ME450 Project

Gearbox Analysis

ME450 Finite Element Analysis Fall Semester, 2007 Prof: Dr. K. Nematollahi Team Members

Aaron Huesman Jae Shin Kelly McCormick

12-10-2007

Objective

Perform structural analysis of two competing designs of a machined aluminum gearbox casing.

Applicable Theory

{F} = [T][K][T]-1{U}

Introduction

Two competing designs Webbed Non-webbed

Previous choice based on ease of machining

Performing structural analysis to confirm choice

Non-Webbed

Webbed

Unigraphics Model

Forces

Ansys Model Details

Model reduced to simplest form One half of casing used (symmetry) Gears removed Bearings simulated

Aluminum alloy material for case Brass material for bearing volumes

Ansys Model

Solid Cylinders Simulate Bearings

Substitute

Bearing Volumes

Boundary Conditions

Boundary Conditions Cont…

Element Type

Utilized ten-node SOLID92 tetrahedral elements Ideal for complicated solids with curved boundaries

Meshing

Automatic meshing option

Analysis

Deformation study Von-Mises Stress study

Consistent boundary conditions and forces applied.

Deformation Distribution

Non-Webbed Webbed

Max: 5.17E-4 in. Max: 5.00E-4 in.

Stress Distribution

Non-Webbed Webbed

Max: 4633.8 psi Max: 3497.4 psi

Results

Non-Webbed

1. Max Deformation

= 0.00051749 in

2. Max Stress

= 4633.8 PSI

3. Mass

= 0.854 lbm

Webbed1. Max

Deformation

= 0.00050028 in

2. Max Stress

= 3497.4 PSI

3. Mass

= 0.878 lbm

%Change1. Max

Deformation

= -3.3%

2. Max Stress

= -24.5%

3. Mass

= +2.7%

Impact Statement

Reduced chance of a failure1. Reduces potential waste of material2. Reduces potential environmental

contamination3. Reduces potential injuries (Robust

design)

Conclusion

Webbed design is superior.

1. Less stress2. Less deformation3. Easier machining4. Minimal change in weight

Bibliography

[1] Moaveni, Saeed. “Finite Element Analysis” Theory and Application with Ansys – 3rd Addition, Pearson Education, Inc., Pearson Prentice Hall, Upper Saddle River, NJ 07458, 2008.

Questions