Energy dissipation in collision of two balls covered by fine particles

Modeling the fine particle impact damper

“…To model the system we assume that: (1) the contact period of the impact is very short and can be neglected; (2) impacts occur just in normal direction; (3) friction can be disregarded because the fine particles adhered on the ball surface may work as a lubricant; and (4) impacts between two oscillators covered by fine particles can be considered as impacts between two fine particles, but the mass and velocity of the fine particles should be substituted by the mass and velocity of the impact partners, that is, the steel ball and the cantilever, respectively [38].…”

“…The time step is taken as 1 e À 4 s. Since impacts occur when the clearance between the steel ball and either end of damper container is less than zero, standard dichotomy approach is used to obtain the exact instant of impacts with a criterion of clearance tolerance 1e À 25 m or time tolerance 1e À 20 s. Then the displacements and velocities of the steel ball and the cantilever beam just before their impact can be obtained. The velocities of the steel ball and the cantilever beam just after the impacts can be obtained by a clamped impact model [38]. Together with the corresponding displacements of the steel ball and the cantilever beam, one can get new initial parameters for the subsequent calculations.…”

“…Instead, a new mechanism is introduced into the FPID. Du et al [38] found that the particles, when clamped by normal impact of two large bodies, can absorb a large amount of kinetic energy. Structures or devices equipped with the FPID could have good performance in vibration environment, which has been verified by experiments [36].…”

Investigation of chattering behavior of impact damper

“…Due to its advantages such as effective damping effect, simple structure, low cost, easy implementation, no power requirement, and suitable for harsh environment, there have been many studies on the device recently, including single impact dampers, [1][2][3][4] BBD impact dampers, 5 multi-body impact dampers, 6 particle dampers, [7][8][9][10][11][12] non-obstructive particle dampers, 13,14 and impact damper with fine particles. [15][16][17][18][19][20] While various types of impact dampers exist, they have the same underlying damping mechanism: during vibration, momentums are exchanged and mechanical energy is dissipated via collisions.…”

A spring-supported fine particle impact damper to reduce harmonic vibration of cantilever beam

“…Li and Darby 11 introduced a buffer region between the mass and the stops to reduce both acceleration and contact force in collisions. Du and colleagues [12][13][14] proposed a new fine particle impact damper which introduces plastic deformation of fine particles to vibration system as perpetual energy dissipation. More and more attentions of researchers have been attracted to investigate the performance of PID.…”