| Abstract: | Failure of composite beams containing initial delamination is investigated under low-speed impact by a dropping weight. Bolotin's theory of dynamic failure (1992) is used. The start and stop time of growth of a nonsymmetric delamination crack is studied. It is found that the initial extension starts and subsequently continues at the crack tip, which is located closer to the impact point. Then extension is observed on the second crack tip, and finally a synchronous growth of delamination occurs at both crack tips. With constant impact energy, the final size of delamination does not depend on its initial size. The start and stop time of delamination growth increases as the initial defect approaches the beam surface.Presented at the 10th International Conference on the Mechanics of Composite Materials (Riga, April 20–23, 1998).Moscow Power Engineering Institute, Technical University, Russia. Translated from Mekhanika Kompozitnykh Materialov, Vol. 34, No. 6, pp. 787–794, November–December, 1998. |
