# Thermo-Mechanical Coupled Analysis of Electric Vehicle Drive Shafts
## 4 Conclusions  
This study presents a novel approach to analyzing and optimizing the design of constant velocity joints (CV joints), a critical component of electric vehicle drive shafts, under high-load and high-speed rotation conditions. By performing thermo-structural coupled analysis, the research aimed to evaluate the thermal and structural changes that occur during operation and support design optimization. The study utilized LS-Dyna for dynamic simulations and Ansys Transient Thermal for modeling thermal behavior. This dual-software approach enabled the efficient analysis of heat generation due to friction during high-speed rotation and the resulting structural stress distribution. The key takeaways from the study are as follows:  
* The proposed methodology consisted of two primary stages. In the first stage, LS-Dyna was employed to perform short-term dynamic analysis and calculate heat flux resulting from friction between the internal components of the CV joint. In the second stage, Ansys Transient Thermal used the derived heat flux data to simulate the long-term temperature distribution and thermal effects under operational conditions.
* The integration of these tools facilitated the prediction of thermal behavior and structural deformation in environments resembling actual operating conditions. The analysis revealed the temperature and stress distributions across key components, including the ball, cage, and outer race, with the cage exhibiting the highest temperature.
* Experimental validation showed that the discrepancy between simulated and measured data was within 6%, confirming the reliability of the proposed methodology.
* These findings demonstrate the effectiveness of the proposed simulation-driven design tool in evaluating the performance of drive shafts under high-speed and high-load conditions. By eliminating the need for repetitive prototyping, the methodology offers significant potential for reducing development time and cost in electric vehicle component design.
* However, this study has limitations, such as the inability to fully account for all detailed contact conditions.
* Future research incorporating diverse operating conditions and more complex friction models is necessary. Such advancements are expected to further enhance the design reliability and durability of electric vehicle drive shafts.  
Figure 8: Experimental validation apparatus.  
**Author Contributions:** Conceptualization, S.-E.K., J.-L.P. and Y.J.; methodology, C.-H.J., M.-G.L. and Y.J.; software, S.-E.K. and C.-H.J.; validation, S.-E.K. and S.H.; investigation, S.-E.K. and S.H.; writing--original draft preparation, S.-E.K. and C.-H.J.; writing--review and editing, S.-E.K., C.-H.J., S.H. and Y.J.; supervision, M.-G.L. and Y.J.; funding acquisition, J.-L.P. and Y.J. All authors have read and agreed to the published version of the manuscript.  
**Funding:** This work was supported by the Technology Innovation Program (or Industrial Strategic Technology Development Program--Automotive Industry Technology Development--Green Car) (20020730--Multi-use, high-performance drive shaft for electric and internal combustion engine vehicle with adjustable-length ball spline) funded by the Ministry of Trade, Industry & Energy (MOTIE, Korea).  
**Institutional Review Board Statement:** Not applicable.  
**Informed Consent Statement:** Not applicable.  
**Data Availability Statement:** The data presented in this study are available at the request of the corresponding author. The data are not publicly available due to the copyright of the company.  
**Conflicts of Interest:** The authors declare no conflict of interest.