A fully-discrete peridynamic modeling approach for tensile fracture of fiber-reinforced cementitious composites

Abstract

In this study, a fully-discrete peridynamic modeling approach is proposed to simulate tensile fracture behavior of fiber-reinforced cementitious composites. In this modeling approach, matrix is described by a peridynamic cohesive model, fibers are modeled as peridynamic bars, and fiber-matrix bond is simulated by a peridynamic interface model. The peridynamic interface model utilizes classic interface constitutive theory to compute the interfacial forces from the corresponding slip displacement calculation. In addition, corrections to interfacial forces are introduced to take the snubbing friction effect into consideration. Fiber elements are randomly distributed in matrix, and these fiber elements do not interact with each other in the peridynamic discretization in order to permit their intersection. The present modeling approach is used in two numerical examples, i.e., single fiber pull-out tests and direct tension tests of double-notched fiber-reinforced mortar specimens, in which its validity is demonstrated by close comparisons with the corresponding experimental tests. As illustrated in the simulation of single fiber pull-out test, the developed peridynamic interface model inherits the description capability of the adopted classical exponential frictional decay interface model, and its sensitivity to the peridynamic discretization is also manifested. While in the direct tension test simulation, the modeling approach captures the tensile fracture behavior of fiber-reinforced mortar specimens with different fiber distributions. Considering the two-dimensional nature of the present modeling approach, the choice of the number of fibers represented by one fiber element is discussed, and the modeling performance for tensile fracture behavior of fiber-reinforced mortar specimens with different volume fractions is evaluated. The proposed fully-discrete peridynamic modeling approach demonstrates its advantages and capabilities of both peridynamics and fully-discrete models in simulation of tensile fracture behavior of fiber-reinforced cementitious composites.