《小议作物茎秆剪切强度与形态特性的相关性》由会员分享，可在线阅读，更多相关《小议作物茎秆剪切强度与形态特性的相关性（2页珍藏版）》请在金锄头文库上搜索。
1、小议作物茎秆剪切强度与形态特性的相关性Relationship Between Stalk Shear Strength and Morphological Traits of Stalk Crops1 Introduction Studying the mechanical properties of crop stalk is an important aspect in the field ofAgricultural Engineering since mechanization of farming proposed. Ince A.studied the bendingand sh
2、earing properties of sunflower stalk residue at different moisture content and differentheight of stalk to help choose the proper cutting time and height of stalk. The effects of loadingspeed and knife bevel angel on the maximum shear strength of sorghum stalk were analyzed. Qingting Liu measured th
3、e cutting force and analyzed the cutting mechanism ofsugarcane. Many other results about shearing properties of stalk crops are also available fordesigning harvesting and processing machinery. Because crops mechanical properties varywith different growth environment, study on the relationship betwee
4、n mechanical properties andmorphological traits might be helpful to adjust the mechanical properties by the agriculturalmeasures. Also, it is assisted to select crop fine variety. Kar kaack and Kai-uwe Schwarz considered the effect of both mechanical and morphological properties of Miscanthus onharv
5、esting. U Zuber, et al. reported the relations between morphological traits and bendingresistance of Spring Wheat. Our research group about plant mechanics is studying the stalk mechanical properties,such as bending, shearing and tensile of main stalk crops planted in northern China. Thecorrelation
6、of stalk mechanical properties and morphological traits of crop are also studied forselecting crop fine varieties. This paper introduces the results about the stalk basal internode shearstrength of wheat, broomcorn, soybean, millet and corn, and the relationship between shearstrength and morphologic
7、al traits.2 Methodology Experiments were conducted on wheat, broomcorn, soybean, millet and corn, and each cropwas chosen one variety. They are “shannong 91003”, “jinza 17”, “jinda 73”, “jingu 21”,“zhengdan 958” respectively. 18 specimens were selected randomly from the field of ShanxiAgricultural U
8、niversity in China from May to October, 2007 at the mature stage of each crop. Theroots and leaves were removed before testing the morphological traits, which are plant height (PH),internode distance (ID), internode weight (IW), moisture content (MC), ear weight (EW), earheight (EH), ear length (EL)
9、 and cross-sectional area (CA). Then, the specimens were cut from thenode (soybean specimen was cut every two nodes) and the basal second internode of eachspecimen (soybean specimen was the basal first internode) was selected as sample to do the sheartest on SANS material testing machine. Each wheat
10、 sample was tested under 5mm/min loadingspeed, while others were tested under 150mm/min. The shear force versus displacement data wererecorded directly by testing system. Figure 1 illustrates the action of shear force on the twocross-sections of crop stalk.3 Results and discussion multiple linear re
11、gression method with SAS. Regression results are listed. Morphological traits of the crops are expressed as x1 x2 x3 x4 x5 x6 x7 ordered from left to right.the shear strength of different crop has varied correlation with theirmorphological traits. However, plant height, ear weight and cross-sectiona
12、l area have closercorrelation with the stalk shear strength than other tested traits. The results can help adjust cropgrowth situation in the process of planting crops with agricultural measures.4 Conclusion In this paper, five stalk crops were chosen to study the relationship between stalk shearstr
13、ength and morphological traits. The following conclusions were drawn from the study: (1) According to the results of the test, the shear strength of soybean stalk was the maximal,while millet and wheat take second place, the broomcorn and corn are the minimal. This is relatedto the structure of stal
14、k material. The soybean stalk, whose cross-section shape is solid, can beregarded as woody material with high stiffness. The cross-section shapes of millet and wheat arehollow so that the load support capability is good. The core structure of broomcorn and corn stalk can be analyzed as cellular stru
15、cture, which has less density and smaller shearing resistance thanthose of solid structure at the same cross-sectional area. (2) The shear strength of different crop has varied correlation with morphological traits. Earweight and cross-sectional area have closer correlation with the stalk shear stre
16、ngth than othertested traits. The optimal regression equation of shear strength and morphological traits weredetermined to predict the shear strength by measuring the corresponding traits. (3) All the test data are at the mature stage of crops, which provide basic information fordesigning harvesting equipment. 热点论文发表网提供大量论文格式，论文提纲，英语论文范文
