Characterisation of the tensile fatigue behaviour of RTM-laminates by isocyclic stress–strain-diagrams

In this work a new evaluation method for the characterisation of the fatigue behaviour of carbon/epoxy laminates, manufactured in the resin transfer molding (RTM) process, is introduced. Fatigue data are represented in isocyclic stress–strain diagrams by plotting associated pairs of stress and strain values for each 10xth cycle. Isocyclic stress–strain curves are comparable to isochronous stress–strain curves for static tests. These curves represent a material law encompassing reversible visco-elastic effects as well as irreversible damage accumulation and can be used in the design of cyclically loaded components to predict their endurance limits. This paper concentrates on the characterisation of laminates made from compacted fabric packages using binder and sewing techniques and infused with RTM epoxy resins.