Notched Strength of Double-Row Multi-Holes Woven Fabric Kenaf Composite Plates with Different Plate Orientations
The implementation of sustainable materials in most engineering sectors has increased rapidly on daily basis. Combination of natural fiber with epoxy polymer able to produce a high performance composite material which potentially substitute synthetic fiber due to comparable specific strength (and stiffness) to glass fiber composites. Kenaf fibers provide advantages in various aspect, for example, relatively cheap, renewable, short harvesting period, less-abrasive, non-irritating to skin and easily available locally. Current project investigates parametric study on notched strength of double-row multi-holes woven fabric kenaf composites with variation of lay-up types, plate thickness and drilled holes numbers of testing coupons. Production of testing coupons started with weaving twisted kenaf yarns by using weaving handloom machine, followed by plate fabrication stage using hand lay-up technique accordance to the designated stacking orientations and compressed under pressure by using hydraulic compression machine. The finishing panels are then cut into testing coupons and drilled with multi-holes as specified in the testing series. As expected, multiple-hole may exhibited more complex failure mechanism due to perturbation of stress distribution occurred within adjacent holes compared to single-hole plates. It was found that cross-ply lay-ups were stronger than quasi-isotropic lay-ups counterparts due to larger volume fractions of 0° fiber directions in cross-ply plates. Thicker plates are associated to larger notched strength due to resistance of fiber bridging as delamination took place. Double-row configurations gave smaller net-tensile area and consequently weaker notched strength than single-row configurations counterparts. Overall, good agreements were found in all testing series investigated.