• 제목/요약/키워드: Strain calculation

검색결과 351건 처리시간 0.022초

단일겹침 접착제 접합부의 응력분포와 강도평가 (Stress Distribution and Strength Evaluation of Adhesive Bonded Single-lap Joints)

  • 이중삼;임재규;김연직
    • Journal of Welding and Joining
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    • 제19권3호
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    • pp.342-347
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    • 2001
  • Recently, adhesive-bonding technique is wifely used in manufacturing structures. Stress and strain analysis of joints are essential to design adhesive-bonded joints structure. The single-lap adhesive joint is the design dominating the range of adhesive joints. In this study, single-lap specimens with different joint dimensions were used for the tensile-shear test and finite element calculation in of order to investigate the effect of overlap length and adhesive-bonding thickness on adhesive strength and stress distribution of the joints. Consequently, it was found that overlap lap size and thickness can be important parameters of structure joints using adhesive bonding, which is effected on adhesive strength.

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용접구조물의 변형 최소화를 위한 최적 용접순서의 해석적 방법 (Analytical Methodology Obtaining an Optimal Welding Sequence for Least Distortion of Welded Structure)

  • 하윤석
    • Journal of Welding and Joining
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    • 제31권3호
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    • pp.54-59
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    • 2013
  • Several methodologies analyzing welding distortions of large shell structures like ship blocks have been developed and utilized in shipyards for a long times ago. In general, one of objects of thermal distortion analysis is to find welding sequence making least-deformation without any suppliance, and it can be solved easily and rapidly by EP strain-boundary method. But after assembly construction, there are usually more than 10 weldments in each process, and the number of sequence will follow the Factorial calculation. In this research, a method has been suggested to decide the best welding sequence by minimum analysis. Using this method, welding deformation could be reduced just analyzing some cases as many as the number of weldments. Experiments and Analysis of all cases were also done, and their best results are good agreements with predictation by suggested methodology.

축 대칭 전방 압출의 극한 해석 (Limit Analysis of Axisymmetric Forward Extrusion)

  • 김병민;최인근;최재찬;이종수
    • 한국정밀공학회지
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    • 제8권3호
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    • pp.93-104
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    • 1991
  • Limit analysis is based on the duality theorem which equates the least upper bound to the greatest lower bound. In this study, limit analysis of axisymmetric forming problem with workhardening materials is formulated by minimizing the upper bound functional and finite element program is developed for forward estrusion. Limit loads, velocity and flow line fields are directly obtained under various process conditions and deformation characteristics such as strains, strain rates and grid distortion are obtained from the optimum velocity components by numerical calculation. The experimental observation was carried out for extrusion and compared with computed results. The good agreement between theoretical and experimental results is shown that the developed programming is very effective for the analysis of axisymmetric extrusion.

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Dynamic simulation models for seismic behavior of soil systems - Part I: Block diagrams

  • Sahin, Abdurrahman
    • Geomechanics and Engineering
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    • 제9권2호
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    • pp.145-167
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    • 2015
  • Digital simulation has recently become the preferred method for designing complex and dynamic systems. Simulation packages provide interactive, block-diagram environment for modeling and simulating dynamic models. The block diagrams in simulation models are flowcharts which describe the components of dynamic systems and their interaction. This paper is the first part of the study for determining the seismic behavior of soil systems. The aim of this part is to present the constructed block diagrams for discrete-time analysis of seismic site amplification in layered media for vertically propagating shear waves. Detailed block diagrams are constructed for single and multiple soil layers by considering wave propagation with and without damping, respectively. The block diagrams for recursive filter to model attenuation in discrete-time form are also constructed. Finite difference method is used for strain calculation. The block diagrams are developed by utilizing Simulink which is a software add-on to Matlab.

반복하중을 받는 철근콘크리트 기둥의 비선형 거동 (Nonlinear Behavior of RC Columns Subjected to Cyclic Loadings)

  • 곽효경;김선필
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2002년도 가을 학술발표회 논문집
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    • pp.475-482
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    • 2002
  • A moment-curvature relationship to simulate the behavior of reinforced concrete (RC) columns under cyclic loading is introduced. Unlike previous moment4curvature models and the layered section approach, the proposed model takes into account the bond-slip effect by using a monotonic moment-curvature relationship constructed on the basis of the bond-slip relation and corresponding equilibrium equation at each nodal point. In addition, the use of curved unloading and reloading branches inferred from the stress-strain relation of steel gives more exact numerical result. The pinching effect caused by axial force is considered with an assumption that the absorbing energy corresponding to any deformation level maintains constant regardless of the magnitude of applied axial lone. The advantages of the proposed model, comparing to layered section approach, may be on the reduction in calculation time and memory space in case of its application to large structures. Finally, correlation studies between analytical result and experimental studies are conducted to establish the validity of the proposed model.

