The initiation and progression of damage for IM7-5250-4 composite laminates, (0-90)_(2S) and (+-30/90_2)_S with open holes was investigated under tension loading. Three hole sizes considered in this study were 0.64, 1.27 and 1.91 cm. Strain gages, acoustic emission and radiography were used to detect onset of damage. During an incremental series of monotonic loadings, strains that were taken in close proximity to the hole boundary were correlated with the analytically calculated strains using spline variational elastic lamination theory. The net stress at damage initiation for a hole specimen is related to that of the unnotched specimen through a reduced stress concentration factor. The effect of hole size on the onset of damage initiation is negligible for those laminates studied.
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