• Journal of Korean Society of Steel Construction
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• v.25 no.2
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• pp.131-139
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• 2013

The object of this paper is to perform the experiments to investigate the relationship of the resistance forces and the failure temperatures on the failure behaviors of H-shaped steel compressive members. H-shaped members(SS400) were used for the test models and the tests for the elevated temperatures were performed by ISO 834 in FILK(Fire Insurers Laboratories of Korea). The local, overall buckling stresses and a yielding stresses for the failure temperatures were compared with the compressive stresses for the loading forces of test models, the yielding strength and elastic modulus reduction factor of the steel at a high temperature were based on the criteria of the EC3(Eurocode 3) Part1.2(1993). The slenderness ratio was fixed by 45.4 and the compressive forces corresponded with 50%, 70% and 80% of the yielding forces at the normal temperatures were chosen for the loading forces of the test models. The failure temperatures of the test models were investigated under three kinds of loading conditions. It was known that the resistance forces have come close to the yielding forces, not the elastic buckling loads evaluated by EC3 at the failure temperatures obtained from the tests which are related to the failure temperatures and the loading stresses.

• Journal of Korean Society of Steel Construction
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• v.19 no.1
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• pp.87-98
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• 2007

Generally, main girders and steel piers of temporary bridges form the steel rahmen structure. In this study, the rational stability design procedure for main members of temporary bridges was presented using a 3D system buckling analysis and second-order elastic analysis. Six types of temporary bridges, which can be designed and fabricated in reality, were chosen and the buckling design for them was performed in consideration ofload combinations of dead and live loads, thermal load, and wind load. Effective buckling length of steel piers, transition of 3D buckling modes, and effects of second-order analysis were investigated through a case study involving six temporary bridges.

• Journal of Aerospace System Engineering
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• v.13 no.1
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• pp.18-28
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• 2019

High speed vehicles are subjected to high thermal loadings due to aerodynamic heating during ascent and reentry. Since a thermal protection system panel is mechanically constrained, it may cause thermal buckling under excessive thermal loadings. The thermal buckling could disturb the field of flow and make aerodynamic characteristics unstable. It is thus necessary to design the thermal protection system panel to prevent thermal buckling. This study defines the analytical model of temperature distribution using the finite difference method for the thermal protection system panel with large temperature differences inside and outside. This paper proposes the approximate model of the thermal buckling characteristics for the thermal protection system panel through the use of the Ritz method. The validity of the present method was verified by comparing the results of the finite element analysis. Furthermore, this research performs the parametric analysis of the thermal buckling characteristics for the thermal protection system panel by using the approximate model.

• Computational Structural Engineering
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• v.4 no.1
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• pp.73-82
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• 1991

Recently, the finite element method has been sucessfully extended to treat the rather complex phenomena such as nonlinear buckling problems which are of considerable practical interest. In this study, a finite element program to evaluate the elasto-plastic buckling stress is developed. The Stowell's deformation theory for the plastic buckling of flat plates, which is in good agreement with experimental results, is used to evaluate bending stiffness matrix. A bifurcation analysis is performed to compute the elasto-plastic buckling stress. The subspace iteration method is employed to find the eigenvalues. The results are compared with corresponding exact solutions to the governing equations presented by Stowell and also with experimental data due to Pride. The developed program is applied to obtain elastic and elasto-plastic buckling stresses for various loading cases. The effect of different plate aspect ratio is also investigated.

• Railway Journal
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• v.19 no.3
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• pp.84-97
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• 2016

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.2
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• pp.414-421
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• 2022

Subsea oil and gas exploration is increasingly moving into deeper water depths, and typically, subsea pipelines operate under high pressure and temperature conditions. Owing to the difference in these components, the axial force in the pipe is accumulated. When a pipeline is operated at a high internal pressure and temperature, it will attempt to expand and contract for differential temperature changes. Typically, the line is not free to move because of the plane strain constraints in the longitudinal direction and soil friction effects. For a positive differential temperature, it will be subjected to an axial compressive load, and when this load reaches a certain critical value, the pipe may experience vertical (upheaval buckling) or lateral (snaking buckling) movements that can jeopardize the structural integrity of the pipeline. In these circumstances, the pipeline behavior should be evaluated to ensure the pipeline structural integrity during operation in those demanding loading conditions. Performing this analysis, the correct mitigation measures for thermal buckling can be considered either by accepting bar buckling but preventing the development of excessive bending moment or by preventing any occurrence of bending.

• 한국방재학회:학술대회논문집
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• 2009.02b
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• pp.63.1-63.1
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• 2009

• Journal of the Korean Society for Precision Engineering
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• v.15 no.3
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• pp.119-126
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• 1998

유리섬유 강화 열가소성 복합재료는 고상성형법에 의해 저렴한 가격으로 큰 부피의 제품의 제조에 널리 사용될 수 있어 아주 좋은 전망을 가지고 있다. 그러나 이러한 재료의 성형성이나 재료거동의 특성은 아직 잘 파악되지 않았다. 본 연구의 주안점은 이러한 재료의 단순 굽힘에서의 굽힘성형성을 연구하는데 두었다. 실험에 사용된 재료는 임의의 방향으로 위치한 유리섬유를 중량비로 20 %, 35 %, 40 % 함유한 폴리프로필렌이다 굽힘시험은 75 $^{\circ}C$에서 150 $^{\circ}C$ 사이의 온도에서 25 $^{\circ}C$ 씩 증가하면서 행했고, 편치속도는 2.54 mm/sec와 0.0254 mm/sec에서 행했다. 단순 굽힘시험에서 측정된 굽힘성형성은 해석적 모델로 예측한 결과와 비교하였다. 실험결과와 예측결과가 비교적 잘 일치함을 보였으며, 굽힘성 map으로써 성형 온도와 펀치반경의 좌굴에 대한 효과를 가시화 함은 물론 좋은 성형조건을 선정할 수 있는 좋은 도구로써 나타내었다.

• Journal of Korean Association for Spatial Structures
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• v.4 no.1 s.11
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• pp.87-95
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• 2004

This paper shows the study on the capacity of H-shape column at elevated temperature in fire. The main parameters are temperatures, slenderness ratios and load ratios. The physical properties of steel material at elevated temperatures are according to EC3 Part 1.2. The critical temperature of local buckling at elevated temperatures are lower when the yield strength of the material is higher, and when the ratios of width-thickness of plates are larger. The evaluation capacity of uniformly heated steel cloumns were considered to axial forces, moments of strong axis and weak axis to the LRFD.

• Proceedings of the Korean Nuclear Society Conference
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• 1995.05a
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• pp.617-622
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• 1995

다목적연구로 HANARO를 이용한 압력용기 재료 조사시험에 이용될 계장캡슐(Instrumented Capsule)의 열적, 역학적 특성분석이 수행되었다. 캡슐에 장입될 조사시편의 온도평가는 GENGTC 와 HEATING 7.2f를 이용 계산하였다. 또한 이들 온도분포로 인하여 발생하는 캡슐외통과 End Plug에서의 응력해석은 전산코드 ANSYS를 이용 수행하고, 냉각수압에 의한 캡슐본체의 좌굴응력을 계산함으로서 강도평가를 하였다.