• 소음진동
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• 제10권4호
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• pp.686-691
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• 2000

In this paper a computer aided analysis method is proposed for durability assessment in the early design stages using dynamic analysis, stress analysis and fatigue life prediction method. From dynamic analysis of a vehicle suspension system, dynamic load time histories of a suspension component are calculated. From the dynamic load time histories and the stress of the suspension component, a dynamic stress time history at the critical location is produced using the superposition principle. Using linear damage law and cycle counting method, fatigue life cycle is calculated. The predicted fatigue life cycle is verified by experimental durability tests.

• 한국전산구조공학회논문집
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• 제29권1호
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• pp.67-75
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• 2016

본 논문에서는 폭발해석에서 주로 사용되는 폭발하중의 압력-시간 이력곡선과 폭발하중 산정식인 Conwep 모델을 소개하고, 이를 더욱 간편하게 계산할 수 있는 간략 폭발하중 산정식을 제안한다. 폭발해석에서 폭발하중은 일반적으로 압력-시간 이력곡선의 형태로 적용되며, 그에 대한 주요 값들은 폭발하중 산정식에 의해 계산된다. 대부분의 폭발해석에서 사용되는 폭발하중 산정식인 Conwep 모델은 환산거리(scaled distance)를 핵심변수로 하여 계산되는데, 그 계산 과정이 매우 복잡한 단점이 있다. 따라서 본 논문에서는 환산거리를 변수로 갖는 간략한 유리식을 사용하여 주요 값들을 계산하고, 단순화된 압력-시간 이력곡선으로 폭발하중을 산정할 수 있도록 제안하였다. 간략식을 찾는 과정에서 Conwep 모델의 계산 결과를 바탕으로 곡선 적합(curve fitting) 방식이 사용되었으며, 제안된 간략식에 의한 주요 값의 계산 결과는 Conwep 모델과 비교하여 1% 미만의 오차를 갖는다. 또한, 유한요소를 이용한 폭발해석에 적용하였으며 Conwep 모델을 적용한 결과와 비교를 통해 검증하였다.

• 한국지진공학회논문집
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• 제27권3호
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• pp.139-145
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• 2023

It is essential to determine a proper earthquake time history as a seismic load in a seismic design for a critical structure. In the code, a seismic load should satisfy a design response spectrum and include the characteristic of a target fault. The characteristic of a fault can be represented by a definition of a type of possible earthquake time history shape that occurred in a target fault. In this paper, the pseudo-basis function is proposed to be used to construct a specific type of earthquake, including the characteristic of a target fault. The pseudo-basis function is derived from analyzing the earthquake time history of specific fault harmonic wavelet transform. To show the feasibility of this method, the proposed method was applied to the faults causing the Gyeong-Ju ML5.8 and Pohang ML5.3 earthquakes.

• Structural Engineering and Mechanics
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• 제52권1호
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• pp.137-147
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• 2014

The present paper deals with the first ply failure analysis of the laminated composite plates under various static and dynamic loading conditions. Static analysis has been carried out under patch load and triangular load. The dynamic failure analysis has been carried out under triangular pulse load. The formulation has been carried out using the finite element method and a computer code has been developed. The first order shear deformation theory has been applied in the present formulation. The displacement time history analysis of laminated composite plate has been carried out and the results are compared with those published in literature to validate the formulation. The first ply failure load for laminated composite plates with various lamination schemes under static and dynamic loading conditions has been calculated using various failure criteria. The failure index-time history analysis has also been carried out and presented in this paper.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 춘계학술대회논문집
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• pp.578-581
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• 2007

In this study, the seismic control performance of energy dissipation devices installed in a shear all-frame structure is investigated through nonlinear time history analysis of a 12-story building. Inelastic shear walls are modeled using the multiple vertical line element model (MVLEM) and inelastic columns and girders were modeled using fiber beam elements. For a seismic load increased by 38% compared to the design load, the seismic control performance was analyzed based on the results of a nonlinear time history analysis in terms of the inter-story drift, the story shear and the flexural strain. Friction type dampers was found to performs best if they are installed in the form of a brace adjacent to the shear wall with the friction force of 15 % of the maximum story shear force induced in the original building structure without dampers.

