• 제목/요약/키워드: static characteristics

검색결과 2,608건 처리시간 0.03초

이차원 소자 시뮬레이터를 이용한 비정질 실리콘 에너지대에 관한 연구 (A Study on the Energy Band of Amorphous Silicon using a Two-Dimensional Device Simulator(TFT2DS))

  • 곽지훈;이영삼;최종선
    • 한국전기전자재료학회:학술대회논문집
    • /
    • 한국전기전자재료학회 1997년도 추계학술대회 논문집
    • /
    • pp.325-327
    • /
    • 1997
  • TFT2DS was developed to provide the usability as an analytic and design tool. The static characteristics of a-Si TFTs demonstrated a good agreement between simulated and measured data. This paper shows that WDS can optimize the physical parameters of a-Si through sensitivity simulations and compute the static characteristics of a-Si TFTs.

  • PDF

전자기 전달관계 해석 기법을 이용한 슬롯리스형 BLDC 전동기의 정특성 해석 (Analysis on Static Characteristics of Slotless BLDC Motor using the Transfer Relations Methodology)

  • 장석명;조한욱;최장영;유대준;이성호
    • 대한전기학회:학술대회논문집
    • /
    • 대한전기학회 2005년도 제36회 하계학술대회 논문집 B
    • /
    • pp.1297-1299
    • /
    • 2005
  • This paper deals with the static analysis of slotless BLDC motor. The transfer relations methodology is employed for predicting the electromagnetic characteristics, with reference to the magnetic field distribution.

  • PDF

Effect of Geometrical Discontinuity on Ductile Fracture Initiation Behavior under Static Leading

  • An, G.B.;Ohata, M.;Toyoda, M.
    • International Journal of Korean Welding Society
    • /
    • 제3권1호
    • /
    • pp.51-56
    • /
    • 2003
  • It is important to evaluate the fracture initiation behaviors of steel structure. It has been well known that the ductile cracking of steel would be accelerated by triaxial stress state. Recently, the characteristics of critical crack initiation of steels are quantitatively estimated using the two-parameters, that is, equivalent plastic strain and stress triaxiality, criterion. This study is paid to the fundamental clarification of the effect of notch radius, which can elevate plastic constraint due to heterogeneous plastic straining on critical condition to initiate ductile crack using two-parameters. Hense, the crack initiation testing were conducted under static loading using round bar specimens with circumferential notch. To evaluate the stress/strain state in the specimens was used thermal elastic-plastic FE-analysis. The result showed that equivalent plastic strain to initiate ductile crack expressed as a function of stress triaxiality obtained from the homogeneous specimens with circumferential notched under static loading. And it was evaluated that by using this two-parameters criterion, the critical crack initiation of homogeneous specimens under static loading.

  • PDF

H-pile의 지지력 특성 및 동역학적 공식의 신뢰도 평가 (Characteristics of Bearing Capacity and Reliability-based Evaluation of Pile-Driving Formulas for H Pile)

  • 오세욱;이준대
    • 한국안전학회지
    • /
    • 제18권1호
    • /
    • pp.81-88
    • /
    • 2003
  • Recently, pile foundations were constructed in rough or soft ground than ground of well condition thus it is important that prediction of ultimate bearing capacity and calculation of proper safety factor applied pile foundation design. This study were performed to dynamic loading tests for the thirty two piles at four different construction sites and selected pile at three site were performed to static loading tests and then compare with measured value and value of static and dynamic loading tests. The load-settlement curve form the dynamic loading tests by CAPWAP was very similar to the results obtained from the static load tests. Based on dynamic and static loading tests, the reliability of pile-driving formula were analyzed and then suggested with proper safety factor for prediction of allowable bearing capacity in this paper.

부방향 동압력을 이용한 압전형 압력센서의 교정기법 (A Dynamic Calibration Technique for Piezoelectric Sensors Using Negative Going Dynamic Pressure)

  • 김응수
    • 한국군사과학기술학회지
    • /
    • 제12권4호
    • /
    • pp.491-499
    • /
    • 2009
  • The determination of response characteristics for pressure sensors is routinely limited to static calibration against a deadweight pressure standard. The strength of this method is that the deadweight device is a primary standard used to generate precise pressure. Its weakness lies in the assumption that the static and dynamic responses of the sensor in question are equivalent. Differences in sensor response to static and dynamic events, however, can lead to serious measurement errors. Dynamic techniques are required to calibrate pressure sensors measuring dynamic events in milliseconds. In this paper, a dynamic calibration using negative going dynamic pressure is proposed to determine dynamic pressure response for piezoelectric sensors. Sensitivity and linearity of sensor by the dynamic calibration were compared with those by the static calibration. The uncertainty of calibration results and the goodness of fit test of linear regression analysis were presented. The results show that the dynamic calibration is applicable to determine dynamic pressure response for piezoelectric sensors.

