Experimental investigation of the mechanical properties of dry microbraids and microbraid reinforced polymer composites

This paper presents a comprehensive series of mechanical tests performed on two high performance polymeric fibres, microbraids and microbraid reinforced polymer composites (mBRPC). Quasi-static tests were performed on the raw materials and the effect of different gauge lengths and strain rates investigated. Then, microbraids having sub-millimetre diameters were manufactured from the raw yarns using a Maypole-type braiding machine. The effects of different braid architectures, number of braided yarns and bias angles were assessed through a series of tensile tests on dry microbraids. A novel and unique manufacturing method of aligning microbraids in a unidirectional fashion via robotised filament winding was developed to manufacture microbraid reinforced polymer composites (mBRPC). Quasi-static tensile tests performed on mBRPC showed improved mechanical properties, for certain architectures, with respect to those noted for unidirectional composites manufactured using same technique.