Abstract
This study conducted experiments to investigate the piston-connecting-rod coupled vibration for four types of connecting-rods with different I-beam section specifications. Furthermore, we analyzed the vibration-transmission and decay characteristics based on time-frequency-dependent combustion-noise-generation model for different connecting-rods and discussed the vibration characteristics on the engine outer surface. The results show that both the length and thickness of I-beam section of connecting-rod affect the piston-connecting-rod coupled vibration frequency, vibration-transmission efficiency, decay rate and the overall level of vibration acceleration. The change in vibration acceleration is mainly caused by the changes in vibration-transmission efficiency. For connecting-rods with same piston-connecting-rod coupled vibration frequency, an increase of thickness of the I-beam-section more greatly leads to a decrease of piston vibration and therefore to a decrease of the vibration-transmission efficiency.
