Evaluation of residual strength of polymeric yarns subjected to previous impact loads

Abstract

The discovery of oil fields in deep and ultra-deep waters provided an opportunity to evaluate theuse of synthetic ropes, complementarily or alternatively to traditional steel-based mooring lines inoffshore units, mainly because of the former’s lower specific weight. Considering the series of complexdynamic-mechanical mainly axial loads to which these structures may be subjected, originated fromdifferent sources, such as wind, water current, tide, etc., there may be cases when at least one ofthese lines may possibly face an abrupt, shock-like axial load of considerably larger magnitude. Thegoal of the present study is to evaluate the residual tensile strength of three different synthetic yarns(polyester, and two grades of high modulus polyethylene) after exposure to such axial impact loads. Itwas observed that, for the tested materials, polyester is the one with the largest impact resistance to theconditions evaluated herein, mainly because of its comparatively greater energy absorption properties.