The project was to design the chassis for FSAE Team so as to minimize the weight to stiffness ratio and Rigid enough to withstand the shock, twist, vibration and other stresses.
Chassis is the main support structure of the vehicle which is also known as ‘Frame’. It bears all the stresses on the vehicle in both static and dynamic conditions. In a vehicle, it is analogous to the skeleton in living organisms.
The design of the chassis must work around a number of parameters and constraints in order for it to perform well and for it to be eligible to compete in the competition. These requirements can be broken into several categories which will be discussed below. If any of these requirements are not met, the consequences range from sub-optimal performance to not being eligible to compete in the competition or even chassis failure.
• Rules- The FSAE Rules majorly define the basic structure of a Chassis. Rules like Cockpit opening, Firewall Barriers, Foot-well Template and 95th Percentile rule form the basic structure.
• Suspension Design and Forces- The suspension design uses unequal length double A-arm suspension with inboard mounted springs connected to the wheels via push-rods and bell-crank rockers. Ideally, the A-arm forces should act as near as possible to a node in the chassis so the reaction forces consist of pure compressive and tensile forces in chassis members.
• Packaging- In conjunction with meeting all the rules and providing attachments for the suspension components, the chassis must also fit the driver and all the required components into the frame like Seat and driver harnesses, Batteries, Electronic control components and Driver controls.
• Driver ergonomics must be considered to ensure the driver is able to complete each driving event comfortably. As mentioned in the rules section, the 95th percentile male must be able to fit in the chassis with clearance to the front and rear roll hoops.
• Material- Material that is to be used for the chassis is chosen to be 1020 alloy steel because of its relatively higher strength and wider availability in various cross-sections in the market as compared to mild steel extrusions.
Chassis designing is the most vital part of the design and analysis of the chassis because it essentially represents the actual chassis in the design domain. The frame of Tuff X was designed in SolidWorks and further, meshed and analyzed in Altair Hyper-works. . The few important features used in the modelling of this component are the structural Member in Weldments (Solidworks), Trim and other basic features.
The results of the various analysis test performed on the chassis are given below.
Torsional Stiffness 3.84kNm/deg
Lateral Stiffness 0.513 kN/mm
Vertical Stiffness 4.09KN/mm
poty2k21 Edu POTY 2021 POTY 2021-Project
