Summary: | 碩士 === 國立屏東科技大學 === 車輛工程系所 === 101 === In this thesis, the fatigue life and lightweight design of electric vehicle body structure are proposed in this study. The lightweight design analysis process includes finite element model analysis and topology optimization analysis. The goal of the body structure weight is less than 100 Kg. The bending stiffness and the torsional stiffness of the body structure must be greater than 1000N/mm and 1500 N.m/deg , respectively.
In this research, finite element models are used for the vibration, bending stiffness, torsional stiffness and collision analyses of a body structure. The effects of four different road payment levels and six different suspension parameters on the fatigue life of the body structure are also studied. The results indicate that the weight of the proposed body structure is 86.5 kg. The first frequency of the body structure is 18.8 Hz. The bending stiffness and the torsional stiffness of the body structure are 1234.6 N/mm and 2373.5 N.m/deg, respectively. The results show that the fatigue life of the body structure is reduced as the road payment level increases. The results also indicate that the fatigue life of body structure increases with an increasing stiffness and damping factor of the suspension system.
The results also show that all the fatigue lifes of the proposed bosy structure are over 5.47 under the conditions of the road level A, B, and C. The maximum deformation for the head-on collision and the side way collision are 140.2 mm, and 50.1mm, respectively. The results show that the proposed body structure can satisfy the requirement specifications of collision.
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