Automated and Generic FEM analysis of Industrial Robot Design

Abstract: In a competitive market it has become necessary to deliver products in a fast and efficient way. The mechanical design process needs to be modified in a way to be able to deliver reliable and fast products. One way of modifying the process is by reducing the amount of manual work by automating the repetitive tasks using scripts built in the computer tools. This thesis work aims to develop a methodology where tedious and repetitive design processes are automated. The design of an industrial robot lower arm will be used as a proof of concept. The modeling is done in the CAD software SolidWorks and is evaluated structurally in the FEM software ANSYS. The FE process in ANSYS is automated by the use of the programming languages Python and JavaScript. Furthermore a user interface is created using Microsoft Excel with Visual Basic. To allow automatic FEM, a parametric CAD model of a Robot lower arm is constructed. To validate its properties, the arm’s mass properties are compared with the real non-parametric model of the Industrial Robot IRB6640. It is shown that the parametric CAD model can be obtained with high accuracy. It has also been possible to validate the automated framework and the parametric design by comparing the Maximum Von Mises Stress of both arm models. Performing a Design of Experiments it was possible to obtain the functional relation between the Mesh Element Size and the FE results. The validation tests conducted further strengthen the hypothesis that tedious and repetitive design processes can be automated in order to reduce the work load of engineers.