Pavan Kapoor: Mechanical Engineering Portfolio

Cooper Union Motorsports: Formula SAE

Body/Cockpit/Safery System Assembly that I Desgined(Excluding frame)

Nosecone

Nosecone Mold Manufacturing

Infusion Layup Setup

Resin Infusion

Post-Processing

Post Vinyl

Anti-Intrusion Plate and Impact Attenuator

AIP Welding

Impact Attenuator Adhesion

Firewall

I designed and manufactured a ballistically protective, electrically, and thermally insulative firewall for an electric racecar.

Materials

The Firewall is made of a sandwich panel of 6 layers of 200 gsm bidirectional basalt fiber with a sheet of Nomex Honeycomb in the middle. It also has a layer of 0.64mm thick 6061 Aluminum facing the tractive system. I used Basalt because it had the highest resistivity and acceptable tensile strength. The Nomex Honeycomb adds thickness which makes the firewall stiffer in bending since the high tensile strength Basalt is further from the neutral axis. It also adds a airgap which increases thermal and electrical insulation.

Design

I designed the firewall based on space constraints in the chassis and manufacturability. There are no complex curves in the design since the aluminum must be bent to the desired shape first. The Aluminum backing facing the driver is connected to low-voltage ground through the mounting tabs. This protects the driver from any high-voltage malfunctions.

The Firewall mounts with quarter turn fastners. This is to improve serviceiblity of low voltage components behind the firewall.

Lower Firewall Manufacturing

I manufactured the firewall with a vacuum layup. I used a sheet metal bender to cut and bend the aluminum.

Foam mold with aluminum backing

Post-Processed

Upper firewall Manufacturing

Bent Aluminum Sheet Metal

Nomex Coring

Layup

Post Processed and mounted

Harness tabs

Design

Harness tab was designed to be able withstand 15,000N of tearout load per tab based on rules from FSAE.

The tabs were designed to be manufactured from rectangular steel tubing so that the bolts were in double shear while being easy and efficient to manufacture since there it was milled out of correctly sized tube rather than a solid block of steel. Although 2 tabs cut from 1/8" sheet metal could have been used, it would have been very challenging to weld the inside edge of the tab as required by rules. The hardware is M12 high-strength alloy steel shouldered bolts.