Tensile Stress-Strain Modeling of Pseudostrain Hardening Cementitious Composites

This study proposes a new theoretical approach for predicting the tensile stress-strain relation of random short-fiber-reinforced cement composites showing pseudostrain hardening. This approach is grounded on the solid basis of micromechanics, which describes the pseudostrain hardening phenomenon in terms of constitutive properties of the fiber, matrix, and fiber/matrix interface. The proposed modeling requires theoretical treatment of an inelastic strain due to multiple cracking. This modeling is achieved by employing a probabilistic description of initial flaw size distribution, which should be known for predicting the stress-strain relation. This study proposes a practical method for this identification using the tensile test result of a reference composite. A comparison with the test data indicates that the proposed model is capable of reasonably reproducing the stress-strain relation of "similar" composites. Such composites have a configuration similar to the reference configuration but different in fiber volume fraction and fiber length. Finally, the proposed theory is a potentially powerful tool for tailoring composites to satisfy targeted structural performance.