• Title/Summary/Keyword: combined load

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Analysis of Behavior of Agricultural Reservoir with Combined Load by 3-D Numerical Analysis (3차원 수치해석을 통한 복합하중이 작용하는 농업용저수지의 거동 분석)

  • Song, Chang Seob;Woo, jea keun;Ahn, kwangkuk;Kim, Myeong Hwan
    • Journal of The Korean Society of Agricultural Engineers
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    • v.60 no.1
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    • pp.59-65
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    • 2018
  • The object of this paper was to analyze combined load acting on agricultural reservoir. This study was carried out to 3-D numerical modeling for displacement characteristic and seismic acceleration characteristic. The results of study were analyzed and summarized as follow. It was found that the displacement caused by combined load acting on railway and agricultural reservoir did not reflect the effect of load and the seismic wave consistently. The ground accelerations that occur in railway and dam were amplified because 3-D numerical analysis program interprets ground as an elastic body. Actual ground shows characteristics of elasticity and plasticity, so measured values will show different tendency. As a result of analyzing displacement characteristics, it is considered to be related to stiffness. The Ofunato seismic wave, the displacement (77.1 mm) of the body satisfied the allowable displacement (220 mm), but The Hachinohe seismic wave (282.8 mm) did not. It is considered that displacement caused by combined load is affected not only by acceleration but also by characteristics of materials.

Closed-Form Plastic Collapse Loads of Pipe Bends Under Combined Pressure and In-Plane Bending (압력과 모멘트의 복합하중을 받는 곡관의 소성 붕괴하중 예측식 개발)

  • Oh Chang-Sik;Kim Yun-Jae
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.30 no.8 s.251
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    • pp.1008-1015
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    • 2006
  • Based on three-dimensional (3-D) FE limit analyses, this paper provides plastic limit, collapse and instability load solutions for pipe bends under combined pressure and in-plane bending. The plastic limit loads are determined from FE limit analyses based on elastic-perfectly plastic materials using the small geometry change option, and the FE limit analyses using the large geometry change option provide plastic collapse loads (using the twice-elastic-slope method) and instability loads. For the bending mode, both closing bending and opening bending are considered, and a wide range of parameters related to the bend geometry is considered. Based on the FE results, closed-form approximations of plastic limit and collapse load solutions for pipe bends under combined pressure and bending are proposed.

Optimum Flow and Pollution Load Monitoring Time of Combined Sewers of Urban Watersheds during Dry Weather (비강우시 도시 합류식 하수도의 오염부하 산정을 위한 최적관측시간 산정연구)

  • Choi, Yong-Hun;Won, Chul-Hee;Park, Woon-Ji;Seo, Ji-Yeon;Shin, Min-Hwan;Lee, Chan-Ki;Choi, Joong-Dae
    • Journal of The Korean Society of Agricultural Engineers
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    • v.51 no.3
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    • pp.9-14
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    • 2009
  • Flow and pollution load were monitored at 2 combined sewer outlets (C-1 and C-2) of urban watersheds during dry weather from September, 2004 to April, 2006 for 20 months. The objectives were to investigate the diurnal variation of flow and pollutant load and to find the proper sampling time that could measure representative flow and pollutant load. Pollution load closed to the average daily load at C-1 could be measured at 00:00 hour and by the mean of 15:00 and 18:00 hour measures, and 15:00 and 21:00 hour measures, respectively. In addition at C-2, it was 21:00 hour and the mean of 15:00 and 18:00 hour measures. This study concluded that arbitrary sampling of flow and water quality could cause large errors in the estimation of urban pollution load and recommended that urban combined sewers should be monitored when flow and water quality showed daily average and concentration.

A Study on the Buckling and Ultimate Strength for Cylindrically curved plate subject to combined load (조합하중을 받는 원통형 곡판구조의 좌굴 및 최종강도 거동에 관한 연구)

  • Oh, Young-Cheol;Ko, Jae-Yong;Lee, Kyoung-Woo
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2007.12a
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    • pp.25-26
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    • 2007
  • Ship are typically thin-walled structures and consists of stiffened plate structure by purpose of required design load and weight reduction etc. Also, a hull structural characteristics are often used in structures with curvature at deck plating with camber, side shell plating at fore and aft parts and bilge circle parts, It have been believed that these structures can be modelled fundamentally by a part of cylinder. Structural component with curvature subjected to combined loading regimes and complex boundary conditions, which can potentially collapse due to buckling. Hence, for more rational and safe design of ship structures, it is crucial importance to better understand the interaction relationship of the buckling and ultimate strength for cylindrically curved plate under these load components. In this study, the ultimate strength characteristic of curved plate under combined load(lateral pressure load + axial compressive load) are investigated through using FEM series analysis with varying geometric panel properties.

