Physical and mechanical properties of wheat straw as influenced by moisture content.

Abstract

The objective of this research was to determine the effects of moisture content and internode position on some physical and mechanical properties of wheat straw. The experiments were conducted at four moisture contents of 10.2, 14.3, 18.4, and 22.6% w.b. and at three internode positions down from the ear. Based on the results obtained, the values of the physical properties increased with increasing moisture content. The physical properties also increased towards the third internode position. For all the physical properties studied, the values of the first internode position had significant differences with those of the other two internode positions. Moreover, for the moisture contents studied in this research, the values of shear strength were within the ranges 6.81-10.78, 7.02-11.49, and 7.12-11.78 MPa for the first, second and third internode positions, respectively. The maximum specific shearing energy was 36.26 mJ mm -2 , which occurred at the third internode position with the moisture content of 22.6% w.b. The bending strength and Young's modulus decreased with increase in the moisture content. Their values also decreased towards the third internode position.