• 한국강구조학회 논문집
• /
• 제21권5호
• /
• pp.461-470
• /
• 2009

기둥은 축하중과 지진하중에 저항하는 주부재로서 구조물에서 가장 중요한 부재중의 하나이다. 이러한 기둥은 화재 시 고온에 의해 그 성능이 저하되어 전체 구조물계에 심각한 균열을 초래할 수 있으며, 구조물의 붕괴로도 이어질 수 있다. 본 연구에서는 새로운 형식의 기둥인 내부구속 중공 콘크리트 충전강관 기둥 (ICH CFT column; Internally Confined Hollow Concrete Filled Tube column)의 내화 성능이 연구되어져 있지 않기 때문에 건축물에 적용을 하여 기준에 맞는 기둥을 만들기 위해서는 내화 성능 평가가 필요하다. 본 기둥은 콘크리트 충전 강관 기둥 (CFT column; Concrete Filled Tube column)과 같이 외부 강관에 의해 콘크리트가 구속되어 기둥의 성능을 발휘하므로, 외부 강관의 항복 여부가 전체 기둥의 강도를 결정하게 될 것이다. 그래서 본 연구에서는 화재에 의한 기둥의 온도 변화에 따른 ICH CFT 기둥의 강도를 콘크리트의 구속효과와 재료비선형성을 고려하여 해석을 수행하였고, 또한 기둥의 중공비, 외부강관의 두께, 콘크리트의 강도를 매개 변수로 선정하여 기둥의 내화 성능을 평가하였으며, 해석에는 범용 프로그램과 전용 프로그램을 병행하여 사용하였다.

• Smart Structures and Systems
• /
• 제6권5_6호
• /
• pp.461-480
• /
• 2010

This paper analyses the data collected from the $2^{nd}$ Jindo Bridge, a cable-stayed bridge in Korea that is a structural health monitoring (SHM) international test bed for advanced wireless smart sensors network (WSSN) technology. The SHM system consists of a total of 70 wireless smart sensor nodes deployed underneath of the deck, on the pylons, and on the cables to capture the vibration of the bridge excited by traffic and environmental loadings. Analysis of the data is performed in both the time and frequency domains. Modal properties of the bridge are identified using the frequency domain decomposition and the stochastic subspace identification methods based on the output-only measurements, and the results are compared with those obtained from a detailed finite element model. Tension forces for the 10 instrumented stay cables are also estimated from the ambient acceleration data and compared both with those from the initial design and with those obtained during two previous regular inspections. The results of the data analyses demonstrate that the WSSN-based SHM system performs effectively for this cable-stayed bridge, giving direct access to the physical status of the bridge.

• 한국융합학회논문지
• /
• 제10권9호
• /
• pp.187-192
• /
• 2019

본 연구에서는 토션빔 후륜 서스펜션의 형상에 따른 구조 및 피로 해석을 하였다. 실제 토션빔 서스펜션의 형상과 비슷한 3종류의 모델들을 해석하여 어떤 것이 강도상에서 가장 좋은 지를 알아본다. 토션빔 서스펜션의 모델들은 CATIA프로그램을 통하여 Model A, B, C 3종류로 설계하였고 ANSYS 프로그램을 이용하여 구조 및 피로 해석의 결과들을 얻었으며, 어떤 Model이 다른 모델에 비해 더 나은 구조적 형상인지 확인한다. 해석 결과에 따르면 변형은 주로 가운데 부분에서 가장 크게 발생하며 Total deformation의 경우 Model B가 model A, C 에 비하여 변형이 가장 적었다. 마찬가지로 Equivalent stress에서도 Model B가 가장 작은 값이 나타난 것으로 보아 Model B가 가장 강도적인 면에서 가장 좋은 것으로 판단되었으며, 후륜 토션빔 서스펜션 설계 시에 디자인 예술과 융합하는 것이 가장 효율적이라고 사료된다.

• 해양환경안전학회지
• /
• 제26권3호
• /
• pp.277-285
• /
• 2020

Recently, studies have been actively conducted on seismic design and improvement of the seismic performance of bridges, buildings, factories, and plants. In particular, heavy items that are being manufactured or waiting to be shipped from factories (such as generators, engines, and boilers) must be equipped with seismic stoppers to prevent them from moving or falling during an earthquake. Seismic stoppers should be suitably determined by the size and weight of these heavy items; however, they have no general design standard. In this study, structural analyses and seismic tests were conducted to evaluate the performance of newly designed seismic stoppers. Structural analysis was performed on three stopper models to estimate the external load at which the yield stress of the material was not exceeded. Based on the analysis results, a seismic test of the stopper was carried out in accordance with the AC156 test method. Finally, product specifications for all three seismic stopper models were determined and their static/dynamic load performance was evaluated.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2001년도 춘계학술대회논문집C
• /
• pp.219-223
• /
• 2001

