http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
등기하해석에 의한 기능경사복합재 판의 역학적 거동 예측
전준태,Jeon, Juntai 한국재난정보학회 2020 한국재난정보학회 논문집 Vol.16 No.4
연구목적: 본 연구에서는 고차전단변형이론을 적용한 등기하해석 방법을 이용하여 기능경사복합재 판의 휨에 의한 역학적 거동을 해석하고자 하였다. 연구방법: 기능경사복합재 판의 역학적 거동을 보다 더 정확하게 해석하기 위해서 전단보정계수를 도입할 필요가 없는 기하학적 비선형을 고려한 고차전단변형이론을 이용하여 휨을 받는 기능경사복합재 판의 평형방정식과 지배방정식을 도출하였으며, 등기하 해석방법에 의한 수정된 Newton-Raphson 반복법을 이용하여 방정식들을 풀었다. 연구결과: 판의 용적비, 길이-두께 비 및 경계조건은 기능경사복합재 판의 휨 거동에 상당한 영향을 미치는 것을 알 수 있었다. 결론: 제안된 등기하해석 방법은 휨을 받는 기능경사복합재 판의 역학적 거동을 해석하는데 있어 정확하고 효과적인 수치해석 방법임을 확인하였다. Purpose: This study attempts at analyzing mechanical response of functionally graded material (FGM) plates in bending. An accurate and effective numerical approach based on isogeometric analysis (IGA) combined with higher-order shear deformation plate theory to predict the nonlinear flexural behavior is developed. Method: A higher-order shear deformation theory(HSDT) which accounts for the geometric nonlinearity in the von Karman sense is presented and used to derive the equilibrium and governing equations for FGM plate in bending. The nonlinear equations are solved by the modified Newton-Raphson iterative technique. Result: The volume fraction, plate length-to-thickness ratio and boundary condition have signifiant effects on the nonlinear flexural behavior of FGM plates. Conclusion: The proposed IGA method can be used as an accurate and effective numerical tool for analyzing the mechanical responses of FGM plates in flexure.
전준태,주부석,손호영,Jeon, Juntai,Ju, Bu-Seog,Son, Hoyoung 한국재난정보학회 2020 한국재난정보학회 논문집 Vol.16 No.4
연구목적: I-Shape 거더를 갖는 곡선교량의 지진 안전성에 미치는 고주파 지진의 영향성을 분석하기 위해 지진 취약도 평가를 수행하였다. 연구방법: I-Shape 단면을 갖는 곡선교량의 선형탄성 유한요소 모델을 구축하고 고주파 영역의 인공지진파를 12개 생성하여 시간이력해석 및 지진 취약도 평가를 수행하였다. 연구결과:변위응답(LS1, LS2)에 대한 한계상태는 0.1g를 넘어서면서 파괴가 발생하였으며 거더의 응력응답 한계상태의 경우 0.2g를 넘어서면서 정해진 한계상태를 초과하는 것으로 나타났다. 결론: 현재 구축된 곡선교량 모델의 경우 고주파 지진에 민감하게 반응하는 것으로 판단된다. Purpose: This is aimed to evaluate the seismic fragility of curved bridge structure with I-shape girder subjected to 12 high frequency ground motions based on Gyeongju earthquake. Method: The linear elastic finite element model of curved bridge with I-Shape cross section was constructed and them linear elastic time history analyses were performed using the 12 artificial ground motions. Result: It was found that displacement response(LS1, LS2) was failed after PGA 0.1g and the stress response also showed failure after PGA 0.2g. Conclusion: The curved bridge with I-shape girder was sensitive to high frequency earthquakes.
