Meshing and Stress Analysisof a “Droop” Limiter

By: Geoffrey L. Ostermeyer

Final Project

For: ME 450

Professor: Dr. Craig Weeks

December 14, 2000

Problem Statement

Model, mesh, and analyze “Droop” Limiter using Ansys for IUPUI Electric Race Car Team.

Analysis should include determination of stress concentrations and damper design.

Background• Designed by Senior

Design Team

• Used on the Electric Race Car

• Limits Rear End Lift to 3/16”

The Droop Limiter

Parts – Defined

Steel Washer

Rubber Washer

-- Damper

Upper Bracket

Tie-Rod

Tie-Rod

Connector A-Frame

Mounting Bolt

Geometry Generation

Import IGES files from Pro-E

Create Volumes in Ansys

Simplified Geometries

Pro-E Imports

Ansys Volumes

Simplified Geometries

From

To

Combining Parts

Volume Adding

Surface Coupling

Contact Surfaces

Adding Volumes

Coupling Surfaces

Contact Surfaces

Assembled Geometries

Meshing

Mapped versus Free

Completed Mesh

Stress Analysis – Tie-Rod Connector

Stress Analysis – Upper Bracket

Stress Analysis – Washer/Tie-Rod Weld

Damper Design

Conclusions

Stress Concentration on Tie-Rod Connector is not expected to be a problem.

Upper bracket and washer/tie-rod weld stress concentrations are potential hazards.

At current dimensions, the damper would require a Young’s Modulus of approximately 30,000 psi (Polyester Elastomer).

A more conventional rubber may be used with a smaller washer thickness.