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실측 풍속 조건을 이용한 소형 풍력발전용 복합재 블레이드의 피로 수명 비교
장윤정(Yun Jung Jang),강기원(Ki Weon Kang) 대한기계학회 2014 대한기계학회 춘추학술대회 Vol.2014 No.5
This study aims to comparison of fatigue life through average wind speed of two area. First, the 1-Hz wind history was generated using a von Karman isotropic turbulence model and the 10-min average wind speed data measured in the Kunsan City, Republic of Korea. A flapwise and edgewise forces were obtained using a BEMT(Blade Element Momentum Theory)-based aerodynamic analysis. Then, combining the generated 1-Hz wind history and the aerodynamic forces led the flapwise and edgewise moment spectra. A S-N curve was obtained by performing the constant amplitude fatigue test for a composite material. In addition, FE analyses were performed to identify the fatigue critical locations(FCLs) and the interaction between flapwise and edgewise moments, respectively. The fatigue stress spectra at FCLs were obtained through above-mentioned procedure, and the fatigue life of a composite blade was predicted using the rainflow cycle counting, the Goodman equation, and the Miner rule. Finally, these result of two area was comparison.
구조시험 및 유한요소해석을 통한 소형풍력발전용 복합재 블레이드의 구조 안전성 평가
장윤정(Yun Jung Jang),이장호(Jang Ho Lee),강기원(Ki Weon Kang) 대한기계학회 2012 大韓機械學會論文集A Vol.36 No.9
본 논문에서는 구조 시험과 유한요소해석을 통하여 소형 풍력발전용 복합재 블레이드의 구조적 안전성을 평가하였다. 먼저, 선행연구에서 공력해석을 수행하여 정격 및 극한 풍속일 때의 블레이드가 받는 굽힘 모멘트를 산출하였다. 이를 이용하여 소형풍력발전기 관련 국제 규격인 IEC 61400-2 에 따른 실규모 구조 시험을 수행하여 구조적 안전성을 평가하였다. 그리고 유한요소법을 이용한 구조 해석을 수행하여 구조 시험 결과와 비교하여 이의 정확성을 판단하였다. 또한, 구조 시험을 통해 블레이드에 대한 과잉 설계가 확인되었으며 이의 해결을 위하여 블레이드의 적층 순서 및 두께를 재선정하여 구조적 안전성을 평가하였다. This study deals with structural analysis and testing under loading conditions calculated by computational fluid dynamics for a small composite blade that is utilized in a dual rotor wind turbine system. First, the aerodynamic forces were analyzed at the rated and cutout wind speed to identify the bending moment distribution along the blade length in previous research. Then, full-scale structural tests were conducted according to IEC 61400-2 to evaluate the tructural integrity of the composite blade. These results were compared with finite element analysis to identify the accuracy of the structural analysis. Based on these results, it was revealed that the existing blade has a very high safety margin. Then, the layup of the composite blade was redesigned and analyzed using finite element analysis to achieve structural integrity and economic efficiency.
학교구강보건실 운영학교와 비운영학교 교사의 구강보건 지식과 구강건강행태
장윤정 ( Yun Jung Jang ) 한국치위생학회(구 한국치위생교육학회) 2014 한국치위생학회지 Vol.14 No.3
Objectives : The purpose of the study is to investigate the oral health knowledge and behavior in teachers with or without the school dental clinic. Methods : The subjects were 133 teachers with or without the school dental clinic in Gunsan. A self-reported questionnaire was filled out by the teachers from September 9 to November 2, 2013. The data were analyzed by SPSS version 21.0. Results : The groups were divided into two. Experimental group was school dental clinic operation group and the control group was no operation group. The experiment group showed the high score of recognition of fluoridation and sealant(p<0.01). The control group showed the high score of recognition of sealant(p<0.01). Conclusions : Continuous operation of the school dental clinic is essential to promote the lifelong oral health care in the elementary school children and the teachers. So the nationwide expansion of the continuous school dental clinic is very important to prevent the dental caries in the elementary school children.