Comparison of Mechanical Properties between Two Varieties of Rice Straw

The objective of this work was to compare the mechanical properties between two varieties of rice straw (Hashemi and Alikazemi). The experiments were conducted at moisture contents of 71.6 and 70.8% w.b. for Hashemi and A likazemi varieties, respectively and three internode positions down from the ear. The average shear strength for Hashemi variety was significantly higher (p＜0.05) than that of Alikazemi variety. The values were 13.08 and 8.56 MPa for Hashemi and Alikazemi varieties, respectively. The shearing energy of Hashemi and Alikazemi varieties increased from 122.76 to 236.06 and 86.89 to 191.31 mJ, respectively, towards the third internode position. The bending strength and Young's Modulus of Hashemi variety were significantly higher (p＜0.05) than those of Alikazemi variety. The results showed that the energy requirement for shearing of Hashemi variety is more than Alikazemi variety.