Investigation of fatigue life and active vibration control via piezoelectric elements in vehicle suspension

As the automotive industry advances toward electrification, intelligence, and high performance, vehicle operating intensity continues to rise, placing greater demands on structural components. The fatigue behavior of the suspension lower control arm plays a critical role in ensuring vehicle handling stability and safety, necessitating thorough analysis and optimization. In this study, a rigid-flexible coupled dynamic model of an independent suspension system is developed, incorporating a finite element-based flexible representation of the lower control arm and a multi-body dynamic model of the suspension assembly. Fatigue life prediction is subsequently conducted, followed by an investigation into the primary influencing factors. Furthermore, piezoelectric ceramic-based active control strategies are introduced to improve the fatigue performance of the lower control arm. Two configurations-surface-bonded and internally embedded piezoelectric ceramics-are employed to enhance static stiffness and dynamic damping characteristics, thereby extending service life. Results indicate that fatigue life is most sensitive to the load amplification factor, followed by surface roughness, tensile strength, and bushing stiffness. Under reverse voltage actuation, the piezoelectric-enhanced lower control arm achieves a minimum fatigue life of 5.076 × 10⁷ cycles, representing a 24.5% improvement.