Mechanical analysis of cluster-grain separator device of a new head of paddy harvesting machine

This paper presents stress and strain analysis of outer shaft shoulder (OSS) and inner shaft shoulder (ISS) of a new paddy harvesting head (PHH) using finite element method (FEM). Snapping grain unit is a part of this head, with OSS and ISS as its members. The analysis was performed using the ABAQUS software with Dynamics Explicit Solution Method. Eight-node block and four-node tetrahedral elements were used to mesh the parts of the head. After the analyses, the stress and strain curves, and their maximum values were estimated for various parts. Analytical method was used to verify the FEM results and to calculate the factor of safety (FS) of the OSS and ISS components and also to estimate the number of cycles to failure of each component. The maximum amount of force applied to each tooth of shoulder was 4.29 Nmm-1. The maximum stress in both shoulders was obtained as 44.43 MPa. Other results showed, fatigue factors of safety for all components were less than their relevant yield factor of safety. Therefore, the fatigue in components would occur first. The study showed the predicted life for OSS and ISS components is more than 106 cycles, thus the components have an infinite-life. A fitted regression line to the data showed that the calculated stresses from analytical method lie within bounds of 7.89 % of the predicted values with a coefficient of determination of 0.98. Hence, it could be concluded that there is a good agreement between the analytical and FEM results.