• 콘크리트학회지
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• 제10권6호
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• pp.253-260
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• 1998

본 논문에서는 장기지속하중을 받는 철근콘크리트 보의 처짐을 계산하는 방법을 제안하였다. 균열단면에 대하여 적합조건 및 평형조건을 적용하여 크리프에 의한 중립축의 변화를 계산하는 효율적인 알고리즘을 제시하였으며, 이 값을 이용하여 임의의 시간에서의 휨강성을 유도하였다. 그리고 유사한 방법으로 비균열단면에서의 휨강성을 계산하고 균열단면과 비균열단면에서 각각 계산된 휨강성을 사용하여 ACI규준식의 유효단면 2차모멘트를 계산하는 것과 유사한 방법으로 휨강성을 계산하여 지속하중을 받는 철근콘크리트 보의 처짐을 예측하는 방법을 제시하였다. 제안된 방법과 기존의 실험결과를 비교하여 볼 때, 제안된 방법이 장기지속하중을 받는 철근콘크리트보의 처짐을 잘 예측하였다.

• 한국공간구조학회논문집
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• 제3권1호
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• pp.87-97
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• 2003

The structural system that discreterized from continuous shells is frequently used to make a large space structures. As well these structures show the unstable phenomena when a load level over the limit load, and snap-through and bifurcation are most well known of it. For the collapse mechanism, rise-span ratio, element stiffness and load mode are main factor, which it give an effect to unstable behavior. In our real situation, most structures have semi-rigid joint that has middle characteristic between pin and rigid joint. So the knowledge of semi-rigid joint is very important problem of stable large space structure. And the instability phenemena of framed space structures show a strong non-linearity and very sensitive behavior according to the joint rigidity For this reason In this study, we are investigating to unstable problem of framed structure with semi-rigidity and to grasp the nonlinear instability behavior that make the fundamental collapse mechanism of the large space frame structures with semi-rigid joint, by proposed the numerical analysis method. Using the incremental stiffness matrix in chapter 2, we study instability of space structures.

• 한국의류산업학회지
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• 제21권5호
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• pp.597-605
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• 2019

This paper examined the garment formability and appearance of perspiration absorption, fast dry, and breathable fabrics. The mechanical properties and seam pucker properties of these fabrics were measured and regression analysis was conducted between fabric structural parameters and their mechanical and seam pucker properties. The superior total appearance value (TAV) of fast dry knitted fabrics for sports-wear was achieved in fabrics with high extensibility and bending rigidity; consequently, it increased with increasing stitch density and tightness factor. The formability of the fast dry knitted fabric also improved with an increasing stitch density and tightness factor. The seam pucker was influenced by bending rigidity and a good seam pucker was exhibited in the fast dry knitted fabrics with low stitch density and tightness factor. However, the formability (F) of the breathable fabric improved by increasing extensibility and bending rigidity that decreased with an increasing cover factor and the thickness of the breathable fabric. In addition, seam pucker deteriorated with an increasing cover factor and the thickness of the breathable fabric, which was similar to the results of the formability predicted in fabric mechanical properties. A superior seam pucker was achieved in fabrics with high extensibility and low bending rigidity.

• 한국공간구조학회논문집
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• 제24권2호
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• pp.65-73
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• 2024

In this study, we propose an optimal design method by applying the Prefabricated Buckling Restrained Brace (PF-BRB) to structures with asymmetrically rigidity plan. As a result of the PF-BRB optimal design of a structure with an asymmetrically rigidity plan, it can be seen that the reduction effect of dynamic response is greater in the case of arrangement considering the asymmetric distribution of stiffness (Asym) than in the case of arrangement in the form of a symmetric distribution (Sym), especially It was confirmed that at an eccentricity rate of 20%, the total amount of reinforced PF-BRBs was also small. As a result of analyzing the dynamic response characteristics according to the change in eccentricity of the asymmetrically rigidity plan, the distribution of the reinforced PF-BRB showed that the larger the eccentricity, the greater the amount of damper distribution around the eccentric position. Additionally, when comparing the analysis models with an eccentricity rate of 20% and an eccentricity rate of 12%, the response reduction ratio of the 20% eccentricity rate was found to be large.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2007년도 정기 학술대회 논문집
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• pp.757-762
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• 2007

The lining segment which is the main structure of the shield tunnel consists of joints, not continua. Past international and domestic design data have been commonly used for design practices without specific verification about the structural analysis model, design load, and affection of the soil constant of the lining segment. In this study, the propriety is estimated through the comparison between analytical solution and numerical solution for segment analysis and design models of the shield tunnel which is being used internationally and domestically. As a result, the full. circumferential beam jointed spring model (1R-S0) is suggested by considering aspects of convenient use, application to field condition, and accuracy of analysis result. With suggested model, the parameter analysis was conducted for joint stiffness, ground rigidity, joint distribution, and joint number.

