عنوان مقاله [English]
In this paper, vibration performance analysis of a nonlinear displacement-velocity-dependent (NDVD) damper is presented. The proposed NDVD damper is constructed using the appropriate changing in the structure of a linear damper which results the damping coefficient of the proposed NDVD damper varies respect to the displacement and the velocity of damper piston. To this end, a solid cone shaped part is assembled in the interior region of the damper cylinder, which causes the fluid moves between the solid cone shaped part and inside the existing orifice on the piston. In fact, the movement of the piston results in changing the size of the gap where the fluid passes and the damping coefficient is consequently varied. In order to obtain more accurate modeling in the vibration analysis, the effect of momentum variation is also applied in the advised NDVD damper. The effect of momentum variation on the motion of a vibratory system equipped with a nonlinear displacement-velocity-dependent (NDVD) damper is elaborated and also compared with the previously published papers. In this paper, the governing equation of a mass-spring system equipped with the NDVD damper as the vibratory system is derived for three cases of free, forced and resonance vibration problems and solved by the numerical fourth-order Runge-Kutta method. The displacement profile, velocity profile, damping force and the force transmitted to the base of the system are evaluated for a mass-spring system equipped with the NDVD damper. In addition, these results for three cases of free, forced and resonance vibration problems are compared with the results obtained from the system equipped with a linear damper as well as the nonlinear displacement-dependent (NDD) damper presented in the previous works. The simulation results confirm that the recommended NDVD damper has much better performance in reducing of vibration in the system compared to the linear and NDD dampers.