PROVE Primary Battery Structure

Author(s) Information

John D. Burkhart, California Polytechnic State University, San Luis ObispoFollow
Andy Mccormick, California Polytechnic State University, San Luis ObispoFollow
Ryan Yu, California Polytechnic State University, San Luis ObispoFollow
Soren Barclay, California Polytechnic State University, San Luis ObispoFollow

College - Author 1

College of Engineering

Department - Author 1

Mechanical Engineering Department

Degree Name - Author 1

BS in Mechanical Engineering

College - Author 2

College of Engineering

Department - Author 2

Mechanical Engineering Department

Degree - Author 2

BS in Mechanical Engineering

College - Author 3

College of Engineering

Department - Author 3

Mechanical Engineering Department

Degree - Author 3

BS in Mechanical Engineering

College - Author 4

College of Engineering

Department - Author 4

Materials Engineering Department

Degree - Author 4

BS in Mechanical Engineering

Date

6-2023

Primary Advisor

Ramanan Sritharan, College of Engineering, Mechanical Engineering Department

Additional Advisors

Eltahry Elghandour, College of Engineering, Mechanical Engineering Department

Abstract/Summary

In conjunction with Prototype Vehicle (PROVE) Laboratory, our group designed, manufactured, and tested a prototype structure to house the battery boxes for PROVE’s endurance vehicle. Our structure was designed to support the batteries during normal use, and in the event of a front crash. Our design is comprised of a secondary composite box to house the battery boxes, a bottom plate to affix the secondary box to the chassis floor, a horizontal plate fastened to the chassis, and a brace structure welded to the chassis. From the outset, we chose to use a secondary box, the primary battery boxes must be removable, and we could not directly affix supports. In areas of less certainty, such as the number of support or the strength of support methods, we initially used intuition to make decisions, and allowed room for iteration once we had sufficient analysis later in the project.

After developing our initial structure, we created FEM case studies on the full assembly, and used hand calculations to verify our FEM. We were most concerned with the deflection of the front wall in a front 20g crash. We used laminate plate theory in a python algorithm to verify FEM results for the front wall deflection. We found that the brace structure failed in the FEM study. However, we also anticipate redesigning or possibly removing the brace in favor of an additional plate joining the chassis tubes parallel to the front wall.

Our team manufactured layups of carbon fiber sandwich panels and L channels for the secondary structure and bottom plate. We successfully integrated the bottom plate and secondary box. However, due to tolerancing issues and discrepancies between the CAD and the physical vehicle our brace structure requires alteration to be integrated. Threaded inserts were manufactured on a lathe and bonded into the panels to allow for them to be integrated onto the chassis. The secondary structure was manufactured smoothly and could fit onto the chassis, which is a great success. One of the two horizontal plates and braces were water jetted and welded respectively, but they need to be redesigned to properly suit their integration. Additionally, our team characterized the Elastic moduli and Poisson’s ratio of carbon fiber material using tensile and strain gauge testing.

URL: https://digitalcommons.calpoly.edu/mesp/706