Abstract: An improved analytical model using the two-phase flow theory of gas-particle is presented based on previous work, in which the effects due to inter-particle collision and friction are all expressed as the equivalent viscosities in a unified way. This makes the entire model has a more complete uniformity and provides convenience for further studies in depth. The analysis results of the free vibration and forced vibration of SDOF systems with particle damping show that the prediction of the improved model is more accuracy than that of the origin model. Furthermore, the forced response of a typical continuum structure, i.e. the cantilever particle-damping beam is predicted and analyzed using this improved model and the finite element method. Numerical results show that the particle damping is a kind of nonlinear damping, which is highly depended on the vibration amplitude. When the particle damper is exerted on different positions of the beam, the damping properties can present an obvious change. The ideal damping effect can be achieved by putting the particle damper on the position of the structure with high-level vibration. The improved model of equivalent viscous damping based on two-phase flow theory of gas-particle developed can lay a theoretical foundation for the prediction on the vibration and sound radiation of more complicated particle-damping composite structures

Key words: Cantilever beam, Particle damping, Two-phase flow theory, Vibration response