High-Performance Plastic Sled Design for Polar Traversing.

摘要

Over-snow resupply traverses in Antarctica and Greenland tow high-efficiency fuel sleds that consist of flexible fuel bladders strapped to flexible sheets of high molecular weight polyethylene (HMW-PE). Despite low towing stresses, initial HMW-PE sheets were prone to cracking and failure within 1 to 2 years of service. This report describes the results of low temperature, uniaxial tensile tests, following ASTM Standard D638, that we used to set specifications on HMW-PE sheets for polar sleds, aiming to increase service life. Tests of the original HMW-PE formulations showed significant reductions in ductility, as measured by percent elongation at break, at 40 C compared with 23 C. HMW-PE manufacturers subsequently cooperated to supply sheets with greater low-temperature ductility, and the rate of sled breakages decreased dramatically. Performance specifications for new HMW-PE sheets for polar traverses now include a requirement for greater than 60% elongation at break at 40 C, as measured using ASTM 638 uniaxial tensile tests.