• Proceedings of the Korea Concrete Institute Conference
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• 2003.05a
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• pp.403-408
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• 2003

The objective of this study is to understand the variables affected the confinement for the transverse reinforcement of the reinforced concrete structural walls with the T-shaped cross section subjected to cyclic lateral loads. The structural performance of T-shaped walls was advanced by the transverse reinforcement which restrained the concrete subjected to compressive stress. If the arrangement of transverse reinforcement was not suitable for the confinement, T-shaped walls happened the brittle failure by web crushing or bucking of vertical reinforcement at the compression zone. It is necessary to confine transverse reinforcement in order to prevent the these failure. But the location of neutral axis and the magnitude of ultimate strain vary according to the section shape, a ratio of axial load, a ratio of wall cross sectional area to the floor-plan area, an aspect ratio and the reinforcement ratio. Therefore, the objective of this research is to grasp the location of neutral axis and the range which needs for the confinement of transverse reinforcement through the results of the sectional analysis which varies the ratio of axial load and the ratio of vertical reinforcement.

• Structural Engineering and Mechanics
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• v.46 no.5
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• pp.629-644
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• 2013

This paper concerns about the raking damages on the ultimate residual hull girder strength of bulk carriers by applying the modified R-D diagram (advanced method). The limited raking damage scenarios, based on the IMO's probability density function of grounding accidents, were carried out by using sampling technique. Recently, innovative method for the evaluation of the structural condition assessment, which covers the residual strength and damage index diagram (R-D diagram), was proposed by Paik et al. (2012). This concept is applied in the present study and modified R-D diagram, which can be considered vessel size effect, is then proposed. Four different types of bulk carrier structures, i.e., Handysize (37K), Supramax (57K), Kamsarmax (82K) and Capesize (181K) by Common Structural Rule (CSR), were applied to draw the general tendency. The ALPS/HULL, intelligent supersize finite element method, was employed for the ultimate longitudinal strength analysis. The obtained empirical formulas will be useful for the condition assessment of bulk carrier structures. It can also cover different sizes of the bulk carriers in terms of ultimate longitudinal strength. Important insights and findings with useful guidelines developed in this study are summarized.

• Steel and Composite Structures
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• v.7 no.2
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• pp.135-160
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• 2007

Recently, CFT column has been well-studied and reported on, because a CFT column has certain superior structural properties as well as good productivity, execution efficiency, and improved rigidity over existing columns. However, CFT column still has problems clearing the capacity evaluation between its steel tube member and high-strength concrete materials. Also, research on concrete has examined numerical values for high-strength concrete filled steel square tube columns (HCFT) to explain transformation performance (M-${\phi}$) when a short-column receives equal flexure-moment from axial stress. Moment-curvature formulas are proposed for HCFT columns based on analytic assumption described in this paper. This study investigated structural properties (capacity, curvature), through a series of experiments for HCFT with key parameters, such as strength of concrete mixed design (58.8 MPa), width-thickness ratio (D/t), buckling length to sectional width ratio (Lk/D) and concrete types (Zeolite, Fly-ash, Silica-fume) under eccentric loads. A comparative analysis executed for the AISC-LRFD, AIJ and Takanori Sato, etc. Design formulas to estimate the axial load (N)-moment (M)-curvature (${\phi}$) are proposed for HCFT columns based on tests results described in this paper.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.554-559
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• 2008

Most of vehicle manufacturers have applied exhaust gas recirculation (EGR) system to the development of diesel engines in order to obtain the high thermal efficiency without $NO_X$ and Particulate Matter (PM) emitted from the engine. EGR system, which reflow a cooled exhaust gas from vehicles burning diesel as fuel to a combustion chamber of engine, has been used to solve this problem. In order to confirm the safety of the EGR system, finite element analysis was carried out. The safety of EGR system against temperature variation in the shell and tubes was evaluated through the thermal and structural analysis, and the modal analysis using ANSYS was also performed. Finally, the performance of EGR system was verified through the experiment and numerical simulation using effectiveness-NTU method. Program for the estimation of the heat exchange efficiency of the EGR system with regard to the dimpled tube shape was developed.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.16 no.4
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• pp.135-139
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• 2017

