Australian Journal of Basic and Applied Sciences, 3(2): 1438-1449, 2009 ISSN 1991-8178 Corresponding Author: Kamran Kheiralipour, Ph.D. Student. Mechanical Engineering of Agricultural Machinery Dept. Faculty of Biosystem Engineering. University of Tehran. Karaj. Iran. E-mail: kamrankheiralipour@gmail.com 1438 Obtaining Maximum Stresses in Different Parts of Tractor (Mf-285) Connecting Rods Using Finite Element Method Mansour Rasekh, Mohammad Reza Asadi, Ali Jafari, Kamran Kheiralipour 1 2 3 4 Associate Professor. Mechanical Engineering of Agricultural Machinery Dept. Faculty of 1 Agricultur. Mohaghegh Ardebili University. Ardebil. Iran. M.Sc. Student. Mechanical Engineering of Agricultural Machinery Dept. Faculty of 2 Agricultur. Mohaghegh Ardebili University. Ardebil. Iran. Associate Professor. Mechanical Engineering of Agricultural Machinery Dept. Faculty of 3 Biosystem Engineering. University of Tehran. Karaj. Iran. Ph.D. Student. Mechanical Engineering of Agricultural Machinery Dept. Faculty of 4 Biosystem Engineering. University of Tehran. Karaj. Iran. Abstract: Tractor MF-285 is a high volume production of Iran Manufacturing Tractor Co. Engine inner part faults of MF-285 are more than other engine components. So stress analysis in rotating parts of tractor MF-285 for optimizing them is important. In this study, detailed load analysis was performed for a MF-285 connecting rod, followed by finite element method. In this regard, In order to calculate stress in connecting rod, the total forces exerted connecting rod were calculated and then it was modeled, meshed and loaded in ANSYS, 9, software. The maximum stresses in different parts of MF-285 connecting rod were determined. The maximum pressure stress was between pin end and rod linkages and between bearing cup and connecting rod linkage. The maximum tensile stress was obtained in lower half of pin end and between pin end and rod linkages. Key words: Tractor; Engine; Connecting Rod; Finite Element; Stress Analyzing. INTRODUCTION Tractor, as the most important agricultural machinery, has main share in planting, retaining and harvesting operations and then in mechanization sector. Hence, in order to reach sustainable agricultural and to increase mechanization level quality and manufacturing technology of this agricultural machinery and also its quantity must be reached to optimum level. Tractor MF-285 is main production of Iran Manufacturing Tractor Co. Researches show that engine inner parts’ faults of MF-285 are more than other engine ingredients (Mahmoodi, A., H. Rezakhah, 2007). Above statements show the importance of stress analysis in rotating parts of tractor MF-285 for optimizing them. In this regard, dynamic stress analysis in connecting rods of this tractor was studied. In 1995, optimizing of geometrical shape of connecting rods considering concentrated mass to properly distribute its stress was studied in Yuan-Ze Inst of Tech Research Center (Lee, H.J., M.C. Lin, 1996). In this research stresses in connecting rod were calculated using Finite Element method and proper profile for that was obtained. In this research, authors embarked on determination of points with maximum stress in tractor MF-285 connecting rod to future optimization. MATERIALS AND METHODS MF-285 engine has 4 reciprocated cylinders with linear arrangement. Engine configuration and qualifications was shown in Table 1.