PERFORMANCE ENHANCEMENT OF AN ELECTRIC VEHICLE PLATFORM USING MULTIDISCIPLINARY DESIGN OPTIMIZATION METHOD

• Main Author: Satryo Sulton Sahara, Muhammad
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/61993
• Institution: Institut Teknologi Bandung

Electric vehicles are now developed as the future’s hope for fighting climate change and reduce the usage of petroleum-based fuels. By using battery, electric vehicles are able to reduce the air pollution emission compared to petroleum-based vehicle. The primary objective of this research is to optimize an electrical bus chassis with considering the chassis’ bending rigidity, torsional rigidity, static test load case, and NVH. On this research, it is studied that the optimum design in one discipline may not be the optimum design for the other discipline. Beside that, this research also studies the final design determination that fulfils all of the discipline. The final design is later tested for its frontal crash safety. The final design performance is later compared to the baseline design chassis and an existing chassis that is available on the market. On this research, the baseline chassis is modified into several variations, to which design factors are assigned based on the L16 orthogonal array. Then, the effects of each level of design variable are calculated by using Taguchi’s Robust Parameter method. The controlled variables are analyzed for their influence on the performance using the Analysis of Variance. After the effects of each level of design variable is acknowledged, the results are then calculated into an objective function using weighted sum method so that one final design can be selected. The final design is determined to be a chassis with the configuration of Geometry K, thickness of 6 mm, and constructed with Al 6005 material. The most influential factor of the chassis’ bending rigidity, torsional rigidity, and static test strength is determined to be the thickness. Meanwhile, the geometry of the chassis is the most influential factor on the NVH discipline. The estimated optimum design has the torsional rigidity of 16.021 kN/mm, bending rigidity of 3.612 kN/mm, static test safety factor of 3.47, and 1 number of natural frequency below 25 Hz. The final design is later tested for its frontal crash safety, where the stress of the battery is evaluated. However, the battery stress exceeds 10 MPa where short circuit occurs. For that reason, the geometry of the chassis is changed to the next-best design, where the Geometry L is chosen. The chassis with the configuration of Geometry L, thickness of 6 mm, and material Al 6005 has passes the frontal crash criteria as the battery stress does not exceed 10 MPa during the frontal crash test. The final design has the torsional rigidity of 14.94 kNm/grad, bending rigidity of 3.613 kN/mm, static test safety factor of 4.27, and 2 number of natural frequencies below 25 Hz (16.95 Hz and 24.72 Hz).