Design and Optimisation of a Double Wishbone Independent Suspension System for an L6 Electric Vehicle: A Response Surface Methodology Based Design Application

Year 2025, Volume: 4 Issue: 1, 21 - 30, 31.03.2025

Mohammad Nassar Kübra Polat , Yağmur Koçlu Mehmet Murat Topaç

Abstract

Suspensions are vital vehicle subsystems that provide ride comfort, stability and handling while absorbing shocks caused by road irregularities. Their designs require careful consideration of structural integrity, weight reduction and performance optimisation. In light electric vehicles, such as those in the L6 class, the design and optimisation of suspension systems becomes even more critical due to design compactness and functionality. The aim of this study is to design a front independent suspension system for an electric L6 class vehicle and to outline an optimisation-based design process of this design by Finite Element Analysis (FEA). In the first stage of the study, various load cases and the effects of these loads on the connection points were determined and force analyses were performed. Then, a preliminary design was built to withstand the types of loading to which it will be subjected. Afterwards, FEA was performed on the preliminary design using the data obtained from the force analysis. As a result of this analysis, critical load case and critical regions were identified. In the optimisation stage, the outer diameter (D), wall thickness (t) and radius of curvature (R) were defined as input parameters, while mass, equivalent stress and total deformation were selected as output parameters. As a result of the optimisation-based design, a stress reduction of approximately 43% was observed at the critical region. In addition, the percentage of the influence was investigated in order to better understand the effects of the basic design parameters. Among the parameters, the wall thickness was found to be the design parameter which has the highest effect on stress distribution and part mass.

Keywords

Electric vehicles, Electromobility, Design optimisation, Independent suspension, Vehicle component design

