The technology development in automobiles is progressing towards providing smarter vehicles with increased efficiency and reduced emission. To cater this need, Electric Vehicles (EV) and Hybrid Electric Vehicles (HEV) are slowly thriving in Indian roads. Conversion of existing IC engine powered vehicle to HEV reduces complication in new vehicle development and also results in vehicles with increased efficiency and reduced emission. In order to convert the Conventional Vehicle to Hybrid Electric Vehicle, drive from electric motor was coupled with existing driveline by modifying mechanical systems suitably. Hybrid vehicle includes systems such as electric motors, inverters, high-voltage batteries and electronic control units, which are mounted in chassis members.
Being a major load carrying member, any modifications in chassis system may affect the performance of vehicle, therefore it is necessary to evaluate the modified design of chassis members. Finite Element (FE) model was built for existing chassis system. The FE modelling was carried with validated Modelling techniques, which gave good correlation with physical testing results. Modal analysis of chassis was carried out to find out the fundamental frequency and its harmonics. When the vehicle ply on road with different loading conditions, the chassis is subjected to twist and bending loads. To capture this, bending stiffness and torsional stiffness of the chassis system were determined using simulation. Apart from this static strength analysis was carried out for Braking, Cornering and Bump Loads. Vibration, Stiffness & Strength Analysis of chassis system was evaluated to ensure the performance of the chassis system. Results from these analysis were set as a benchmark target. Initially Subsystem level Strength Analysis of mountings have been carried out for newly added components, to ensure that they are not failing in static loading conditions.
The Modified Chassis system meeting the functional requirements for converting into HEV, was again analysed for modal frequencies, stiffness and strength load cases. The results were in line with target values. Rear impact analysis was carried out in existing vehicle to check whether any deformation affecting the battery package. However, it was found that there was no deformation in battery mounting location. This boosts the confidence to implement the changes in chassis system of proto vehicle. With the validated changes in chassis members, Proto Vehicle have been built and it was tested for its functional requirements.