급결제 함유량에 따른 습식 Shotcrete 리바운드 감소량에 대한 실험적 연구
전준태(Jeon, Jun Tai),박홍태(Park, Hong Tae),이양규(Lee, Yang Kyu) 대한토목학회 2012 대한토목학회논문집 D Vol.32 No.6D
숏크리트는 현장에서 빠른 시공을 실시하여 굴착면을 침식으로부터 보호하고 암괴의 전단이동방지, 암괴의 붕괴방지, 개구 절리의 봉합, 응력의 집중완화, 응력전달효과 등에 의하여 후속작업의 원활한 진행이 될 수 있도록 굴착면을 방지하여 지내력을 증대시키는 것이 주목적이다. 숏크리트공법으로는 건식과 습식의 두 가지방법이 있으며, 1997년 이후부터는 건식보다 습식 숏크리트가 많이 이용되고 있다. 그러나 작업 중 목적물에 부착되지 않고 반발되는 현상, 즉 리바운드가 많이 발생하며 이러한 많은 양의 리바운드는 숏크리트와 전체 공사비 원가에 중대한 영향을 미치게 된다. 특히 숏크리트는 재료비, 배합, 타설시간 증가, 재료의 취급과 계량장치에 소요되는 인력 및 버력제거를 위한 비용 증가 발생원인이 되고 있다. 이 연구에서는 국내현장에서 시행한 급결제 함유량에 따른 일반 습식 숏크리트 및 강섬유 습식 숏크리트공법의 시공실적을 분석 하여 반발 양 및 강도의 실험적인 분석을 실시하였다. 또한 국내 건설공사에 실제 사용할 수 있는 효과적이고 합리적인 방법을 제시하였다. The aim of shotcrete is to increase the bearing capacity and to protect the excavated surface from erosion by preventing failing of rock mass. Shotcreting method is divided into two types as dry process and wet process. Since 1997, wet process method has been used more frequently than dry process method in field works. The failure to bond, so called rebound, occurs in many case during shotcrete works. The excess amount of rebound has a significant effect on the total construction cost. For example, material and craft-man cost increases, the shooting time delays due to deceleration of work execution stage, work efficiency of craft-man decreases and additional cost to remove the muck generates. In this study, therefore, the experimental analysis of rebound amount and strength was conducted by analyzing the actual construction data for wet process type of shotcreting method upon accelerator contents. Also, the effective and rational method was suggested, which can be actually implemented in the Korea construction sites.
UL 1699B 기반 태양광 DC 직렬 아크 검출에 필요한 FFT와 DWT 기법 비교 분석 연구
전준태(Jeon Juntae),박태준(Park Taejun),임선우(Lim Sunwoo),도진호(Do Jinho),이효준(Lee Hyojun),김범준(Kim Beomjun),이영권(Lee Youngkwon),송승호(Song Seungho),최주엽(Choi Juyeop) 한국태양에너지학회 2024 한국태양에너지학회 논문집 Vol.44 No.3
Considering the dangers of DC serial arcs in PV systems and the time when arcs are caused by electrical fire, we aimed to quickly detect DC serial arcs within 0.5 s. To quickly analyze and identify the frequency characteristics of arcs, fast Fourier transform (FFT) and discrete wavelet transform (DWT), which have been the most widely used frequency analysis methods in recent years, were compared and analyzed to implement an algorithm for detecting the most accurate and efficient DC arc. In this study, an experiment was conducted based on the UL 1699B arc test conditions. At this time, the arc energy does not exceed 750 J, and the arc must be detected within 2.5 s. In the overall process, components other than the arc were removed by applying a band pass filter to detect a specific frequency component of the arc. ADC was performed to convert the current value into a digital signal, and signal processing was performed using FFT and DWT using the filtered signal. Finally, after calculating the energy, which is a component of the frequency for each specific period, the threshold of each energy value was set to determine whether the arc exceeds a specific threshold.
전준태 ( Jun-tai Jeon ) 한국고등직업교육학회 2001 한국고등직업교육학회논문집 Vol.2 No.1
The behavior of stress of steel pipe welding joint under tension load was investigated by 3-dimension elastoplastic FEM analysis. When steel pipe was jointed by welding, circumferential residual stress and radial residual stress near the welding joint on the outer and inner surface of steel pipe were tensile. It is known that axial residual stress on the inner surface was tensile. In the opposite direction, axial residual stress on the outer surface contrary to the case of inner surface was compressive. In the case that tensile load is loading on the steel pipe generated residual stress. Compressive residual stress was smaller than residual stress generated by welding. Axial stress near the welding joint on the outer and inner surface of steel pipe was tensile. Circumferential stress was generated compressive stress on inner surface and generated tensile stress on outer surface.
전준태 ( Jun-tai Jeon ),송재필 ( Jae-pil Song ) 한국고등직업교육학회 2006 한국고등직업교육학회논문집 Vol.7 No.4
In this study the dynamic measuring system for a structure was developed High speed digital communication method was applied to this dynamic measuring system for the purpose of reducing electric noise. This dynamic measuring system consist of signal conditioned amp, local module and measuring server. It can be seen that this dynamic measuring system can obtain more precision and noiseless measuring data, by use of high speed digital communication. And this fact was certified from the comparative test.