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음극 인가전위 하에서 type 2205과 type 316L의 수소취성 저항성 (Comparison of hydrogen embrittlement resistance between 2205 duplex stainless steels and type 316L austenitic stainless steels under the cathodic applied potential)

  • 서동일;이재봉
    • Corrosion Science and Technology
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    • 제15권5호
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    • pp.237-244
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    • 2016
  • 2205 duplex stainless steels have been used for the construction of the marine environment, because of their excellent corrosion resistance and high strength. However, the resistance to hydrogen embrittlement (HE) may be less than that of 316L austenitic stainless steel. The reason why 316L stainless steels have better resistance to HE is associated with crystal structure (FCC, face centered cubic) and the higher stacking faults energy than 2205 duplex stainless steels. Furthermore 2205 stainless steels with or without tungsten were also examined in terms of HE. 2205 stainless steels containing tungsten is less resistible to HE. It is because dislocation tangle was formed in 2205 duplex stainless steels. Slow strain-rate tensile test (SSRT) was conducted to measure the resistance to HE under the cathodic applied potential. Hydrogen embrittlement index (HEI) was used to evaluate HE resistance through the quantitative calculation.

기하학적 정보를 이용한 이중곡률 형상의 레이저 성형 (Laser Forming of Sheet Metal by Geometrical Information)

  • 김지태;나석주
    • 대한용접접합학회:학술대회논문집
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    • 대한용접접합학회 2005년도 춘계학술발표대회 개요집
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    • pp.91-93
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    • 2005
  • Forming sheet metal by laser-induced thermal stresses (laser forming) has been extensively studied, and the research has focused on two-dimensional geometries using a multi-pass straight line scan. Recently there came out some useful studies or three-dimensional laser forming which is applied to doubly curved shapes. The task of 3D laser forming sheet metal is to determine a set of process parameters such as laser scanning paths, laser power and scanning speed that will make a given shape. New method for laser forming of a doubly curved surface by using geometrical information was proposed and verified by experiments. This method shows good performance in the sense of calculation time and accuracy compared to the inherent strain method.

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Construction and Application of Experimental Formula for Nonlinear Behavior of Ferroelectric Ceramics Switched by Electric Field at Room Temperature during Temperature Rise

  • Ji, Dae Won;Kim, Sang-Joo
    • 한국세라믹학회지
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    • 제55권1호
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    • pp.67-73
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    • 2018
  • A poled lead zirconate titanate (PZT) cube specimen that is switched by an electric field at room temperature is subject to temperature increase. Changes in polarization and thermal expansion coefficients are measured during temperature rise. The measured data are analyzed to obtain changes in pyroelectric coefficient and strain during temperature change. Empirical formulae are developed using linear or quadratic curve fitting to the data. The nonlinear behavior of the materials during temperature increase is predicted using the developed formulae. It is shown that the calculation results can be compared successfully with the measured values, which proves the accuracy and reliability of the developed formulae for the nonlinear behavior of the materials during temperature changes.

인버터로 구동되는 유도전동기의 정수 및 특성에 관한 연구 (A Study on the Parameters and Characteristics of Induction Motor driven by Inverter)

  • 전내석;김종윤;박찬근;엄상오;이성근;김윤식
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2000년도 하계학술대회 논문집 B
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    • pp.1111-1113
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    • 2000
  • This paper presents the calculation method for the equivalent-circuit parameters and torque characteristics of squirrel-cage induction motors. The measurement of motor parameters were calculated by the stator resistance test, the blocked rotor test and no load test to T type equivalent-circuit. Especially, this paper describes the test results obtained by using hall sensor and strain gauge for the current and torque characteristics of induction motors. Three-phase squirrel-cage induction motor which has 1[hp] was used to the test and the parameters obtained by the test were compared with the maker parameters.

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모멘트-곡률 관계에 기초한 반복하중을 받는 철근콘크리트 보의 비선형 해석 (Nonlinear Analysis of RC Beams under Cyclic Loading Based on Moment-Curvature Relationship.)

  • 곽효경;김선필
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2000년도 가을 학술발표회논문집
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    • pp.190-197
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    • 2000
  • A moment-curvature relationship to simulate the behavior of reinforced concrete beam under cyclic loading is introduced. Unlike previous moment-curvature models and the layered section approach, the proposed model takes into consideration the bond-slip effect by using monotonic moment-curvature relationship constructed on the basis of the bond-slip relation and corresponding equilibrium equation at each nodal point. In addition, the use of curved unloading and reloading branches inferred from the stress-strain relation of steel gives more exact numerical result. The advantages of the proposed model, comparing to layered section approach, may be on the reduction in calculation time and memory space in case of its application to large structures. The modification of the moment-curvature relation to reflect the fixed-end rotation and pinching effect is also introduced. Finally, correlation studies between analytical results and experimental studies are conducted to establish the validity of the proposed model.

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