Objectives  Wave Propagation Approach(WPA)has unique advantage in analyzing the offset mechanism of elastic wave in hybrid system such as floating raft.

  Methods  Based on WPA, this paper analyzes structure-borne noise via differential equation of vibration from the perspective of propagation and reflection of elastic wave.

  Results  It is shown that, WPA enables researchers to further investigate the kernel characteristics(elastic wave)from apparent parameters such as vibration acceleration, and reveal the relationship among the vibration energy injection and transmission, and the wave and acoustic radiation. This approach can take the phase of harmonic force into consideration, allowing for study of the multi-source offset mechanism. Besides, by virtue of exponential function, the governing equation is derived with regularity. Therefore, this approach can be used by engineers to make an in-depth analysis of the mechanism.

  Conclusions  By employing this approach, it is easier to find out the general law for common and key aspects from complex system to simple system, setting the stage for sophisticated design of the system dynamics.