Experimental Study On Particle Damping Of Flexible Cable And Micro-particle Damping Parameter Analysis

Cable-stayed bridge is a bridge system widely used in modern transport. With the development of design theory, computational method and material technology, and the continual improvement of construction method and the level of facilities and equipments, the span of cable-stayed bridge as well as the length of cable is becoming larger and larger. With the increase of cable length, the cables vibrate more significantly, as may cause severe damage to the bridge. At present, the measures of reducing the cable vibration are mainly based on the change of structural and mechanical properties of cable and consist of three types:aerodynamic measure, mechanical damping measure and structural damping measure.Non-obstructive particle damping (NOPD) technology was first put forward by Dr. Pan Ossian. It is a new type of compound damping technique which combines effectively the impact damping and the friction damping, by inserting a suitable amount of metal or nonmetal particles in cavities within or attached to the vibrating structure. When the structure vibrates, the particles exchange the momentum and absorb kinetic energy of the structure through continuous collisions and frictions between the moving particles and the hole walls and among the particles themselves, so as to swiftly attenuate the vibration of the structure.Based on the free vibration experiments on flexible cable specimen, this paper attempts to study the cable damping measure with significant capability of energy dissipation by combining the aerodynamic measure of cable with non-obstructive particle damping, investigate the reasonable particle arrangement, cavity size and its energy dissipation mechanism.In order to understand the specific movement rule of particle in cavity, simulation analyses are performed for both rectangular hollow box and cylindrical cavity tube, using the EDEM software and based on the discrete element method theory, to study the influence of particle size, particle filling ratio, cavity shape and vibration frequency on the structural damping and explore the energy dissipation mechanism of particle damping.