• Proceedings of KOSOMES biannual meeting
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• 2004.11a
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• pp.129-135
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• 2004

Plate has cutout inner bottom and girder and floor etc in hull construction absence is used much, and this is strength in case must be situated, but establish in region that high stress interacts sometimes fatally in region that there is no big problem usually by purpose of weight reduction, a person and change of freight, piping etc. Because cutout's existence gnaws in this place, and, elastic budding strength by load rouses large effect in ultimate strength. Therefore, perforated plate elastic budding strength and ultimate strength is one of important design criteria which must examine when decide structural elements size at early structure design step if ship. Therefore, and, reasonable elastic budding strength about perforated plate need design ultimate strength. Calculated ultimate strength change several aspect ratioes and cutout's dimension, and thickness in this investigation. Used program applied ANSYS F.E.M code based on finite element method

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.8
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• pp.780-788
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• 2009

AE technique was applied to the static structural test of the composite wing structure to evaluate the structural integrity and damage. During the test, strain and displacements measurement technique were used to figure out for static structural strength. AE parameter analysis and source location technique were used to evaluate the internal damage and find out damage source location. Design limit load test, the 1st and 2nd design ultimate load tests and fracture test were performed. Main AE source was detected by an sensor attached on skin near by front lug. Especially, at the 1st design ultimate test, strain and displacements results didn't show internal damage but AE signal presented a phenomenon that the internal damage was formed. At the fracture test, AE activities were very lively, and strain and displacements results showed a tendency that the load path was changed by severe damage. The internal damage initiation load and location were accurately evaluated during the static structural test using AE technique. It is certified from this paper that AE technique is useful technique for evaluation of internal damage at static structural strength test.

• Journal of the Korea institute for structural maintenance and inspection
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• v.15 no.4
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• pp.99-106
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• 2011

This study performed research for improvement on basic concept of PBD applying suitable design method before and after LB-DECK composition. According to study, in this case, before composition, it can reduce minuteness cracks by increasing bending tensile strength utilizing polymer concrete, can expect sensuous effect, improve durability as to low permeability, and was evaluated that can reduce covering depth according as it. Also, because LB-DECK baseplate that apply the empirical design method composite is superior load resistance ability than general baseplate, safety is increased, it is expected to secure constructibility and economic performance at the same time because reinforcement arrangement method and reinforcement amount are fixed even if span effective span is increased at ultimate strength design method application.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 2001.11a
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• pp.46-52
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• 2001

본 연구에서는 롤러로 지지된 슬래브 구조물인 연결통로 구조물에 대한 구조해석을 수행하여, 고정하중(사하중)과 활하중 작용시 대상구조물에 발생되는 최대 변위 및 최대 단면력을 해석하였으며, 극한강도설계법에 의하여 극한강도 및 설계강도를 비교·검토함으로써 대상 연결통로 구조물의 안전성을 평가하였다. 구조해석시 대상구조물을 3차원 뼈대 요소 및 shell 요소로 형상화하여 모델링하였으며, 현재 가장 널리 사용되고 있는 범용 구조해석 프로그램인 SAP 2000 Nonlinear에 의해 구조해석을 수행하였다.(중략)

• Journal of the Computational Structural Engineering Institute of Korea
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• v.22 no.3
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• pp.277-287
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• 2009

Recently, the high-strength steel of 400~600MPa tensile strength is producing in the country. Use of high-strength steel member in the design of high-rise buildings is expected to increase the efficiency of structural design in the aspect of structure material weight and cost, however it has been used only a narrow extent. No efficient design method to use high-strength steel in the design of high-rise buildings has been developed. Therefore, in this study structural cost optimization technique that can minimize the structural material cost of high-rise buildings using high-strength steels is developed. The efficiency of the technique is evaluated by comparing the experience-based design for 6 high-rise building examples. As a result, the proposed techniques can save 7~21% of structural material cost compared with experienced-based design. And also, the rough guideline for effective use of high-strength steels in the structural design of high-rise buildings is introduced on the basis of results.

