Physical and mechanical properties of selected forage materials

Afzalinia, S. and Roberge, M. 2007. Physical and mechanical properties of selected forage materials. Canadian Biosystems Engineering/Le genie des biosystemes au Canada 49: 2.23-2.27. The static coefficient of friction of alfalfa, barley straw, wheat straw, and whole green barley on a polished steel surface was determined. Four levels of moisture content were considered for alfalfa and barley straw, while the coefficient of friction was measured at one level of moisture content for wheat straw and whole green barley. Coefficient of internal friction of alfalfa and barley straw was determined at four cut lengths. Both coefficients of external and internal frictions at each of the moisture contents and cut lengths were determined using five levels of normal pressures. Results of this study showed that the static coefficient of friction increased with an increase in material moisture content from 12.0 to 45.7% (wb) for alfalfa and barley straw. This coefficient ranged from 0.15 to 0.26 and 0.14 to 0.27 for alfalfa and barley straw, respectively. The static coefficient of friction for wheat straw at 10% moisture content (wb), and whole green barley at 51% moisture content (wb) were 0.13 and 0.21, respectively. Cut length had no significant effect on the coefficient of internal friction of barley straw and had a slight effect on the coefficient of internal friction of alfalfa. The static coefficient of friction of alfalfa on a polished steel surface was a quadratic function of material moisture content, while the relationship between the coefficient of friction of barley straw on a polished steel surface and material moisture content was best expressed by a linear equation.