Design and fatigue analysis of the lower arm element of the three-point hitch in tractors

In this study, the design of the lower lifting arm, which is an element of the three-point hitch in a tractor, and the 55Cr3 and 42CrMo4 steels are taken into account, and it is aimed to perform the forces under the influence of them in different positions and the static stress and fatigue analysis due to them. The design of the lower lifting arm was carried out with the Solidworks program. Ansy Workbench software was used for analysis processing. For the analysis, the forces acting on the system are considered as the maximum load lifting condition of the lower lifting arm, the lower position, the horizontal position, the upper position and the drawbar condition. Material properties and boundary conditions are defined in Ansys Workbench software. Accordingly, total deformation, principal stress and elastic principal strain were chosen as static stress analysis solution information. In addition, total deformations in x and y axes, fatigue life, safety factor were chosen as solution information in fatigue analysis. First of all, static stress analyzes were carried out in different situations such as maximum load lifting, lower position, horizontal position, upper position and drawbar. After the static stress analysis, fatigue analysis was carried out. As a result of the analysis, total deformation, principal stress, elastic principal strain gradients and fatigue life, safety factors were determined for each different position. According to this; The highest principal stress occurs in the maximum loadbearing condition, and the lowest principal stress occurs in the drawbar condition. Due to the difference in the yield strengths of the materials, the stresses obtained at the same location are approximate, but the safety coefficients provided by the materials are different. Fatigue life was obtained as 106 cycles for both materials. Minimum safety factor is 3.41 for 55Cr3 steel; 2 for 42CrMo4 steel. Keywords: Fatigue, 55Cr3, 42CrMo4, Maximum Principal Stress, Total Deformation