• Journal of the Korean Society of Hazard Mitigation
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• v.9 no.5
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• pp.23-30
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• 2009

According to Korea Highway Bridge Design Code the bridge deck is designed by the strength design method and is regarded as a beam possessing the unit width based on the bending theory. By many researches it is revealed that the existing bridge deck is failed by punching shear. For evaluating the ultimate capacity of bridge deck it is important to estimate the behavior of bridge deck under the punching shear. For the punching strength it is difficult that the existing research results are applied to the simplified composite deck. In this study for comparing characteristics on punching shear the punching shear tests on simplified composite deck and RC deck are performed. The punching shear strength of simplified composite deck is compared with several bridge design codes.

• Journal of Korean Society of Steel Construction
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• v.30 no.1
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• pp.25-35
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• 2018

Resisting strength of ring-stiffened cylindrical steel shell under uniform external pressure was evaluated by geometrically and materially nonlinear finite element method. The effects of shape and amplitude of geometric initial imperfection, radius to thickness ratio, and spacing of ring stiffeners on the resisting strength of ring-stiffened shell were analyzed. The resisting strength of ring-stiffened cylindrical shells made of SM490 obtained by FEA were compared with design strengths specified in Eurocode 3 and DNV-RP-C202. The shell buckling modes obtained from a linear elastic bifurcation FE analysis were introduced in the nonlinear FE analysis as initial geometric imperfections. The radius to thickness ratios of cylindrical shell in the range of 250 to 500 were considered.

• Communications for Statistical Applications and Methods
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• v.15 no.2
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• pp.235-244
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• 2008

Balanced arrays which are generalized orthogonal arrays, introduced by Chakravarti (1956) can be used to construct the fractional factorial designs. Especially for 2-level factorials, balanced arrays with strength 4 are identical to the resolution-V fractional designs. In this paper criteria for evaluation the degree of the orthogonality of balanced arrays of 2-levels with strength 4 are developed and some application methods of the suggested criteria are discussed. As a result, in this paper, we introduce the constructing methods of near orthogonal saturated balanced resolution-V fractional 2-level factorial designs.

• Journal of the Korea Concrete Institute
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• v.23 no.2
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• pp.185-193
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• 2011

In the present study, a unified shear design method was developed to evaluate the shear strength of concrete beams with and without FRP shear reinforcement. The contributions of FRP and concrete on shear strength were defined separately. By comparing the current design method calculated results with the existing test results, it was found that Triantafillou model shows a reliable prediction of FRP effective strain and FRP shear strength contributions. The concrete shear strength contribution was defined by the strain-based shear strength model developed in the previous study. The shear strength of concrete compression zone was evaluated based on the material failure criteria of the concrete subjected to the compressive normal and shear stresses. The proposed strength model was verified by comparing its prediction results to prior test results. The comparisons showed that the proposed method accurately predicts the strengths of the test specimens for both FRP shear reinforced and unreinforced concrete beams.

• Journal of the Korea institute for structural maintenance and inspection
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• v.11 no.1
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• pp.77-84
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• 2007

In this paper presented, a design method of sandwich slab bridge of simple supported made by composite materials. Many of the bridge systems, including the girders and cross-beams, and concrete decks behave as the special orthotropic plates. Such systems with sections, boundary conditions other than Navier or Levy solution types, or with irregular cross sections, analytical solution is very difficult to obtain. Thus, Finite Difference Method is used for analysis of the pertinent problem. For the design of bridge made by the composite materials, cross-section is used the form-core shape because of this shape is economical and profitable, and for output of the stress value used F.D.M. Based the experimental of a composite specialist, an equation expressing the rate of decrease of tensile strength of glass fibers based on increase of mass was obtained. From these equations, one can estimate the rate of tensile strength reduction due to increased size. Tasi-Wu failure criterion for stress space is used. Strength-failure analysis procedure, using these reduced tensile strength, is presented.