Uniaxial tensile performance of fiber reinforced cementitious composite is simulated based on fracture mechanics criteria, with the specific objective to study the phenomena of strain-hardening and multiple cracking under direct tension. In the model, instead of describing the matrix fracture…
Uniaxial tensile performance of fiber reinforced cementitious composite is simulated based on fracture mechanics criteria, with the specific objective to study the phenomena of strain-hardening and multiple cracking under direct tension. In the model, instead of describing the matrix fracture resistance by a single pa- rameter at the crack tip, we separate it into two parts, a crack tip toughness (KIC_M) and a tension softening curve representing the interlocking effect of aggregates. The latter is added to the fiber bridging stress to come up with the overall bridging stress vs crack opening relation for fracture analysis. To analyze crack propaga- tion, a superposition method is employed to calculate the stress intensity factor at the crack tip resulted from both the applied load and the crack bridging stress. For a particular crack size, the corresponding load is calcu- lated as the value when KIC_M is reached at the crack tip. Using the model, the effects of various material pa- rameters, including matrix toughness, initial flow size, fiber content and specimen geometry on the tensile per- formances are investigated. The requirements for tensile strain-hardening and multiple cracking are analyzed and possible methods for material performance optimization are discussed.