• 한국공간구조학회논문집
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• 제3권4호
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• pp.69-76
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• 2003

In case of rectangular latticed pattern which shearing rigidity is very small, it has a concern to drop Buckling-strength considerably by external force. So, by means of system to increase buckling-strength, there is a method of construction that lattice of dome is reinforced by braced member. In a case like this, shearing rigidity of braced member increase buckling-strength of the whole of structure and can be designed economically from the viewpoint of practice. Therefore, this paper is aimed at investigating how much does rigidity of braced member united with latticed member bearing principal stress of dome increase buckling-strength of the whole of structure. the subject of study is rectangular latticed domes that are a set of 2-way lattice dome which grid is simple and number of member gathering at junction is small. Analysis method is based on FEM dealing with the geometrically nonlinear deflection problems.

• Journal of Biosystems Engineering
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• 제26권2호
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• pp.105-114
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• 2001

Modulus of elasticity, modulus of rigidity, damping ratio, and natural frequency of three varieties of boxthorn (Lycium chinense Mill) (Cheongyang #2, Cheongyang gugija, and Cheongyang native) branches were analyzed. Modulus of elasticity and modulus of elasticity and modulus of rigidity of the boxthorn branch was determined using standard formula after simple beam bending and torsion test, respectively, using an universal testing machine. Damping ratio and natural frequency of branches were determined using a system consisted of an accelerometer, a PC equipped with A/D converter, and a software for data analysis. Relationship between the elastic modulus and branch diameter in overall varieties and branch types showed a good correlation (r -0.81). There was, however, no correlation between torsional rigidity and branch diameter. The internal damping results were highly variable and the overall range of the damping ratio of the boxthorn branch was 0.014-0.087, which indicated that the branch was a lightly damped structure. The natural frequency of the boxthorn branch was in the range of 89-363 rad/s for the overall varieties and branch types. A good correlation (r 0.82) existed between the natural frequency and branch diameter in overall varieties and branch type.

• Steel and Composite Structures
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• 제10권6호
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• pp.489-500
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• 2010

The rigid connections of I-beams to Rectangular Hollow Sections (RHS) in steel structures usually behave as semi-rigid connection. This behavior is directly related to the column face deformation. The deformation in the wall of RHS column in the connection zone causes a relative rotation between beam end and column axis, which consequently reduces the rigidity of beam-column connection. In the present paper, the percentages of connection rigidity reduction for serviceability conditions are evaluated by using the finite element analysis. Such percentages for RHS columns without internal stiffeners are considerable, and can be calculated from presented graphs.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 가을 학술발표회논문집(I)
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• pp.745-750
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• 2000

The rigidity of pier is important in the analysis of rail on high speed railway bridges. This study is being performed because of followings. 1) Actual longitudinal stiffness of the structure including substructure should be considered in the calculation of longitudinal stresses in rails. 2) There are many uncertainties in piers and foundations for design. 3) Actual guideline for the design of piers is necessary. 4) Measurement on the rigidity of pier according to the types of pier, foundation and soil-condition is needed. Curve for rigidity will be obtained through this study and applied for actual design as the guideline. Stresses in rails can be estimates accurately. A pair of piers, which consists of pot-bearing for fixed support and pad-bearing for movable support, is loaded by steel frame through steel wire ropes. The responses which are intended to measure in the field test are displacements, forces and tilts on the top of piers.

• Steel and Composite Structures
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• 제7권3호
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• pp.241-251
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• 2007

The purpose of this study is to calculate the torsional rigidity of arbitrarily shaped composite sections on the basis of hybrid finite element approach. An analogy is used between the torsion problem and deformation of a plate which exhibits only shear behavior. In the analysis a simple hybrid finite element based on Hellinger-Reissner functional is presented and a set of numerical examples are performed to demonstrate and asses the performance of the developed element in practical applications.