In this study, an irregular lattice model is developed to simulate the failure behavior of fiber-reinforced cementitious composites (FRCCs) subjected to extreme loadings with various strain rates. The numerical method is based on the Rigid-Body-Spring-Network(RBSN), which is an irregular lattice…
In this study, an irregular lattice model is developed to simulate the failure behavior of fiber-reinforced cementitious composites (FRCCs) subjected to extreme loadings with various strain rates. The numerical method is based on the Rigid-Body-Spring-Network(RBSN), which is an irregular lattice model. The matrix of material domain is discretized by the Delaunay/Voronoi dual tessellation, and the lattice nodes are connected by spring sets. Generally, cementitious materials are rate dependent, meaning that their mechanical properties change according to the rates of loading [1- 3]. In dynamic failure analysis, considering the rate dependency, the response of a material is obtained in every time step by using, for example, explicit time integration schemes. During the numerical analysis, in order to achieve this material characteristic, a rheological unit, which contains springs and dashpots, is adopted into the rigid-body-spring elements of the lattice model [4, 5]. The rheological unit represents sources of rate dependency, including inertia of mass and Stepan’s effects. In the previous researches, the strain rate dependency was shown for plain concrete and expanded to the case of reinforced concrete. In this research, the method to handle the interface property, which is rate sensitive, are demonstrated for the case of fiber pull-out from a cementitious matrix. A semi- discrete method is chosen since fiber addition does not add degrees of freedom(DOF) into the lattice model [6, 7]. This method is computationally efficient since no additional DOF are introduced when adding fibers to the matrix. In this paper, we are focusing on the interface for a single fiber with several RBSN cells to check the developed algorithm. To identify the correlation between the interfacial properties and the overall failure behavior of FRCCs under different loading rates, related parameter studies are fully conducted.