Bending and Shearing Properties of Safflower Stalk

Authors
F. Shahbazi 1
M. Nazari Galedar 2
1 Department of Agricultural Machinery, Faculty of Agriculture, Lorestan University, Khoram abad, Islamic Republic of Iran.
2 Department of Agricultural Machinery, Faculty of Bio System Engineering, University of Tehran, Karaj, Islamic republic of Iran.
Abstract
The research was conducted in order to determine the bending stress, Young’s modulus, shearing stress, and shearing energy of safflower stalk as a function of moisture content and stalk region. The bending forces were measured at different moisture contents and the bending stress and the Young’s modulus were calculated from these data. For measuring the shear forces, the stalk specimens were severed by using a computer aided cutting apparatus. The shear energy was calculated by using the area under the shear force versus displacement curve. The experiments were conducted at four moisture contents (8.61, 16.37, 25.26, and 37.16% wb) and at three stalk regions (bottom, middle, and top). Based on the results obtained, the bending stress decreased as the moisture content increased. The value of the bending stress obtained at the lowest moisture content was approximately 2 times higher than that of the highest moisture content. Bending stress values also decreased from top to the bottom of stalks. The average bending stress value varied from 21.98 to 59.19 MPa. The Young’s modulus in bending also decreased as the moisture content and diameter of stalks increased. The average Young's modulus varied between 0.86 and 3.33 GPa. The shear stress and the shear energy increased with increasing moisture content. Values of the shear stress and energy also increased from top to the bottom of stalks due to the structural heterogeneity. The maximum shear stress and shear energy were found to be 11.04 MPa and 938.33 mJ, respectively, both occurring at the bottom region with the moisture content of 37.16%.

