Fatigue Delamination Propagation in a DCB Specimen Composed of a Plain Weave Multi-Directional Laminate Composite Subjected to Different Load Ratios

摘要

Double cantilever beam (DCB) specimens fabricated from 15 plies of plain woven prepreg(G0814/913) arranged in a multi-directional layup were tested by means of constant amplitudefatigue cycles under displacement control. Four different displacement cyclic ratios were used,namely 0.1, 0.33, 0.5 and 0.75. The delamination propagation rate da/dN was calculated fromthe experimental data and plotted with respect to different functions of the mode I energy releaserate GI . When one of those functions, denoted here as KIeff was used, all of the data obtainedfor the different displacement ratios collapsed into one master curve. The experimental data wasthen back calculated from the master curve, enabling a reliable prediction of the delaminationpropagation rate da/dN for any given load ratio for this type of material and layup.