Fatigue Behavior of Unidirectional Jute Spun Yarn Reinforced PLA

Abstract

Abstract Natural fiber reinforced composites, which can be carbon-neutral materials, have been investigated for use as alternative materials to glass-fiber reinforced plastics (GFRP). The fatigue properties of natural fiber reinforced plastics are, however, not well known. In this study, uniaxial tensile fatigue tests of unidirectional jute spun yarn reinforced polylactic acid (PLA) were conducted in order to clarify the fatigue strength. The damage and fracture morphology of composite specimens were observed to elucidate the fatigue mechanism. Results show that the fatigue strength decreases concomitantly with increasing number of cycles. The fatigue strength at 106 cycles was 55% of the ultimate strength, which is an almost identical percentage to that of GFRP. The fatigue failure of composite specimens was probably caused by the breakage of jute filaments at the tips of fatigue cracks in PLA. This implies that the fatigue strength of the composite was strongly affected by the fatigue properties of PLA.