeline model is generated by connecting the extracted information of pipes, elbows and branches.

• 한국통신학회논문지
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• 제22권4호
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• pp.793-803
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• 1997

Open networking architecture is required to support new multimedia services as integrated functions of network management and service architecture. In this paper, we propose the methodology of building block modeling using object grouping concepts and the sharing scheme of different distributed processing environments based on open networking architecture. The building block has the functions of object management, security object instance registry and object mapping in object group. It is necessary for the connection management information to be shared on the interworking between two domains. We implemented and validated connection management functions using computational object modeling and building block modeling in different distributed processing environments.

• Structural Engineering and Mechanics
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• 제35권4호
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• pp.431-457
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• 2010

This article provides a discussion of the mathematic modeling of connections for designing and qualifying structures, systems, and components subject to monotonic or cyclic loading. To characterize the force-deformation behavior of connections under monotonic loading, a review of the Ramberg-Osgood, Richard-Abbott, and Menegotto-Pinto models is conducted, and it is shown that these nonlinear functions can be mathematically derived by scaling up or down a linear force-deformation function. A generalized four-parameter model for simulating connection behavior is investigated to facilitate nonlinear regression analysis. In order to perform seismic analysis of frameworks, a hysteretic model accounting for loading, unloading, and reloading is described using the established monotonic model. For preliminary analysis, a method is provided to quickly determine the model parameters that fit approximately with the observed data. To reach more accurate values of the parameters, the methods of nonlinear regression analysis are investigated and the modified Levenberg-Marquardt and separable nonlinear least-square algorithms are applied in determining the model parameters. Example case studies illustrate the procedure for the computation through the use of experimental/analytical data taken form the literature. Transformation of connection curves from the three-parameter model to the four-parameter model for structural analysis is conducted based on the modeling of connections subject to fire.

• Structural Engineering and Mechanics
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• 제12권2호
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• pp.201-214
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• 2001

Four finite element (FE) models are examined to find the one that best estimates moment-rotation characteristics of top- and seat-angle with double web-angle connections. To efficiently simulate the real behavior of connections, finite element analyses are performed with following considerations: 1) all components of connection (beam, column, angles and bolts) are discretized by eight-node solid elements; 2) shapes of bolt shank, head, and nut are precisely taken into account in modeling; and 3) contact surface algorithm is applied as boundary condition. To improve accuracy in predicting moment-rotation behavior of a connection, bolt pretension is introduced before the corresponding connection moment being surcharged. The experimental results are used to investigate the applicability of FE method and to check the performance of three-parameter power model by making comparison among their moment-rotation behaviors and by assessment of deformation and stress distribution patterns at the final stage of loading. This research exposes two important features: (1) the FE method has tremendous potential for connection modeling for both monotonic and cyclic loading; and (2) the power model is able to predict moment-rotation characteristics of semi-rigid connections with acceptable accuracy.

• Computers and Concrete
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• 제32권3호
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• pp.339-349
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• 2023

Fast-built construction is a key feature for successful applications of precast concrete (PC) moment frame system in recent construction practices. To this end, by introducing some unique splicing details in precast connections, especially between PC columns including panel zones, use of temporary supports and bracings can be minimized based on their self-sustaining nature. In addition, precast wide beams are commonly adopted for better economic feasibility. In this study, three self-sustaining precast concrete (PC) wide beam-column connection specimens were fabricated and tested under reversed cyclic loadings, and their seismic performances were quantitatively evaluated in terms of strength, ductility, failure modes, energy dissipation and stiffness degradation. Test results were compared with ASCE 41-17 nonlinear modeling curves and its corresponding acceptance criteria. On this basis, an improved macro modeling method was explored for a more accurate simulation. It appeared that all the test specimens fully satisfy the acceptance criteria, but the implicit joint model recommended in ASCE 41-17 tends to underestimate the joint shear stiffness of PC wide beam-column connection. While, the explicit joint model along with concentrated plastic hinge modeling technique is able to present better accuracy in simulating the cyclic responses of PC wide beam-column connections.

• 한국건축시공학회지
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• 제22권5호
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• pp.451-462
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• 2022

이 연구의 목적은 다양한 접합상세를 갖는 프리캐스트 콘크리트(precast concrete, 이하 PC) 전단벽에 대한 BIM 모델링 절차를 정립하는 것이다. 그 결과 스케치업(SketchUp)의 프로그램과 컴포넌트 기능과 IFC(Industry foundation classes)파일 형식을 이용하여 BIM 프로그램에서 사용가능한 PC 전단벽 패밀리 라이브래리를 구축 할 수 있었다. 스플라이스 슬리브, 볼트 또는 용접접합공법을 이용한 PC 전단벽은 BIM 프로그램으로부터 배근된 철근들의 간섭여부와 콘크리트, 철근 및 철재 재료들의 물량을 정확히 평가할 수 있었다. 평가 결과 용접접합 공법을 이용한 PC 전단벽은 판재, 볼트 및 너트를 사용하였음에도 스플라이스 슬리브로 연결된 PC 전단벽에서 사용된 재료들의 전체물량, 경제성 및 환경영향성이 비슷한 수준에 있었다. 결과적으로 볼트 또는 용접접합 공법은 PC 전단벽에서 적용가능성이 높은 공법이며, 특히 시공성까지 고려한다면 스플라이스 슬리브 공법보다도 더 유용한 연결공법이 될 것으로 판단된다.

• Structural Engineering and Mechanics
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• 제6권3호
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• pp.259-274
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• 1998

The test results from non-destructive and destructive field testing of a three-span deteriorated reinforced concrete slab bridge are used as a vehicle to examine the reliability of available tools for finite-element analysis of in-situ structures. Issues related to geometric modeling of members and connections, material models, and failure criteria are discussed. The results indicate that current material models and failure criteria are adequate, although lack of inelastic out-of-plane shear response in most nonlinear shell elements is a major shortcoming that needs to be resolved. With proper geometric modeling, it is possible to adequately correlate the measured global, regional, and local responses at all limit states. However, modeling of less understood mechanisms, such as slab-abutment connections, may need to be finalized through a system identification technique. In absence of the experimental data necessary for this purpose, upper and lower bounds of only global responses can be computed reliably. The studies reaffirm that success of finite-element models has to be assessed collectively with reference to all responses and not just a few global measurements.

• Advances in concrete construction
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• 제15권6호
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• pp.391-404
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• 2023

In this study, the modeling of the transverse connection of fully precast steel-UHPC (Ultra-High-Performance Concrete) lightweight composite bridges were conducted. The transverse connection between precast components plays a critical role in the overall performance and safety of the bridge. To achieve an accurate and reliable simulation of the interface behavior, the cohesive model in ABAQUS was employed, considering both bending-tension and compression-shear behaviors. The parameters of the cohesive model are obtained through interface bending and oblique shear tests on UHPC samples with different surface roughness. By validating the numerical simulation against actual joint tests, the effectiveness and accuracy of the proposed model in capturing the interface behavior of the fully precast steel-UHPC lightweight composite bridge were demonstrated.