Journal of Wind Energy (풍력에너지저널)

Korea Wind Energy Association (한국풍력에너지학회)
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Design investigation of the stress reduction of bolted joint connection components in a large wind turbine blade

대형 풍력발전기 블레이드의 볼트체결부 응력감소를 위한 설계연구

  • 하광태 (울산대학교 부유식해상풍력학과 ) ;
  • 허준 (울산대학교 부유식해상풍력학과) ;
  • 정재호 (가천대학교 기계공학부)
  • Received : 2022.08.11
  • Accepted : 2022.10.25
  • Published : 2022.12.30
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Abstract

Today, the power capacity of a wind turbine and the size of a blade is increasing to capture more wind resources, reduce the number of wind turbines on a wind farm, and reduce the cost of energy. As the blade size becomes larger, attention is being paid to the structural integrity of the blade root connection due to the heavy gravitational load effect and increased aerodynamic loads on the large blade, which could cause catastrophic failure of the blade. Therefore, the secure bolted joint connection of the blade to the hub is very important. In this paper, attention was given to the stress concentration factor (SCF) at the first thread between the M42 bolt and nut. The effect of various design parameters on the stress concentration factor was investigated, which included nut type, nut height, and reduced shank bolt. From a close design investigation of the numerical results, it turned out that the use of a reduced shank bolt resulted in the largest reduction of the stress concentration factor by 40 %, and the round nut type also reduced the SCF by 10 %, which will be beneficial to large wind turbine blades over 100 meters.

Keywords

Acknowledgement

본 연구는 산업통상자원부의 재원으로 한국에너지기술평가원의 지원을 받아 수행한 신재생에너지핵심기술사업(20213030020380, "육상풍력운송한계돌파를 위한 70m이상 접착식 분리형 블레이드 개발")의 연구결과임. 본 연구는 2022년도 산업통상자원부의 재원으로 한국에너지기술평가원(KETEP)의 지원을 받아 수행한 연구 과제(No. 20203020020030)의 연구결과임. 연구비 지원에 감사를 드립니다.

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