• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2007년도 정기 학술대회 논문집
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• pp.283-288
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• 2007

This paper presents an analytical prediction of Nonlinear characteristics of prestressed concrete bridges by strengthened of externally tendon considering the work sequence, using beam-column element based on flexibility method and tendon element. The beam-column element was developed with reinforced concrete material nonlinearities which are based on the smeared crack concept. The fiber hysteresis rule of beam-column element is derived from the uniaxial constitutive relations of concrete and reinforcing steel fibers. The tendon element represent the bonded tendon and unbonded tendon behaviors. Beam-column element and tendon element was be subroutine A computer program, named RCAHEST (Reinforced Concrete Analysis in Higher Evaluation System Technology), for the analysis of RC and PSC structures was used. The proposed numerical method for prestressed concrete structures by strengthened of externally tendon is verified by comparison with reliable experimental results.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1997년도 봄 학술발표회 논문집
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• pp.375-382
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• 1997

In this paper, a unified micromechanics-based model which can be applied to both tensile and compressive member of concrete is suggested and to the analysis of the strain-localization in concrete. From the comparison of the analysis results obtained from different size of concrete members with experimental data, it id shown that the model in this paper can be applied to the analysis of the strain localization concrete. For the finite element analysis of the strain-localization in concrete, the localized zone in concrete under strain localization is modeled as ad plastic model which can consider nonlinear strain softening and the non-localized zone is modeled as a nonlinear elastic-damage model. Using developed finite element analysis program. strain localization behaviors under compressive force for the different sizes of concrete having different sizes of the localized zone are simulated.

• 한국전자통신학회논문지
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• 제7권6호
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• pp.1443-1447
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• 2012

본 논문에서는 수 변전 설비의 열화진단을 위해서 열화상 카메라로 측정한 온도에 대한 시계열 데이터를 타켄스의 매립법을 이용하여 2차원 위상 공간으로 변환하여 패턴 변화에 따른 온도 변화 특성을 살펴보았다. 시뮬레이션 결과 위상 공간에서의 완전한 비선형적인 특성 거동을 확인할 수 없었지만 특정한 패턴을 가지고 있어 앞으로 추가적인 연구를 통한 검증 방법이 요구된다.

• 전기학회논문지
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• 제61권12호
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• pp.1880-1885
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• 2012

Nonlinear dynamical behaviors in thermionic low pressure discharge are investigated using a particle-in-cell(PIC) simulation. An electrostatic PIC code is developed to model the plasma discharge system including the kinetic effects. The elastic collision, excitation collision, ionization collision, and electron-ion recombination collision are considered in this code. The generated electrons and ions are traced to analyze physical characteristics of the plasma. The simulation results show that the nonlinear oscillation structures are observed for cold plasma in the system and the similar structures are observed for warm plasma with a shift in values of the bifurcation parameter. The detailed oscillation process can be subdivided into three distinct mode; anode-glow, temperature-limited, and double-layer modes.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2000년도 가을 학술발표회논문집
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• pp.133-140
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• 2000

A suspension bridge with long span is distinguished by aesthetic point of view, but it is difficult to analyze the structural behaviors due to its geometric nonlinear characteristics. Futhermore, because the chance of design such special bridges is very rare, the assumption of initial dimensions of geometrical shapes and structural sections may be much difficult also. In this paper, the brief data base on the important structural dimensions of suspension bridges is constructed after the informations on existing suspension bridges are collected and classified from various texts and internet web sites. Therefore this data base may be utilized very easily by the designers who tries to design such bridges in the preliminary design step. Also the static geometric nonlinear analysis program is added to assist the designer in simple decision of safety check for assumed dimensions.

• Computers and Concrete
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• 제1권1호
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• pp.77-98
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• 2004

This paper presents a numerical model for simulating the nonlinear response of reinforced concrete (RC) shear walls subject to cyclic loadings. The material behavior of cracked concrete is described by an orthotropic constitutive relation with tension-stiffening and compression softening effects defining equivalent uniaxial stress-strain relation in the axes of orthotropy. Especially in making analytical predictions for inelastic behaviors of RC walls under reversed cyclic loading, some influencing factors inducing the material nonlinearities have been considered. A simple hysteretic stress-strain relation of concrete, which crosses the tension-compression region, is defined. Modification of the hysteretic stress-strain relation of steel is also introduced to reflect a pinching effect depending on the shear span ratio and to represent an average stress distribution in a cracked RC element, respectively. To assess the applicability of the constitutive model for RC element, analytical results are compared with idealized shear panel and shear wall test results under monotonic and cyclic shear loadings.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 추계 학술발표회 제16권2호
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• pp.425-428
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• 2004

Nonlinear finite element analysis is conducted to predict the structural behavior of precast concrete column and steel beam connected by using bolted connections. The Nonlinear FEM program is based on the modified compression field theory which has good accuracy in the concrete structures. The link element is properly used to model the discontinuity between precast concrete column and steel beam. Predictions from the proposed model are compared with experimental results and it is concluded that structural behaviors of the composite structures, such as strength capacity, crack pattern and failure mode, can be predicted quite successfully.

• Journal of Advanced Marine Engineering and Technology
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• 제23권2호
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• pp.150-158
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• 1999

The process of designing protective circuits against damage by transient overvoltages requires much work and expensive equipment. However computer simulation using PSpice can overcome these problems. In this paper a gas tube and a ZnO varistor Pspice-model considering the steepness of the wave-front were presented. The effects of various waveforms on the transient behaviors and firing volt-ages of a gas tube were modeled by controlled voltage source E controlled current source G and TABLE function of PSpice. And the nonlinear characteristics of a ZnO varistor were modeled by controlled voltage source E and H. To estimate the characteristics of the models proposed various waveforms specified in IEC Std. 1000310-4-5 were used in the simulation and the actual tests. The simulation results were compared with test results and showed good agreement.

• International Journal of Naval Architecture and Ocean Engineering
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• 제12권1호
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• pp.902-909
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• 2020

It is announced a new procedure for the real-time overall hull response monitoring system depends on inclinometer sensor data. The procedure requires a few inclinometer sensors' data, located on the deck. Sensor data is used to obtain curvature values; and curvature values are used to find out displacements or relevant moment values according to pre-calculated moment-curvature diagrams. Numerical studies are demonstrated with reasonable accuracy for the pre-ultimate and the post-ultimate nonlinear behaviors. Elastic, inelastic, and post-collapse structural bending moment capacity determination of the hull has been presented. The proposed inverse engineering technique will be able to see the response of the hull in real-time with high accuracy to manage the course and speed when cruising or control the loading and the unloading process at the port.

• 반도체디스플레이기술학회지
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• 제21권3호
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• pp.135-139
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• 2022

The current-voltage modeling plays an important role in characterizing photovoltaic systems. A solar cell has a nonlinear characteristic with various parameters influenced by the external environments such as the irradiance and the temperature. In order to accurately predict current-voltage characteristics at low irradiance, the artificial neural networks are applied to effectively quantify nonlinear behaviors. In this paper, a multi-layer perceptron scheme that can make accurate predictions is employed to learn complex formulas for large amounts of continuous data. The simulated results of artificial neural networks model show the accuracy improvement by using MATLAB/Simulink.