| Summary: | The effect of natural rubber (NR) coating on the quasi-static tensile properties of unidirectional Dyneema® SK-76 single yarn is experimentally studied. Single Dyneema® SK-76 yarns are uniformly coated with pre-vulcanized natural rubber latex. Quasi-static tensile tests are performed on plain (uncoated) and NR-coated samples at the strain rates of 0.006 s-1, 0.06 s-1 and 0.6 s-1. The force and strain at peak, and the tenacity of the plain and NR-coated yarns are obtained for each strain rate. The results show that the peak force in the plain samples increases with strain rate to a maximum of 163 N. The tenacity (breaking force per denier) of the uncoated yarns also, in correspondence, increases with strain rate. In contrast, the tenacity of the NR-coated samples remained constant at but a lower value than that of the plain samples. It is observed that peak force sustained by the NR-coated yarns is insensitive to strain rate and up to 560% higher than that supported by the plain yarns. The peak strain of both the plain and NR-coated samples varies with strain rate in a comparable fashion. However, the peak strain values of the NR-coated yarn are greater by an average of 20% than of the plain yarn. The experimental data thus reveal that NR coating has a constructive effect on the peak force and peak strain of the yarn but decreases its tenacity to a constant value. Micrographs of the fractured samples obtained from Field Emission Scanning Electron Microscope are studied to explore the role of NR in the failure mechanism of the coated yarn. Copyright © 2012 by ASME.
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