This paper introduces DS/Block-Structure - a structural analysis module of DS/Block, which is a Design System to simulate the behavior of a ship block in various crane operations and to evaluate its structural deformation using the finite element method. It runs based on a CAD program, Pro/ENGINEER, and structural analyses are performed by a developed FE code. Boundary conditions for the FE analysis of a ship block under lifting and turnover operation are also considered.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2008년도 추계학술대회논문집
• /
• pp.175-179
• /
• 2008

In this study, computational structural vibration analysis of helicopter search light exposing unsteady buffet load have been conducted using combined advanced numerical methods. Unsteady CFD method based on Navier-Stokes equations is used to predict viscous buffet load due to flow separation effects. Full three-dimensional finite element model is constructed in order to conduct static and structural dynamic analyses of the search light model for two different typical flight speeds. Also, the correct performance of the search light can be physically estimated to examine the actual lighting area considering the effects of structural deformations.

• 한국원자력학회:학술대회논문집
• /
• 한국원자력학회 1998년도 춘계학술발표회논문집(2)
• /
• pp.175-180
• /
• 1998

The U-Zr metallic alloy with low swelling HT9 cladding is the candidate for the KALIMER fuel rod. The fuel rod should be able to maintain the structural integrity during its lifetime in the reactor. In a typical metallic fuel rod, load is mainly applied by internal gas pressure, and the deformation is primarily caused by creep of the cladding. The three-dimensional FEM modelling of a fuel rod is important to predict the structural behavior in concept design stage. Using the ANSYS code, the 3-D structure analyses were performed for various configuration, element and loads. It has been shown that the present analysis model properly evaluate the structural integrity of fuel rod. The present analysis results show that the fuel rod is expected to maintain its structural integrity during normal operation.

• 한국생산제조학회지
• /
• 제22권6호
• /
• pp.901-907
• /
• 2013

The development of high-rise firefighting vehicles warrants thorough structural analysis for ensuring vehicle stability. A few structural analyses were carried out using CAD data, material properties, load conditions, and boundary conditions for evaluating the structural stability of an overloaded multi-aerial platform for firefighting and rescue. Structural analysis was performed with an analytical model consisting of a turntable, six booms, two jib booms, and a basket structure. This model was operated in eight modes. All simulation was performed using NASTRAN, a commercial code. As a result, we confirm that the position of local stress exceeds that of the yield strength. Therefore, stress concentration relaxation is possible by introducing reinforcing boom structures, changing the shape, or imparting a larger moment of inertia to the booms' cross sections.

• Structural Engineering and Mechanics
• /
• 제38권1호
• /
• pp.125-140
• /
• 2011

This study presents an innovative method to estimate the reliability sensitivity based on the low-discrepancy sampling which is a new technique for structural reliability analysis. Two advantages are contributed to the method: one is that, by developing a general importance sampling procedure for reliability sensitivity analysis, the partial derivative of the failure probability with respect to the distribution parameter can be directly obtained with typically insignificant additional computations on the basis of structural reliability analysis; and the other is that, by combining various low-discrepancy sequences with the above importance sampling procedure, the proposed method is far more efficient than that based on the classical Monte Carlo method in estimating reliability sensitivity, especially for problems of small failure probability or problems that require a large number of costly finite element analyses. Examples involving both numerical and structural problems illustrate the application and effectiveness of the method developed, which indicate that the proposed method can provide accurate and computationally efficient estimates of reliability sensitivity.

• Wind and Structures
• /
• 제30권1호
• /
• pp.29-35
• /
• 2020

This paper presents a comparative structural analysis of lattice hybrid tower with six legs with conventional tubular steel tower for an onshore wind turbine using finite element method. Usually a lattice hybrid tower will have a conventional industry standard 'L' profile section for the lattice construction with four legs. In this work, the researcher attempted to identify and analyze the strength of six legged lattice hybrid tower designed with a special profile instead of four legged L profile. And to compare the structural benefits of special star profile with the conventional tubular tower. Using Ansys, a commercial FEM software, both static and dynamic structural analyses were performed. A simplified finite element model that represents the wind turbine tower was created using Shell elements. An ultimate load condition was applied to check the stress level of the tower in the static analysis. For the dynamic analysis, the frequency extraction was performed in order to obtain the natural frequencies of the tower.