• Title/Summary/Keyword: equivalent linear model

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Development of Environmental Load Calculation Method for Airport Concrete Pavement Design (공항 콘크리트 포장 설계를 위한 환경하중 산정방법 개발)

  • Park, Joo-Young;Hong, Dong-Seong;Kim, Yeon-Tae;Jeong, Jin-Hoon
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.33 no.2
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    • pp.729-737
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    • 2013
  • The environmental load of concrete pavement can be categorized by temperature and moisture loads, which mean temperature distribution, and drying shrinkage and creep in the concrete slab. In this study, a method calculating the environmental load essential to mechanistic design of airport concrete pavement was developed. First, target area and design slab thickness were determined. And, the concrete temperature distribution with slab depth was predicted by a pavement temperature prediction program to calculate equivalent linear temperature difference. The concrete drying shrinkage was predicted by improving an existing model to calculate differential shrinkage equivalent linear temperature difference considering regional relative humidity. In addition, the stress relaxation was considered in the drying shrinkage. Eventually, the equivalent linear temperature difference due to temperature and the differential shrinkage equivalent linear temperature difference due to moisture were combined into the total equivalent linear temperature difference as terminal environmental load. The environmental load of eight civilian and two military airports which represent domestic regional weather conditions were calculated and compared by the method developed in this study to show its application.

Equivalent linearization of a Friction Damper and Brace System (마찰감쇠기-가새 시스템의 등가선형화 기법에 관한 연구)

  • Min, Kyung-Won;Park, Ji-Hun;Kim, Dae-Hyun;Kim, Hyung-Seop;Moon, Byoung-Wook;Kang, Sang-Hoon
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2005.05a
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    • pp.750-753
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    • 2005
  • An equivalent linearization technique based on Rayleigh peak distribution for friction damper and brace system (FDBS) under stochastic excitation is proposed. For verification, shaking table test of a small scale 3-story building model with the FDBS is conducted for various slip moment levels. Using experimental result, equivalent linearization of the FDBS is conducted based on Rayleigh peak distribution, which is compared with measured peak distribution. For comparative study, model updating technique is applied based on identified modal properties. Finally, complex modal analysis and time history analysis for the obtained equivalent linear systems are conducted and compared with experimental result

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Damping updating of a building structure installed with an MR damper

  • Woo, Sung-Sik;Lee, Sang-Hyun
    • Smart Structures and Systems
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    • v.12 no.6
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    • pp.695-705
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    • 2013
  • The purpose of this paper is to identify through experiments the finite element (FE) model of a building structure using a magnetorheological (MR) fluid damper. The FE model based system identification (FEBSI) technique evaluates the control performance of an MR damper that has nonlinear characteristics as equivalent linear properties such as mass, stiffness, and damping. The Bingham and Bouc-Wen models were used for modeling the MR damper and the equivalent damping increased by the MR damper was predicted by applying an equivalent linearization technique. Experimental results indicate that the predicted equivalent damping matches well with the experimentally obtained damping.

Earthquake Response Analysis at Port Island during the 1995 Hyogoken-nanbu Earthquake(Japan) (일본 한신 대지진에 있어서의 포트 아일랜드의 지진응답해석)

  • 황성춘
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2000.04a
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    • pp.477-484
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    • 2000
  • Earthquake response analyses are conducted for the investigation of the ground shaking during the 1995 Hyogoken-nambu earthquake. Port Island a man made island with about 8{{{{ KAPPA m^2 }} area is chosen for this purpose Because earthquake measurement with vertical array was conducted there. Strain dependent characteristics of soil can be modeled well into Hardin-Drnevich Model. Four analyses are conducted : total stress analysis by equivalent linear method non-linear method. and two effective stress analyses. All analyses except equivalent linear analysis show fairy good agreement with observed record mainly because the non-linear behavior of Holocene clay layer has predominant effect on the behavior of fill, However detailed investigation show that effective stress analyses give much better prediction than total stress analyses.

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The Characteristic Analysis of Vector Control in a Linear Induction Motor Considering Static and Dynamic End Effects (정적 및 동적 단부효과를 고려한 선형 유도 전동기의 벡터제어 특성해석)

  • Kim, Dae-Gyeong;Gwon, Byeong-Il;U, Gyeong-Il
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.51 no.8
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    • pp.413-424
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    • 2002
  • Recently, in the linear motion system, high performances are required In dynamic characteristics. Vector control method is capable of instantaneous thrust control can meet these high performance requirements. Linear induction motor(LIM) have static and dynamic end effects due to its finite core length, so that per-phase impedances are asymmetric and an air gap flux distribution is distorted. These points of the d-q axis equivalent circuit model considering both end effects is more complicated. This paper proposes the d-q axis equivalent circuit and the vector control method considering both static and dynamic end effects of the LIM. As a result, it is shown that the results of the equivalent circuit method(ECM) have a good agreement with those of the finite element method(FEM).

