Abstract
We investigated the influence of connecting-rod I-beam-section specification on combustion-induced vibration by both experiment and simulation. Main findings are as follows: By shortening the length of connecting-rod I-beam section, the natural frequency of piston-connecting rod coupled vibration shifts from 2.5 kHz to 2.8-2.9 kHz. The biggest value of vibration transmission efficiency, which represents the transmission degree from the combustion impact to the vibration on the outer surface of the engine, is around the natural frequency of piston-connecting rod coupled vibration. The decay rate of vibration at the natural frequency of piston-connecting rod coupled vibration is bigger than the that of the other connecting rod on same frequency. These two results may come from the asperity contact of main bearing.
