🏎️ TEKNOFEST

Carbon Fiber Monocoque Chassis Project

High performance sandwich composite monocoque chassis designed, manufactured and optimized for Efficiency Challenge Electric Vehicle Racing

12kg

Total Weight

22mm

Panel Thickness

6 Floors

Carbon Fiber

1.5 Days

Curing Time

🎯

Purpose and Scope of the Project

The main aim of this project is to TÜBİTAK organized by TEKNOFEST Efficiency Challenge Electric Vehicle RacesOur aim was to develop an innovative chassis that combines performance, safety and lightness criteria for our team that will participate in the . The importance of electric vehicles is increasing day by day due to increasing fossil fuel prices and strict emission standards.

⚖️ Lightness and High Strength Minimizing the vehicle's overall weight and maximizing structural integrity by using a sandwich composite structure of carbon fiber and PVC foam instead of traditional chassis materials.	🔩 Rigidity To provide torsional and bending rigidity, which is critical for the vehicle's handling and driving dynamics.
🛡️ Safety and Ergonomics To create an ergonomic design that complies with competition regulations, ensures pilot safety.	🏭 Manufacturability Transforming the theoretical design into a physical product with modern composite production techniques such as vacuum bagging.

💻

Design Process (CAD)

chassis design, Solidworks It was carried out with meticulous work using a solid modeling program. The following parameters were taken into account during the design phase:

Parameter	Description
Regulations	The minimum width and length measurements specified in the TEKNOFEST specifications have been complied with.
ergonomics	An interior volume has been designed to fit two Sparco Sprint racing seats side by side, ensuring the comfort and safety of the pilots.
Mechanical Integration	The locations of critical mechanical components such as the ability of the wheels to rotate at a rotation angle of 30-35° and the placement of the engine, battery and suspension systems were taken into account.

📐 Sandwich Building Configuration

200 gr/m² 3k plain carbon fiber fabric with 3 layers on the bottom and 3 layers on top between these layers 20mm thick Airex C70.48 PVC foam created by placing 22mm thick A sandwich monocoque structure was designed.

📊

Finite Element Analysis (FEA) and Optimization

In order to verify the theoretical performance of the design and detect structural weaknesses ANSYS Workbench 2021 R2 program was used. Due to the complex structure of composite materials, analyzes are carried out by experts in this field. ACP (ANSYS Composite PrepPost) It was carried out with the module.

Analysis Phase	Details
Model Preparation	The model designed in Solidworks was converted to a surface model in Ansys DesignModeler.
Material Data	Engineering data of carbon fiber and Airex foam materials taken from the MATWEB database were entered into the system.
Lamina Structure	In the ACP module, a lamina structure consisting of 6 layers of carbon fiber and foam core, which will be placed at angles of 0-90° and ±45°, is defined.
Load Condition	Static structural analysis was performed by applying a pressure load of 0.1 MPa to the chassis.

⚠️ First Analysis Result

As a result of the first analysis, in the middle part of the chassis 154.69mm A high deformation value such as was observed. This result showed that the design had a weak point.

✅ Optimization Process

In the light of the data obtained from the analysis, we returned to the Solidworks model and added structural reinforcements to the middle part of the chassis and designed the design. has been revised. This iterative process increased the strength of the design and reduced deformation to acceptable levels. This step proves that the project is not just a design study, but also an engineering optimization process.

🔧

Physical Production Process (Manufacturing)

After the design and analysis stages were successfully completed, physical production of the optimized chassis started. As a production method, it provides high fiber volume ratio and low void ratio. Vacuum Bagging Method was preferred.

📦 Materials Used

🧵 224 Plain Carbon Fiber Fabric	🧱 Airex C70.48 and C70.75 PVC Foam
🧪 MGS L160-H160 Epoxy Resin	📦 Vacuum Bagging Set

🔄 Production Steps

Mold Preparation

The wooden mold surface is cleaned to prevent the piece from sticking. wax (mould release agent) It was covered with.

Lower Carbon Fiber Layers

The first 3 layers of carbon fiber fabric were laid on the mold and each layer by hand deposit method It was saturated with epoxy resin prepared in a ratio of 100:25.

Foam Core Placement

A resin-impregnated PVC foam core was placed on top of layers of carbon fiber.

Top Carbon Fiber Layers

The remaining 3 layers of carbon fiber were laid on the foam in the same way and resinized.

Auxiliary Material Layers

In order to absorb excess resin and bond the layers tightly, the structure is peel cloth, escape bag and vacuum blanket It was covered with.

Vacuum Application

whole structure vacuum bag It was taken inside, sealed with sealing tape, and the air inside was completely removed with the vacuum pump.

curing

building, 1.5 days It was left to cure (freeze) under vacuum for a long time.

🏆

Project Result

Successfully Completed!

12kg

At the end of all these challenging processes, a carbon fiber composite monocoque chassis with high strength and rigidity, ready for TEKNOFEST races, was successfully produced.

High Strength Low Weight Optimized Ready to Race Sandwich Composite

This project covers everything from concept to design, simulation to optimization and finally physical production. all engineering disciplines It was a comprehensive comprehensive study.

Software and technologies used within the scope of this project:

Solidworks ANSYS Workbench ANSYS ACP Vacuum Bagging Carbon Fiber Composite