In recent years, the optical fiber laser has been widely used in industrial fields due to its excellent economical efficiency and its suitability for industrial applications. This usage has increased even further since the KW class Laser was developed. In this paper, structural analysis and heat transfer analysis of a 500W class optical fiber laser end cap module was performed. The stability of end cap housing with the efficient heat dissipation structure of a 500W-class end cap was evaluated. This research determined the optimal design that should be applied to the design and evaluation of future KW class laser output modules.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.3
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• pp.57-62
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• 2020

Concrete pump cars are a type of construction equipment that continuously supplies concrete using hydraulic pressure. When manually casting concrete, there may be a problem in the final quality of the concrete due to differences in the degree of cure between the pre-poured and subsequent concretes. Concrete pump cars are the most efficient machines to supply concrete in the shortest time; however, it is difficult to calculate their margin of safety during operation. In this paper, we verified the structural safety of the concrete pump car using a static/dynamic analysis at various position angles. Next, these results were compared with experimental results; strains using strain gages were compared with the strains measured using FEM software to verify the static analysis. In addition, the maximum displacement during the pumping was measured and it was used for fatigue analysis to evaluate the dynamic structural safety.

• Journal of the Korea institute for structural maintenance and inspection
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• v.7 no.2
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• pp.159-167
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• 2003

Cracks in reinforced concrete structures reduce overall durability by allowing the penetration of water and aggressive agents, thereby accelerating the deterioration of the reinforcing steel. Highway pavement and bridge decks are especially susceptible to this type of deterioration since these structures exhibit high rates of shrinkage and are frequently exposed to aggressive environmental conditions. The objectives of this investigation included the development of experimental procedures for assessing shrinkage cracking potential of recycled aggregate concrete, the evaluation of mix composition on shrinkage cracking potential, and the development of theoretical models to simulate early-age cracking behavior. Specifically, the influences of shrinkage-reducing admixture(SRA) and recycled aggregate concrete were investigated. The shrinkage-reducing admixture substantially reduces free shrinkage and restrains shrinkage cracking while providing similar mechanical properties. A fracture mechanics modeling approach was developed to predict the behavior of a variety of restrained concrete specimens. This modeling approach was used to successfully explain experimental results from a variety of mixture compositions. The model was used to demonstrate the influence of material and structural properties on the potential for cracking.

• Journal of Korean Society of Steel Construction
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• v.21 no.3
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• pp.233-243
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• 2009

The objective of this study was to investigate the effect of openings on the structural behavior of SC walls. The FEM program ABAQUS was used in this analytical study. The main parameters were the locations and sizes of the openings: a total of 20 locations and a total of four opening sizes were adopted. The analysis results were compared with the results of the currently applied evaluation methods. The strength reduction factor method may be used to safely design SC walls with openings. The strength reduction factor of the effective strut method is more similar to that of the analysis results.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.04a
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• pp.663-670
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• 2011

In this study, the design and verification of 6kW class lift-type vertical-axis wind turbine (VAWT) has been conducted using advanced CAE technique based on computational fluid dynamics (CFD), finite element method (FEM), and computational structural dynamics (CSD). Designed aerodynamic performance of the VAWT model is tested using unsteady CFD method. Designed structural safety is also tested through the evaluation of maximum induced stress level and resonance characteristics using FEM and CSD methods. It is importantly shown that the effect of master eccentricity due to rotational inertia needs to be carefully considered to additionally investigate dynamic stress and deformation level of the designed VAWT system.

• Journal of the Korean Society of Clothing and Textiles
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• v.31 no.8
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• pp.1240-1251
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• 2007

The purpose of this study was to examine the relationship between weight of fabrics and texture and sensibility and preference of consumers for F/W women's jacket fabrics. Structural Equation Model(SEM) using AMOS program was conducted to analyze the relationships. Then, this study aimed to provide useful information in planning designing fabrics through predicting the subjective characteristics analyzed. The main survey was developed the 7-point semantic differential scale of subjective texture, sensibility and preference. Fifty trained female panelists of 20-30 years old were participated and questionnaire method was used with 20 kind of fabric. The evaluation methods such as by the sense of sight & touch were used when fabrics were estimated subjectively. When evaluated by the sense of sight & touch, fabric's weight did not have effect directly on preference, but had effect indirectly on preference through the texture and the sensibility..