Experiment on stalk mechanical properties of legume forage and grasses

In order to evaluate forage stalk with mechanical properties, four kinds of stalks in harvesting period of perennial forage legumes and grasses such as Medicago sativa, Coronilla varia, Bromus inermis Leyss, Agropyron cristatuml were chosen to perform the experiments of tensile and shear by means of 500 N electronic universal testing machine. The mechanical properties such as maxinum loads, stress, strain and young’s modulus were measured and relevant changing trends were studied with statistical software. The results showed that it was power function negative correlation between the diameter and the tensile strength of forage legumes and grasses. It was not significantly different between perennial forage legumes and grasses’stalks in diameter. The stalk diameter of forage legume was a little larger than that of grass, but the tensile strength of grasses’stalks was 3-4 times than that of forage legumes’stalks. The experiment also testified that the shear strength decreased along with the increasing of diameter. At the speed of 100 mm/min of load addition, the resistance of vertical cutting was the largest. The resistance of oblique cutting was reduced by 30%-40% compared with that of vertical cutting. The resistance of slippery cutting was reduced by 50%-60% compared with that of vertical cutting with the slippery angle of 30°. The conclusions provide the theoretical foundation to design herbage haverster, baler and herbage deep processing facility.