Strain Localization Analysis of an Elastic-Plastic Model for High Performance Fiber Reinforced Cementitious Composites

Abstract

The main goal of this study was to develop and implement a combined analyticalnumerical algorithm that can capture a stress-strain response and onset of strain localization in elastic-plastic fiber-reinforced cementitious composites. Multi-directional fibers are embedded into a matrix and the resulting composite is described by different non-linear, non-associated DruckerPrager hardening plasticity models. The corresponding macroscopic tangent stiffness moduli tensor of the fiber reinforced composite is derived by consistently homogenizing the contribution of fibers in a representative volume element (RVE). Several actual uniaxial tension tests on non-reinforced cementitious composite as well as on the High Performance Fiber Reinforced Cementitious Composites (HPFRCC) were modelled. It was found that the presence of fibers delayed the inception of strain localization in all uniaxial tension tests on the HPFRCC as compared to the plain mortar. However, the onset of strain localization always coincided with yielding, thus indicating a slight fiber induced increase in the yield stress. More importantly, the results indicate that a significant increase in the peak load that is exhibited by HPFRCC is due to a distributed cracking that causes a global level hardening culminating in the significantly increased peak loads. Furthermore, the results also indicate that presence of fibers did not have any effect on the orientation and mode of accompanying deformation bands.