• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2007년도 춘계학술대회 논문집
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• pp.71-74
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• 2007

Substitution of the stacked antenna for the normally pressed antenna in the mobile phone was tried for the purpose of decreasing its size. However, reduced size resulted in the difficulties obtaining the targeted characteristics with the bandwidth over 70MHz. The cross-section of the vias in the low temperature co-firing ceramics process was studied to find out effects on the bandwidth characteristics. Circular and rectangular cross-section of the via beneath different types of antenna patterns were simulated. Better bandwidth characteristics were acquired for the larger diameter of the circular section and for the rectangular section as the cross-section area increased. From the viewpoint of the shape of the cross-section, rectangular area showed better characteristics than the circular area with the same longest length in the cross-section.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2005년도 학술발표회 논문집
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• pp.345-352
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• 2005

The purpose of this study is to analyze the stress-strain behavior of confined concrete columns with rectangular section. Uniaxial concentric loading tests of nineteen concrete columns with rectangular section ($150{\times}100$, $250{\times}100$, $350{\times}100\;mm$) were conducted. The main variables are transverse reinforcement volumetric ratio and spacing, cross tie arrangement, cross-section aspect ratio, and concrete strength. From the present experiments, it was found that the increase of transverse reinforcement ratio increases the maximum stress and ductility ratio and the reduction of the spacing of transverse reinforcement also increases the ductility and effective confinement. The increase of the aspect ratio of the cross-section does not influence much the stress-strain behavior of rectangular columns within the aspect ratio range of 3.5. The effect of concrete strength on ductility is also discussed.

• 소성∙가공
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• 제20권6호
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• pp.450-455
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• 2011

This paper presents an inverse design methodology for the cross section geometry of mold spring with a rectangular cross section as the starting material for a coiling process. The cross-sections of mold springs are universally rectangular, as the parallel sides minimize the possibility of failure under high service loads. Pre-coiled wires are initially designed to have a trapezoidal cross section, which becomes a rectangle by the coiling process. This study demonstrates a numerical exercise to predict changes in the sectional geometry in spring manufacture and to obtain the initial cross section which becomes the exact rectangle desired from the manufacturing process. Finite element analysis was carried out to calculate the sectional changes for various mold springs. Geometrical parameters were the widths at inner and outer radii, the inner and the outer corner radii, and the height. A partial least square regression analysis was carried out to find the main contributing factors for deciding initial design values. The height and the width mainly affected various initial parameters. The initial width at the inner radius was mostly affected by various specification parameters.

• Structural Engineering and Mechanics
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• 제3권6호
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• pp.555-567
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• 1995

Design curves have been prepared for prestressed rectangular beam section based on BS 8110, for determining area of steel for any given cross section, for stresses in concrete and steel and for the design moment. The design moment and the area of steel have been expressed in dimensionless form in terms of cross sectional dimensions and the characteristic strength of concrete. The choice and combination of design parameters result in considerably less number of curves as aid for design of rectangular prestressed beam sections, than those reported in CP 110 (Part 3).

• Structural Engineering and Mechanics
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• 제90권5호
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• pp.505-515
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• 2024

In this study, obtaining theoretical stress-strain curves and determining the parameters defining the equivalent rectangular stress block were aimed for 3 and 4-layered rectangular Reinforced Concrete (RC) cross-sections subjected to flexure. For these aims, the analytical stress-strain model proposed by Hognestad was chosen for the concrete grades (20 MPa≤fck≤60 MPa) used in this study. The tensile strength of the concrete was neglected and the thickness of the concrete layers in the compression zone of the concrete cross-section was taken as equal. In addition, while concrete strength was kept constant within each layer, concrete strengths belonging to separate layers were increased from the neutral axis towards the outer face of the compression zone of the concrete cross-section. After the equivalent rectangular stress block parameters were determined by numerical iterations, variations of these parameters depending on concrete strength in layers and layer numbers were obtained. Finally, some analytical equations have been proposed to predict the equivalent stress block parameters for the 3 and 4-layered RC cross-sections and validities of these proposed equations were shown by different metrics in this study.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.1087-1090
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• 2003

In this study, experimental procedures were suggested to investigate the sloshing behavior of a liquid storage tank subjected to inevitably external vibrating conditions. For this purpose. liquid storage tank with rectangular cross section was made of an acrylic resin for the visualization of liquid fluctuation. A specially designed vibrator was used to provide a specified vibrating condition to the liquid storage tank. Extrapolation technique was applied to determine sloshing natural frequency by using various sloshing frequencies at each vibrating displacement and liquid contents at a fixed vibrating frequency. Sloshing mode was also determined from continuous images or liquid fluctuation captured from a video camera. In addition, change in the height of the liquid free surface was measured by using a floating target and a laser displacement sensor. It is found that the suggested method can be applicable to identify the sloshing behavior of liquid storage tank with rectangular cross section.

