Experimental study on uniaxial time-dependent cyclic character of carbon fiber reinforced PEEK resin matrix composite

The uniaxial time-dependent cyclic of carbon fiber/polyether ether ketone(PEEK) composite was studied experimentally. The volume fraction of carbon fiber was 30%. The property under stress-control led and stress-controlled loading and the ratcheting behaviors of carbon fiber/PEEK composite were discussed under different conditions. It was shown that the creep behavior of carbon fiber/PEEK composite is better than that of PEEK. In the experiment of strain-controlled cyclic, the stress amplitude has a close relationship with the applied strain loading rate and strain amplitude. Due to the stress relaxation, the responded stress amplitude will decreases as the hold time at strain peak increase. The ratcheting occurs in the composite to asymmetrical stress-controlled, and the ratcheting strain depends on the stress amplitude and stress loading rate. The stress holding time and low loading rate lead to an increased ratcheting strain. The carbon fiber will fail as the peak holding time beyond the range.