Analysis of Recoil Compressive Failure in High Performance Polymers Using Two and Four Parameter Weibull Models

In this study, large amounts of recoil compressive failure data were gathered for Kevlar-29 fibers. Once the dependence of failure frequency on stress level had been determined experimentally, two-parameter and four-parameter Weibull models were used to represent the data. An analysis of these results shows that each model represents the failure well, but that the four-parameter model offers little improvement over the two-parameter Weibull model. Deconstruction of the four-parameter model indicated that a single failure mechanism dominated and that this mechanism could be well represented by the two-parameter Weibull model. These results imply that while recoil compressive failure is more complicated than tensile failure, recoil failure is dominated by a single flaw distribution and can be represented by a more simple model than tensile failure.