• EDISON SW 활용 경진대회 논문집
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• 제5회(2016년)
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• pp.256-261
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• 2016

In this paper, Shape optimal design for a chair with 4 legs and 2 stretchers consisting of stainless steel was conducted. The shape was transformed by identifying stress and deformation for the part of leg and stretcher. In addition, load condition and mesh was designed using Hypermesh. The stress analysis was carried out using CSD_Elast that is one of EDISON program. In seat test, Maximum equivalent stress was showed at the contact part between seat and legs. As a result, a leg cross-section with rectangular and arch was designed. And optimal height of stretcher was found to reduce a deformation. Also, maximum deformation was reduced by designing a stretcher with ellipse cross-section. So, Optimal chair having 4 legs with rectangular cross section and 2 stretchers with ellipse cross section was shown to satisfy the safety ratio.

• 한국수자원학회논문집
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• 제37권7호
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• pp.527-540
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• 2004

다중 만곡부에서의 주흐름과 이차류의 흐름 특성을 분석하기 위하여 중심각 120$^{\circ}$인 두 개의 만곡부로 이루어진 사행수로에서 실험을 수행하였다. 실험수로의 횡단면은 직사각형과 곡선형 두 가지 형태로 제작하였으며, 곡선형 단면 형상 결정에는 베타함수를 이용하였다. 3차원 유속장의 측정은 micro-ADV를 이용하였다. 실험결과, 직사각형 수로에서 주흐름은 수로의 가장 짧은 경로를 따라 발생하였으며, 이는 기존 연구자들의 결과와 일치한다. 곡선형 수로에서도 주흐름이 직사각형 수로에서의 주흐름의 거동과 비슷한 양상을 보이는 것으로 밝혀졌다. 곡선형 수로에서의 실험결과가 실제 자연하천의 만곡부에서의 주흐름 거동(최심선을 따라 발생)과 상이하게 나타나는 이유는 실험수로의 바닥 조도와 사행도에 기인한 것으로 사료된다. 이차류의 정량적인 분석을 위하여 흐름함수를 도입한 결과, 만곡부에서 주 셀 뿐만 아니라 바깥제방 셀의 위치 및 형태를 확인할 수 있었다. 또한 이차류 강도를 계산한 결과, 직사각형 및 곡선형 수로에서 최대값은 두 번째 만곡부의 정점 부근에서 가장 크게 나타나며 곡선형 수로의 이차류의 강도가 직사각형 수로의 값보다 크게 나타나고 있음을 알 수 있었다. 직사각형 수로의 경우, 하폭 대 수심비가 커질수록 이차류의 강도가 증가하고 있음을 확인하였다.

• Structural Engineering and Mechanics
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• 제44권2호
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• pp.239-255
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• 2012

This work presents a contribution to understand the inverted trussed beams behavior. The system has a main beam and struts with rectangular cross section associated to a wire rope enlaced to the main beam. It is an unpublished system with the advantage of easy positioning of the wire rope, once it is a continuous and connected by turnbuckles. It is a system that can be used as support for concrete formworks or for rehabilitation wooden beams proposal. The enlacement of the cable demands a small notch at the top of the cross section and a cross pin at the bottom. Six inverted trussed beams were tested, with spans of 180 cm with cables diameter of 1/4". Additionally, four simple beams without any external steel cable were also tested with material from the same lot of wood, allowing a comparison in rupture. The results showed capacity gain of around 60% compared to a simple beam. Once the wire rope characteristics and anchoring are very important for structure response, some improvement suggestions for the efficiency of the cables are also presented.

• Steel and Composite Structures
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• 제19권2호
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• pp.327-348
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• 2015

A numerical procedure is presented that provides ultimate curvature and moment domains for composite rectangular and circular cross-sections of reinforced concrete columns with or without an embedded steel section subjected to combined axial loading and biaxial bending. The stress resultants for the concrete and reinforcement bars are calculated using fiber analysis and the stress resultants for the encased structural steel are evaluated using an exact integration of the stress-strain curve over the area of the steel section. A dimensionless formula is proposed that can be used for any section with similar normalized geometric and mechanical parameters. The contribution of each material to the bearing capacity of a section (resistance load and moments) is calculated separately so that the influence of each geometric or mechanical parameter on the bearing capacity can be investigated separately.