- 잣 수확의 기계화 연구(II) -잣나무 가지의 전단 특성-
- ㆍ 저자명
- 강화석,김상헌,이재선,Kang. W.S.,Kim. S.H.,Lee. J.S.
- ㆍ 간행물명
- 한국농업기계학회지
- ㆍ 권/호정보
- 1994년|19권 1호|pp.17-21 (5 pages)
- ㆍ 발행정보
- 한국농업기계학회
- ㆍ 파일정보
- 정기간행물| PDF텍스트
- ㆍ 주제분야
- 기타
This reasearch was performed to provide the fundamental intonation for the mechanization of Korean pine cone harvest when the shoot shearing method is adopted. Shear force and stress of pine cone shoots were measured and analyzed for this purpose. Samples are selected along their harvesting time and tested in 17 levels of shoot diameter from 10 to 26mm with 1mm increment. 1) Shear force-deformation characteristics showed that shoot reached its rupture point after 2 to 4 of bio-yield points. It was supposed that these multiple bio-yield points were caused by the discrete compression of wood parts which are composed of water, nutrient, resin, etc. 2) Required shear force to shear shoot was proportional to the square of shoot diamter, however, shear force for shoots of early harvesting time(Aug. 31) was proportional to the shoot diameter. Variance of shear force was increased as the harvesting time was delayed. Shear forces were distributed from 468N(Aug. 31, 12mm dia) to 4153N(Aug. 31, 26mm dia) disregarding the sampling date. 3) The average shear stresses by sampling dates were 744,822, and 883N/m2, respectively, and for the earlier shoot samples shear stress was quite smaller than the others. Shear stress was proportional to shoot diameter squared, and the effect of shoot diameter on the shear stress was decreased as harvesting time was delayed.