Accurate Non-Quasi-Static Gate-Source Impedance Model of RF MOSFETs

  • Lee, Hyun-Jun;Lee, Seonghearn
    • JSTS:Journal of Semiconductor Technology and Science
    • /
    • 제13권6호
    • /
    • pp.569-575
    • /
    • 2013
  • An improved non-quasi-static gate-source impedance model including a parallel RC block for short-channel MOSFETs is developed to simulate RF MOSFET input characteristics accurately in the wide range of high frequency. The non-quasi-static model parameters are accurately determined using the physical input equivalent circuit. This improved model results in much better agreements between the measured and modelled input impedance than a simple one with a non-quasi-static resistance up to 40GHz, verifying its accuracy.

Analysis of the Static and Dynamic Stability Properties of the Unmaned Airship

  • Lee, Hae Chang
    • International Journal of Aeronautical and Space Sciences
    • /
    • 제2권2호
    • /
    • pp.82-94
    • /
    • 2001
  • The purpose of this paper is to analyze the static and dynamic stability-of the unmanned airship under development ; the target airship's over-all length of hull is 50m and the maximum diameter is 12.5m. For the analysis, the dynamic model of an airship was defined and both the nonlinear and linear dynamic equations of motion were derived. Two different configuration models (KA002Y and KA003Y) of the airship were used for the target model of the static stability analysis and the dynamic stability analysis. From the result of analyses, though the airship is unstable in static stability, dynamic characteristics of the airship can provide the stable dynamic stability. All of the results, airship models and dynamic flight equations will be an important basement and basic information for the next step of developing the automatic flight control system(AFCS) and the stability augmentation system(SAS) for the unmanned airship as well as for the stratospheric airship in the future.

  • PDF

Analysis of static and dynamic characteristics of strain gradient shell structures made of porous nano-crystalline materials

  • Hamad, Luay Badr;Khalaf, Basima Salman;Faleh, Nadhim M.
    • Advances in materials Research
    • /
    • 제8권3호
    • /
    • pp.179-196
    • /
    • 2019
  • This paper researches static and dynamic bending behaviors of a crystalline nano-size shell having pores and grains in the framework of strain gradient elasticity. Thus, the nanoshell is made of a multi-phase porous material for which all material properties on dependent on the size of grains. Also, in order to take into account small size effects much accurately, the surface energies related to grains and pores have been considered. In order to take into account all aforementioned factors, a micro-mechanical procedure has been applied for describing material properties of the nanoshell. A numerical trend is implemented to solve the governing equations and derive static and dynamic deflections. It will be proved that the static and dynamic deflections of the crystalline nanoshell rely on pore size, grain size, pore percentage, load location and strain gradient coefficient.

디스크 받침용 고무패드의 거동 및 강성추정 (The Behavior and Estimated Stiffness Rubber Pad for Disk Bearing)

  • 조성철;최은수;박주남;김만철
    • 한국철도학회:학술대회논문집
    • /
    • 한국철도학회 2009년도 춘계학술대회 논문집
    • /
    • pp.599-605
    • /
    • 2009
  • The aim of the present study is the characteristics of bridge rubber pads and suggested how to determine the stiffness the pads. A disk bearing is operated as an elastic bearing in the vertical direction and is composed of a Polyether Urethane (polyurethane) disk for elastic support and Polytetrafluoroethylene (PTFE) to accommodate movement. Static tests are conducted in a laboratory to determine the static behavior of a Polyurethane disk. Finite Element (FE) analysis is also performed to verify the static performance. For dynamic behavior, four disk bearings having the identical Polyurethane disk used in the static tests are installed in a full size railway bridge and tested under a running locomotive. From the tests results, the static and dynamic stiffness of disk bearings are estimated and compared with each other. In the procedure to estimate the stiffness of a pad, the dead load(pre-load) of a bridge and live load of a vehicle are considered.

  • PDF

자동차용 고무부품에 대한 대변형 유한요소해석 (Large deformation finite element analysis for automotive rubber components)

  • 김헌영;최천;방원준;김재수
    • 오토저널
    • /
    • 제15권1호
    • /
    • pp.107-119
    • /
    • 1993
  • The objective of this study is to analyze the static and dynamic characteristics of automotive rubber components by computer simulation. Bush / rectangular type engine mounts and wind shield weather strip are analyzed by using the commercial code ABAQUS and the results are verified by experiments. Large deformation static response is analyzed in order to get the information about the deformation pattern and static stiffness of engine mounts, and about the seperation force of wind shield weather strip from body. The isothermal steady-state dynamic response of components which have been subjected to an initial static pre-load is analyzed for the dynamic stiffness of engine mount rubber components. There are good agreements between simulation and experiments. So it is possible to apply the computer simulation to the design of automotive rubber components.

  • PDF