• Title/Summary/Keyword: Design parameter

Search Result 871, Processing Time 0.121 seconds

Prediction of Changed Design Parameter of Proportional Damping Structure by Using Modified Dynamic Characteristics (동특성 변화를 이용하여 비례감쇠 구조물의 변경된 설계파라미터 예측)

  • Lee, Jung-Youn
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.34 no.7
    • /
    • pp.873-879
    • /
    • 2010
  • It is common to predict structural dynamic design parameters due to the change of design parameter, but to predict the amount of changed design parameter where the mass and stiffness are being modified are rarely found in previous literature. In this study, the changed design parameter in a proportional damping system is predicted by using sensitivity coefficients and an iterative method. The sensitivity coefficients are determined from the changes in eigenvectors; these changes are due to modification. This method is applied to a three-story shear structure. To validate the prediction of the changed design parameter, the results are compared to the reanalysis results; both results are in good agreement.

Design-Parameter Computation of Subsurface Investigation Profile on Probability Method (확률론적 방법에 의한 지반조사 자료의 설계정수 산정)

  • 신은철;김종인;이준철
    • Proceedings of the Korean Geotechical Society Conference
    • /
    • 2003.03a
    • /
    • pp.833-840
    • /
    • 2003
  • The stability of structure, effectiveness of design and construction are very important factors in soil-structure design. The design-parameter is based on the test through laboratory-test and field-test. There are two ways to obtain the design-parameter. One is to through test, and the other is through relative documents and references. Recently, statistics has been used to get reliable data. In this study, Kriging method as Geostatistics and the theory of Bayesian's inference are used and the design-parameters are obtained. As the result of this study to the design-parameter is reliable and information about soil condition and soil properties in design and construction is easily found.

  • PDF

Calculation of Design parameter of Si3N4 for Engineering part through the Measurement of Tensile strength (인장강도 시험을 통한 질화규소 소재의 설계계수 계산)

  • Choi, Young-Min;Lee, Jae-Do;Ko, Jun
    • Journal of the Korean Ceramic Society
    • /
    • v.33 no.6
    • /
    • pp.709-717
    • /
    • 1996
  • Design parameter of Si3N4 for engineering part could be calculated through the measurement of tensile strength with cylindrical specimen($\Phi$=7.15, ι=110mm) Relative densities of Si3N4 test specimen prepared by pressure-less sintering (PLS) and sinter/HIP were 98.5 and 99.2% respectively. Tensile strength of Si3N4 was 378 MPa for PLS and 509 MPa for sinter/HIP. By the Weibull statistic Design parameter such as Weibull modulus m=8-12 could be calcuated. Fracture strength of Si3N4 related to volume could be effectively pridicted by using Weibull theory.

  • PDF

Derivation of Design Parameter for Heat Regenerator with Spherical Particles (구형축열체를 이용한 축열기의 설계인자도출)

  • Cho, Han-Chang;Cho, Kil-Won;Lee, Yong-Kuk
    • Transactions of the Korean Society of Mechanical Engineers B
    • /
    • v.27 no.10
    • /
    • pp.1412-1419
    • /
    • 2003
  • Heat regenerator occupied by regenerative materials improves thermal efficiency of combustion system through the recovery of sensible heat of exhaust gases. By using one-dimensional two-phase fluid dynamics model, the unsteady thermal flow of regenerator with spherical particles, was numerically analyzed to evaluate the heat transfer and pressure losses and to derive the design parameter for heat regenerator. It is confirmed that the computational results, such as air preheat temperature, exhausted gases outlet temperature, and pressure losses, agreed well with the experimental data. The thermal flow in heat regenerator varies with porosity, configuration of regenerator and diameter of regenerative particle. As the gas velocity increases with decreasing the cross-sectional area of the regenerator, the heat transfer between gas and particle enhances and pressure losses decrease. As particle diameter decreases, the air is preheated higher and the exhaust gases are cooled lower with the increase of pressure losses. Assuming a given exhaust gases temperature at the regenerator outlet, the regenerator need to be linearly lengthened with inlet Reynolds number of exhaust gases, which is defined as a regenerator design parameter.

Development of Analysis Model and Sensitivity Analysis for High-Power Hydraulic Drifter Design (고출력 유압 드리프터 설계를 위한 해석모델 개발 및 민감도 분석)

  • Noh, Dae-Kyung;Lee, Dae-Hee;Yun, Joo-Seop;Lee, Dong-Won
    • Journal of the Korea Society for Simulation
    • /
    • v.27 no.2
    • /
    • pp.11-24
    • /
    • 2018
  • The purpose of the present study is to develop an analysis model to analyze the design parameter sensitivity of a high-power drifter suitable for implementation in Korean hydraulic drills. This study aims to establish a basis for the optimization of the impact performance and stability of a high-power drifter by investigating the effects of each design parameter on the impact performance via design parameter sensitivity analysis. To begin, an analysis model of drifter dynamics is developed, and the reliability of the analysis model is verified by comparing the analysis results to the experimental results. The drifter is then redesigned for compatibility with Korean hydraulic drills. Finally, design parameter sensitivity analysis of the redesigned drifter is conducted to determine the effects of the design parameters on the impact performance, and to extract the high-sensitivity parameters. SimulationX, which is multi-physics analysis software, is used to develop the analysis model, and EasyDesign is employed for design parameter sensitivity analysis.

