Characterization of Delamination Onset and Growth in a Composite Laminate

作者：TK O’Brien · 年份：1982 · DOI：10.1520/stp34325s · 被引用次数：532 · 研究领域：Mechanical Behavior of Composites、Fatigue and fracture mechanics、Structural Behavior of Reinforced Concrete

The onset and growth of delaminations in unnotched [±30∕±30∕90∕90¯]s graphite-epoxy laminates is described quantitatively. These laminates, designed to delaminate at the edges under tensile loads, were tested and analyzed. Delamination growth and stiffness loss were monitored nondestructively. Laminate stiffness decreased linearly with delamination size. The strain energy release rate, G, associated with delamination growth, was calculated from two analyses. A critical G for delamination onset was determined, and then was used to predict the onset of delaminations in [+45n/−45n/0n/90n]s (n = 1,2,3) laminates. A delamination resistance curve (R-curve) was developed to characterize the observed stable delamination growth under quasi-static loading. A power law correlation between G and delamination growth rates in fatigue was established.