• International Journal of Naval Architecture and Ocean Engineering
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• 제5권2호
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• pp.227-245
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• 2013

Reliable strength assessment of the Liquefied Natural Gas (LNG) cargo containment system under the sloshing impact load is very difficult task due to the complexity of the physics involved in, both in terms of the hydrodynamics and structural mechanics. Out of all those complexities, the proper selection of the design sloshing load which is applied to the structural model of the LNG cargo containment system, is one of the most challenging one due to its inherent randomness as well as the statistical analysis which is tightly linked to the design sloshing load selection. In this study, the response based strength assessment procedure of LNG cargo containment system has been developed and proposed as an alternative design methodology. Sloshing pressure time history, measured from the model test, is decomposed into wavelet basis function targeting the minimization of the number of the basis function together with the maximization of the numerical efficiency. Then the response of the structure is obtained using the finite element method under each wavelet basis function of different scale. Finally, the response of the structure under entire sloshing impact time history is rapidly calculated by synthesizing the structural response under wavelet basis function. Through this analysis, more realistic response of the system under sloshing impact pressure can be obtained without missing the details of pressure time history such as rising pattern, oscillation due to air entrapment and decay pattern and so on. The strength assessment of the cargo containment system is then performed based on the statistical analysis of the stress peaks selected out of the obtained stress time history.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2007년도 정기 학술대회 논문집
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• pp.375-380
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• 2007

The goal of this paper is to develop a rational static method which consider efficiently the dynamic effect of the gravity load following sudden removal of element. For this goal this paper introduce the equivalent load for element stiffness which is a preceding research result and will develop equivalent static analysis which will be able to predict the maximum behavior considering dynamic effect. Some examples are provided to verify it. Equivalent static analysis is compared with the analysis method which is recommended by the GSA2003 guidelines and the time-history analysis which is the most accurate for dynamic behavior.

• 한국전산구조공학회논문집
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• 제27권6호
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• pp.533-542
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• 2014

본 연구에서는 차량과 교각의 직접충돌해석을 통하여 기존 설계기준(도로교설계기준, AASHOTO LRFD)에서 아직 고려하고 있지 않은 동적영향을 고려한 실제 교각의 충돌 파괴 거동을 다양한 경계조건별로 검토하였다. 선정된 차량은 10톤, 16톤, 38톤의 Cargo 트럭이며 교각은 경부고속도로 상 일반적인 제원으로 선정하였다. 해석결과 가장 많은 파괴는 상부구조의 고려없이 교각의 상부면을 구속하였을 시에 발생하였으며 상부구조는 2차적인 영향을 교각에 전달하기 보다는 충돌에너지를 일부 흡수하는 역할을 하며 파괴를 감소시키는 것으로 확인되었다. 또한 해석의 효율성을 위해 차량과 강체간 충돌시 발생하는 충돌하중이력곡선을 교각에 외력으로 부여한 간접충돌해석을 수행하고, 이를 직접충돌해석 결과와 비교하였다. 해석 결과 직접충돌해석 결과와 매우 유사하게 교각의 거동을 예측하는 것으로 확인되었으며 해석효율성 또한 높아져 해석시간은 약 92%정도 감소하였다. 이러한 간접충돌해석법은 다양한 기존 모델이나 다른 해석프로그램에도 쉽게 부여될 수 있어 그 활용범위가 증가할 것으로 판단된다.

• 한국해양공학회지
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• 제33권6호
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• pp.627-631
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• 2019

Recently, researchers in Korea and abroad actively have conducted research activities using the ARAON, a Korean icebreaking research vessel. The ARAON regularly conduct research activities in the Arctic and Antarctic waters every year. The icebreaking mode, which can be either continuous breaking or ramming, is determined by the conditions of the ice and the ice-covered waters. When the icebreaker encounters thick sea ice or an ice ridge, ramming is used. At that time, the speed of the ship generally is slower than that of continuous icebreaking. In this study, the ice load signal at the time of repetitive ramming during ARAON's 2012 Antarctic research voyage was analyzed. The time history of the ice load signal and the change in the speed of the ship used in ramming were compared with these values during continuous icebreaking.

• Earthquakes and Structures
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• 제10권4호
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• pp.913-938
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• 2016

'Stepped building' frames, with vertical geometric irregularity, are now increasingly encountered in modern urban constructions. This paper proposes a new approach to determine the lateral load pattern, considering the contributions from the higher modes, suitable for pushover analysis of stepped buildings. Also, a modification to the displacement coefficient method of ASCE/SEI 41-13 is proposed, based on nonlinear time history analysis of 78 stepped frames. When the newly proposed load pattern is combined with the modified displacement coefficient method, the target displacement for the stepped building frame is found to match consistently the displacement demand given by the time history analysis.