Analytical Study on Inner Flow and Structural Stiffness in Vane Type of Vacuum Pump (베인형 진공펌프의 내부유동과 구조 강성에 관한 해석적 연구)

  • Son, Taekwan
    • Transactions of the Korean Society of Automotive Engineers
    • /
    • v.25 no.2
    • /
    • pp.201-206
    • /
    • 2017
  • In the study, the inner flow characteristics were analyzed by modifying the inner design parameter of the vane-type vacuum pump. The effect of pressure generated by the inner flow of pump on the rotor and vane was analyzed. The design parameter was analyzed using the angle variation of tilting and rotation of the vane. MRF was used for the analysis conducted using a virtual condition where the rotor and vane are rotated. The pressure gained from the load of the rotor and vane in the flow analysis is used for the structure analysis. Based on the results, the effect of variable vane design was revealed in structural strength. The effect of centrifugal and friction force generated during pump operation on structural strength was also analyzed.

Robust Design of Composite Structure under Combined Loading of Bending and Torsion (굽힘-비틀림 복합하중을 받는 복합재료 구조물의 최적 강건 설계)

  • Yun, Ji-Yong;O, Gwang-Hwan;Nam, Hyeon-Uk;Han, Gyeong-Seop
    • Proceedings of the Korean Society For Composite Materials Conference
    • /
    • 2005.11a
    • /
    • pp.211-214
    • /
    • 2005
  • This research studied robust design of composite structure under combined loading of bending and torsion. DOE (Design of Experiment) technique was used to find important design factors. The results show that the beam height, beam width, layer thickness and stack angle of outer-layer are important design parameter. The $2^{nd}$ DOE and RSM (Response Surface Model) were conducted to obtain optimum design. Multi-island genetic algorithm was used to optimum design. An approximate value of 6.65 mm in deflection was expected under optimum condition. Six sigma robust design was conducted to find out guideline for control range of design parameter. To acquire six sigma level reliability, the sigma level reliability, the standard deviation of design parameter should be controlled within 2.5 % of average design value.

  • PDF

A Study on the Performance Improvement of a Nonlinear Fuzzy PID Controller (비선형 퍼지 PID 제어기의 성능 개선에 관한 연구)

  • 김인환;이병결;김종화
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.27 no.7
    • /
    • pp.852-861
    • /
    • 2003
  • In this paper, in order to improve the disadvantages of the fixed design-parameter fuzzy PID controller. a new fuzzy PID controller named a variable design-parameter fuzzy PID controller is suggested. The main characteristic of the suggested controller is to adjust design-parameters of the controller by comparing magnitudes between fuzzy controller inputs at each sampling time when controller inputs are measured. As a result. all fuzzy input partitioned spaces converge within a time-varying normalization scale. and the resultant PID control action can always be applied precisely regardless of operating input magnitudes. In order to verify the effectiveness of the suggested controller. several a computer simulations for a nonlinear system are executed and the control parameters of the variable design-parameter fuzzy PID controller are throughly analyzed.

Design Impact evaluation through CFB Boiler Design Parameter and Lower Furnace Fraction of Combustion Heat (순환 유동상 연소로 설계 인자 및 하부 연소율에 따른 설계 영향 평가)

  • Yang, Jongin;Kim, Taehyun;Choi, Sangmin
    • 한국연소학회:학술대회논문집
    • /
    • 2012.04a
    • /
    • pp.41-42
    • /
    • 2012
  • Circulating fludized bed(CFB) furnace which can use a variety of low-grade fuels because of high heat capacity and good mixing characteristic in its furnace have turned out to be effective system. There is no many research to design CFB boiler in korea. thus, we feel necessity to research design method. So far accurate hydrodynamics and combustion mechanism information in CFB furnace has been lacked. Therefore, design method that derives design parameter is being made. so, this study is aimed to derive design parameters of CFB furnace from heat and mass balance by using existing plant data.

  • PDF

New State Feedback Control for Series Resonant Converter (직렬공진형 컨버터의 새로운 상태궤환 제어)

  • 조일권;김만고;이대식;윤명중
    • The Transactions of the Korean Institute of Electrical Engineers
    • /
    • v.39 no.8
    • /
    • pp.828-835
    • /
    • 1990
  • A new state feedback control scheme is proposed to improve the stability and dynamic performances of the series resonant converter (SRC). The proposed scheme can be easily implemented without speed limitation. Design parameter of the proposed control is the ratio of the state feedback gains. A closed loop dynamic modeling for the SRC with the proposed control law is derived. Parametric curves which can be used to select the design parameter in the control system are presented. The experimental results show that the excellent dynamic performance of the converter can be obtained by properly selecting the design parameter. The results are further compared with both the theoretical analysis and the frequency control.

  • PDF