This study aims to examine the uniaxial and biaxial ratchetting responses of glass fibre reinforced epoxy (GRE) composite by experiment and finite element (FE) analysis. The uniaxial ratchetting of GRE composite laminate was tested under cyclic axial stress with a constant mean stress of 40 MPa and an amplitude stress between 26.67 MPa and 53.33 MPa. The biaxial ratchetting test was also performed on 50 mm diameter of GRE composite straight pipe. The GRE pipe was subjected to a constant internal pressure of 1.875 MPa and 1% of cyclic axial strain. The FE models were simulated using Abaqus in similar loading cases. The uniaxial ratchetting strain was found to increase with the number of cycles, but the ratchetting strain rate was decreased. The specimen showed no further ratchetting and exhibited shakedown after some strain accumulation. On the basis of the experiment and simulation in the biaxial test, it appears that ratchetting would occur in the hoop direction for a GRE pipe with no ratchetting observed in the axial direction. The results showed that the FE analysis over-predicts the ratchetting rate for uniaxial ratchetting test as compared to the experimental values, but under-predicts in the biaxial ratchetting test at initial cycles.
