• Title/Summary/Keyword: generated load

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A Study on the Estimation of the Fatigue Life Using the Stress Generated Models in the Steel Railroad Bridges (강철도교의 응력발생모형을 이용한 피로수명 추정에 관한 연구)

  • Yong, Hwan Sun;Kim, Seok Tae;Lee, Seong Soo
    • Journal of Korean Society of Steel Construction
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    • v.8 no.4 s.29
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    • pp.19-29
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    • 1996
  • In this paper, it is presumed that the stress time history was generated by simulation method and investigated compatibility in regard to the reappearance of stress time history. In this procedure, the identified frequency distribution of stress range of the steel railroad bridge varies with the rational values of cut off point and bar width. Thus, we show variable aspect of the equivalent stress range results from change of cut off point and bar width. In addition, we analyze the variable of RMC and RMS model due to the cut off point and bar width of the measured stress history which influencs the prediction of fatigue life in the steel railroad bridge. The simulated stress time history is carried out by the superposition method incorporating the vertical load with rotation moment obtained from the Hermition interpolation function, and compared with developing stress results from measured maxi mum stress. Through this study, we can estimate the remaining fatigue life from a safety point of view and comparative accuracy.

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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
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    • v.25 no.2
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    • pp.201-206
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    • 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.

Design and Analyses of Vibration Driven Electromagnetic Energy Harvester with High Power Generation at Low Frequency (저주파수에서 고출력을 갖는 진동형 전자기식 에너지 하베스터의 설계 및 해석)

  • Chung, Gwiy-Sang;Ryu, Kyeong-Il
    • Journal of Sensor Science and Technology
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    • v.20 no.1
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    • pp.25-29
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    • 2011
  • This paper describes the design and analyses of vibration driven electromagnetic energy harvester with high power generation which is suitable for supplying power generator from human body motion. The proposed harvester consists of magnet, coil, and SM (Soft magnetic Material). In order to generate more induced voltage, the SM to concentrate flux lines from end of magnetic poles was arranged into insert moving magnet. Each model was designed and analyzed by using ANSYS software to simulation. The maximum power is generated when load resistance of $1303\;{\Omega}$ is equal to coil resistance. The generated maximum power of for harvesters with SM is $677.85\;{\mu}W$ and 5.46 times higher than without SM at 6 Hz vibration frequency.

An Advanced Three-Phase Active Power Filter with Adaptive Neural Network Based Harmonic Current Detection Scheme

  • Rukonuzzaman, M.;Nakaoka, Mutsuo
    • Journal of Power Electronics
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    • v.2 no.1
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    • pp.1-10
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    • 2002
  • An advanced active power filter for the compensation of instantaneous harmonic current components in nonlinear current load is presented in this paper. A novel signal processing technique using an adaptive neural network algorithm is applied for the detection of harmonic components generated by three-phase nonlinear current loads and this method can efficiently determine the instantaneous harmonic components in real time. The control strategy of the switching signals to compensate current harmonics of the three-phase inverter is also discussed and its switching signals are generated with the space voltage vector modulation scheme. The validity of this active filtering processing system to compensate current harmonics is substantiated on the basis of simulation results.

Automated Modeling and Structure Analysis of Bellows (벨로우즈 자동 모델링과 구조해석)

  • Lee, Seungwoo;Yang, Chulho
    • Transactions of the Korean Society of Automotive Engineers
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    • v.22 no.7
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    • pp.152-157
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    • 2014
  • Pro-program function of Pro/E has been utilized to expedite the design process of bellows. Design parameters selected for bellows design are manipulated to obtain the shapes user specified. User-oriented function may automate the bellows design process and this function may enable to reduce the design time remarkably. Generated bellows solid model has been applied to study of design sensitivity and optimum design. Among the selected design parameters, thickness of bellows affects system response most. Control-ring installed bellows may reduce the stress and prove to be an effective element for heavy load. The finite element analysis results combined with 3D model generated by pro-program may provide the feasible design directions to the bellows designer.

Technical Trend on Excitation Capacitors on Harmonic Amplification of Wind Induction Generator (풍력 유도발전기의 여자 축전지에 따른 고주파 증폭에 관한 기술 동향)

  • Rho, Sang-Pil;Park, Jung-Seok;Lee, Young-Gil;Choi, Yong-Sung;Lee, Kyung-Sup
    • Proceedings of the KIEE Conference
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    • 2007.07a
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    • pp.1976-1977
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    • 2007
  • This paper introduce the electrical quantities of a three-phase-connected wind induction generator (WIG) under sudden connection of static loads. An intelligent power-system recorder/monitor is employed to measure threephase voltages and currents of the studied system at WIG's terminals and load's terminals for 5 minutes. A laboratory 300 W wound-rotor induction machine driven by a blushless DC motor is utilized as the studied WIG. Since the generated harmonic currents are randomly varied, total harmonic distortion (THD) of current using cumulative probability density function is employed to determine the penetration of harmonic distortion. The results show that the harmonic currents generated by the studied WIG may be severely amplified to a high level by the connected self-excited capacitance at the stator's terminals.

