• Journal of the Computational Structural Engineering Institute of Korea
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• v.19 no.4 s.74
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• pp.369-374
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• 2006

This paper describes dynamic characteristics of a power transmission tower consisting of lots of power lines and insulators. A numerical 3D modeling for the static, dynamic and buckling analyses of the power transmission tower is presented considering the case when the power lines are cut. Eigenvalue analysis indicates that the transmission tower shows different behavior comparing to usual structures governed by several low modes. The transmission tower is governed by lots of modes. It is verified that the transmission tower is structurally safe against the static wind and buckling loads. But the structural and buckling safety is not guaranteed when all power lines are cut, which comes to collapse the transmission tower. Further study is in need to overcome such case. Wind dynamic analysis shows that fluctuating wind loads increase the response of the tower.

• Journal of the Korean Geotechnical Society
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• v.22 no.11
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• pp.123-131
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• 2006

Liquefaction-induced lateral spreading has been the most extensive damage to pile foundations during earthquakes. Several cases of pile failures were reported despite the fact that a large margin of safety factor was employed in their design. In this study, 1-g shaking table tests were performed in order to analyze the failure behavior of piles embedded in liquefied soil deposits by buckling instability. As a result, it can be concluded that the pile subjected to excessive axial loads $(near\;P_{cr})$ can fail easily by buckling instability during liquefaction. When lateral spreading took place in sloping grounds, it was found that lateral loading due to lateral spreading increased lateral deflection of pile and reduced the buckling load. In addition, from the buckling shape of pile, difference between Euler's buckling and pile buckling vat observed. In the case of pile buckling, hinge formed at the middle point of the pile, not at the bottom. And in sloping grounds, location of hinge formation got lower compared with level ground because of the soil movements.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 1998.05a
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• pp.227-232
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• 1998

강상형교(Steel Box Girder Bridge)는 휨강성 및 비틀림강성이 I형이나 II형 단면에 비해서 현저하게 크고 가설시의 안전성도 우수하며, 완성후의 내하력도 크다는 장점을 갖고 있어 지간이 40-80m인 교량에 적용되는 대표적인 교량형식이며, 또한 경제적, 구조적인 특성을 고려하여 대분분이 연속교 형식으로 건설되고 있다. (중략)

• Journal of the Korean Society of Safety
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• v.14 no.1
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• pp.33-40
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• 1999

In this paper, a damaged example of hanging guide frame used in the lifting of shore protection caisson was investigated. An examination of the stress and stability of members was carried out by structural analysis and the causes of damages was investigated. The stability analysis considering local and global stress buckling was performed. As a result of stability analysis. the first structure was unstable structure. Therefore improved structure was examined and the best effective methodology was the reassignment of wire.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.7
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• pp.1259-1266
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• 2022

Recently, due to the specialization of structural design standards and evaluation methods, the classification rules are being integrated. A good example is the common international rules (CSR). However, detailed regulations are presented only for the cargo hold area where the longitudinal load is greatly applied, and no specific evaluation guidelines exist for the bow and stern structures. Structural design of the mentioned area is carried out depending on the design experience of the shipbuilder, and because no clear standard exists even in the classification, determining the root cause is difficult even if a structural damage problem occurs. In this study, an engineering-based solution was presented to identify the root cause of representative cases of buckling damage that occurs mainly in the stern. Buckling may occur at the panel wall owing to hull girder bending moment acting on the stern structure, and the plate thickness must be increased or vertical stiffeners must be added to increase the buckling rigidity. For structural strength verification based on finite element analysis modeling, reasonable solutions for load conditions, boundary conditions, modeling methods, and evaluation criteria were presented. This result is expected to be helpful in examining the structural strength of the stern part of similar carriers in the future.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.3
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• pp.75-83
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• 2018

In study, Structural stability was considered when applying the high strength strut method with improved general strut method. considered whether there is sufficient stiffness to so as not buckling to the maximum hypothetical earth pressure. also structure stability of the strut component was reviewed. The high strength strut method is a technique used in place of the general strut method. high strength prefabricated Strut method is a technique that has bolt holes drilled in the upper flange at regular intervals. As a result of the buckling analysis, it was considered that the safety factor increased by about 5 %. also Since the stress generated is below the allowable stress, it is judged that structural stability of the strut is ensured. In particular, the safety factor of axial compressive stress increases about 16 % with use of high strength steel when applying the high strength prefabricated strut method. the high strength strut method is construction method may shorten the construction period and there is no expense to purchase additional materials.

• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.6
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• pp.738-745
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• 2014

In this paper, It is performing to the elastic and elasto-plastic large deformation series analysis using a numerical method for the initial deflection effect of the aluminum alloy rectangular plate in the elasto-plastic loading area patch loading size. It is assumed a boundary condition to be a simply supported condition and consider the initial deflection amplitude, aspect ratio. It examined the critical elastic buckling load and post-buckling behaviour of aluminium alloy A6082-T6 rectangular plate. It used a commercial program for the elastic and elasto-plastic deformation series analysis. If the initial deflection amplitude is smaller, the in-plane rigidity with increasing to load is reduced from the start and occurs significantly more increasing the amplitude. More higher the aspect ratio, the initial yield strength is gradually decreased, and the plate thickness thicker and occurs larger than the thin walled plate a reduction ratio of the initial yield strength of the patch loading size as 0.5.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1998.04a
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• pp.433-440
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• 1998

For many decades, railroad technology was used to set up tracks with jointed rails and lengths in accordance with rolling and handling technology. The joints lead to drawbacks in the track and in controlling rising maintenance costs. So, railroad engineers became interested in eliminating joints to increase loads, speeds and improvements in rolling, welding, and fastening technology. Continuous welded rail(CWR) track has many advantages over the conventional jointed-rail track. In the case of the elimination of rail joints, it may cause the track to be suddenly and laterally buckled by thermal forces and vehicle load. Thermal forces are caused by an increase in the temperature of railway track. For many years, many analytical and experimental investigations have been conducted to improve the safety of CWR track by various research center in many country. In this paper, CWR track model and CWRB program is developed for buckling analysis using finite element method(FEM). The finite element discretization is used for a rail element with a total of 14 degrees of freedom. The stiffness of the fasteners, tie, and ballast bed is included by a set of spring elements. The investigation on the buckling modes and temperature of CWR track is presented in this paper

• Earthquakes and Structures
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• v.13 no.1
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• pp.67-77
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• 2017

Oil storage tanks are vital life-line structures, suffered significant damages during past earthquakes. In this study, a numerical model for an unanchored vertical vaulted-type tank was established by ANSYS software, including the tank-liquid coupling, nonlinear uplift and slip effect between the tank bottom and foundation. Four actual earthquakes recorded at different soil sites were selected as input to study the dynamic characteristics of the tank by nonlinear time-history dynamic analysis, including the elephant-foot buckling, the liquid sloshing, the uplift and slip at the bottom. The results demonstrate that, obvious elephant-foot deformation and buckling failure occurred near the bottom of the tank wall under the seismic input of Class-I and Class-IV sites. The local buckling failure appeared at the location close to the elephant-foot because the axial compressive stress exceeded the allowable critical stress. Under the seismic input of Class-IV site, significant nonlinear uplift and slip occurred at the tank bottom. Large amplitude vertical sloshing with a long period occurred on the free surface of the liquid under the seismic wave record at Class-III site. The seismic properties of the storage tank were affected by site class and should be considered in the seismic design of large tanks. Effective measures should be taken to reduce the seismic response of storage tanks, and ensure the safety of tanks.

• Steel and Composite Structures
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• v.19 no.4
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• pp.967-993
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• 2015

The aim of this paper is to investigate the appropriateness of current codes of practice for predicting the axial load capacity of high-strength Concrete Filled Steel Tubular Columns (CFSTCs). Australian/New Zealand standards and other international codes of practice for composite bridges and buildings are currently being revised and will allow for the use of high-strength CFSTCs. It is therefore important to assess and modify the suitability of the section and ultimate buckling capacities models. For this purpose, available experimental results on high-strength composite columns have been assessed. The collected experimental results are compared with eight current codes of practice for rectangular CFSTCs and seven current codes of practice for circular CFSTCs. Furthermore, based on the statistical studies carried out, simplified relationships are developed to predict the section and ultimate buckling capacities of normal and high-strength short and slender rectangular and circular CFSTCs subjected to concentric loading.