Modeling and predicting the compression strength limiting mechanisms in Z-pinned textile composites

Motivated by experimental results on Z-pinned plain weave glass fiber textile composites that show kink banding of fiber tows to be a strength limiting mechanism of failure in compression, computational results are presented for the effects of Z-pin diameter and Z-pin density on compression strength. Distortion to the textile fiber tows introduced by the insertion of Z-pins is found to be the dominant cause for initiating kink bands while the type of bond between the Z-pin and the surrounding matrix is found to influence the post-kinking response. When the Z-pin diameter remains unchanged, the composite strength decreases as the Z-pin density increases, while, when the Z-pin density is fixed, the composite strength decreases as the Z-pin diameter decreases in agreement with experimental observations.