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Study of micro-plastics separation from sea water with electro-magnetic force

  • Nomura, Naoki;Mishima, Fumihito;Nishijima, Shigehiro
    • Progress in Superconductivity and Cryogenics
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    • v.23 no.3
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    • pp.10-13
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    • 2021
  • The method of removing micro-plastics from sea water has been developed using electro-magnetic force. Plastics are difficult to decompose and put a great load on the marine environment. Especially a plastic with a size of 5 mm or less is defined as micro-plastic and are carried by ocean currents over long distances, causing global pollution. These are not easily decomposed in the natural environment. The Lorentz force was generated in simulated sea water and its reaction force was applied to the micro-plastic to control their motion. Lorentz force was generated downward and the reaction force to the plastics was upward. The plastic used in the experiment was polystyrene with a diameter of 6 mm, and the density was 1.07 g/cm3. The polystyrene sphere levitated at the current density of 0.83 A/cm2 and the external field of 0.87T. The particle trajectory calculation was also made to design separation system using superconducting magnet.

Clustering of PV Load Patterns Based on Any Colony Centroid Model

  • Munshi, Amr
    • International Journal of Computer Science & Network Security
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    • v.22 no.5
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    • pp.67-72
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    • 2022
  • There has been a significant growth in global population and industrialization, as a consequence demand for electricity is increasing rapidly and the power systems need to increase the electricity generation. Currently, most of generated electricity is generated from fossil fuels. However, there are many financial and environmental concerns associated with the generation of electricity from such resource. Photovoltaic )PV) solar as a renewable resource is promising. The power output of PV systems is mainly affected by the solar irradiation and ambient temperature. This paper attempts at reducing the burden and improving the accuracy of the extensive simulations related to integrating PV systems into the electrical grid.

Life cycle reliability analyses of deteriorated RC Bridge under corrosion effects

  • Mehmet Fatih Yilmaz
    • Earthquakes and Structures
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    • v.25 no.1
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    • pp.69-78
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    • 2023
  • Life-cycle performance analysis of a reinforced concrete box section bridge was generated. Moreover, Monte Carlo simulation with important sampling (IS) was used to simulate the bridge material and load uncertainties. The bridge deterioration model was generated with the basic probabilistic principles and updated according to the measurement data. A genetic algorithm (GA) with the response surface model (RSM) was used to determine the deterioration rate. The importance of health monitoring systems to sustain the bridge to give services economically and reliably and the advantages of fiber-optic sensors for SHM applications were discussed in detail. This study showed that the most effective loss of strength in reinforced concrete box section bridges is corrosion of the reinforcements. Due to reinforcement corrosion, the use of the bridge, which was examined, could not meet the desired strength performance in 25 years, and the need for reinforcement. In addition, it has been determined that long-term health monitoring systems are an essential approach for bridges to provide safe and economical service. Moreover the use of fiber optic sensors has many advantages because of the ability of the sensors to be resistant to environmental conditions and to make sensitive measurements.

Structural Safety Evaluation of Stabbing System for Pre-Piling Jacket Substructure Considering Pile Construction Errors (파일의 시공오차를 고려한 스태빙시스템의 구조안전성 평가)

  • Youngcheol Oh;Jaeyong Ryoo;Daeyong Lee
    • Journal of Wind Energy
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    • v.14 no.3
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    • pp.109-119
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    • 2023
  • A structural safety evaluation was conducted for the stabbing system for the pre-piling jacket substructure currently being developed in South Korea, considering pile construction errors due to its lateral movement that may occur during construction in the ocean. Based on (1) the maximum stress generated by the stabbing system, (2) the maximum rotational displacement of the guide cone, and (3) the maximum stress generated by the horizontal hydraulic pressure cylinder, the structural safety of the stabbing system was examined under the initial loading condition and three possible load combinations during its construction. In order to evaluate the structural safety of the stabbing system, a concept of stress safety factor (= Yield stress / Max. Von-Mises stress) was used. It was found that the stabbing system considered in this study has a sufficient margin of safety.