Document Type : Research Paper
Authors
1 M. Sc. Student of Mechanical Engineering of Agricultural Machinery, Department of Mechanical Engineering of Biosystems, Faculty of Agriculture, University of Shahrekord
2 Assistant Professor, Department of Mechanical Engineering of Biosystems, Faculty of Agriculture, University of Shahrekord,
3 Lecturer, Department of Mechanical Engineering of Biosystems, Faculty of Agriculture, University of Shahrekord
Abstract
In this research the effects of moisture content and cutting speed on the specific shearing energy and shearing stress for four variety of almond tree (Mamayy, Rabi, Sefid and Shahrodi12) was investigated and results the each any the varieties were compared with each other. Shear properties of almond wood varieties in this study, using a universal testing machine manufactured STM20 Sntam was determined. Knife bevel form of one-sided and edge angle is 40 degree.The characteristics at three moisture levels of 18, 25 and 45% (w.b.) wet basis, three cutting speed levels of 20, 30 and 40 mm/min and in three size 6, 9 and 12 mm were determined. The results of analysis of variance (ANOVA) showed specific shearing energy and shearing stress to all test factors were response significant (P<0.01). The results showed that Both specific shearing energy and shearing stress increased with an increase in moisture content. While increasing cutting speed of 20 to 40 mm per minute, these values are reduced. Based on the results of the study the average specific shearing energy were determined for varieties Mamayy, Rabi, Sefid and Shahrodi12 59.41, 56.088, 54.38 and 77.57 J/ mm2 respectively and for shearing stress, 16.01, 14.34, 13.73 and 19.35 MPa, respectively. Also, the study effect of test factor in the shear test results can be explained factors moisture content and variety most effect and relatively less effect in cutting speed factor.
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