Strain rate effects on dynamic tensile properties of open-hole composite laminates

The effect of both strain rates and perforations on tensile properties of composite laminates was extensively studied in the past decades, respectively. However, their coupling effect has not been well investigated till now. Here the strain rate effects on mechanical properties of open-hole composite laminates are analyzed by conducting dynamic tensile tests. Our experimental results show that both the tensile strength and failure strain of the open-hole laminates remarkably increase with increasing strain rate, where the stress concentration obviously appears at the hole edge perpendicular to the loading direction. A progressive damage model is established by finite element (FE) method to predict the response and failure of present structures under different loading rates, where four different damage patterns of composite laminates respectively governed by fiber and resin matrix can be identified. Checking against our test results shows that the present FE model has sufficient accuracy to demonstrate the whole damage process of the material and to reveal the influence of strain rate and perforation on its tensile properties.