Kinematics and Finite Element Analysis of Excavator Attachments

Abstract

This dissertation work describes an approach of the kinematics and Finite Element Analysis (FEA) of robotic excavator attachments. Excavation tasks range from loading a pile of soil to cutting a geometrically described volume of earth for a trench or foundation footing. Full kinematics model of the excavator Attachments, regarded as a planar manipulator with four degrees of freedom, were derived. The forward and inverse kinematics is used for positioning the robotic excavator.

The main objective of this project is to validate the existing design and redesign the attachments by analyses which are failing under the given operating conditions. During operation of excavator at different positions the stresses induced in the attachments varies. Considering the fact that, corner tooth loading is the critical one, a FEA has been carried out to understand the behavior of the structure. The forces applied in the analysis were calculated by using MathCAD and Design View (DV) software. Meshing of the attachments is done by using HyperMesh-6.0. Solution and post processing is done in I-DEAS-8.

The FEA result of the Dipper/Arm, Offsetboom and Lowerboom shows high stress in some regions. For reducing stresses, some design change and also plate thickness of attachments is changed. After this changes the stress in the attachment are coming under allowable limit.