Study on the Shearing characteristics of Forage

목초(牧草)의 전단(剪斷) 특성(特性)에 관(關)한 연구(硏究)

Importance has been increased on farming mechanization in harvesting, handling and processing of forage in Korea. Small grasslands are most spread and popular in Korea in comparison with those of Europe and America. Therefore shearing characteristics of some major forage crops should be studied to be contributed to the basic data to develop a moderate size forage harvester being suitable to the small grassland. They were studied on six kinds of forage crops - reed canarygrass, alfalfa, red clover, orchardgrass, meadow fescue and birdsfoot trefoil-in regarding with moisture content levels and shearing angles. The results were as follows; 1. The increase rate of the linear density in relation to the diameter was greater in red clover than other kinds, and order of increase rate in greatness was reed canarygrass, alfalfa and meadow fescue. 2. The increase rates of the maximum shear forces were high in relation to their cross - sectional area in alfalfa and birdsfoot trefoil with hard stems, and the shear energy were comparatively large in orchardgrass and meadow fescue with soft stems, also reed canarygrass and red clover had high values in both the maximum shear force and the shear energy. 3. The shear energy per unit area or shear strength in relation to moisture content showed concave curves with the minimum values at about 70%w. b. which was in the beginning stage of drying in meadow fescue and orchardgrass, nevertheless reed canarygrass and red clover had convex curves with the maximum values at about 40%w.b. 4. The shear force in relation to the shear angle decreased generally with decrease of shear angle from $90^{\circ}$ to $70^{\circ}$ or $50^{\circ}$.

목초(牧草) 수확기(收穫機)의 설계(設計) 및 목초(牧草)의 처리가공(處理加工)의 기초자료(基礎資料)로서 기여(寄與)하고저 6개(個) 종류(種類)의 목초(牧草)-reed canarygrass, alfalfa, red clover, orchardgrass, meadow fescue 및 birdsfoot trefoil-을 공시건초(供試乾草)로 사용(使用)하여 자연건조(自然乾燥)에 따른 함수율변화(含水率變化)와 전단(剪斷) 각변화(角變化)가 전단력(剪斷力) 및 전단(剪斷) energy에 미치는 영향(影響)을 포함(包含)한 목초(牧草)의 전단특성(剪斷特性)을 측정분석(測定分析)한 결과(結果)는 다음과 같다. 1. 건초(牧草)의 linear density는 직경(直徑)의 증가(增加)에 따라 증가(增加)하는 경향(傾向)이었으며 그 증가율(增加率)은 red clover에서 가장 컷다. 2. 전단면적(剪斷面積)의 증가(增加)에 따른 전단력(剪斷力)의 증가율(增加率)은 alfalfa에서 가장 큰 값을 나타냈고 meadow fescue에서 가장 작은 값을 나타냈다. 3. 전단면적(剪斷面積)의 증가(增加)에 따른 전단(剪斷) energy의 증가율(增加率)은 reed canarygrass, red clover 및 alfalfa에서 컷고 birdsfoot trefoil, orchardgrass 및 meadow fescue는 작은 값을 나타냈다. 4. 함수율(含水率)이 전단특성(剪斷特性)에 미치는 영향(影響)은 비교적 컷으며 reed canarygrass 및 red clover는 약 40% 함수율(含水率)에서 전단력(剪斷力) 및 전단(剪斷) energy가 최대치(最大値)를 나타냈으며 반면(反面) meadow fescue 및 orchardgrass는 감소초기(減少初期)인 약 70% 부근(部近)에서 최소치(最小値)를 나타냈다. 5. 전단각(剪斷角)이 $90^{\circ}$에서 $70^{\circ}$, $50^{\circ}$로 감소(減少)할때 전단력(剪斷力)도 감소(減少)하였다.