• 한국지진공학회:학술대회논문집
• /
• 한국지진공학회 1999년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Fall
• /
• pp.220-227
• /
• 1999

The Purpose of this paper is to evaluate the buckling strength of conceptually designed KALIMER reactor vessel. For evaluation of the buckling load buckling load the design equations and the finite element analysis are used. In finite element method the eigenvalue buckling analysis nonlinear elastic buckling analysis using snap-through buckling method and nonlinear elastic-plastic buckling analysis are carried out. the calculated buckling loads of KALIMER reactor vessel using the finite element method are in well agreement with those of the design equations. From the calculated results of buckling load in KALIMER rector vessel it is shown that the plasticity of vessel materials significantly affects the buckling load but the initial imperfection has little effects, In checking the limits of bucking load of KALIMER reactor vessel using the ASME B & PV Section III. Subsection NH the non-seismic isolation design can not satisfy the buckling limit requirements but the seismic isolation design can sufficiently satisfy the requirements.

• 한국산업융합학회 논문집
• /
• 제15권1호
• /
• pp.5-11
• /
• 2012

The Buckling of the member under compressive stress is likely to occur, which is an important factor determining the strength of structures. The objective of this study was to evaluate the member buckling strength of a circular hollow steel with ball joints and to compare with design specifications for load resistance factor of our country. Furthermore, we would like to suggest basic data for evaluation of buckling length of a circular hollow steel with ball joints according to comparative analysis. These results were summarized as follows: Buckling stress according to the test results on buckling was 1.21 times greater than LSD specifications of our country estimated the entire length of circular hollow steel with ball joints as buckling length. In addition, it was 1.16 times greater than when estimating the length except the ball as buckling length and 1.14 times grater than when excluding the ball and sleeve. Therefore, when estimating buckling stress of circular hollow steel with ball joints, their buckling length may be measured by the length except ball and sleeve.

• 한국기계가공학회지
• /
• 제20권1호
• /
• pp.7-15
• /
• 2021

Buckling of cylindrical structures has been extensively researched, because it is an important phenomenon to be considered in structural design. However, the evaluation of thermal effects on the buckling of cylindrical structures has been insufficient; therefore, this study evaluates this thermal effect using shell elements. In addition, the thermal effect on the buckling of temperature-dependent nonlinear materials was evaluated. Nonlinear and linear buckling analyses were performed using the arc-length method to investigate the behavioral characteristics of a cylindrical structure. The basic theory of the linear buckling analysis of a cylindrical structure subjected to thermal stress was derived and presented by applying the thermal stress basic theory.

• 한국전산구조공학회논문집
• /
• 제15권3호
• /
• pp.535-543
• /
• 2002

본 논문의 목적은 전단하중을 받는 얇은 원통구조물의 세장비에 따른 좌굴특성을 보다 깊이 있게 검토하는 것이다. 이를 위하여 J. Okada 등이 제안한 좌굴평가식을 사용하여 세장비에 따른 좌굴강도 평가를 수행하였다. 좌굴강도 평가 결과들로부터 세장비 L/R=3.1, 1.6, 그리고 1.0을 갖는 세가지 좌굴시험체를 결정하고 이에 대한 수치해석과 좌굴특성시험을 수행하였다. 그 결과, 세장비 L/R=3 이상인 경우 평가식에서 예측된 바와 같은 굽힘좌굴이 지배적으로 나타났으며 세장비 L/R=1.0이하로 작을 경우에는 전단좌굴이 지배적으로 나타났고, 세장비 L/R=1.6 영역에서는 전단과 굽힘좌굴이 동시에 발생하는 복합자굴 특성이 나타났다 그리고 수치해석과 평가식에 의한 좌굴특성평가 결과는 시험결과들과 잘 일치하였다.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2004년도 추계학술대회 논문집
• /
• pp.677-680
• /
• 2004

This study investigates the buckling evaluation of connecting rods used in the diesel engine through finite element analysis. The Rankine formula, which is modified from classical Euler‘s formula, has been widely accepted in automotive industry to evaluate the buckling of connecting rods. Apparently, this formula is most suitable for the straight and idealized rod shape, and over-simplifies the geometric complexity associated with connecting rods. The subspace iteration method in FEA is used to predict the critical buckling stress of a connecting rod with certain slenderness ratio. To create models with various slenderness ratios for shank portion in the rod, the automatic meshing preprocessor was implemented. Results from FEA were verified by the experiments, in which the embedded strain gages measured for the connecting rod running at 4000rpm. The result indicates that the buckling prediction curve through FEA and experiment is effectively different from the curve of classical Rankine formula.

