SAE BAJA PROJECT FRAME DESIGN

Robert GolmonAdvisor: Dr. LeeInstructor: Cris KoutsougerasEt 494 - Senior Design Fall 2012

IntroductionThe Baja SAE project is a competition that simulates real-world

engineering design projects and their related challenges. Engineering students are given the task to design and build an off-road vehicle that will survive the severe punishment of rough terrain.

ObjectivesThe objective of my part of the baja project is

to design and construct the chassis/frame of the vehicle from the ground up. Some challenges to are I need to keep the frame both light and strong while I try to keep the cost down. I will need to calculate the proper frame diameter and test the whole design by doing a stress analysis.

• To draw my frame I decided to use Inventor professional 2011.• Similar to auto cad but also has a FEM(finite element method) software built

INVENTOR 2011

Fall 2012 • Add to my design by adding suspension mounts and other suspension components, using approved steering design.• Run stress analysis with FEM software on the new frame assembly. • After the design is approve I will need to build the frame

Rear Suspension DesignFour link suspension uses links to prevent the axle from

moving side to side or back or forth while allowing it to go up and down as well as articulate. A well designed and tested four link will provide a superior translation to the ground and higher ride quality.

Four Link Design

Frame Analysis

• For the analysis the weight of the driver an the weight of the engine were added where they connect to the frame.• I ran the analysis on different tubing sizes ranging from 1x.133- 1.25x .065 to find the smallest diameter pipe that would satisfy the max stress for the design factor .

Design Factor

Results

The tubing that satisfied the conditions and gave use the most weigh advantage was the 1.25x.065

Sy/8.7= 30043.54/8.7= 3453.28 psi

Name Minimum Maximum

Displacement

Displacement 0.000 in 0.014 in

Forces

Fx-167.671 lbforce

167.330 lbforce

Fy-25.769 lbforce

26.240 lbforce

Fz-72.074 lbforce

210.373 lbforce

Mx-163.865 lbforce in

169.013 lbforce in

My-690.276 lbforce in

214.525 lbforce in

Mz-56.091 lbforce in

56.071 lbforce in

Normal Stresses

Smax -78.571 psi 2983.580 psi

Smin -2759.543 psi 723.430 psi

Smax(Mx) 0.000 psi 1869.558 psi

Smin(Mx) -1869.558 psi -0.000 psi

Smax(My) 0.000 psi 2372.986 psi

Smin(My) -2372.986 psi -0.000 psi

Saxial -247.848 psi 723.430 psi

Final Frame Design

• Material = 1020 Dom 1.25x.065

tubing

• Weight = 78.7 lbs using 96 ft of

tubing

• Cost=$186.24

Timeline

September 12- Proposal

October 1- have the altered design in cad

October 27- have the stress analysis for the new design

December 1 – Constructed frame