Characterization of delamination onset and growth in a composite laminate

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