Statistical Scatter of Creep and Fatigue Failure Times for CFRP Laminates

Abstract

This article is concerned with the prediction of statistical scatter for the creep and fatigue failure times of CFRP laminates by using the statistical scatter of strength measured at constant strain rate tests (CSR strength) based on the kinetic crack growth law (Christensen and Miyano). First, the time- and temperature-dependent CSR strengths for CFRP laminates were measured at two levels of temperatures, room temperature and 120°C, in the vicinity of glass transition temperature, and the statistical scatter of these CSR strengths were determined at these two levels of temperature. Furthermore, the statistical scatters of the creep and fatigue failure times at an arbitrary load level and a constant frequency at these two levels of temperatures were predicted using the statistical scatters for CSR strengths based on the kinetic crack growth law. On the other hand, the creep and the fatigue failure times were experimentally measured at the same conditions. It was clear that the statistical scatter for creep and fatigue failure times of CFRP laminates can be predicted using those for CSR strengths from the agreement of the experimental results and the predicted ones.