Creep/Fatigue Response of Resin Infused Biaxial (Double Bias) Glass Fabric Laminates in Reversed Loading

摘要

The creep and fatigue behavior of double bias (±45) glass/epoxy laminates has been explored with a variety of tests, including conventional sine-wave fatigue loading at six loading conditions (R-values), residual property stress-strain tests, square wave fatigue tests, creep tests, and loading-unloading-reloading (LUR) tests. The fatigue results are presented as a strain-based constant life diagram (CLD) representing a 50% strain increase which correlates with a transition to rapid strain increase and failure. Reversed loading effects are explored in detail, and show a substantial creep response during both the tensile and compressive parts of the wave-form, which correlate with creep test data. The baseline epoxy resin is compared with a urethane resin, showing the effects of a tougher but more creep sensitive resin on the creep and fatigue resistance for unidirectional and ±45 laminates.