Meshing and Stress Analysis of 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 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.