ABSTRACT: The stitching process has been widely utilized for the improvement of through-thickness property of theconventional laminated composites. This paper reports the effects of stitching on the flexural and interlaminar shearproperties of multi-axial warp knitted (MWK) composites in order to identify the mechanical property improvements.In order to minimize the geometric uncertainties associated with the stacking pattern of fabrics, the regular lay-up wasconsidered in the examination of the stitching effect. The key parameters are as follows: the stitch spacings, thestitching types, the stitching location, and the location of compression fixture nose. These parameters have little effecton the flexural and interlaminar shear properties, except for the case of stitching location. However, the geometryvariations caused by the stitching resulted in minor changes to the mechanical properties consistently. Stitching on the0o fibers showed the lowest flexural strength and modulus (12% reduction for both properties). The stitch spacing of5 mm resulted in 8% reduction for the case of interlaminar strength compared with that of 10 mm spacing.

Keywords: Stitching, MWK (Multi-axial Warp Knit), Flexure, Interlaminar, Stitching parameter, Regular stacking