Keywords

1. Annoussamy, M., Richard, G., Recous, S. and Guerif, J. 2000. Change in Mechanical Properties of Wheat Straw Due to Decomposition and Moisture. Appl. Eng. Agric., 16(6): 657-664
2. ASAE Standards. 1985. S368.1. Compression Test of Food Materials of Convex Shape. ASAE, St. Joseph, Mich..
3. ASAE Standards. 2008. S358.2 DEC98. Moisture Measurement: Forages. ASAE, St. Joseph, Mich..
4. Baumler, E., Cuniberti, A., Nolasco, S. M. and Riccobene, I. C. 2006. Moisture Dependent Physical and Compression Properties of Safflower Seed. J. Food. Eng., 72(2): 134–140.
5. Bright, R. E. and Kleis, R. W. 1964. Mass Shear Strength of Haylage. Trans. ASAE., 7(2): 100-101.
6. Cakir, E. 1995. The Mechanics of Cutting Plant Residues on a Rigid and Soil Surface. PhD. Thesis, Auburn University, Auburn, Ala..
7. Chattopadhyay, P. S. and Pandey, K. P. 1999. Mechanical Properties of Sorghum Stalk in Relation to Quasi-static Deformation. J. Agric. Eng. Res., 73: 199-206.
8. Chen, Y., Gratton, J. L. and Liu, J. 2004. Power Requirements of Hemp Cutting and Conditioning. Biosys. Eng., 87(4): 417-424.
9. Choi, C. H. and Erbach, D. C. 1986. Corn Stalk Residue Shearing by Rolling Coulters. Trans. ASAE, 29(6): 1530-1535.
10. Crook, M. J. and Ennos, A. R. 1994. Stem and Root Characteristics Associated What Lodging Resistance in Poor Winter Wheat Cultivars. J. Agric. Sci., 126: 167-174.
11. Curtis, L. M. and Hendrick, J. G. 1969. A Study of Bending Strength Properties of Cotton Stalk. Trans. ASAE, 12(1): 39-45.
12. El Hag, H. E., Kunze, O. R. and Wilkes, L. H. 1971. Influence of Moisture, Dry-matter Density and Rate of Loading on Ultimate Strength of Cotton Stalks. Trans. ASAE, 14(4): 713-715.
13. Esehaghbeygi, A., Hoseinzadeh, B. and Masoumi, A. A. 2009. Effects of Moisture Content and Urea Fertilizer on Bending and Shearing Properties of Canola Stem. Appl. Eng. Agric., 25(6): 947-951
14. FAO. 2006. Available from .
15. Gere, J. M. and Timoshenko, S. P. 1997. Mechanics of Materials. PWS Press, Boston, MA, USA. 450 P.
16. Grundas, S. and Skubisz, G. 2008. Physical Properties of Cereal Grain and Rape Stem. Res. Agr. Eng. , 54: 80-90.
17. Ince, A., UOurluay, S., Guzel, E. and Ozcan, M. T. 2005. Bending and Shearing Characteristics of Sunflower Stalk Residue. Biosys. Eng., 92(2): 175-181.
18. McRandal, D.M. and McNulty, P.B.1980. Mechanical and physical properties of grasses. Trans.ASAE., 23(4): 816-821.
19. Mohsenin, N. N. 1986. Physical Properties of Plants and Animal Materials. Gordon and Breach Press, New York, USA. 891P.
20. Nazari Galedar, M., Tabatabaeefar, A., Jafari, A., Sharifi, A., O’Dogherty, M. J., Rafee, S. and Richard, G. 2008a. Effects of Moisture Content and Level in the Crop on the Engineering Properties of Alfalfa Stems. Biosys. Eng., 101(2): 199-208.
21. Nazari Galedar, M., Tabatabaeefar, A., Jafari, A., Sharifi, A. and Rafee, S. 2008b. Bending and Shearing Characteristics of Alfalfa Stems. Agric. Eng. Int.: The CIGR Ejournal, Manuscript FP 08 001, Vol. X.
22. O’Dogherty, M. J., Hubert, J. A., Dyson, J. and Marshall, C. J. 1995. A Study of the Physical and Mechanical Properties of Wheat Straw. J. Agric. Eng. Res., 62: 133-142.
23. Persson, S. 1987. Mechanics of Cutting Plant Material. ASAE Press, St. Joseph, MI, USA. 288 P.
24. Pourdad, S. S., Moghadami, M. J., Hatamzadeh, H. and Alipour, S. 2008. The First Released Safflower Variety for Dry-lands of Iran. In: Proceeding of 6th International Safflower Conference, November 3-6, Wagga, Australia, PP.177.
25. Prasad, J. and Gupta, C. B. 1975. Mechanical Properties of Maize Stalks as Related to Harvesting. J. Agric. Eng. Res., 20(1): 79-87.
26. Prince, R. P., Bartok, T. W. and Bradway, D. M. 1969. Shear Stress and Modulus of eElasticity of Selected Forages. Trans. ASAE, 12(3): 426-429.
27. Sacilik, K., Tarimci, C. and Colak, A. 2007. Moisture Content and Bulk Density Dependence of Dielectric Properties of Safflower Seed in the Radio Frequency Range. J. Food. Eng., 78: 1111–1116.
28. Sakharov, V. V., Rakmanberdiew, G. G. and Guagev G. G. 1984. An Investigation into the Severing of Pre-tensed Mulberry Stems by a Screw Type Cutter. Mekhanizatsiya I Elekfikikatsiya Sel'Skaogo Khozyaistva., 3: 61-62.
29. Shaw, M. and Tabil, L. 2006. Mechanical Properties of Selected Biomass Grinds. Agric. Eng. Int.: The CIGR Ejournal, Manuscript FP 07 006. Vol. IX.
30. Simonton, W. 1992. Physical Properties of Zonal Geranium Cuttings. Trans. ASAE, 35(6): 1899-1904.
31. Skubisz, G. 2001. Development of Studies on the Mechanical Properties of Winter Rape Stems. Int. Agrophysics, 15: 197-200.
32. Skubisz, G. 2002. Method for the Determination of the Mechanical Properties of Pea Stems. Int. Agrophysics., 16: 73-77.
33. Tavakoli, H., Mohtasebi, S. S. and Jafari, A. 2009. Physical and Mechanical Properties of Wheat Straw as Influenced by Moisture Content. Int. Agrophysics, 23: 175-181.
34. Yiljep, Y. D. and Mohammed, U. S. 2005. Effect of Knife Velocity on Cutting Energy and Efficiency during Impact Cutting of Sorghum Stalk. Agric. Eng. Int.: The CIGR Ejournal, Manuscript PM 05 004. Vol. VII.
Journal of Agricultural Science and Technology
Volume 14, Issue 4
July and August 2012
Pages 743-754