Frame Design of a Passenger Vehicle of M3 Category Using Design of Experiments

Chassis frame of a passenger vehicle is one of the primary load bearing components of the vehicle. All the aggregates such as engine, radiator, fuel tank, EATS, air tanks, body and cowl etc. are mounted on to the frame. It should have sufficient stiffness and strength to withstand the static and dynamic loads. At the same time it should also be light in weight as it helps in reducing the fuel consumption and emissions coming out of the vehicle. The main objective of this work is to design a chassis frame of a passenger vehicle of M3 category using Design of Experiments by considering the stiffness and the natural frequency of a similar type of vehicle’s frame (Benchmark) as the target values i.e. the final design of the frame should match the stiffness and natural frequency values of the benchmarked frame with a specified tolerance set as per the general methodology of frame design. Apart from these, the frame’s design is also optimized to attain a minimum weight by adding/removing reinforcements etc. in order to keep the weight of the frame to a minimum value, without compromising on its stiffness and natural frequency values that are to be matched with the legacy frame’s values (Benchmark) in all the loading cases. As weight optimization of chassis frame is an iterative process, we use Central Composite Design technique in Design of Experiments to find out the optimized cross section for long member of frame such that the frame assembly can match the stiffness and natural frequency values with that of the legacy frame’s values in all loading cases, thereby minimizing unwanted iterations.