• Journal of The Korean Digital Architecture Interior Association
• /
• v.11 no.2
• /
• pp.31-39
• /
• 2011

Concrete-filled steel tube(CFT) columns have become popular for building construction due to not only composite effect of steel tube and infilled concrete, but also more economical. The purpose of this paper is to propose the applicable boundary formula of width-to-thickness ratio for rectangular steel tube as using CFT column. A parametric study was performed taking width-to-thickness ratio of rectangular steel tube and compressive strength of concrete as the main parameter. The strength of concrete are selected to 30, 60, 90MPa. The non-linear analysis was adopted in order to take into account the effect of concrete strength. Finally, from the test and analysis results, the effect of increasing strength according to concrete strength and width-to-thickness of steel tube and plastic behavior of specimens were verified distinctly.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.21 no.4
• /
• pp.189-195
• /
• 2017

In the seismic design of building structural members, due to the complexity of the placement of PC steels in prestressed concrete members, it is necessary to review and define the definition of member damage in comparison with reinforced concrete members. In this study, the results of past experiments compared with the calculation results by 'section Analysis Method', with the aim of reviewing the precision of calculation results when member damage evaluation is performed using the section analysis method. Furthermore, it is also compared with the calculation results by the 'split Element Method'. In addition, parametric studies were carried out, and the influence of the difference between the amount of PC steels and reinforced bar on the residual strain was examined.

• Proceedings of the KSME Conference
• /
• 2001.11a
• /
• pp.16-21
• /
• 2001

The PTS reference temperature of reactor pressure vessel for one of the Korean NPPs has been predicted to exceed the screening criteria before it reaches it's design life. To cope with this issue, a plant-specific PTS analysis had been performed in accordance with the Regulatory Guide 1.154 in 1999. As a result of that analysis, it was found that current methodology of RG. 1.154 was very conservative. The objective of this study is to examine the effects of changing various input parameters and to determine the amount of conservatism of the current PTS analysis method. To do this, based on the past PTS analysis experience, parametric study were performed for various models using modified VISA-II code. This paper discusses the analysis results and recommendations to reduce the conservatism of current analysis method.

• Journal of Ocean Engineering and Technology
• /
• v.18 no.3
• /
• pp.20-25
• /
• 2004

For the structural foundation above the soft clay layer conditions, the design charts are first presented for the evaluation of both bearing capacity and total settlement in the basic raft foundation system. wad settlement relationship curves are used to evaluate the ultimate soil bearing capacity. The total settlement is evaluated by applying various traditional factors into the ultimate bearing capacity. Then, the parametric studies are carried out for the piled-raft foundation system. In the numerical analysis, the elasto-pastic finite element model(Mohr-Coulomb model) is used to present the foundation response and design charts, which enable the determination of the raft size and pile length and spacing.

• Journal of the Korean Society of Safety
• /
• v.15 no.2
• /
• pp.51-58
• /
• 2000

Recently, the J/T analysis based on elastic-plastic finite element analysis is popularly used in the nuclear industry to assess the integrity of a cracked pipe. The objective of this paper is to evaluate the effect of stress-strain curve for weld metal, variation of crack incremental length(${\delta}a$), and crack face pressure on the J/T analysis result. For this purpose, a parametric analysis was performed and the results calculated from finite element analysis were compared with those from the piping experimental data(stainless steel weldment pipe with circumferential through-wall crack). The numerical result using base metal material property is in agreement with the experimental one and the maximum load is decreased as the ${\delta}a$ for J/T analysis is increased.

• Steel and Composite Structures
• /
• v.16 no.6
• /
• pp.639-655
• /
• 2014

The mechanical characteristic of reinforced concrete filled steel tubular (RCFT) structures are differed from that of concrete filled tubular steel (CFT) structures because the reinforcement in RCFT largely affects the performance of core concrete such as ductility, strength and toughness, and hence the performance of RCFT should be evaluated differently from CFT. To examine the effect axial reinforcement on bending performance, an investigation on RCFT beams with varying levels of axial reinforcement is performed by the means of numerical parametric study. According to the numerical simulation results with 13 different ratios of axial reinforcement, it is concluded that the reinforcement has obvious effect on bending capacity, and the neutral axis of RCFT is different from CFT, and an evaluation equation in which the effect of axial reinforcement is considered for ultimate bending strength of RCFT is proposed.

• Computers and Concrete
• /
• v.26 no.5
• /
• pp.397-409
• /
• 2020

The current study targets to estimate the contribution of the end-anchored FRP composites in resisting shear force using a soft computing tool i.e., adaptive neuro-fuzzy inference system (ANFIS). A total of 107 sets of data accumulated from literature was utilized for the development and evaluation of the current ANFIS model. A comparative analysis between the ANFIS predictions and the acquired experimental results has shown that the ANFIS predictions are in very good agreement with that of experimental ones. Additionally, the accuracy of the current ANFIS model has been weighed up against the estimates of nine widely adopted design guidelines. Based on various statistical parameters, it has been deduced that the effectiveness of the current ANFIS model is better than the considered design guidelines. Besides this, a parametric study was carried out to explore the combined effect of different parameters as well as the impact of individual parameters.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2009.01a
• /
• pp.703-708
• /
• 2009

The present paper describes the application of an improved impression transfer vector method (Sakurai et al., 2007) to transform the three basic dimensions (Evaluation, Activity, and Potency) of higher-order impression. First, a set of shapes and surface textures of faces was represented by multi-dimensional vectors. Second, the variation among faces was coded in reduced parameters derived by applying principal component analysis. Third, a facial attribute along a given impression dimension was analyzed to select discriminative parameters from among principal components with higher sensitivity to impressions, and obtain an impression transfer vector. Finally, the parametric coordinates were changed by adding or subtracting the impression transfer vector and the image was manipulated so that its facial appearance clearly exhibits the transformed impression. A psychological rating experiment confirmed that the impression transfer vector modulated three dimensions of higher-order impression. We discussed the versatility of the impression transfer vector method.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2006.05a
• /
• pp.113-114
• /
• 2006

Vibration of a non-linear system under random excitations was evaluated by probabilistic methods. The non-linear characteristic terms of a system structure were quasi-linearized and excitation terms were remained as they were. An analytical method where the square mean of error was minimized was used. An alternative method was an energy method where the damping energy and restoring energy of the linearized system were equalized to those of the original non-linear system. The numerical results were compared with those obtained by Monte Carlo simulation. The comparison showed the results obtained by Monte Carlo simulation located between those by the analytical method and those by the energy method.

• Proceedings of the KSME Conference
• /
• 2001.06a
• /
• pp.441-446
• /
• 2001

In the integral type reactor, SMART, all the major components such as steam generators, pressurizer and pumps are located inside the single reactor pressure vessel. The objective of this study is to evaluate the structural integrity for RPV of SMART under the postulated pressurized thermal shock by applying the finite element analysis. Input data for the finite element analysis were generated using the commercial code I-DEAS, and the fracture mechanics analysis was performed using the ABAQUS. The crack configurations, the crack aspect ratio and the clad thickness were considered in the parametric study. The effects of these parameters on the reference nil-ductility transition temperature were also investigated.