A stochastic multiscale peridynamic model for corrosion-induced fracture in reinforced concrete

Abstract

Concrete fracture caused by corrosion of reinforcing bars may cause subsequent structure failure. To better predict this process, we introduce a partially-homogenized stochastic peridynamic model with the simplest constitutive relation (linear elastic with brittle failure). The model links microscale information (phase volume fractions of mortar, aggregates, interfaces) to macroscale fracture behavior, while costing the same as a fully homogenized model. We show, and explain why a fully-homogenized peridynamic model fails to capture the correct concrete fracture modes/patterns, while the new model succeeds. The multiscale model predicts the evolution of fracture in reinforced concrete caused by corrosion products expansion in samples with a single or multiple rebars. Non-uniform expansion of corrosion products is enforced here as preset, incremental radial displacements. The computed fracture patterns and the order in which various cracks develop match what is seen in experiments. The model's robustness is tested under different stochastic realizations and discretization grid types.

An algorithm for imposing local boundary conditions in peridynamic models on arbitrary domains

“…For spatial discretization, we discretize the peridynamic body uniformly [26] into cells with nodes in the center of those cells. [20,53,54], which may conform better for shapes with, for example, rounded boundaries [49], but this is not pursued in this work.…”

“…This algorithm also works for damage without explicit surfaces, such as distributed damage (a subdomain containing nodes with damage indices smaller than the threshold for a crack surface, e.g. 0.4) [49]). This topic, however, is left for future research.…”

Crack nucleation in brittle and quasi-brittle materials: A peridynamic analysis

“…PD nodes are the centroids of corresponding finite elements in the grid and nodal areas are the element areas (see Section 2.2). We consider regions of fictitious nodes with the width of δ at the top and bottom of the plate to apply the displacements that control the loading ( [59,60]). For example, for the horizon factor of m = 5, five rows of fictitious nodes in the top and bottom of the plate are considered.…”

“…The PD models discussed so far are homogeneous. Real materials are heterogeneous, and a closer representation of them is given by the IH-PD model ( [5,6,33,60]), which is a stochastic PD model able to take into account, for example, the presence of pores/defects/phases into the elastic and failure behavior of materials ( [5,6]) without having to include the detailed representation of such pores/defects/phases. Our previous studies showed such models are able to capture initiation of damage and failure in materials with critical pre-notches, matching experimental observations (see [5,6]).…”

Comparison of peridynamic and phase-field models for dynamic brittle fracture in glassy materials

“…Crack branching is a common occurrence in dynamic brittle fracture and has been studied for many decades, theoretically [1,2], experimentally [3][4][5][6][7], and computationally [7][8][9][10]. Some analytical solutions for crack branching in brittle systems exist, but they are generally limited to a crack running in an infinite domain and at constant speed [11] .…”