experimental and theoretical investigation of the effects of moisture content and internodes position on shearing characteristics of sugar cane stems

in the present study, shearing properties of sugar cane stems were determined at five moisture content levels (46, 54, 62, 70 and 78% wb), three shearing speed (5, 10 and 15 mm min-1) and at ten positions on the stem. for measuring the shearing forces, the stems were severed by using a computer aided cutting apparatus. decrease in moisture content of stem from 78 to 46% wb led to 16.3 and 16.7% decrease in the shearing strength and specific shearing energy, respectively. the maximum and average values of shearing strength of the two moisture contents were found to be 3.482 and 3.1 mpa, and the specific shearing energies were 112 mj mm-2 and, 102.6 mj mm-2, respectively. both the shearing strength and the specific shearing energy were found to be higher in the lower region of the stem due to structural heterogeneity. results showed that with the increase in shearing speed from 5 to 15 mm min-1, shearing strength and the specific shearing energy increased 3.2 and 4.6%, respectively. the results of anova indicated that effects of the mentioned factors were significant at 1% probability level. the shearing model assessment revealed that the third order polynomial model exhibited the best performance in fitting with experimental data and, by using this model, a significant correlation was found between shearing strength, specific shearing energy, and moisture content (r2= 0.989 and se= 0.001). also, a significant correlation was found between shearing strength, specific shearing energy, and shearing speed by using hoerl model (r2= 0.989 and se= 0.005).