• Nuclear Engineering and Technology
• /
• 제35권6호
• /
• pp.537-546
• /
• 2003

The purpose of this paper is to investigate the buckling characteristics of a conceptually designed KALIMER-150(Korea Advanced LIquid MEtal Reactor, 150MWe) reactor vessel and verify the buckling behavior using the reduced scale cylindrical shell structures. To do this, nonlinear buckling analyses using finite element method and evaluation formulae are carried out. From the results, the KALIMER-150 reactor vessel exhibits a dominant bending buckling mode and is significantly affected by the plastic behavior. The interaction effects with the vertical seismic load cause the lateral buckling load to be slightly decrease. From the results of the buckling experiments using reduced scaled cylindrical shell structures, it is verified that the buckling modes such as pure bending, pure shear, and mixed(bending plus shear) mode clearly appear under a lateral load corresponding to the slenderness ratio of cylinder.

• 대한조선학회 특별논문집
• /
• 대한조선학회 2017년도 특별논문집
• /
• pp.38-45
• /
• 2017

FPSO is widely used to develop deep sea oil fields and HHI has constructed ten(10) FPSOs. During these constructions, relevant structural design criteria such as yielding, buckling, fatigue, collision and impact strength were applied to verify structural safety. To apply the buckling strength evaluation for structures, the critical buckling stresses and applied stresses of relevant panels should be calculated. The plate and stiffened panels are to be idealized, which are needed much time and efforts by designers. Therefore, program development is necessary in order to evaluate the buckling strength conveniently and accurately. In this study, the buckling strength assessment system by using offshore code, DNV-RP-C201 was developed under MSC/PATRAN, pre-post program of finite element method. Graphic user interface program is written in MSC/PATRAN PCL functions. Source program to evaluate the buckling strength is developed in FORTRAN programming languages. The developed program is verified by comparing with the results of the Nauticus Hull developed by DNV Classification Society, and applied to the marine construction project conducted by Hyundai Heavy Industries LTD.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2010년도 춘계학술대회 논문집
• /
• pp.305-309
• /
• 2010

The buckling behavior of CWR tracks is affected by the various parameters such as stiffness and geometry of track panel, ballast resistance, rail temperature, initial imperfection, and wheel load. Until now, CWR tracks were managed by the dichotomous logic (deterministic approach) despite these influence factors are having the nature of random variables. So, the design method and existing management process to prevent the track buckling can be very non-economic since the value of these influence factors to calculate the track buckling strength are selected by considering the worst track condition. In this study, buckling probability evaluation process is proposed which is based on the reliability index, AFOSM method, and limit state equation.

• 한국전산구조공학회:학술대회논문집
• /
• 한국전산구조공학회 1988년도 가을 학술발표회 논문집
• /
• pp.36-42
• /
• 1988

In this study, a formulation of the idealized plate element based upon the idealized structural unit method(ISUM) firstly proposed by Ueda et．al is made in an attempt to analyze the geometric nonlinear behaviour up to the buckling strength of thin-walled long structures like box-column structure including the coupling effect between local and global buckling. An application to the example box-column is also performed and it is found that the present method gives reliable results with consuming very short computing times and therefore is very useful for evaluation of the buckling strength of thin-walled long structures.

• International Journal of Railway
• /
• 제3권4호
• /
• pp.126-133
• /
• 2010

The thermal buckling analysis of curved continuous welded rail (CWR) is studied for the lateral buckling prevention. This study includes a thermal buckling theory which accounts for both thermal and vehicle loading effects in the evaluation of track stability. The parameters include rail size, track lateral resistance, track longitudinal and torsional stiffnesses, initial misalignment amplitude and wavelength, track curvature, tie-ballast friction coefficient and truck center spacing. Parametric studies are performed to evaluate the effects of the individual parameters on the upper and lower critical buckling temperatures. The results show that the upper critical buckling temperature is highly affected by the uplift due to vehicle loads. This study provides a guideline for the improvement of stability for dynamic buckling in curved CWR track.