Research on damping model of reinforced concrete frame structures
Liang Chaofeng1; Liu Tiejun2
(1. Department of Civil Engineering, Shaoxing University, Shaoxing Zhejiang, 3120002. Shenzhen Graduate School of Harbin Institute of Technology, Shenzhen, 518055)
Abstract:In tradition, the damping for structural dynamic analysis was simply considered by Rayleigh damping or its different development forms, which had not an explicit physics meaning. In this paper, concrete materials, considered as a viscoelastic material may be described by Kelvin model, the relationship between viscous coefficient of concrete materials and damping matrix of shear-type RC frame in elastic stage was derived by the dynamic analysis, and a judgment criterion of the proportional damping matrix was obtained. Then the expression of damping matrix and 1st modal damping ratio of 10-floor RC frame structure with fibers were given on the basis of the damping experimental results of fiber reinforced concrete materials. It has been found that the damping matrix can represent quantitatively similar to the structural mass and stiffness and possess an explicit physical meaning. Compared with an ordinary reinforced concrete frame, the fiber-reinforced concrete frame structure had larger 1st modal damping ratios. The mechanism on damping reinforcement of RC frames with latex powder or fibers lies in the polymer molecules’ dissipating energy ability and interfaces’ friction of fibers and cement hydration products.