References

• 1. Shaw, R. P. (1992). The impact of population growth on environment: The debate heats up. Environmental Impact Assessment Review, 12(1-2), 11-36.
• 2. Schafer, A. (1998). The global demand for motorized mobility. Transportation Research Part A: Policy and Practice, 32(6), 455-477.
• 3. Teixeira, A. C. R., da Silva, D. L., Machado Neto, L. D. V. B., Diniz, A. S. A. C., & Sodré, J. R. (2015). A review on electric vehicles and their interaction with smart grids: the case of Brazil. Clean Technologies and Environmental Policy, 17, 841-857. https://doi.org/10.1007/s10098-014-0865-x
• 4. Borowski, P. F. (2022). Mitigating climate change and the development of green energy versus a return to fossil fuels due to the energy crisis in 2022. Energies, 15(24), 9289. https://doi.org/10.3390/en15249289
• 5. European Commission. (2011). A roadmap for moving to a competitive low carbon economy in 2050 (COM/2011/144 final). European Union. Retrieved April 3, 2024, from https://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=COM:2011:0144:FIN:EN:PDF
• 6. Ewert, A., Schmid, S., Brost, M., Davies, H., & Vinckx, L. (2021). Small electric vehicles: An international view on light three- and four-wheelers (p. 189). Springer Nature. https://doi.org/10.1007/978-3-030-65843-4
• 7. Jazar, R. N. (2008). Vehicle dynamics (Vol. 1). Springer.
• 8. Sancibrian, R., Garcia, P., Viadero, F., Fernandez, A., & De-Juan, A. (2010). Kinematic design of double-wishbone suspension systems using a multiobjective optimisation approach. Vehicle System Dynamics, 48(7), 793–813. https://doi.org/10.1080/00423110903156574
• 9. Littman, M. L. (1996, April). Simulations combining evolution and learning. In Santa Fe Institute Studies in the Sciences of Complexity-Proceedings Volume (Vol. 26, pp. 465–478). Addison-Wesley Publishing Co.
• 10. Reimpell, J., Stoll, H., & Betzler, J. (2001). The automotive chassis: Engineering principles. Elsevier.
• 11. Mahla, S. K., Safieddin Ardebili, S. M., Mostafaei, M., Dhir, A., Goga, G., & Chauhan, B. S. (2024). Multi-objective optimization of performance and emissions characteristics of a variable compression ratio diesel engine running with biogas-diesel fuel using response surface techniques. Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 46(1), 15737–15754. https://doi.org/10.1080/15567036.2020.1813847
• 12. Ardebili, S. M. S., Calam, A., Solmaz, H., Böğrek, A., & Haşimoğlu, C. (2024). Improving the combustion process of a homogeneous charge compression ignition engine running with triple fuel blend using response surface methodology. Journal of the Brazilian Society of Mechanical Sciences and Engineering, 46(8), 486. https://doi.org/10.1007/s40430-024-05060-0
• 13. Kocakulak, T., Arslan, T. A., Şahin, F., Solmaz, H., Ardebili, S. M. S., & Calam, A. (2023). Determination of optimum operating parameters of MWCNT-doped ethanol fueled HCCI engine for emission reduction. Science of The Total Environment, 895, 165196. https://doi.org/10.1016/j.scitotenv.2023.165196
• 14. Bildirici, D., Topaç, M. M., Polat, K., Zavrak, T., & Arman, Y. (2024). Failure analysis-based mass reduction of an aluminium alloy engine mounting bracket using Design of Experiments approach. Engineering Failure Analysis, 166, 108927. https://doi.org/10.1016/j.engfailanal.2024.108927
• 15. Yildirim, A., Demirci, E., Karagöz, S., Özcan, Ş., & Yildiz, A. R. (2023). Experimental and numerical investigation of crashworthiness performance for optimal automobile structures using response surface methodology and oppositional based learning differential evolution algorithm. Materials Testing, 65(3), 346–363. https://doi.org/10.1515/mt-2022-0304
• 16. Topaç, M. M., Deryal, U., Bahar, E., & Yavuz, G. (2015). Optimal kinematic design of a multi-link steering system for a bus independent suspension: An application of response surface methodology. Mechanics, 21(5), 404–413. https://doi.org/10.5755/j01.mech.21.5.11964
• 17. Odabaşı, V., Maglio, S., Martini, A., & Sorrentino, S. (2019). Static stress analysis of suspension systems for a solar-powered car. FME Transactions, 47(1), 70–76. https://doi.org/10.5937/fmet1901070o
• 18. Li, J., Tan, J., & Dong, J. (2020). Lightweight design of front suspension upright of electric formula car based on topology optimization method. World Electric Vehicle Journal, 11(1), 15. https://doi.org/10.3390/wevj11010015
• 19. Tanik, E., & Parlaktaş, V. (2015). Design of a very light L7e electric vehicle prototype. International Journal of Automotive Technology, 16, 997–1005. https://doi.org/10.1007/s12239-015-0102-6
• 20. Yu, B., Wang, Z., Zhu, D., Wang, G., Xu, D., & Zhao, J. (2020). Optimization and testing of suspension system of electric mini off-road vehicles. Science Progress, 103(1), 0036850419881872. https://doi.org/10.1177/0036850419881872
• 21. Montgomery, D. C. (2000). Design and analysis of experiments (5th ed.). John Wiley & Sons.
• 22. Myers, R. H., Montgomery, D. C., & Anderson-Cook, C. M. (2009). Response surface methodology: Process and product optimization using design of experiments (3rd ed.). John Wiley & Sons.
• 23. Han, H., & Park, T. (2004). Robust optimal design of multi-body systems. Multibody System Dynamics, 11, 167–183. https://doi.org/10.1023/B:MUBO.0000025414.28789.34
• 24. Aydın, M., & Ünlüsoy, Y. S. (2012). Optimization of suspension parameters to improve impact harshness of road vehicles. International Journal of Advanced Manufacturing Technology, 60, 743–754. https://doi.org/10.1007/s00170-011-3589-7
• 25. Rodriguez, R., Mazza, G., Zalazar-García, D., Fernandez, A., & Fabani, M. P. (2023). Polyphenol extraction from bio-wastes: Optimization and kinetic analysis. Studies in Natural Products Chemistry, 79, 317–339. https://doi.org/10.1016/B978-0-443-18961-6.00010-X
• 26. Gregor, M., Grznar, P., Mozol, S., & Mozolova, L. (2023). Design of simulation experiments using Central Composite Design. Acta Simulatio, 9(2). https://doi.org/10.22306/asim.v9i2.99
• 27. Topaç, M. M., Olguner, C., & Bahar, E. (2022). Development of an independent front suspension for truck tractors. Mechanics, 28(2), 121–129. https://doi.org/10.5755/j02.mech.29092
• 28. Heißing, B., Ersoy, M., & Gies, S. (Eds.). (2011). Fahrwerkhandbuch (738 p.). Vieweg+Teubner Verlag, Springer Fachmedien Wiesbaden GmbH.
• 29. Blundell, M., & Harty, D. (2004). The multibody systems approach to vehicle dynamics. Elsevier.