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The Proposition of Efficient Nonlinear Solution Technique for Space Truss (공간 트러스에 대한 효율적인 비선형 해석 기법 제안)

  • 석창목;권영환
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.15 no.3
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    • pp.481-490
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    • 2002
  • The purpose of this paper is to evaluate the efficiency of various solution techniques and propose new efficient solution techniques for space trusses. Solution techniques used in this study are three load control methods (Newton-Raphson Method, modified Newton-Raphson Method, Secant-Newton Method), two load-displacement control methods(Arc-length Method, Work Increment Control Method) and three combined load-displacement control methods(Combined Arc-length Method I , Combined Arc-length MethodⅡ, Combined Work Increment Control Method). To evaluate the efficiency of these solution techniques, we must examine accuracy of their solutions, convergences and computing times of numerical examples. The combined load-displacement control methods are the most efficient in the geometric nonlinear solution techniques and in tracing post-buckling behavior of space truss. The combined work increment control method is the most efficient in tracing the buckling load of spate trusses with high degrees of freedom.

A new model for T-shaped combined footings part II: Mathematical model for design

  • Luevanos-Rojas, Arnulfo;Lopez-Chavarria, Sandra;Medina-Elizondo, Manuel
    • Geomechanics and Engineering
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    • v.14 no.1
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    • pp.61-69
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    • 2018
  • The first part shows the optimal contact surface for T-shaped combined footings to obtain the most economical dimensioning on the soil (optimal area). This paper presents the second part of a new model for T-shaped combined footings, this part shows a the mathematical model for design of such foundations subject to axial load and moments in two directions to each column considering the soil real pressure acting on the contact surface of the footing with one or two property lines restricted, the pressure is presented in terms of an axial load, moment around the axis "X" and moment around the axis "Y" to each column, and the methodology is developed using the principle that the derived of the moment is the shear force. The classic model considers an axial load and a moment around the axis "X" (transverse axis) applied to each column, i.e., the resultant force from the applied loads is located on the axis "Y" (longitudinal axis), and its position must match with the geometric center of the footing, and when the axial load and moments in two directions are presented, the maximum pressure and uniform applied throughout the contact surface of the footing is considered the same. To illustrate the validity of the new model, a numerical example is presented to obtain the design for T-shaped combined footings subjected to an axial load and moments in two directions applied to each column. The mathematical approach suggested in this paper produces results that have a tangible accuracy for all problems.

Damage Effects on the Ultimate Strength of Offshore Tubular Members (해양구조물 원통부재의 최종강도에 대한 손상의 영향)

  • Paik, Jeom-Ki;Shin, Byung-Cheon
    • Journal of Ocean Engineering and Technology
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    • v.3 no.2
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    • pp.577-577
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    • 1989
  • In this paper, a detail evaluation of ultimate strength of offshore unstiffened tubular members with bending and local denting damage which are subjected to combined axial force and bending moment and to component load is presented through theoretical and experimental approaches. Based upon the results obtained here, the damage effect on the ultimate strength of tubular member under combined loads and component load is investigated.

Damage Effects on the Ultimate Strength of Offshore Tubular Members (해양구조물 원통부재의 최종강도에 대한 손상의 영향)

  • Paik, Jeom-Ki;Shin, Byung-Cheon
    • Journal of Ocean Engineering and Technology
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    • v.3 no.2
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    • pp.77-86
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    • 1989
  • In this paper, a detail evaluation of ultimate strength of offshore unstiffened tubular members with bending and local denting damage which are subjected to combined axial force and bending moment and to component load is presented through theoretical and experimental approaches. Based upon the results obtained here, the damage effect on the ultimate strength of tubular member under combined loads and component load is investigated.

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A Study on the Radiation and Convection Component Separated from Surface Combined Heat Transfer Coefficient on Dynamic Heat Load Simulation (표면 열전달율의 복사.대류성분 분리와 비정상 열부하 계산에 관한 연구)

  • Kim, Young-Tag;Choi, Chang-Ho
    • Journal of the Korean Solar Energy Society
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    • v.25 no.3
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    • pp.1-9
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    • 2005
  • The purpose of this paper was to analyze the influence of radiation and convection component separated from surface heat combined transfer coefficient on dynamic Heat load simulation. In general, it was not considered the mutual radiation of walls that heat load simulation calculated by surface combined heat transfer coefficient. In order to solve this problem, we had developed new simulation program to calculate radiation heat transfer and convection heat transfer respectively, and verified the influence of radiation component with this new program, in indoor heat transfer process.

Limit Loads for Pipe Bends under Combined Pressure and in-Plane Bending Based on Finite Element Limit Analysis (압력과 모멘트의 복합하중을 받는 곡관에 대한 유한요소 한계하중 해석)

  • Oh Chang-Sik;Kim Yun-Jae
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.30 no.5 s.248
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    • pp.505-511
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    • 2006
  • In the present paper, approximate plastic limit load solutions fur pipe bends under combined internal pressure and bending are obtained from detailed three-dimensional (3-D) FE limit analyses based on elastic-perfectly plastic materials with the small geometry change option. The present FE results show that existing limit load solutions for pipe bends are lower bounds but can be very different from the present FE results in some cases, particularly for bending. Accordingly closed-form approximations are proposed for pipe bends under combined pressure and in-plane bending based on the present FE results. The proposed limit load solutions would be a basis of defective pipe bends and be useful to estimate non-linear fracture mechanics parameters based on the reference stress approach.