This study combines unique modeling approaches to simulate the progressive failure of ultra short carbon fiber composite materials. The reinforcement phase in traditional chopped fiber composites generally consists of glass fibers 10 μm in diameter with lengths on the order of 15 mm in length. Ultra short carbon fiber composites with lengths of 3 mm show promise as a versatile inexpensive reinforcement. Furthermore, some level of microstructural design may be achieved by inducing uniform alignment in the ultra short fiber arrays. In order to investigate progressive failure of various microgeometries, finite element based micromechanical approaches are utilized to perform virtual tests on highly detailed microstructural representations. This study demonstrates viable approaches to build models large enough to capture all relevant micromechanical damage effects, especially the interactions between fibers across the entire domain. Both the Abaqus/Standard and Abaqus/Explicit finite element codes are used together to efficiently simulate progressive damage on a large scale. Careful parametric analysis elucidates the effects of various microstructural factors, including: fiber-matrix interface effects, fiber diameter, chopped fiber length, uniform fiber alignment / misalignment, occasional fiber misalignment, fiber spacing, and the constituent properties of both fiber and matrix. Furthermore, the generation of geometries and meshes is accomplished programmatically, which enables the simulated testing of a large and high-resolution parameter space. Trends in microstructural effects on material performance will be carefully analyzed to provide guidance for processing targets to achieve desired properties in tailorable feedstock.