A New Approach for Material Damping Analysis of Steel Fiber Reinforced Concrete Components under Axial Cycle Loads

Extensive research has shown that steel fiber reinforced concrete (SFRC) has excellent plastic deformation and dynamic performance. Material damping (MD) is one of the most crucial aspects of structure damping which reflects energy dissipation characteristics of structural system during vibration. This paper presents a new approach to analysis MD of SFRC. Based on the study of the relation between MD and stress amplitude (SA) by Lazan, the area of hysteresis loop of SFRC components under axial cycle loads is calculated with Karsan-Jirsa loading-unloading law by OpenSEES system. The value of energy dissipation is then obtained. It is indicated that energy dissipation per unit of SFRC increases with the increase of maximum SA and decreases with the increase of concrete strength. The relation formula of energy dissipation of SFRC with maximum SA, concrete strength and steel fiber ratio is established by nonlinear regression with SPSS and will be helpful in material character study of SFRC and dynamic response computation of SFRC structures.