Evaluation of Static Line Webbing Materials Subjected to Simulated Airdrop Operating Conditions

摘要

An investigation was conducted to evaluate the mechanical performance of two types of static line webbing materials. Conventional Type VIII static line webbing and a proposed replacement, referred to as AbsorbEdge, were the primary subjects of the investigation. Tests were performed to evaluate the effect of each identified and simulated airdrop operating condition. Test methods used in the investigation included straight and 900 bend tensile tests to evaluate the effects of straining over a series of specified bend radii. Additional tests were performed to investigate the effect of textured bend surfaces, the number of twists in a line between test grips, the effect of retained water in the line, the effect of mechanical fatigue, and the effect of various cotton and polymer-based textile sheaths located at the bend fixture/ specimen interface. Results from these and other tests are contrasted against the results of straight-pull tests to evaluate the adverse effect of the test variables on the baseline strength of each material. A theory regarding how the line construction distributes tensile loads around a door edge and decays line system strength is presented. Test results are used to compliment failure observations and are presented within this report.