-

In this paper, the results are presented of the experiments and the data reduction schemes for evaluation of the
mode-I interlaminar fracture energy of
unidirectional glass/epoxy composites. All tests, including the material elastic properties tests, are performed according to the ASTM standard practices. In the interlaminar fracture tests, the double cantilever beam (DCB) specimens are employed. Several data reduction schemes are used for calculating tt1e mode-I fracture energy. It is found that the accuracy of the experimental delamination length data has
a great effect on the calculated fracture energy. A novel method is then introduced which is capable of determining the fracture energy without using delamination length data which are the most error prone part of the test data. The method is based on the previously developed finite element modelling of delamination growth in the specimen. The modelling technique makes the practical use of linear elastic fracture mechanics incorporating the strain energy
release rate analysis. It is shown that the new method can practically be used for calculating the interlaminar fracture energy and/or evaluating the DCB test accuracy.