Comparative Studies between Prediction for a Building Structure with MR Damper using Linearization Technique and Experimental System Identification (선형화 기법에 기반한 MR 감쇠기가 설치된 건물의 동적모델 예측과 시스템식별 실험결과의 비교연구)

  • 이상현;민경원;이명규
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2004.10a
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    • pp.323-330
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    • 2004
  • The purpose of this paper is to experimentally identify the finite element (FE) model of a building structure with magnetorheological (MR) fluid damper. Using FE model based system identification (FEBSI) technique, The model of MR damper having nonlinear characteristics is expressed with equivalent linear properties such as mass, stiffness, and damping. Bingham model is used for MR damper modeling. The equivalent stiffness and damping matrices of MR damper are predicted by applying an equivalent linearization technique, and those values are compared with the experimentally obtained ones.

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External Electrode Fluorescent Lamp Model Based on the Equivalent Resistance and Capacitance Variation

  • Cho, Kyu-Min;Oh, Won-Sik;Moon, Gun-Woo;Park, Mun-Soo;Lee, Sang-Gil;Kim, Min-Gyu
    • 한국정보디스플레이학회:학술대회논문집
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    • 2006.08a
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    • pp.1263-1266
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    • 2006
  • A circuit model simulating the electrical characteristics of EEFL(External Electrode Fluorescent Lamp) is proposed. The model is based on linear approximation that represents the equivalent resistance and capacitance as a function of power. Simulation waveforms and experimental results are presented to verify feasibility of the equivalent model.

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Construction of T-S Fuzzy Model for Nonlinear Systems (비선형 시스템에 대한 T-S 퍼지 모델 구성)

  • 정은태;권성하;이갑래
    • Journal of Institute of Control, Robotics and Systems
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    • v.8 no.11
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    • pp.941-947
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    • 2002
  • Two methods of constructing T-S fuzzy model which is equivalent to a given nonlinear system are presented. The first method is to obtain an equivalent T-S fuzzy model by using the sum of linearly independent scalar functions with constant real matrix coefficients. The sum of products of linearly independent scalar functions is used in the second method. The former method is to formulate the procedures of T-S fuzzy modeling dealt in many examples of previous publications; the latter is a new method. By comparing the number of linearly independent functions used in the two methods, we can easily find out which method makes fewer rules than the other. The nonlinear dynamics of an inverted Pendulum on a cart is used as an equivalent T-5 fuzzy modeling example.

Multi-scale heat conduction models with improved equivalent thermal conductivity of TRISO fuel particles for FCM fuel

  • Mouhao Wang;Shanshan Bu;Bing Zhou;Zhenzhong Li;Deqi Chen
    • Nuclear Engineering and Technology
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    • v.55 no.3
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    • pp.1140-1151
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    • 2023
  • Fully Ceramic Microencapsulated (FCM) fuel is emerging advanced fuel material for the future nuclear reactors. The fuel pellet in the FCM fuel is composed of matrix and a large number of TRistructural-ISOtopic (TRISO) fuel particles which are randomly dispersed in the SiC matrix. The minimum layer thickness in a TRISO fuel particle is on the order of 10-5 m, and the length of the FCM pellet is on the order of 10-2 m. Hence, the heat transfer in the FCM pellet is a multi-scale phenomenon. In this study, three multi-scale heat conduction models including the Multi-region Layered (ML) model, Multi-region Non-layered (MN) model and Homogeneous model for FCM pellet were constructed. In the ML model, the random distributed TRISO fuel particles and coating layers are completely built. While the TRISO fuel particles with coating layers are homogenized in the MN model and the whole fuel pellet is taken as the homogenous material in the Homogeneous model. Taking the results by the ML model as the benchmark, the abilities of the MN model and Homogenous model to predict the maximum and average temperature were discussed. It was found that the MN model and the Homogenous model greatly underestimate the temperature of TRISO fuel particles. The reason is mainly that the conventional equivalent thermal conductivity (ETC) models do not take the internal heat source into account and are not suitable for the TRISO fuel particle. Then the improved ETCs considering internal heat source were derived. With the improved ETCs, the MN model is able to capture the peak temperature as well as the average temperature at a wide range of the linear powers (165 W/cm~ 415 W/cm) and the packing fractions (20%-50%). With the improved ETCs, the Homogenous model is better to predict the average temperature at different linear powers and packing fractions, and able to predict the peak temperature at high packing fractions (45%-50%).

Analysis of the Actuator Winding to a Frequency Characteristic based on Energy Conversion Theory (에너지 변환 이론에 의한 액추에이터 권선부의 주파수 특성 해석에 관한 연구)

  • 김양호;이해경;황석영
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.18 no.4
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    • pp.83-87
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    • 2004
  • In this paper, an electrical equivalent circuit is derived by solving system equations. A frequency characteristics graph is calculated and the characteristics curve of the linear Actuator Model System are simulated by the Matlab program The frequency characteristics of a linear actuator are analyzed on the structure of the linear Actuator Model System This paper proposed and analyzed the linear Actuator Model(LAM) by using Matlab program with linear actuator was verified computer simulation based on the energy conversion theory.