Modelling the stochastic tensile behavior and multiple cracking of strain-hardening cementitious composites (SHCCs)

Strain-hardening cementitious composites (SHCCs) have gained the growing application in the infrastructures with exhibiting superior tensile behavior by the formation of the fine multiple cracking. The micromechanics-based method is in the light of governing mechanisms of the multiple cracking by considering the interaction between the fiber, the matrix and the fiber/matrix interface, and thus has the ability to model the tensile behavior of SHCCs, crack characteristics in particular. However, the variability of the tensile behavior (i.e., the tensile strain capacity, the tensile strength, the multiple cracking sequence, the crack spacing, and the crack width) are observed due to the heterogeneity nature of fiber-reinforced cementitious composites, which cannot be completely considered in the existing models. The heterogeneity may originate from variation of properties of ingredients such as inconsistent fiber diameter and fiber strength, processing (variation of flaw size and distribution and non-uniform fiber distribution), and curing. In this paper, a micromechanics-based stochastic model to capture the variability of SHCC multiple cracking and tensile behavior is developed. The modelling approach is based on the multi-scale linking from micro-mechanical properties to macro tensile properties through fiber-bridging properties and matrix properties at the meso-level. The pivotal idea is to treat all the micro-mechanical parameters as stochastic variables at the micro-level, in addition, the multiple cracking criteria was firstly introduced in the model to capture the variability of the tensile behavior. Since this analytical model was implemented in a numerical way, it would become a flexible and easy-to-use software package for the engineering application in the future. The capability of the proposed model was confirmed compared with experimental results. Using the newly developed model, parametric studies were conducted to point out that σ , V, and τ are the most critical parameters to affect the tensile strain capacity of SHCCs.