Design of the Ethiopian and plough using structural analysis validated with finite element analysis

The Ethiopian and plough ' Maresha ' is a tillage tool that most farmers still use for land preparation. The production of the wooden structure is based on experience, culture, and trial and error methods. In this paper, the basic design of the and plough is presented. The mathematical descriptions (traditional force analysis) are based on static analysis at equilibrium of the structure. The forces considered were the pulling forces provided by a pair of draught animals, the operator input force, gravitational weight of the implement, the normal and tangential interfacial forces acting on the ploughshare and wooden side-wings and the inertial force. The draught, vertical, tangential interfacial and normal interfacial forces of the implement were determined. Moreover, sensitivity of draught and vertical forces to different pulling angles and sensitivity of normal and tangential interfacial forces to different rake angles were investigated. The force analysis was validated by means of the finite element (FE) analysis using the ABAQUS package. It was confirmed that draught force on the ploughshare increased with pulling angle. Similarly, the tangential interfacial force of the implement was higher than the normal interfacial capacity at lower pulling angles. The output of the FEM and traditional calculation resulted in small errors of less than 3% for draught and 5% for vertical forces for small pulling angles <= 30 degrees. This study integrates the previous research experiences with theory and computer-based analysis and simulations. The design guidelines and considerations for improving or developing small-scale tillage implements are presented. (C) 2007 IAgrE. All rights reserved. Published by Elsevier Ltd