Calculation of Static Forces and Finite Element Analysis of Attachments of an Excavator

Abstract

The continued tremendous growth of knowledge of kinematics and dynamics of machinery has resulted in development of improved version of earth moving equipment. In the era of globalization , it is not only sufficient that the machine should perform satisfactorily for predicted life but it is equally important to optimize the machine to reduce the cost. In today’s competitive market, reduction of cost of machine without affecting the performance has become the necessity for any machine manufacturer.

Static force calculation This project is intended to cover static force calculation and Finite Element Analysis of an attachment of excavator. With the help of Design View software , Assembly of parts of an excavator is made. Parts are exported from Auto-Cad file as DXF file. After making assembly various constraints are given by writing the equations. Forces acting on various parts are then calculated from that equation.

Validation of forces by MathCAD output Validation of the result is done by comparing the forces with the MathCAD program output. Math Cad program is developed for this excavator. MathCAD gives very accurate results and it is extremely useful for solving vector mechanics problems and matrices. It is useful for solving all mathematical formulas like integration, differentiation, matrix operations etc.

Finite Element Analysis Solid model of different components are analyzed using FEA software. Model is exported through IGES file and cleaned for analysis purpose. Meshing is done using suitable type of elements. Material property is assigned, Boundary conditions and the forces are applied. Modal Analysis is done to find the natural frequency of the component.

Solution is obtained using Linear Static Analysis. Von-Mises stress plot and deflection plot is taken from the software. For Finite Element Analysis I-deas CAD/CAM/ CAE software is used. Meshing is done using Hyper mesh for Dipper. Bucket is analysed using Pro-mechanica (Independent mode) software. Optimization can be done using the same software and that is how excess material can be removed by changing the shape of the component or by changing the size of the component. If the parts are failing then redesign can be done. Fatigue analysis of Boom and Dipper is also done using static fatigue module FEA technique is very widely used when closed form solution is not available. Using this technique nature of failure of component in different situation can be predicted.

To develop a broad and basic comprehension, all the methods of analysis and development common to the literature of the field are employed.