12 Fatigue Analysis in the Connecting Rod of MF285 Tractor by Finite Element Method

In this study, detailed load analysis under service loading conditions was performed for connecting rod of MF-285 tractor engine (by using the Mathematica software), followed by finite element analysis (FEA) to capture stresses and fatigue cycle (by using ANSYS software). The results of the study shows that maximum tensile stress occurs on the small end of connecting rod caused by inertia loads and friction between piston pin and connecting rod bush and equals 280 MPa, maximum compressive stress occurs on the big end of connecting rod caused by preload of screws and equals 165 MPa. In new connecting rods whit structure like structure of this connecting rod stresses are between 160 to 250 MPa. Fatigue cycle was calculated equal 108 cycles. Proper fatigue cycle for connecting rods equals 108 to 109. According to that maximum stresses was more than common rang, seems it caused to happen least fatigue cycle. According to results of this study, it could be proposed to lessen friction between piston pin and connecting rod bush, changing in manufacture process, changing in connecting rod material, optimization of reciprocating mass and increasing the diameter of small end of connecting rod to redesign and optimize the model for better resistance under hard loads.