Fatigue of carbon-fibre-reinforced plastics under block-loading conditions

Following an earlier study of block-loading fatigue on a high-performance T800/5245 carbon-fibre composite laminate of [(+/-45, 0(2))(2)]s construction, further experiments of a similar nature have now been carried out on other CFRP laminates with the same lay-up but with different fibre/resin characteristics. In this more recent work, comparable T800/924 and IM7/977 materials and a lower-performance HTA/913 laminate appear to behave in a similar manner to that previously found for the T800/5245 composite. The most significant common feature of the behaviour is that combinations of tension and compression loading are more damaging than purely tensile or purely compressive stress cycling regimes. (C) 1997 Elsevier Science Limited.